Siga este link para ver outros tipos de publicações sobre o tema: Weed.
Artigos de revistas sobre o tema "Weed"
Crie uma referência precisa em APA, MLA, Chicago, Harvard, e outros estilos
Veja os 50 melhores artigos de revistas para estudos sobre o assunto "Weed".
Ao lado de cada fonte na lista de referências, há um botão "Adicionar à bibliografia". Clique e geraremos automaticamente a citação bibliográfica do trabalho escolhido no estilo de citação de que você precisa: APA, MLA, Harvard, Chicago, Vancouver, etc.
Você também pode baixar o texto completo da publicação científica em formato .pdf e ler o resumo do trabalho online se estiver presente nos metadados.
Veja os artigos de revistas das mais diversas áreas científicas e compile uma bibliografia correta.
1
Place, G. T., S. C. Reberg-Horton, D. L. Jordan, T. G. Isleib e G. G. Wilkerson. "Influence of Virginia Market Type Genotype on Peanut Response to Weed Interference". Peanut Science 39, n.º 1 (1 de janeiro de 2012): 22–29. http://dx.doi.org/10.3146/ps10-12.1.
Texto completo da fonteResumo:
Abstract Differences in the ability of cultivars to compete with weeds are not well-defined for peanut. Research was conducted in 2007 and 2008 to compare the growth and competitiveness of the virginia market type cultivars NC 10C, NC-V 11, NC 12C, Phillips, VA 98R, and breeding lines N99027L, N01013T, and N02020J under weedy and weed-free conditions. Weed-free peanut was established by applying preemergence and postemergence herbicides throughout the growing season supplemented by weekly hand removal of weeds. Clethodim was applied to weedy peanut to eliminate annual grass interference but not interference from broadleaf weeds and sedges. Weed-free peanut biomass, weedy peanut biomass, and weed biomass were not affected by genotype 10 weeks after peanut emergence. Although substantial yield loss was noted in presence of weeds, the percent yield loss did not vary by genotype when comparing weedy and weed-free yield. These data suggest that cultivar selection within virginia market type peanut will have limited utility in a comprehensive weed management strategy.
2
Dekker, Jack. "Weed diversity and weed management". Weed Science 45, n.º 3 (junho de 1997): 357–63. http://dx.doi.org/10.1017/s0043174500092985.
Texto completo da fonteResumo:
The story of agriculture is the story of weed interference. After millennia of weed control we still have weeds. This situation has led many growers to observe that “the weeds always win.” One of the most important reasons weeds are so successful is their biodiversity. Biodiversity is an inevitable consequence of the struggle an individual weed species undergoes in the presence of neighbors, and by occupying a physical space in an agroecosystem. Weeds have evolved in response to cropping system practices by adapting and occupying niches left available in agroecosystems. Forces created by our cropping practices over evolutionary time have led to the weed diversity we observe today. Diversity underlies weed management in several important ways. A plant experiences diversity among its neighbors in at least five different ways. Weeds have adapted to selection in agroecosystems in several ways: (1) genetic variants within a species; (2) somatic polymorphism of plant parts; (3) success in diverse habitat microsites; (4) temporal adaptations within the community; and (5) floristic diversity of a community at higher levels than the species. Herein, weed diversity is discussed in this broader context, in terms of population behaviors that emerge as a consequence of the activities of individual components at lower levels of organization. Diversity is also discussed in terms of its implications for weed management. The potential exists to develop management strategies based on differences in weed and crop diversity. These strategies might be developed by characterization of weedy genetic and phenotypic diversity; enhancement of crop, cropping system, and agroecosystem diversity; and characterization of the spatial distribution of weed populations.
3
A.Y, Mamudu,, e Adeyemi, M. "CRITICAL PERIOD OF WEED INTERFERENCE ON SOYBEAN (GLYCINE MAX (L) MERRILL)". Reviews In Food and Agriculture 3, n.º 2 (6 de janeiro de 2022): 76–79. http://dx.doi.org/10.26480/rfna.02.2022.76.79.
Texto completo da fonteResumo:
Weeds are one of the important factors affecting agriculture production, weeds and inadequate weed control and management pose a detrimental factor affecting crop production. The experiment was conducted at the Teaching and Research Farm of Federal University Technology, Minna, Nigeria, to determine the effectiveness of different weeding regime and critical period of weed interference in the growth and yield of soyabean. The treatments were laid out in a Randomized Complete Block Design (RCBD) and replicated three times. There are ten treatments consisting of weed infested and weed-free as follows T1= soybean + weeding for 2 weeks, T2= soybean + weeding for 4 weeks, T3= soybean + weeding for 6 weeks, T4= soybean + weeding for 8 weeks, T5= soybean + weedy for 2 weeks, T6= soybean + weedy for 4 weeks ,T7= soybean + weedy for 6 weeks, T8= soybean + weedy for 8 weeks, T9= soybean + weed-free plot till end and T10= soybean + no weeding till end. Data were collected on weed cover score, weed dry weight, plant height, pod weight and grain yield. The Data were subjected to analysis of variance using SAS, software version 9, 2002. The results showed that soyabean with weed-free plot for 4, 6 8 and weed-free throughout significantly P<0.05 suppressed weed and increases yield by 70 % compared to other treatments The use of early maturing variety of soybean in addition to weed-free plot throughout the growth stage and weed-free for 8 weeks could be recommended in controlling weed interference in soybean for better soybean growth and yield.
4
Shahzad, Muhammad, Khawar Jabran, Mubshar Hussain, Muhammad Aown Sammar Raza, Leonard Wijaya, Mohamed A. El-Sheikh e Mohammed Nasser Alyemeni. "The impact of different weed management strategies on weed flora of wheat-based cropping systems". PLOS ONE 16, n.º 2 (18 de fevereiro de 2021): e0247137. http://dx.doi.org/10.1371/journal.pone.0247137.
Texto completo da fonteResumo:
The world population will rise in future, which would demand more wheat production to fulfil dietary needs of wheat-dependent population of the world. Food security in wheat-dependent regions will greatly rely on wheat productivity. Weed infestation is a major constraint reducing wheat productivity globally. Nonetheless, cropping systems and weed management strategies strongly influence weed infestation in modern agriculture. Herbicides are the key weed management tool in conventional agriculture. However, frequent use of herbicides have resulted in the evolution of herbicide-resistance weeds, which made weed management a challenging task. Sustainable and eco-friendly weed management strategies shift weed-crop competition in the favour of crop plants. Limited studies have evaluated the interactive effect of cropping systems and weed management strategies on weed flora of wheat-based cropping systems (WBCSs). This two-year study evaluated the impact of different weed management strategies (WMSs) on weed flora of WBCSs, i.e., fallow-wheat (FW), rice-wheat (RW), cotton-wheat (CW), mungbean-wheat (MW) and sorghum-wheat (SW). The WMSs included in the study were, false seedbed, allelopathic water extracts and herbicide application, while weed-free and weedy-check were maintained as control treatments. Data relating to diversity and density of individual and total broadleaved and narrow-leaved weeds were recorded. The WBCSs, WMSs and their interaction significantly altered diversity and density of individual, total, broadleaved and narrow-leaved weeds. Weed-free and weedy-check treatments recorded the lowest and the highest values of diversity and density of individual, total, broadleaved and narrow-leaved weeds. Herbicide application effectively reduced density and diversity of weeds. Allelopathic water extracts and false seedbed proved less effective than herbicides. On the other hand, SW cropping system not only reduced weed density but also limited the weed flora. It is concluded that false seedbed and SW cropping system can be efficiently used to manage weeds in WBCSs. However, long-term studies are needed to infer the impact of SW cropping system and false seedbed on soil properties, soil microbes and productivity of wheat crop.
5
LEMIEUX, C., A. K. WATSON e J. M. DESCHÊNES. "WEED POPULATION DYNAMICS IN RECENTLY ESTABLISHED TIMOTHY STANDS: GROWTH AND PHYSIOGNOMY OF THE WEED COMPONENTS". Canadian Journal of Plant Science 67, n.º 4 (1 de outubro de 1987): 1035–44. http://dx.doi.org/10.4141/cjps87-139.
Texto completo da fonteResumo:
In two experiments conducted in the field between 1983 and 1985, timothy was established with or without barley, red clover, grassy weeds and broadleaf weeds. The plots were sampled during establishment and production years. At each sampling, the botanical composition was evaluated to characterize the weed populations. Throughout establishment, the weed populations were dominated by annual broadleaf and grassy weeds which, when growing separately, produced comparable amounts of biomass. However, when growing together, the grassy weeds were clearly dominated by the broadleaf weeds. During the subsequent production years, the weedy populations were dominated by perennial broadleaf weeds. Neither the structure of the weed populations, nor the short-term dynamics of the grassy weed populations were affected by the management system used. However, the short-term dynamics of the broadleaf weed populations were influenced by barley, red clover and the weed control treatments applied during the year of establishment. The use of barley accelerated the growth of the broadleaf weed populations while red clover delayed it. Subsequent broadleaf weed populations were noticeably larger in the plots where they were allowed to grow during the establishment year.Key words: Broadleaf weeds, grassy weeds, Phleum pratense, competition, short-term dynamics
6
Mubeen, Khuram, Muhammad Shehzad, Naeem Sarwar, Haseeb ur Rehman, Tauqeer Ahmad Yasir, Allah Wasaya, Matlob Ahmad et al. "The impact of horse purslane (Trianthema portulacastrum L.) infestation on soybean [Glycine max (L.) Merrill] productivity in northern irrigated plains of Pakistan". PLOS ONE 16, n.º 9 (20 de setembro de 2021): e0257083. http://dx.doi.org/10.1371/journal.pone.0257083.
