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1
Villanueva-Mosqueda, Eduardo, i Michael J. Havey. "Genetic Analyses of Seed Yield in Onion". Journal of the American Society for Horticultural Science 126, nr 5 (wrzesień 2001): 575–78. http://dx.doi.org/10.21273/jashs.126.5.575.
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Development of two-way onion (Allium cepa L.) hybrids is difficult due to poor seed yields on inbred female parents. Seed yield of onion is affected by inbreeding depression and the seed-production environment. A standard diallel was used to estimate combining abilities for seed yield among seven inbred onion lines. Males and hybrids differed significantly (P < 0.05) for seed yields. Combinations of relatively high-by-high seed-yielding inbred parents were not always the best combinations; combinations of medium-by-medium or medium-by-high seed yielders also produced good F1 seed yielders. For the seven inbred lines, significant correlations (P < 0.05) were observed between mean seed yield per bulb and scape height. Parent-offspring regressions revealed no significant relationship between seed yields of randomly selected, open-pollinated bulbs and their S1 families. Results indicate that relative seed yields of individual bulbs after self-pollination cannot be used to predict seed yields of progeny families. However, the seed yield of inbred lines of onion may reflect the potential seed yield of F1 male-sterile lines.
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Tautges, Nicole, Claire Flavin, Thomas Michaels, Nancy Ehlke, John Lamb, Jacob Jungers i Craig Sheaffer. "Rotating alfalfa with dry bean as an alternative to corn-soybean rotations in organic systems in the Upper Midwest". Renewable Agriculture and Food Systems 34, nr 1 (6.06.2017): 41–49. http://dx.doi.org/10.1017/s1742170517000321.
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AbstractDry bean (Phaseolus vulgaris) can be grown as a local food source and as an alternative to soybean (Glycine max) to diversify organic crop rotations. To understand the benefits of diversification of organic cropping systems, the effects of preceding alfalfa (Medicago sativa) and corn (Zea mays) crops on yields of five dry bean types and one soybean type, and the effect of bean type on following spring wheat (Triticum aestivum) yields, were tested at four Minnesota locations. Dry bean and soybean yields following alfalfa were 25% greater than yields following corn at two of four locations, though bean yields following corn were greater at one location. A preceding alfalfa crop benefited bean yields at locations where hog manure or no manure was applied to corn, whereas bean yields following corn fertilized with cow manure were similar to or greater than bean yields following alfalfa. Among dry bean types, black bean yielded similarly to soybean at three of four locations, but dark red kidney bean consistently yielded 25–65% lower than soybean. Navy, pinto and heirloom dry bean types yielded similarly to soybean at two of four locations. Across locations, weed biomass was 3–15 times greater in dry bean than in soybean and dry bean yield response to weed competition varied among bean types. However, dry bean, regardless of the preceding crop, demonstrated the potential to produce yields comparable with soybean in organic systems and the substitution of dry bean for soybean did not affect subsequent wheat yields. More studies are needed to identify nitrogen fertility dynamics in organic systems as they relate to dry bean yield.
3
HOEKSTRA, G. J., L. W. KANNENBERG i B. R. CHRISTIE. "GRAIN YIELD COMPARISON OF PURE STANDS AND EQUAL PROPORTION MIXTURES FOR SEVEN HYBRIDS OF MAIZE". Canadian Journal of Plant Science 65, nr 3 (1.07.1985): 471–79. http://dx.doi.org/10.4141/cjps85-068.
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The objective of this study was to compare yielding ability and competitive effects in pure stands and equal-proportion mixtures of maize hybrids. Seven maize (Zea mays L.) hybrids were grown for 2 yr in pure stand and in all equal-proportion, two-component mixtures at plant densities of 61 500 and 136 000 plants per hectare. In 1978, a year of severe moisture stress, mixtures yielded 6% more grain on average than expected on the basis of pure stand yields. Half of the mixtures yielded more than the pure stand yield of the high-yielding component; however, one mixture yielded significantly less than predicted based on pure stand yields. In 1979, mixtures yielded as expected based on pure stand yields. The yield difference between 1978 and 1979 for mixtures was less than the difference between pure stands indicating that mixtures were, on average, more consistent in performance across environments than their components. The yield advantage of mixtures in 1978, however, was too low to recommend growing blends as a production practice. Relative yields of individual hybrids were different in pure stands compared to mixtures. Furthermore, the order of hybrids ranked according to their pure-stand yields differed from the order based on yielding ability in mixtures. In general, a direct relationship existed between yielding ability in mixtures and competititve influence. Hybrids with a high average yield across mixtures yielded more in mixtures with low-yielding hybrids than in mixtures with high-yielding hybrids. Conversely, low-yielding hybrids produced less grain when in mixtures with a high-yielding hybrid than in mixtures with a low-yielding hybrid. However, the one hybrid which was consistently the most competitive was not the highest yielding under stress conditions.Key words: Blends, corn, grain yield, hybrid mixtures, population stress, Zea mays
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Kulla, L., J. Tutka i R. Marušák. "Forest yield index and its applicability to the assessment of future forest yields". Journal of Forest Science 55, No. 1 (3.02.2009): 41–50. http://dx.doi.org/10.17221/45/2008-jfs.