Texto completo da fonteResumo:
Horse purslane (Trianthema portulacstrum L.) is an important weed of soybean crop capable of causing significant yield reduction. Therefore, this study assessed the impact of horse purslane and other weeds’ infestation on the productivity of soybean. Ten treatments, i.e., weed-free throughout the growing season, horse purslane-free till 20, 40 and 60 days after emergence (DAE), all weeds-free till 20, 40 and 60 DAE, weedy-check (excluding horse purslane), weedy-check (horse purslane alone) and weedy-check (all weeds) were included in the study. Data relating to density and dry weight of recorded weed species, and yield and related traits of soybean were recorded. Overall, infestation percentage of horse purslane was 33.10 and 51%, whereas dry weight was 12 and 44 g m-2 during 1st and 2nd year, respectively. The highest dry weight of all weed species was recorded at 45 DAE in weedy-check all weeds treatment during both years. The lowest relative density and frequency of horse purslane were recorded in the treatment where it was controlled until 20 DAE during 2018 at 30 DAE, whereas the same treatment recoded the lowest density of horse purslane at 45 DAE during 2019. The relative frequency of horse purslane was non-significant for weedy-check horse purslane and weedy-check all weeds treatments during 2018, whereas former treatment had higher relative frequency of horse purslane in weedy-check all weeds than the later during 2019. Yield and related traits significantly differed among different treatments used in the study. The treatment all weeds controlled until 40 DAE recorded higher number of pods per plant, 1000-seed weight and seed yield during both years. The yield reduction in weedy-check treatments was; weedy-check all weeds > weedy-check all weeds except horse purslane > weedy-check horse purslane only. It is concluded that horse purslane was not the sole weed interfering soybean fields and weed flora consisted of false amaranth [Digera muricata (L.) Mart.] and purple nut sedge (Cyperus rotundus L.). Hence, if the soybean fields in northern irrigated plains of Pakistan are infested with horse purslane or heavily infested with horse purslane or other weeds, these should be controlled in initial 40 DAE to improve soybean productivity.
7
Ellis, P. R. "Weeds —influences of weed vegetation in ipm and non-chemical weed control". Phytoparasitica 20, S1 (março de 1992): S71—S75. http://dx.doi.org/10.1007/bf02980412.
Texto completo da fonte
8
Shahabuddin, M., MM Hossain, M. Salim e M. Begum. "Efficacy of pretilachlor and oxadiazon on weed control and yield performance of transplant Aman rice". Progressive Agriculture 27, n.º 2 (17 de agosto de 2016): 119–27. http://dx.doi.org/10.3329/pa.v27i2.29320.
Texto completo da fonteResumo:
Two experimentswere carried out at the Agronomy Field laboratory, Bangladesh Agricultural University, Mymensingh during July to December 2014 to study the effectiveness of pretilachlor and oxadiazon on weed control and yield performance oftransplant aman rice. In experiment I BRRI dhan31and in experiment II BRRI dhan46 was transplanted with eight weeding practices viz., weedy check; one hand weeding; two hand weeding; weed free;Pretilachlor only;Oxadiazon only;Pretilachlor + one hand weeding; and Oxadiazon+ one hand weeding. The design was split-plot with three replications. Eleven weed species were found to be infested in the experimental plots. Although weeds were completely controlled in weed free treatment, it is not practicable.Pretilachlor oroxadiazon with one hand weeding performed the best in terms of weed density and weed biomass over single application of each and even manual weeding. Weeds were completely resistant to weedy check, poorly susceptible to one hand weeding, moderately susceptible to two hand weeding and single application of both herbicide and highly susceptible to both herbicides with one hand weeding while weeds were completely susceptible to weed free treatment. Herbicides produced slight phyto-toxicity which was recovered by two weeks of application. The highest grain yield was recorded from weed free treatment and was statistically identical to pretilachlor oroxadiazon with one hand weeding. Single application of pretilachlor oroxadiazon ranked the third in terms of yield and statistically similar to two hand weeding followed by one hand weeding. Weedy check performed the worst.Progressive Agriculture 27 (2): 119-127, 2016
9
Abbas, Rana Nadeem, Asif Iqbal, Muhammad Aamir Iqbal, Omar M. Ali, Raees Ahmed, Raina Ijaz, Adel Hadifa e Brandon J. Bethune. "Weed-Free Durations and Fertilization Regimes Boost Nutrient Uptake and Paddy Yield of Direct-Seeded Fine Rice (Oryza sativa L.)". Agronomy 11, n.º 12 (30 de novembro de 2021): 2448. http://dx.doi.org/10.3390/agronomy11122448.
Texto completo da fonteResumo:
Under the changing climate, fertilization regimes and weed infestation management in aromatic direct-seeded fine rice (DSR) remain vital for curbing environmental hazards and ensuring food security. A multi-year field study was undertaken to appraise the influence of fertilization techniques and weed-free periods on weed dynamics, nutrient uptake and paddy yield in a semi-arid environment. Treatments included two fertilization methods (broadcasting and side placement) and five weed-free durations (20, 30, 40, 50 post-seeding days, DAS) along with a weed-free crop for a whole season. Weed competition for a season-long crop (weedy check) was maintained for each fertilizer application method. Our results revealed that the side placement of fertilizers resulted in a significantly lower weed density and biomass, even under season-long weed competition. The highest paddy yield was recorded for a crop without weeds, while weed-free duration of up to 50 DAS followed it. The uptake of nitrogen (N), phosphorus (P) and potassium (K) for a weed-free duration of up to 50 DAS were only 19%, 9% and 8%, respectively, as compared to the weedy check. The uptake of N, P and K by weeds in the broadcast method was 18%, 30% and 24% higher, compared to side-placed fertilizers. The period of 20–50 DAS remained critical in DSR as far as weed control was concerned. Thus, the side placement of fertilizers and controlling weeds for up to 50 days after rice sowing can be recommended for general adoption in semi-arid agro-ecological conditions.
10
Roland, Gerhards, Bezhin Kostyantyn e Santel Hans-Joachim. "Sugar beet yield loss predicted by relative weed cover, weed biomass and weed density". Plant Protection Science 53, No. 2 (25 de janeiro de 2017): 118–25. http://dx.doi.org/10.17221/57/2016-pps.
Texto completo da fonteResumo:
Sugar beet yield loss was predicted from early observations of weed density, relative weed cover, and weed biomass using non-linear regression models. Six field experiments were conducted in Germany and in the Russian Federation in 2012, 2013 and 2014. Average weed densities varied from 20 to 131 with typical weed species compositions for sugar beet fields at both locations. Sugar beet yielded higher in Germany and relative yield losses were lower than in Russia. Data of weed density, relative weed cover, weed biomass and relative yield loss fitted well to the non-linear regression models. Competitive weed species such as Chenopodium album and Amaranthus retroflexus caused more than 80% yield loss. Relative weed cover regression models provided more accurate predictions of sugar beet yield losses than weed biomass and weed density.
11
Kharwal, Nitesh, e Deependra Yadav. "Effect of Integrated Weed Management Practices on Growth and Yield of Green Chilli (Capsicum annum L.)". International Journal of Plant & Soil Science 35, n.º 18 (7 de agosto de 2023): 1763–70. http://dx.doi.org/10.9734/ijpss/2023/v35i183456.
Texto completo da fonteResumo:
Weed infestation in chilli production, especially during early growth stages, is a major constraint leading to significant yield loss. Effective weed management during this critical phase is crucial for maximizing chilli crop productivity. Keeping this in view a field experiment was conducted at the research farm of Abhilashi University, Mandi (H.P) during the Kharif season of 2022-23. The main objective was to assess the impact of various integrated weed management strategies on the growth and yield of green chilli crops. The experiment consisted of seven treatments with control, laid out in Randomized Block Design with three replications. The treatment details viz., T1[Weedy check (Control)], T2(Weed free), T3[Hand weeding at 30 and 60 days after transplanting (DAT)], T4[organic mulch (paddy straw)], T5 (Oxyfluorfen 1.0 kg/ha, T6 Pendimethalin 1.0 kg/ha) and T7 (Pendimethalin 1.0 kg/ha. + HW after 60 DAT). The results of the study revealed that the "Weed-free" treatment (T4) exhibited the highest plant height (80.35 cm), number of leaves per plant (120), number of fruits per plant (85) with an average weight of fruits per plant (276.74 g), dry weight of fruits per plant (33.21 g) and yield (7.56 kg/plot and 189.05 q/ha). The treatment "Pendimethalin 1.0 kg/ha + Hand weeding after 60 DAT" (T7) followed closely, recording the plant height (75.78 cm), number of leaves per plant (114.66), number of fruits per plant (82.33) with an average weight of fruits per plant (251.56 g), dry weight of fruits per plant (32.7 g) and yield (7.12 kg/plot and 178.08 q/ha). The "Weedy check" treatment (T1) required the longest duration for 50% flowering and the first and final harvest, with 76, 108 and 124 days, respectively. On the other hand, the "Weed-free" treatment (T2) required the shortest period, with 66, 93, and 106 days, respectively. Regarding weed-related parameters, the "Weedy check" treatment (T1) demonstrated the highest weed count (110), fresh weight of weeds (2160.03 g) and dry weight of weeds (388.81 g), while the "Weed-free" treatment (T2) exhibited the minimum weed count (0.00), fresh weight of weeds (0.00 g) and dry weight of weeds (0.00 g). The highest weed control efficiency (WCE) of 100% and the lowest weed index (0.00%) were observed in the "Weed-free" treatment (T2), whereas the lowest WCE (0.00%) and the highest weed index (69.69%) were recorded in the "Weedy check" treatment (T1). Economically, the combined treatment of "Pendimethalin 1.0 kg/ha with hand weeding after 60 DAT" (T7) resulted in the highest net return of 4,39,192.78 ₹/ha, followed by the "Weed-free" treatment (T2) with 4,35,207 ₹/ha. The lowest net return was observed in the "Weedy check" treatment (T1) with 62,117.28 ₹/ha.
12
Tadele, Worku, Taye Tessema e Samuel Tegene. "Determination of critical period of weed competition in Sugarcane (Saccharum officinarum L.) at Arjo Didessa sugar estate, western Ethiopia". Journal of Current Opinion in Crop Science 3, n.º 2 (28 de junho de 2022): 62–71. http://dx.doi.org/10.62773/jcocs.v3i2.165.
Texto completo da fonteResumo:
Weeds limit sugar cane production. A field experiment employing cultivar NCO334 and Randomized Complete Block Design (RCBD) was done to assess weed competition crucial period. After planting, experimental plots were either weed-free or weedy (0, 25, 50, 75, 100, 125, and 150 DAP). Weed density, weed dry weight, sugarcane sprout, tiller number, cane height, millable cane number, girth, weight, and predicted cane and sugar production traits were evaluated. For different periods, weed competition affects tiller number, cane height, girth, weight, millable cane number, and cane and sugar yield. Tiller production, cane height, girth, weight, millable canes, and cane and sugar output rose with more extended weed-free periods. Weeds in sugarcane caused 90. 5% and 94.6% cane and sugar yield losses, respectively. Cane girth, height, weight, tiller number, cane, and sugar production correlated positively and negatively with weed density and dry weight. weed crop competition begins between 17 and 131 DAP. To limit the impact of weeds on sugar cane yield, weed management measures should be implemented in sugarcane plantations during this important period.
13
Lueschen, William E., e Thomas R. Hoverstad. "Imazethapyr for Weed Control in No-Till Soybean (Glycine max)". Weed Technology 5, n.º 4 (dezembro de 1991): 845–51. http://dx.doi.org/10.1017/s0890037x00033960.
Texto completo da fonteResumo:
Lack of consistent weed control has been a major limiting factor in the adoption of no-till soybean production. Field studies were conducted at Waseca, MN from 1987 through 1990 to evaluate the efficacy of imazethapyr applied either alone or in combination with other herbicides for weed control in no-till soybean. Fall applications of imazethapyr did not provide acceptable weed control. Imazethapyr applied 2 to 4 wk before planting provided a weed-free seedbed whereas burndown treatments applied 1 to 3 d before planting failed to do so. Early preplant imazethapyr applied during the second week of April did not control weeds as well as imazethapyr applied during the last week of April. Imazethapyr applied alone PRE failed to control weeds adequately. A split application of early preplant plus PRE imazethapyr resulted in excellent weed control, especially when metribuzin was added with each application. Imazethapyr is a promising herbicide for weed control in no-till soybean production.
14
Colquhoun, Jed B., Christopher M. Konieczka e Richard A. Rittmeyer. "Ability of Potato Cultivars to Tolerate and Suppress Weeds". Weed Technology 23, n.º 2 (junho de 2009): 287–91. http://dx.doi.org/10.1614/wt-08-062.1.
Texto completo da fonteResumo:
Potato producers rely heavily on herbicides for the majority of weed control. However, recent occurrences of herbicide-resistant weed populations and the lack of new herbicide registrations have stimulated interest in alternative strategies. The choice of potato cultivars that can suppress or tolerate weed competition could be a component of an integrated weed management system to reduce reliance on herbicides. The competitive ability of 10 potato cultivars—‘Atlantic’, ‘Bannock Russet’, ‘Dark Red Norland’, ‘Goldrush’, ‘Rodeo’, ‘Russet Burbank’, ‘Russet Norkotah’, ‘Snowden’, ‘Superior’, and ‘Villetta Rose’—was evaluated in 2006 and 2007 in Hancock, WI. Weed competition treatments included (1) weedy throughout the season, (2) weed-free from emergence to 4 wk after emergence (WAE) by hand-weeding, and (3) weed-free by hand-weeding for the entire season. Potato cultivars did not differ in ability to reduce weed biomass. Early-season time of potato emergence and canopy closure, as well as weed competition treatments, were strongly related to potato tuber yield. In general, Bannock Russet yield relative to weed-free controls of the same cultivar was less than that of most other cultivars. Overall, Atlantic, Russet Burbank, Snowden, and Superior yields (relative to weed-free control yields) usually were greater than the yields of other cultivars under weedy conditions. Although the ability to suppress weeds was similar among cultivars, differences in yield among cultivars grown in the presence of weeds suggest differential tolerances of weed competition.
15
Sidik, Jatmiko Umar, Dad Resiworo Jekti Sembodo, Rusdi Evizal e Hidayat Pujisiswanto. "EFIKASI HERBISIDA PARAKUAT UNTUK PENGENDALIAN GULMA PADA BUDIDAYA KELAPA SAWIT (Elaeis guineensis Jacq) TANAMAN BELUM MENGHASILKAN". Jurnal Agrotek Tropika 8, n.º 2 (20 de maio de 2020): 355. http://dx.doi.org/10.23960/jat.v8i2.3910.
Texto completo da fonteResumo:
Good plantation management is important to increase the productivity of immature oil palm plants, one of which is chemical weed control. This study aims to (1) determine the dosage of paraquat herbicide which is effective in controlling weeds in the area of immature oil palm plantations, (2) find out the differences in the composition of weed species on immature oil palm plates after application of the paraquat herbicide, (3) find out the phytotoxicity of paraquat herbicides in immature oil palm plants after the application of the paraquat dichloride herbicide. This research was carried out in the farmers' oil palm plantation in Jontor Village, Gayabaru District , Central Lampung Regency and Weed Laboratory of the Faculty of Agriculture, University of Lampung from November 2017 to February 2018. This research used a Randomized Block Design (RBD) with 4 replications and 6 treatments consisting dose of paraquat dichloride herbicide of 375g / ha, 500 g / ha, 625 g / ha, 750 g / ha, and mechanical weeding and without weed control (control). Homogeneity of the various data was tested by the Bartlett test, data additivity was tested by the Tukey test and the difference in the mean was tested with the Least Significant Difference (LSD) test at α 5 level. The result of the study showed that : (1) the herbicide paraquat dichloride dose of 375-750 g / ha effectively control weeds in total, weed leaf width of up to 8 week after application, weed grasses and weeds puzzle to 4 week after application, (2) the herbicide paraquat dichloride dose of 375-750 g / ha is effective in controlling Praxelis clematidea weeds up to 8 week after application, weed Ottochloa nodosa and Asystasia gangetica up to 4 week after application, (3) paraquate dichloride dosage levels 375-750 g / ha resulting in differences in weed composition at 4, 8 and 12 week after application , (4) dosages of 375 - 750 g / ha parakuat dichloride herbicides applied to dishes not poisoning immature oil palm plants.
16
Takim, F. "Weed competition in maize (Zea mays L.) as a function of the timing of hand-hoeing weed control in the southern Guinea savanna zone of Nigeria". Acta Agronomica Hungarica 60, n.º 3 (1 de setembro de 2012): 257–64. http://dx.doi.org/10.1556/aagr.60.2012.3.8.
Texto completo da fonteResumo:
Field studies were conducted in 2010 and 2011 at the Teaching and Research Farm of the University of Ilorin, Nigeria (9°29′ N, 4°35′ E) to evaluate the effect of early weed competition on the growth and yield of maize. The experiment was designed as a randomized complete block (RCBD) with a split-plot arrangement and three replications. The main plots consisted of three weed control treatments included weedy (no herbicide), grass weeds (pre-emergence atrazine) and broadleaf weeds (pre-emergence metolachlor), while the sub-plots consisted of six durations of weed infestation (3, 4, 5, 6, 7 and 8 weeks after emergence). The pre-emergence herbicides had a greater effect on weed density and weed dry weight. Weed seedling emergence and weed dry weight increased significantly with an increase in the duration of weed interference. The grasses and broadleaf weeds had a similar influence on the growth and grain yield of maize. Three to five weeks of weed interference gave similar grain yields, which were significantly higher than those obtained in plots that had 6-8 weeks of weed interference. These results suggest that the maize crop must be kept free of weeds for 6-8 weeks after the application of pre-emergence herbicide to minimize weed-crop competition and harvest a good grain yield.
17
SEN, SUMAN, Y. K. ZIAR, T. K. DAS e RISHI RAJ. "Effect of herbicides on distribution and interference of weeds, growth and yield of wheat (Triticum aestivum) in Kandahar, Afghanistan". Indian Journal of Agricultural Sciences 92, n.º 5 (14 de junho de 2022): 563–66. http://dx.doi.org/10.56093/ijas.v92i5.124623.
Texto completo da fonteResumo:
Weeds are the major constraint to achieving higher wheat yield in Afghanistan. To evaluate weed interference and its impact on wheat, a field experiment was undertaken during winter season in 2014–15 at Afghanistan National Agricultural Science and Technology University (ANASTU), Kandahar. Seven weed control treatments comprising isoproturon 0.75 and 1.0 kg/ha at 35 days after sowing (DAS), sulfosulfuron 20 and 25 g/ha at 35 DAS, isoproturon + 2,4-D 0.75 + 0.5 kg/ha at 35 DAS (tank-mix), weed-free check and weedy check were laid out in a randomized complete block design with three replications. Results showed that grassy weeds constituted 62.7% of the total weeds and were mostly dominant. All herbicides/weed control treatments influenced weed interference, wheat cropgrowth and yield significantly. Sulfosulfuron 25 g/ha at 35 DAS resulted in significant reduction in weed density by 95.2% (i.e. weed control efficiency) and dry weight by 95.1% (i.e. weed control index), respectively. This treatment led to significant improvements in wheat growth (Leaf area index, dry matter accumulation) and grain (4.6 t/ha) and biological yields (10.6 t/ha), and was superior to other herbicide treatments. It increased wheat grain and biological yields by 24.3% and 17.8%, respectively, compared to weedy check. Therefore, the application of sulfosulfuron 25 g/ha at 35 DAS may be recommended for better weed control and higher wheat yield in Kandahar, Afghanistan, and in similar agro-ecologies of the tropics and sub-tropics.
18
Maxwell, Bruce D. "Weed Thresholds: The Space Component and Considerations for Herbicide Resistance". Weed Technology 6, n.º 1 (março de 1992): 205–12. http://dx.doi.org/10.1017/s0890037x00034576.
Texto completo da fonteResumo:
As an extension of weed threshold models in which crop losses are based on weed density, an alternative model for grass weeds in cereal crops is proposed that incorporates the theoretical importance of selection for herbicide resistance, initial weed population frequency, and weed seed dispersal. Simulations suggest optimum weed population levels (thresholds) for maintaining genotypes that are susceptible to control practices and which minimize crop yield reductions. Weed population frequency, in combination with dispersal and competitive traits may determine optimum weed management strategies/Model simulations indicate that understanding how agricultural practices select for “weedy” traits (e.g. herbicide resistance, competitive ability, dispersal potential) may be important in determining weed density thresholds.
19
Bussan, Alvin J., Orvin C. Burnside, James H. Orf, Eric A. Ristau e Klaus J. Puettmann. "Field evaluation of soybean (Glycine max) genotypes for weed competitiveness". Weed Science 45, n.º 1 (fevereiro de 1997): 31–37. http://dx.doi.org/10.1017/s0043174500092444.