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The paper suggests and examines a simplified relative indicator of forest production, with special regard to possibilities of its use in projecting future forests. Forest yield index (<I>I</I><sub>Y</sub>), based on an economic parameter “value of final cutting yield” was proposed, and examined in the model territory of Kysuce in north-western Slovakia. The current values of final cutting yield, dependent on tree species, site index and the length of rotation period served as a basis for the assessment of expected yields. The possibilities and limitations of index applicability in long-term strategic forest management decision-making are discussed, considering the uncertainty of ecological and economic conditions during the long forest production cycle, as well as the complexity of tree species growth and production in the mixed forests, uneven aged forests and forests under climate change.
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Pelikán, J. "Yield evaluation of varieties from the world collection of birdsfoot trefoil (Lotus corniculatus L.)". Plant, Soil and Environment 48, No. 6 (11.12.2011): 265–70. http://dx.doi.org/10.17221/4240-pse.
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In field trials in 1998–2000, ten varieties of the world collection of birdsfoot trefoil (Lotus corniculatus) were evaluated for herbage and hay yields. In all the years of testing yields from three cuttings and total annual production were evaluated. In 1999, seed yield was also recorded. As a control, alfalfa (Medicago sativa) variety was included in the experiment. The test varieties showed good productivity in the first and especially in the second year of testing, most of them exceeded alfalfa in herbage yield in individual cuttings and in total productions. As for hay yield, the differences were not so great. Local varieties showed very good productivity, predominantly in herbage yields. Of foreign varieties, the best herbage, hay and seed yielder was the Hungarian variety Puszta. There were no statistical differences in seed yield between the varieties. The yields were, however, relatively low.
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Jubinski, Daniel, i Amy F. Lipton. "Equity volatility, bond yields, and yield spreads". Journal of Futures Markets 32, nr 5 (26.05.2011): 480–503. http://dx.doi.org/10.1002/fut.20521.
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Bevilaqua, Julia, Galina B. Hale i Eric Tallman. "Corporate yields and sovereign yields". Journal of International Economics 124 (maj 2020): 103304. http://dx.doi.org/10.1016/j.jinteco.2020.103304.
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Pilbeam, C. J., G. Duc i P. D. Hebblethwaite. "Effects of plant population density on spring-sown field beans (Vicia faba) with different growth habits". Journal of Agricultural Science 114, nr 1 (styczeń 1990): 19–33. http://dx.doi.org/10.1017/s0021859600070957.
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SUMMARYDeterminate varieties of Vicia faba are smaller and may require higher plant population densities than their conventional indeterminate counterparts to attain high yields. This hypothesis was examined at the University of Nottingham farm at Sutton Bonington, UK, and at INRA, Dijon, France in 1986 and 1987. The determinate varieties Ticol and TP667 and indeterminate M5.1 and Maris Bead were sown in the spring to give a range of densities of 10–100 plants/m2.Yields generally increased as population density increased. The optimum density for determinate varieties was higher than for indeterminate varieties. Indeterminate varieties yielded more than determinate varieties at all plant densities, perhaps because of their larger canopy. Seed yields were affected by year and location. Greater yields were associated with heavier seeds and more seeds per pod.Although several yield components, when expressed per unit area, were significantly correlated with seed yield, their coefficients of determination were never very large. This confirmed the plasticity of yield in field beans.
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Taylor, B. R., i J. Y. Chambi. "Sesame Agronomy in South-east Tanzania. I. Plant Population and Sowing Method". Experimental Agriculture 22, nr 3 (lipiec 1986): 243–51. http://dx.doi.org/10.1017/s0014479700014411.
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SUMMARYField trials are described in which the seed yield response of row-sown sesame to increasing plant population was examined, and in which row-sowing was compared with broadcasting at different seed rates. Maximum yields were obtained at an intended 200 to 250 × 103 plants ha−1 but yields were not greatly affected by a wider range of populations. Broadcasting, the normal local practice, gave yields slightly higher than those from rows 50 cm apart, the un-thinned rate of 800 × 103 viable seeds sown ha−1 yielded as well as treatments thinned to the optimum population, and double this seed rate, unthinned, gave the lowest yields, especially in rows.
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Narwal, S. S., D. S. Dahiya, G. Singh i D. S. Malik. "Response of maize cultivars to sowing in the winter". Journal of Agricultural Science 109, nr 2 (październik 1987): 303–7. http://dx.doi.org/10.1017/s0021859600080722.