Texto completo da fonteResumo:
In the first of 2 field studies, weed biomass and soybean seed yield were used to evaluate 16 soybean genotypes for competitive ability against 12 weed species at Rosemount, MN, in 1992 and 1993. The yield and ranking of soybean genotypes often varied with the weed species. Grass weed species reduced yields the most, and small-seeded broadleaf weeds reduced yields the least across years. ‘Parker’ was highly competitive, as it suppressed weed biomass and produced high soybean yield. ‘Kato,’ ‘Kasota,’ ‘Dawson,’ and ‘Glenwood’ minimized weed biomass and maintained soybean yield while in competition with grass weeds but yielded poorly relative to other soybean genotypes in weed-free conditions. ‘Lambert’ produced high soybean yield in weed-free conditions, but yield dropped markedly when in competition with grass weeds. ‘Grande,’ ‘Heifeng 25,’ and ‘Norman’ soybeans were poor competitive genotypes in weedy situations and low yielding in weed-free conditions. A 2nd field study conducted at Rosemount and St. Paul, MN, during 1993 evaluated 16 soybean genotypes under 4 levels and durations of weed pressure for weed competitiveness. Parker, ‘Sturdy,’ and M89-794 were most competitive in suppressing weed biomass and producing high yields. Lambert yielded fairly well but allowed high weed biomass. M89-1743, M89-1006, ‘Archer,’ and ‘Ozzie’ yielded poorly and did not sup press weed biomass production. No relationship was found between weed competitiveness and soybean canopy area, height, and volume measured 30–45 d after planting (DAP).
20
Hamada, Azhari Abdelazim. "Weeds and Weed Management in Sudan." Journal of Weed Science and Technology 45, n.º 2 (2000): 131–36. http://dx.doi.org/10.3719/weed.45.131.
Texto completo da fonte
21
Njoroge, J. M. "Weeds and Weed Control in Coffee". Experimental Agriculture 30, n.º 4 (outubro de 1994): 421–29. http://dx.doi.org/10.1017/s0014479700024662.
Texto completo da fonteResumo:
SUMMARYThe effects of weeds on coffee productivity and the methods used for their control are discussed. The more common weeds are listed, together with the control methods that can be used at various phases of coffee production.Malezas y control de las mismas en el café
22
Kumar, Manoj, R. C. Meena e C. Tara Satyavathi. "Integrated weed management in pearl millet [Pennisetum glaucum (L.) R. Br.]". INTERNATIONAL JOURNAL OF AGRICULTURAL SCIENCES 18, n.º 1 (15 de janeiro de 2022): 231–34. http://dx.doi.org/10.15740/has/ijas/18.1/231-234.
Texto completo da fonteResumo:
The scarcity of labour in agriculture and change in behaviour, weed management in rain fed pearl millet is very difficult. Further, to improve/ fine tune the existing recommendation of weed management in pearl millet, this experiment was planned. A field experiment was carried out during the rainy (Kharif) seasons of 2012 to 2014 in sandy loam soils at ICAR-All India Coordinated Research Project on Pearl Millet, Research Farm, Agricultural Research Station, Mandor, Jodhpur (Agriculture University, Jodhpur), to evaluate the effect of integrated weed management in rainfed pearl millet (Pennisetum glaucum L.) with pre-emergence application of atrazine 0.5 kg/ha + 1 HW at 35 DAS, four levels of post-emergence application of atrazine (0.1, 0.2, 0.3 and 0.4 kg/ ha) along with one hand weeding at 35 DAS, two hand weeding and hoeing (at 20 and 40 DAS). Eight treatment combinations were laid out in randomized block design in four replications. All weed management practices caused significant improvement in grain and dry fodder yield of pearl millet compared to the weedy check (1943 kg/ha and 30.86 q/ha). The best treatment was found weed free and it was followed by post emergence application of Atrazine @ 0.4 kg/ha. In comparison to the weed dry matter recorded at harvest with weedy check (547.1 kg/ha), all weed management practices recorded quite lower dry matter of weeds and were found to be at par in managing weeds compared to the weed free plot. Efficiency of post emergence application of Atrazine @ 0.2,0.3 and 0.4 kg/ha was found more better in controlling weeds than the recommended practice of managing weeds by pre emergence application of Atrazine. Weed control efficiency were also found higher in weed free and it was followed by two hand weeding and post emergence application of Atrazine @ 0.4 kg treatments, respectively.
23
Putniece, Gundega, Ingrīda Augšpole e Inta Romanova. "Population of Weeds in a Plantation of Red Raspberries (Rubus Idaeus L.)". Proceedings of the Latvian Academy of Sciences. Section B. Natural, Exact, and Applied Sciences. 76, n.º 4 (1 de agosto de 2022): 551–54. http://dx.doi.org/10.2478/prolas-2022-0085.
Texto completo da fonteResumo:
Abstract Data from monitoring of weed populations are relevant for successful integrated weed management. The purpose of this experiment was to compare the diversity of weed species in red raspberry plantation rows. The red raspberry plantation was established in August 2019. The plantation is located in the south part of Latvia, Zemgale region (N56°33’29.5302”, E23°46’26.04”). The red raspberry cultivars ‘Daiga’, ‘Shahrazada’, ‘Norna’, and ‘Polana’ were grown in the plantation. The bushes were spaced at 0.6 m in rows and 3 m between rows in a plot with size 0.51 ha. Weed infestation in the red raspberry plantation was determined by using the counting method. The counting of weeds and identification of weed species were done three times during the vegetation at the 16th,22nd, and 30th week of 2021. In total, 34 weed species, including 18 annual and 16 perennial weeds were present in the red raspberry plantation. Poa annua (5–60 plants per m-2) and Elytrigia repens (6–393 plants m−2) were found as dominant weeds. During experiment there were differences in weed populations and density between red raspberry cultivars. The cultivar ‘Norna’ was dominated by perennial weeds, while ‘Polana’ by annual weeds.
24
Nadeem, Muhammad Ather, Bilal Ahmad Khan, Asim Riaz Chadar, Rizwan Maqbool, Ali Raza, Muhammad Mansoor Javaid, Athar Mahmood, Muhammad Ishfaq Khan, Masood Ahmad e Muhammad Irfan. "Weed control and sustainable rice production through rice intensification system and conventional practices of weed competition periods and age of transplanted seedlings". Semina: Ciências Agrárias 43, n.º 5 (17 de novembro de 2022): 2271–92. http://dx.doi.org/10.5433/1679-0359.2022v43n5p2271.
Texto completo da fonteResumo:
Rice is an important cereal crop of global interest based on its daily uses. It was observed that the average yield of rice is low than its potential production due to the traditional growing techniques and weed intensification. Recently, the rice intensification system (RIS) has emerged as an alternative to the conventional rice cultivation system. A two-year field study was carried out to investigate the impact of seedling age (14, 21 & 28 days) and the weed competition periods (weedy check, 20, 40, 60, 80 DAT and weed-free throughout the growing season) in rice cultivated through RIS. Weedy check and weed-free for the growing season were kept as a control treatment. The results of our study revealed that a maximum dry weight (108.7 and 111.79 gm-2) and weeds density (101.7 and 110.6 plants m-2) of weed recorded in weedy check plot where 28 days old seedlings was transplanted while minimum dry weight (11.01 and 10.3 gm-2) and weeds density (9.7 and 10.9 m-2) were achieved in plots where 21 days old seedlings were transplanted and remain weed free. It was noted that weed density and weed dry biomass were gradually increased with increasing weed competition period at all ages of the rice seedling. Purple nutsedge (C. rotundus) exhibited maximum relative proportion in total weed’s density and dry biomass and also ranked first by weed summed dominance ratio (WSDR). Agronomic yield and yield contributing traits such as number of fertile tillers per hills (58.1 and 56.0), plant height (130.5 cm and 125.6 cm), kernels per plant (186.4 and 179.4), straw yield (7.8 t ha-1 and 7.5 t ha-1) and kernel yield (5.2 and 5.0 t ha-1) were maximum in plot that remained weed-free throughout the growing season with a seedlings age of 21 days during 2010 and 2011 respectively. Percent yield losses were minimum in plots with 21 days old seedling transplantation and at 20 days of weed competition period. Hence, present study concludes that 21 days old fine rice seedlings should be transplanted and weeds should be controlled within 20 DAT under SRI for effective weed control to avoid yield losses.
25
Sairam, Gaini, A. K. Jha, Badal Verma, Muskan Porwal, Abhijeet Dubey e R. K. Meshram. "Effect of Mesotrione 40% SC on Weed Growth, Yield and Economics of Maize (Zea mays L.)". International Journal of Environment and Climate Change 13, n.º 7 (16 de maio de 2023): 608–16. http://dx.doi.org/10.9734/ijecc/2023/v13i71913.
Texto completo da fonteResumo:
Newer herbicides are required to reduce the losses cause by the weeds in maize crop. Therefore, a field experiment was conducted during kharif 2019 at Research Farm, AICRP on Forage Crops, Department of Agronomy, Jawaharlal Nehru Krishi Vishwa Vidyalaya, Jabalpur (Madhya Pradesh) to study the effect of different weed management practices on productivity of Maize (Zea mays L.). The experiment was conducted in randomized block design with eight treatments (six herbicidal treatments with hand weeding twice at 20 and 40 DAS and weedy check) replicated thrice. Observations were recorded for various weed parameters and crop growth parameters. All the weed management treatments significantly reduced the total weed density and total dry weight of weeds as compared to weedy check. Among herbicidal treatments, mesotrione 350 g ha-1 recorded the lowest total weed density and total dry weight of weeds as compared to other herbicides. While highest total weed density and total dry weight were recorded under weedy check treatment. Significantly higher growth parameters and yield attributing traits were recorded with the application of mesotrione 350 g ha-1 which resulted in higher grain and stover yields (2447.22 and 21804.72 kg ha-1) followed by mesotrione 300 g ha-1. Maximum net returns and Benefit: Cost ratio was also obtained with the application of mesotrione 350 g ha-1.
26
Maroli, Amith S., Todd A. Gaines, Michael E. Foley, Stephen O. Duke, Münevver Doğramacı, James V. Anderson, David P. Horvath, Wun S. Chao e Nishanth Tharayil. "Omics in Weed Science: A Perspective from Genomics, Transcriptomics, and Metabolomics Approaches". Weed Science 66, n.º 6 (30 de agosto de 2018): 681–95. http://dx.doi.org/10.1017/wsc.2018.33.
Texto completo da fonteResumo:
AbstractModern high-throughput molecular and analytical tools offer exciting opportunities to gain a mechanistic understanding of unique traits of weeds. During the past decade, tremendous progress has been made within the weed science discipline using genomic techniques to gain deeper insights into weedy traits such as invasiveness, hybridization, and herbicide resistance. Though the adoption of newer “omics” techniques such as proteomics, metabolomics, and physionomics has been slow, applications of these omics platforms to study plants, especially agriculturally important crops and weeds, have been increasing over the years. In weed science, these platforms are now used more frequently to understand mechanisms of herbicide resistance, weed resistance evolution, and crop–weed interactions. Use of these techniques could help weed scientists to further reduce the knowledge gaps in understanding weedy traits. Although these techniques can provide robust insights about the molecular functioning of plants, employing a single omics platform can rarely elucidate the gene-level regulation and the associated real-time expression of weedy traits due to the complex and overlapping nature of biological interactions. Therefore, it is desirable to integrate the different omics technologies to give a better understanding of molecular functioning of biological systems. This multidimensional integrated approach can therefore offer new avenues for better understanding of questions of interest to weed scientists. This review offers a retrospective and prospective examination of omics platforms employed to investigate weed physiology and novel approaches and new technologies that can provide holistic and knowledge-based weed management strategies for future.
27
Samanta Tanu, Shaon, Purnendu Biswas, Sultan Ahmed e Swadesh Chandar Samanta. "EFFICACY OF SUNFLOWER RESIDUES AND HERBICIDES IN CONTROLLING WEEDS IN TRANSPLANTED RICE". International Journal of Applied Biology 4, n.º 1 (29 de junho de 2020): 100–114. http://dx.doi.org/10.20956/ijab.v4i1.10360.
Texto completo da fonteResumo:
The experiment was conducted at Agronomy Field Laboratory of Patuakhali Science and Technology University, Dumki, Patuakhali, Bangladesh from July 2018 to November 2018 to find out the effect of sunflower residues and herbicides on weed control and yield of T. Aman rice. Weed control methods tested were T1= weedy check,T2 = Weed free check, T3 = Pendimethalin,T4 = Pretilachlor,T5= Butachlor,T6 = Pyrazosulfuron ethyl,T7 = Bensulfuron methyl + Acetachlor,T8 = Bispyriback sodium,T9 =2,4-D amine,T10 =MCPA,T11 = Sunflower residues ,T12 = Sunflower residues + 100%Pyrazosulfuron ethyl,T13 = Sunflower residues + 75%Pyrazosulfuron ethyl,T14 = Sunflower residues + 50%Pyrazosulfuron ethyl. The weed spectrum of the experimental field consisted of all the three groups of weeds viz., grasses (15.78%), sedges (59.02%) and broad-leaved weeds (25.2%). The dominants weeds were Cynodon dactylonand Echinochloa crusgalli among grasses; Cyperus difformis, Fimbristylis miliacea and Scirpus supinus among sedges and Jussiaea decurrens among broad-leaved weeds. Hand weeding recorded the highest weed control efficiency (99.05%) and weedy check recorded the lowest. Among different herbicides applied alone, butachlor had the highest weed control efficiency (87.59%).Hand weeding produced the highest grain yield (5.14 t ha-1) which was statistically similar to butachlor, pendimethalin, pretilachlor, bensulfuron methyl + acetachlor and sunflower residues + 100% pyrazosulfuronethyl. Application of sunflower residues along with the reduced rate (75 or 50%) of pyrazosulfuron ethyl had effective weed control and satisfactory yield comparable to butachlor. The farmers can use this technology as an eco-friendly approach in transplanted Aman rice field.
28
Malviya, Shreya, e Mukesh Kumar Saini. "Effect of Herbicide (Propaquizafop and Imazethapyr) on Weed Flora Associated with Blackgram in Central India". International Journal of Environment and Climate Change 13, n.º 10 (19 de agosto de 2023): 675–86. http://dx.doi.org/10.9734/ijecc/2023/v13i102703.
Texto completo da fonteResumo:
An experiment was conducted at Product Testing Unit, Department of Agronomy, JNKVV, Jabalpur to study the effect of application of propaquizafop and imazethapyr herbicide on weeds associated with blackgram. The experimental field was having mixed weed flora comprising of grassy as well as broad leaved weeds. Nine treatments comprised of four rates of application of propaquizafop+ imazethapyr at 47+70, 50+75, 53+80 and 56+85 g/ha and alone application of propaquizafop (100 g/ha), imazethapyr (100 g/ha), pendimethalin (1500 g/ha) and hand weeding twice at 20 and 40 DAS including weedy check, were laid out in Randomized Block Design with three replications. All herbicide treatments were applied in 500 liters of water per hectare, using flat fan nozzle as per the treatments. The dominant weed flora, species wise weed density, weed biomass, Weed control efficiency and weed index were recorded at different interval. The study revealed that the Echinochloa colona (29.39%) and Dinebra retroflexa (24.30%) were the found as dominant weeds in the field whereas, other monocot weeds like Cyperus iria (18.19%) and dicot weeds like Mullugo pentaphylla (12.23%), Eclipta alba (7.58%) and Alternanthera philoxeroides (8.31%) were also present in less numbers in blackgram under weedy check plots. Among the herbicidal treatments, activity of propaquizafop+imazethapyr mixture at the dose 53+80 and 56+85 g/ha emerged as effective control for the weeds associated with blackgram.
29
MOHAMMAD HASANAIN, D.K. SHUKLA, R.K. SINGH, HIMANSU SEKHAR GOUDA, RAHUL SADHUKHAN, V.K. SINGH e JITENDER KUMAR. "Effect of fertility levels and weed-management practices on weed-control efficiency, yield and nutrients uptake in summer mung bean (Vigna radiata)". Indian Journal of Agronomy 64, n.º 3 (10 de outubro de 2001): 418–21. http://dx.doi.org/10.59797/ija.v64i3.5295.
Texto completo da fonteResumo:
A field experiment was conducted in a split-plot design during the summer season (zaid) of 2016 at the Norman Borlaug Crop Research Centre, Pantnagar, Uttarakhand, to evaluate the influence of various fertility levels and weed-management practices on weeds, crop yield and nutrients uptake in summer mung bean [Vigna radiata (L.) R. Wilczek]. All fertilizer treatments showed significant effect on grain yield, while weed-control treatments signifi- cantly reduced the weed growth and nutrient removal by weeds compared with the weedy check. Among the fertil- izer treatments, an application of 18 kg N + 48 kg P O + 24 kg K O/ha (recommended dose of fertilizer) along with 2 5 2 micronutrients (Zn-EDTA 0.045% + boric acid 0.1% + ammonium molybdate 0.1%) as foliar spray at 20 and 40 days after sowing (DAS) resulted in significantly higher grain yield (853 kg/ha) than rest of the treatments. How- ever, pre-emergence application of pendimethalin (1 kg/ha) followed by 1 hand-weeding (HW) at 30 DAS signifi- cantly reduced the weed density and weed dry-matter, with highest weed-control efficiency (63.4%). This combi- nation resulted in the highest grain yield (1,064 kg/ha) with 147% increase over the weedy check and the lowest nutrient removal by weeds, and thus proved to be the best weed-control option in summer mungbean.
30
James, T. K., A. Rahman e J. Mellsop. "Weed competition in maize crop under different timings for postemergence weed control". New Zealand Plant Protection 53 (1 de agosto de 2000): 269–72. http://dx.doi.org/10.30843/nzpp.2000.53.3706.
Texto completo da fonteResumo:
The effect of early weed competition was determined for a maize (Zea mays) crop grown in Waikato Maize was established in three different environments viz weedy (no herbicide) grass weeds (preemergence atrazine) and broadleaf weeds (preemergence metolachlor) Surviving weeds were controlled with postemergence nicosulfuron (60 g/ha) after different periods of competition and the plots kept weed free for the remainder of the trial Weeds left completely uncontrolled for 4 weeks after emergence significantly reduced crop yields When a preemergence herbicide was used surviving weeds began to reduce maize yields after about 6 weeks with grasses having greater effect than broadleaf weeds The actual period before the weeds started affecting crop growth and yield appeared to be related to the time taken by the weeds to achieve complete ground cover
31
Fedoruk, L. K., E. N. Johnson e S. J. Shirtliffe. "The Critical Period of Weed Control for Lentil in Western Canada". Weed Science 59, n.º 4 (dezembro de 2011): 517–26. http://dx.doi.org/10.1614/ws-d-11-00051.1.
Texto completo da fonteResumo:
Weed control in lentil is difficult because lentil is a poor competitor with weeds and few POST broadleaf herbicides are available. Imadazolinone-tolerant lentils have more herbicide options, but the optimum timing for herbicide application is not known. The critical period of weed control (CPWC) is the period in a crop's life cycle when weeds must be controlled in order to prevent yield loss. The objective of this research was to determine the CPWC for lentil. We made lentil remain weedy or weed-free from 0 to 11 aboveground nodes to investigate the durations of weed interference and weed-free period, respectively. It was found that lentil has a CPWC beginning at the five-node stage and continuing to the 10-node stage. There was an inverse relationship between weed biomass and lentil yield; that is, lentil yield was highest when weed biomass is minimal. We propose that the CPWC begins when weeds start to accumulate significant biomass and ends with crop canopy closure. Therefore, to maximize lentil yields, growers should consider using a POST residual herbicide that can control weeds during the CPWC.
32
Moyer, J. R., S. N. Acharya e Z. Mir. "Weed management at the time of perennial cereal rye establishment". Canadian Journal of Plant Science 82, n.º 2 (1 de abril de 2002): 457–62. http://dx.doi.org/10.4141/p01-087.
Texto completo da fonteResumo:
Perennial cereal rye (PC rye) is a new crop that is being developed at the Lethbridge Research Centre for the production of silage for cattle. Its ability to compete with weeds during establishment and tolerance to herbicides for weed control was unknown. Therefore, experiments were established with PC rye, and several herbicide treatments were applied to test crop tolerance and weed control. PC rye was not injured by bromoxynil/MCPA, 2,4-D, thifensulfuron/tribenuron, fenoxaprop, clodinafop-propargyl, and tralkoxydim. Combinations of herbicides for broadleaf weed control and annual grass control usually reduced weed dry matter (DM) to < 5 g m-2 in the establishment year. Weeds made up 20 to 36% of the total DM when herbicides were not applied. However, this level of weed content did not affect the digestibility of the forage samples or the total DM produced as weed DM compensated for reduced PC rye yield in weedy plots. Also, the presence of weeds during establishment of PC rye did not affect weed content or PC rye yields the year after establishment. Key words: Acid detergent fibre, digestibility, neutral detergent fibre, perennial cereal rye, weed control, yield
33
I.B. PANDEY e D.K. DWIVEDI. "Effect of planting pattern and weed-control methods on weed growth and performance of wheat (Triticum aestivum)". Indian Journal of Agronomy 52, n.º 3 (10 de outubro de 2001): 235–38. http://dx.doi.org/10.59797/ija.v52i3.4931.
Texto completo da fonteResumo:
A field experiment was conducted during 2000-01 and 2001 -02 at Pusa, Bihar to study weed growth, nutrient removal, weed-control efficiency and yield, and nutrient uptake by wheat (Triticurn aestivurn L. emend. Fiori & Paol.) as influenced by planting pattern [criss-cross (20 cm x 20 cm), normal line sowing (20 cm) and broadcast] as well as weed-control treatment [weedy check, hand-weeding (30 days after sowing), isoproturon @ 0.75 kg/ ha (pre-emergence), sulfosulfuron @ 33.3 glha (post-emergence) and 2,4-D Na salt @ 0.80 kglha (post-emer- gence)]. Criss-cross sowing significantly reduced the weed biomass and hence lowered the nutrient depletion by weeds, ultimately resulting in higher nutrient uptake and yield of wheat crop. Normal line sowing and broadcast- ing methods recorded 7.29 and 19.93% less grain yield than criss-cross sowing. Amongst the weed-control treat- ments, post-emergence application of sulfosulfuron was found on a par with hand weeding treatment for control- ling weeds and producing grain yield of wheat. The different weed-control measures led to 119.5-139.0, 123.2- 141.3 and 120.4-138.5% increase in N, P and K uptake by wheat respectively, and 59.9-74.6, 60.2-75.0 and 60.0-75.5% reduction in the depletion by weeds over the weedy check.
34
GUZZO, CAIO D., LEONARDO B. DE CARVALHO, PAULO R. F. GIANCOTTI, PEDRO L. C. A. ALVES, ELAINE C. P. GONÇALVES e JOSÉ V. F. MARTINS. "Impact of the timing and duration of weed control on the establishment of a rubber tree plantation". Anais da Academia Brasileira de Ciências 86, n.º 1 (março de 2014): 495–504. http://dx.doi.org/10.1590/0001-37652014119113.
Texto completo da fonteResumo:
Rubber tree production is reduced by weeds that compete for environmental resources; therefore, the timing and duration of weed control influences weed interference. The objectives of this study were to evaluate the growth of rubber tree (Hevea brasiliensis) plants, to determine the critical period for weed control, and to evaluate the growth recovery of rubber trees that coexisted with weeds for different periods of time after planting. Two groups of treatments were established under field conditions in the first year of the investigation: one group contained crescent periods of weed infestation, while the other contained crescent periods of weed control, also including a weed-free check and a total weedy check. In the second year of the investigation, the weeds were totally controlled. Urochloa decumbens was the dominant weed (over 90% groundcover). Crop growth was greatly reduced due to the weed interference. Plant height decreased more rapidly than did any other characteristic. Plant height, leaf dry mass, and leaf area decreased by 99%, 97% and 96%, respectively, and were the most reduced characteristics. Plant height also recovered more rapidly than did any characteristic when the period of weed control was lengthened. However, stem dry mass increased by 750%, making it the most recovered characteristic. The critical period for weed control was between 4 and 9½ months after planting in the first year; however, the rubber trees showed an expressive growth recovery when the weeds were controlled throughout the second year.
35
Mwitta, Canicius, Glen C. Rains e Eric Prostko. "Evaluation of Diode Laser Treatments to Manage Weeds in Row Crops". Agronomy 12, n.º 11 (28 de outubro de 2022): 2681. http://dx.doi.org/10.3390/agronomy12112681.
Texto completo da fonteResumo:
Herbicides have been the primary weed management practice in agriculture for decades. However, due to their effects on the environment in addition to weeds becoming resistant, alternative approaches to weed control are critical. One approach is using lasers, particularly diode lasers because of their portability, low power demand, and cost effectiveness. In this research, weeds’ response to diode laser treatments was investigated. Three experiments were conducted. The first experiment involved treating two species of weeds with four different laser powers to determine the time it takes to sever the weed stem. The second experiment involved monitoring the status of two species of weeds for a week after treating them with two lasers at constant application times of 1 s, 2 s, and 3 s. The third experiment was a repeat of the second with higher laser powers and shorter treatment times. The results showed diode lasers have a potential to be an effective weed controlling tool. Weed stem diameter, laser power, treatment duration, and distance between laser and weed were all statistically significant in weed mortality, with weed species having no significance. Furthermore, it was found that weed management is possible by exposing the stem of the two weed species between 0.8 and 2.65 mm diameter to a laser beam dosage without necessarily severing it, with 80% effectiveness at 0.5 s treatment time, and 100% effectiveness using a 6.1 W laser for 1.5 s.
36
Broatch, Jim S., Lloyd M. Dosdall, John T. O'Donovan, K. Neil Harker e George W. Clayton. "Herbicide Rate Effects on Weed and Root Maggot Dynamics in Canola". Weed Science 56, n.º 3 (junho de 2008): 477–83. http://dx.doi.org/10.1614/ws-07-172.1.
Texto completo da fonteResumo:
Weed management strategies can influence insect infestations in field crops, yet no attempts have been made previously to manipulate weed populations in canola for integrated weed and insect management. Field studies were conducted during 2003 to 2005 at Lacombe and Beaverlodge, Alberta, Canada to manipulate weed and root maggot, Delia spp. (Diptera: Anthomyiidae), interactions in canola. Densities of monocot weeds were varied by altering herbicide applications, with rates ranging from 0 to 100% of the rate recommended. Weed populations declined, and yields were variable with increased herbicide rates. Root maggot damage decreased with increases in monocot weed dry weight for both canola species at both study sites. Results support the hypothesis that heterogenous environments, arising from mixed populations of monocot weeds with canola, minimize opportunities for females of Delia spp. to complete the behavioral sequence required for oviposition, leading to reduced infestation levels in weedy systems. However, effects of dicot weeds on root maggot infestations varied between sites as a result of site-related differences in weed species complexes. When wild mustard was common, crop damage increased, because this weed can serve as an alternate host for root maggots. The study emphasizes the importance of adopting crop management practices that are compatible for both weed and root maggot control.
37
Gibson, Kevin D., Richard Dirks, Case R. Medlin e Loree Johnston. "Detection of Weed Species in Soybean Using Multispectral Digital Images". Weed Technology 18, n.º 3 (setembro de 2004): 742–49. http://dx.doi.org/10.1614/wt-03-170r1.
Texto completo da fonteResumo:
The objective of this research was to assess the accuracy of remote sensing for detecting weed species in soybean based on two primary criteria: the presence or absence of weeds and the identification of individual weed species. Treatments included weeds (giant foxtail and velvetleaf) grown in monoculture or interseeded with soybean, bare ground, and weed-free soybean. Aerial multispectral digital images were collected at or near soybean canopy closure from two field sites in 2001. Weedy pixels (1.3 m2) were separated from weed-free soybean and bare ground with no more than 11% error, depending on the site. However, the classification of weed species varied between sites. At one site, velvetleaf and giant foxtail were classified with no more than 17% error, when monoculture and interseeded plots were combined. However, classification errors were as high as 39% for velvetleaf and 17% for giant foxtail at the other site. Our results support the idea that remote sensing has potential for weed detection in soybean, particularly when weed management systems do not require differentiation among weed species. Additional research is needed to characterize the effect of weed density or cover and crop–weed phenology on classification accuracies.
38
Cherry, Ron, e Andy Bennett. "Effect of Weeds on Rice Stink Bug (Hemiptera: Pentatomidae) Populations in Florida Rice Fields". Journal of Entomological Science 40, n.º 4 (1 de outubro de 2005): 378–84. http://dx.doi.org/10.18474/0749-8004-40.4.378.
Texto completo da fonteResumo:
The effect of weeds on rice stink bug, Oebalus pugnax (F.), populations was studied in Florida rice fields. Fall panicum, Panicum dichotomiflorum Michaux, was the most common grassy weed found in weedy areas of rice fields, and significantly more rice stink bugs were found in these weedy areas vs nonweedy areas in the fields. Large numbers of rice stink bugs also were found in unmowed roadsides containing heading weeds, especially coast cockspur, Echinochloa walteri (Pursh) Heller. In contrast, few rice stink bugs were found in mowed roadsides which prevented weed heading around rice fields. Our study shows that weed control helps reduce rice stink bug populations in Florida rice.
39
Averill, Kristine M., Anna S. Westbrook, Laura Pineda-Bermudez, Ryan P. O’Briant, Antonio DiTommaso e Matthew R. Ryan. "Effects of Tertill® Weeding Robot on Weed Abundance and Diversity". Agronomy 12, n.º 8 (26 de julho de 2022): 1754. http://dx.doi.org/10.3390/agronomy12081754.
Texto completo da fonteResumo:
Robotic weed control may reduce labor requirements, soil disturbance, and amount of herbicide applied relative to non-robotic methods. Tertill® is among the first weeding robots to become commercially available. This solar-powered robot moves in a random walk, avoiding obstacles using capacitive sensors, and cuts weeds with a string trimmer. We tested the effects of Tertill (two hours per week) with and without the string trimmer and hand weeding (from 3 to 5.6 min per week with a stirrup hoe) on weed communities at two field sites in Ithaca, NY. Tertill with trimmer and hand weeding provided similar levels of weed control (visual estimates averaging 2–9% ground cover at the end of the experiment, compared to 14–48% in the unweeded control). Without the string trimmer, Tertill was ineffective. Tertill did not significantly reduce monocot weed density but did reduce dicot weed density. At one site, Tertill reduced species richness and increased evenness based on density. Overall, these results suggest that Tertill can effectively remove newly emerged weed seedlings. Future research should investigate Tertill performance against more established weeds and the long-term effects of Tertill on weed community composition (e.g., possible selection for monocots and other species with low growing points).
40
Goff, William D., Michael G. Patterson e Mark S. West. "Orchard Floor Management Practices Influence Elemental Concentrations in Young Pecan Trees". HortScience 26, n.º 11 (novembro de 1991): 1379–81. http://dx.doi.org/10.21273/hortsci.26.11.1379.
Texto completo da fonteResumo:
Nutrient status of young pecan [Carya illinoensis (Wangenh.) C. Koch] trees grown under eight combinations of orchard floor management and irrigation was determined by leaf and soil analyses. Orchard floor management practices were weedy-unmowed, weedy-mowed, weed control with herbicides, and weed control by disking, with trees either irrigated or nonirrigated. The element most affected by treatment was K. Mean leaf K for the two sample years was significantly (P < 0.01) lower in the weedy plots (0.56% K) than in those where weeds were controlled (0.76% K), suggesting a highly competitive effect of weeds for K with young pecan trees. Weed competition also suppressed leaf Ca and Mg, but presence of weeds or sod resulted in higher soil pH and higher leaf Zn. Leaf concentrations of N, P, B, Cu, and Fe were not significantly affected by the treatments.
41
S.P. SINHA, S.M. PRASAD e S.J. SlNGH. "Nutrient utilization by winter maize (Zea mays) and weeds as influenced by integrated weed management". Indian Journal of Agronomy 50, n.º 4 (10 de outubro de 2001): 303–4. http://dx.doi.org/10.59797/ija.v50i4.5133.
Texto completo da fonteResumo:
An experiment was carried out during the winter seasons of 1998-98 and 1999-2000 at Pusa with 14 weed- management practices to study the nutrient-depletion patterns by winter maize (Zea mays L.) and associated weeds. Amongst the weed-management practices, nutrient depletion by weeds was minimum under hand-weed- ing and maximum (22.97 kg N, 4.87 kg P20, and 27.57 kg K20/ha) in weedy condition, whereas total nutrient up- take by winter maize was maximum (169.41 kg N, 55.67 kg, P20, and 60.77 kg K20/ha) under the treatment alachlor + French bean (Phaseolus vulgaris L.) as smother crop followed by hand-weeding (137.70 kg N, 44.15 kg P20, and 106.22 kg, K20/ha). The nutrient uptake by crop in weedy condition was least. Chemical weeding checked nutrient drain by weeds significantly compared with weedy check.
42
Singh, Ajay. "Effect Of Sequential Application Of Pre And Post-Emergence Herbicides On Dynamics Of Weeds Associated With DSR System Andrice-Growth And Sustained Yield". Agriculture Association of Textile Chemical and Critical Reviews Journal 11, n.º 4 (setembro de 2023): 8–14. http://dx.doi.org/10.58321/aatccreview.2023.11.04.08.
Texto completo da fonteResumo:
The sustained rice yield plays an important role in the country’s GDP. The diverse weed flora is a potential biotic threat to the sustained yield in the DSR system. The crop faces severe competition the resources from its beginning (germination of crop seedlings) to the panicle initiation with the diverse weeds flora as it grows quickly in moist conditions, resulting in severe yield losses up to 65 per cent. Thus, an effective and economical weed control strategy in DSR is often required to overcome the losses. In such situations, sequential application of herbicides may provide broad-spectrum weed control in DSR. A field experiment was conducted on silty loam soils to assess the herbicidal effects on weed dynamics and growth & yield productivity of direct-seeded rainy (Kharif) rice at Agronomy Research Farm of Narendra Deva University of Agriculture and Technology, Kumarganj, Ayodhya (U.P.) during the years, 2016 and 2017. The field trial was carried out in Randomized complete block design (RCBD) with three replications and twelve treatments. The treatments consisted of nine pre & post-emergent herbicide combinations along with three distinct controls, i.e. a) Hand weeding (at 20 & 40 DAS), b) Weed Free (weeding at every 15 days interval from seedling to the PI stage), and c) Weedy Check. The results of the field study revealed that the weed-free plots recorded the highest weed control efficiency, and they registered the least weeds density and dry weight of weeds associated with direct seeded rice fields. However, the application of herbicides, namely, pendimethalin (1000 g a.i. ha-1) as pre-emergent and Bispyribac-Na (1000 g a.i. ha-1) as post-emergent coupled with a hand weeding at 40 DAS provided the statistically comparable results to weed-free and is effectively controlled the diverse weed flora by 81.9-84.5 per cent in DSR system. And both the treatments gave significantly better growth (plant height, number of tillers, dry matter, LAI) and yields (grain and straw) of rice as compared to the weedy-check. Among the diverse weeds associated with the DSR fields, sedges were dominant as compared to broad leaves and grasses. The study also recorded the rice-grain yield reduction by 40.9 per cent due to the presence of diverse weed flora in weedy check plot as to weed-free plot.
43
Kashe, Keotshephile, Dikungwa Ketumile, Paul Kristiansen, Cornelius Mahilo e Thebeetsile Moroke. "Evaluation of pre-emergence herbicides for weed control in maize". Welwitschia International Journal of Agricultural Sciences 2 (5 de dezembro de 2020): 5–18. http://dx.doi.org/10.32642/wijas.v2i.1437.
Texto completo da fonteResumo:
Weed management is an ongoing constraint in southern Africa for conventional farming systems and in emerging conservation agriculture systems, which are more heavily reliant on herbicides for primary weed control. The challenge of rising labour costs and decreasing availability creates a greater need to develop effective and efficient weed management methods in key crops such as maize. Field experiments were conducted at Sebele Agricultural Research Station, Botswana in the 2011/12 and 2012/13 cropping seasons to evaluate pre-emergence application of atrazine at 1,000 and 2,000 g a.i. ha-1 and S-metolachlor at 1,440 and 2,880 g a.i. ha-1, and a tank mixture of atrazine at 1,000 and S-metolachlor at 1,440 g a.i. ha-1. Atrazine at either rate alone, effectively controlled annual broadleaf weeds: Acanthospermum hispidum, Datura ferox and Sesamum alatum, but failed to control annual grass weeds (Tragus berteronianus and Urochloa spp.). Conversely, sole application of S-metolachlor at either rate provided complete control of annual grass weeds, but poorly controlled annual broadleaf weeds except small-seeded Amaranthus hybridus and Amaranthus thunbergii. A tank mixture of atrazine and S-metolachlor provided broad-spectrum weed control and successfully controlled both annual broadleaf and grass weeds. Atrazine alone and in tank mixture with S-metolachlor significantly reduced annual broadleaf weed density and biomass and increased maize grain yield by more than 80% when compared with the weedy treatment. High weed density and biomass of annual broadleaf weeds in S-metolachlor treatments significantly reduced maize grain yield to levels similar to the weedy treatment. A pre-mixture of atrazine and S-metolachlor is recommended for broad-spectrum weed control. Using a combination of herbicides with different modes of action may reduce selection pressure for herbicide resistance.
44
Harker, K. Neil, e John T. O'Donovan. "Recent Weed Control, Weed Management, and Integrated Weed Management". Weed Technology 27, n.º 1 (março de 2013): 1–11. http://dx.doi.org/10.1614/wt-d-12-00109.1.
Texto completo da fonteResumo:
Integrated weed management (IWM) can be defined as a holistic approach to weed management that integrates different methods of weed control to provide the crop with an advantage over weeds. It is practiced globally at varying levels of adoption from farm to farm. IWM has the potential to restrict weed populations to manageable levels, reduce the environmental impact of individual weed management practices, increase cropping system sustainability, and reduce selection pressure for weed resistance to herbicides. There is some debate as to whether simple herbicidal weed control programs have now shifted to more diverse IWM cropping systems. Given the rapid evolution and spread of herbicide-resistant weeds and their negative consequences, one might predict that IWM research would currently be a prominent activity among weed scientists. Here we examine the level of research activity dedicated to weed control techniques and the assemblage of IWM techniques in cropping systems as evidenced by scientific paper publications from 1995 to June 1, 2012. Authors from the United States have published more weed and IWM-related articles than authors from any other country. When IWM articles were weighted as a proportion of country population, arable land, or crop production, authors from Switzerland, the Netherlands, New Zealand, Australia, and Canada were most prominent. Considerable evidence exists that research on nonherbicidal weed management strategies as well as strategies that integrate other weed management systems with herbicide use has increased. However, articles published on chemical control still eclipse any other weed management method. The latter emphasis continues to retard the development of weed science as a balanced discipline.
45
KOUSTA, Angeliki, Panayiota PAPASTYLIANOU, Nikolina CΗΕΙΜΟΝΑ, Ilias TRAVLOS, Ioanna KAKABOUKI e Dimitrios BILALIS. "Effect of Fertilization and Weed Management on Weed Flora of Hemp Crop". Bulletin of University of Agricultural Sciences and Veterinary Medicine Cluj-Napoca. Horticulture 77, n.º 2 (18 de novembro de 2020): 44. http://dx.doi.org/10.15835/buasvmcn-hort:2020.0013.
Texto completo da fonteResumo:
Hemp is known to have a competitive advantage over weeds. Despite its suppressive ability, weed infestation remains an important issue during the early growth of the crop. The aim of this study was to determine the effect of fertilization and weed management on weed flora and hemp growth parameters during initial growth in the 2019 season. The experiment was laid out in a split-split plot design with three replicates: three hemp cultivars as main plots, three fertilization treatments as sub-plots and two sub-sub-plots (weedy, weed free). For the computation of height and biomass weight, 10 plants were randomly selected in each plot. Weed species were collected by quadrate and density and biomass weight were determined. ANOVA revealed that all factors and their interactions significantly affected plant traits. Hemp cultivars showed different competitive ability. ‘Futura 17’ reduced weed measurement traits better than ‘Uso 31’. Density and biomass of nitrophilous weeds increased with the higher N dose compared to control (up to 56% and 79% respectively), therefore negatively affecting the growth of the hemp plants. Further research is needed in order to identify useful information on interactions between weeds and hemp crop to address potential yield losses under different weed management systems.
46
Al-Hinai, Yahya K., e Teryl R. Roper. "Temporal Effects of Chemical Weed Control on Tart Cherry Tree Growth, Yield, and Leaf Nitrogen Concentration". HortScience 36, n.º 1 (fevereiro de 2001): 80–82. http://dx.doi.org/10.21273/hortsci.36.1.80.
Texto completo da fonteResumo:
This experiment was conducted to determine temporal weed management parameters for tart cherry (Prunus cerasus L.) orchards. Annual ryegrass (Lolium multiflorum L.) and lambsquarter (Chenopodium album L.) were planted in tree rows of a 4-year-old tart cherry orchard. Weeds either were not controlled or controlled with nonresidual herbicides during the following intervals: all-summer; May, June, July, or August; preharvest (April-July); or postharvest (late July to frost). Trees in all-summer, June, and preharvest weed-free plots had more shoot growth, more nodes, longer internodes, greater leaf area, and higher concentrations of leaf nitrogen than did those in the weedy control and postharvest, July, or August treatments. A larger increase in trunk circumference was observed in all-summer and preharvest weed-free plots than in postharvest and weedy plots. Early-summer weed control was important for tree vegetative growth. Tree yield (fruit weight and number) was greater on trees without weed competition postharvest than in those treated in May, June, July, or in weedy controls. Late-season (after late July) weed control is therefore important for fruit yield.
47
S.K. TRIPATHY, S. MOHAPATRA, A.K. MOHANTY, N. PANIGRAHY e S. LENKA. "Productivity of winter (rabi) onion (Allium cepa) as influenced by sole and sequential application of herbicides". Indian Journal of Agronomy 64, n.º 2 (10 de outubro de 2001): 248–52. http://dx.doi.org/10.59797/ija.v64i2.5262.
Texto completo da fonteResumo:
A field experiment was conducted during the winter (rabi) seasons of 201415 and 201516 to study the effect of sole and sequential application of different herbicides on weed control in onion (Allium cepa L.). Sequential ap- plication of pendimethalin @ 750 g/ha at 3 days after transplanting (DAT) + oxyfluorfen @ 100 g/ha at 20 DAT controlled the grasses, sedges and broad-leaf weeds most efficiently and was at par with oxadiargyl @ 90 g/ha at 3 DAT + oxyfluorfen @ 100 g/ha at 20 DAT. Weed competition resulted in about 54.8% yield loss of onion in weedy check plot. The lowest values of total weed density (18.6/m 2), dry weight (6.8 g/m 2), weed index (6.2%) and the highest values of weed control efficiency (89.2%), bulb yield (21.89 t/ha) and benefit: cost ratio (2.84) were registered with sequential application of pendimethalin @ 750 g/ha at 3 DAT + oxyfluorfen @ 100 g/ha at 20 DAT. In weedy check, weeds removed 23.9 kg N, 3.8 kg P and 27.6 kg K/ha.
48
Nazir, Aijaz, Mohammad Anwar Bhat, Tauseef Ahmad Bhat, Suhail Fayaz, Mohammad Salim Mir, Umar Basu, Shafat Ahmad Ahanger et al. "Comparative Analysis of Rice and Weeds and Their Nutrient Partitioning under Various Establishment Methods and Weed Management Practices in Temperate Environment". Agronomy 12, n.º 4 (27 de março de 2022): 816. http://dx.doi.org/10.3390/agronomy12040816.
Texto completo da fonteResumo:
A research trial was conducted at Agronomy Farm (SKUAST-K, Wadura, Jammu & Kashmir), during kharif 2017 and 2018 to evaluate nutrient removal in rice under various rice establishment methods and weed control measures. The study comprised of two factors: rice establishment techniques {Transplanting (TPR); Direct seeding (DSR) and System of rice intensification (SRI)} as main plot treatments and weed control measures {Butachlor @ 1500 g a.i ha−1 (B); Penoxsulam @ 22.5 g a.i ha−1 (P); Pyrazosulfuron ethyl + Pretilachlor @ 15 and 600 g a.i ha−1 (PP); Bensulfuron methyl + Pretilachlor @ 60 and 600 g a.i ha−1 (BP); 2 Conoweeding/Hand Weeding (CW/HW); Weed free (WF) and weedy check (WC)} as sub-plot treatments meant to evaluate the best establishment method and weed management practice for rice. Over DSR and transplanted rice, the SRI technique yielded a significant increase in dry biomass accumulation (17.04 and 17.20 t ha−1) and grain (7.92 and 8.17 t ha−1) and straw (9.60 and 10.17 t ha−1) yields. Penoxsulam herbicide significantly showed higher grain and straw yield of 8.19 and 8.28 t ha−1 and 10.13 and 10.44 t ha−1, respectively, than other weed management measures by comparing the means using critical difference. TPR excelled in reducing dry weed biomass more than other established methods. All herbicides considerably reduced dry weed biomass, but Penoxsulam herbicide showed the greatest reduction in dry weed biomass and proved superior against complex weed flora. Weeds showed maximum contribution towards total Biomass under DSR, among rice establishment techniques. In contrast, among different weed control measures, it was maximum in weedy check treatment (Untreated Control) and minimum in penoxsulam treatment. SRI significantly excelled in crop (grain and straw) nutrient uptake compared to the DSR and TPR method, although different crop establishment techniques non-significantly influenced nutrient concentrations. Furthermore, penoxsulam treatment demonstrated higher crop (grain and straw) nutrient uptake among the various weed management measures. However, available soil nutrients were observed among establishment techniques, highest in DSR and lowest in SRI. Moreover, direct-seeded rice excelled SRI and transplanted rice in weed nutrient uptake, and among the different herbicidal treatments, penoxsulam recorded the lowest uptake in weeds. Nutrient budgeting demonstrated that DSR showed the maximum percentage of nutrient removal by weeds, and the minimum ratio was in TPR. In contrast, the lowest rate of nutrients removed via weeds were seen in penoxsulam application under various weed management measures.
49
Gairola, Ananya, Satish Kumar, Pawan Kumar, Jyoti, Sunil Kumar Prajapati e Vipin Kumar. "Evaluation of the Impact of Herbicidal Weed Management Practices on Weed Density, Yield Attributes and Yield of Irrigated Chickpea (Cicer arietinum L.)". International Journal of Environment and Climate Change 13, n.º 11 (2 de dezembro de 2023): 4153–65. http://dx.doi.org/10.9734/ijecc/2023/v13i113595.
Texto completo da fonteResumo:
In the Rabi season of 2021-22, an experiment was conducted at the Agronomy Research Farm of CCS Haryana Agricultural University in Hisar. The aim was to examine how herbicidal weed management affects irrigated chickpea. The experiment was laid out in Randomised Block Design (RBD) with thirteen treatments, each repeated three times. The treatments included various herbicides applied at different stages, such as pre-plant incorporation (PPI), pre-emergence (PRE), and post-emergence (POE). Interestingly, the Ready mix (RM) herbicide application of pendimethalin + imazethapyr (RM) @ 1000 g a.i ha-1, applied both as PPI and PRE, outperformed the herbicides applied solely as PPI, PRE, or POE. Among the herbicidal treatments, the combined during PPI and PRE stages exhibited excellent control over a diverse weed population, leading to a significant increase in chickpea yield compared to the weedy check. The number of seeds per pod, pods per plant, and branches per plant varied significantly with different weed control treatments. Weed-free plots showed the highest values in these parameters. The uncontrolled growth of weeds in the weedy check resulted in a 55.2% reduction in seed yield as compared to weed-free plots. The maximum seed yield (1968 kg ha-1) and favorable yield attributes were observed in the weed- free treatment, statistically comparable to the yield obtained from two hand weeding at 30 and 50 days after sowing (1940 kg ha-1). Among herbicidal treatments, the highest seed yield was achieved with the PRE application of pendimethalin + imazethapyr (RM) @ 1000 g a.i. ha-1 (1827 kg ha-1). The dominant weed flora consisted of Chenopodium album, Fumaria parviflora and Anagallis arvensis. Density of different weed species was significantly influenced by different weed control treatments. All the weed control treatments significantly reduced the total weed density and dry matter accumulation by weeds in comparison to weedy check. Weed free and two hand hoeing reduced the weed population drastically which was statistically at par with PRE application of pendimethalin + imazethapyr (RM) at 1000 g a.i. ha-1. Chenopodium album, Fumaria parviflora and Anagallis arvensis were effectively controlled by RM irrespective of its time of application.
50
Boutin, Céline, Benoît Jobin, Luc Bélanger e Line Choinière. "Comparing weed composition in natural and planted hedgerows and in herbaceous field margins adjacent to crop fields". Canadian Journal of Plant Science 81, n.º 2 (1 de abril de 2001): 313–24. http://dx.doi.org/10.4141/p00-048.
Texto completo da fonteResumo:
Hedgerows and field margins are common features of the agricultural landscape in southern Québec. In the last decade, hedgerow establishment has been encouraged primarily for the prevention of soil erosion, though many farmers view them as reservoirs of invasive weeds and pests. In this study, we compared weed assemblages of several hedgerow types and herbaceous field margins. Ranking that takes into consideration weed abundance was clearly demonstrated: planted hedgerows > herbaceous field margins > natural woody hedgerows. The latter harboured many perennial plant species of less weedy propensity than planted hedgerows, which accommodated a larger number of weedy species. In planted hedgerows close to 50% of plants were weeds, even in their central position, although planted and natural hedgerows sheltered similar weed composition in their central parts. Likewise, most species inventoried in adjacent fields were weeds. Weeds characterising the central position of hedgerows/field margins were often species of wet habitats (Lythrum salicaria L., Equisetum arvense L., Cicuta maculata L.). Management practices of hedgerows and perhaps of crop fields adjacent to hedgerows may be mostly responsible for the abundance of weeds in hedgerows and field margins. Key words: Hedgerow, field margins, weed, management practices, pesticide, fertiliser