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SummaryIn a 2-year field study, all the maize cultivars tried (Partap-1 Ageti-76, Ganga-5 and DHM-103) produced similar length of ears and equivalent grain yields. However, Partap-1 and Ganga-5 produced greater 100-kernel weight and greater grain yield per ear but fewer ears per hectare than Ageti-76 and DHM-103. The yield attributes and grain yields of maize sown on 19 December, 29 December and 8 January were identical and were superior to those of the 19 January sowing. Maize sown on 19 December, 29 December and 8 January exhibited longer ears, more ears and fully developed kernels and thereby produced greater grain yields than the 18 January sowing.During 1983–4, in the 19 December and 29 December sowings all the cultivars gave identical grain yields. In the 8 January sowing Partap-1 and Ageti-76 produced similar yields and proved better than Ganga-5 and DHM-103. In the 18 January sowing Ageti-76, Ganga-5 and DHM-103 yielded more than Partap-1.
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Reid, PE, NJ Thomson, PK Lawrence, DJ Luckett, GT McIntyre i ER Williams. "Regional evaluation of cotton cultivars in eastern Australia, 1974-85". Australian Journal of Experimental Agriculture 29, nr 5 (1989): 679. http://dx.doi.org/10.1071/ea9890679.
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In 1974, a district cotton cultivar trial was initiated to assess the yield and fibre quality of promising cultivars in all major Australian cotton growing areas over 1 or more years. A nearly 5-fold range in site yields (595-2451 kg/ha) occurred across locations and years. Yields were usually higher in the last 6 years of the trial (overall mean 1688 kg/ha) than in the first half (overall mean 1223 kg/ha). Queensland sites (except Theodore) were lower yielding than average, while New South Wales sites (except Warren) were higher yielding. Deltapine cultivars from the U.S.A. have been the dominant commercial cultivars during 1974-85, and in the first 9 years of the trials USA. or Australian-bred Deltapine types produced the highest overall lint yields. Since 1982, Australian-bred Siokra lines have been the highest yielding with their resistance to bacterial blight apparently being an important factor in their performance. The rate of genetic gain in lint yield, as assessed from the overall year means and the mean yield of the 2 control cultivars (Deltapine 16 and Namcala) grown in all 12 years of the trials, was 2.3% per year. These yield increases were also accompanied by improvements in fibre strength and micronaire value in some of the recently developed lines or cultivars. A number of genotypes with mutant traits associated with host plant resistance to insect pests were compared with their near-isogenic counterparts. Superokra leaf yielded 6% less than normal leaf, nectariless yielded similarly to nectaried, and glabrous yielded similarly to delta-smooth pubescence. Frego bract yielded less in 1 comparison but in 2 others was similar to the normal counterpart, while glabrous and frego bract together led to reduced yields. Intra-varietal selection was shown to produce useful gains in yield between 3 to 6.5%.
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Stock, Duane, i T. K. Bhattacharya. "Bond yields compared to amortizing yields". Review of Quantitative Finance and Accounting 3, nr 3 (wrzesień 1993): 325–37. http://dx.doi.org/10.1007/bf02406995.
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Thomson, E. F., S. Rihawi i N. Nersoyan. "Nutritive Value and Yields of Some Forage Legumes and Barley Harvested as Immature Herbage, Hay and Straw in North-West Syria". Experimental Agriculture 26, nr 1 (styczeń 1990): 49–56. http://dx.doi.org/10.1017/s0014479700015398.
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SUMMARYThe nutritive value and yield of forage legumes and barley harvested as immature herbage, hay and straw were measured in two experiments. The voluntary feed intake of peas at all stages of maturity and immature herbage from woollypod vetch was substantially lower than that of common vetch and chickling. At each stage of maturity barley was less digestible than all the forages except immature peas. Despite exceptionally cold weather in February/March 1985, yields of common vetch were higher in 1984/85 than in 1985/86 when there was less rain. Peas yielded the most hay, and chickling yielded less seed and straw than common vetch, peas and barley. Yields of digestible dry matter from straw and seed exceeded those from hay but protein yield at the two stages was similar. Mechanical baling substantially reduced the yields of baled hay but these losses would be reduced to less than 10% if the residues were grazed.
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Bussan, Alvin J., Orvin C. Burnside, James H. Orf, Eric A. Ristau i Klaus J. Puettmann. "Field evaluation of soybean (Glycine max) genotypes for weed competitiveness". Weed Science 45, nr 1 (luty 1997): 31–37. http://dx.doi.org/10.1017/s0043174500092444.
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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).
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Brumfield, R. G., F. E. Effiom i S. Reiners. "ECONOMIC ANALYSIS OF THREE TOMATO PRODUCTION SYSTEMS". HortScience 27, nr 6 (czerwiec 1992): 664e—664. http://dx.doi.org/10.21273/hortsci.27.6.664e.
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Fresh tomatoes grown under three production cropping systems at the Rutgers University's Snyder Research and Extension Farm were compared for differences in yields, gross revenues, production costs and net returns. Maximum marketable yields were obtained using the Integrated Pest Management (IPM) system, followed closely by the conventional system. Yields of the organic plots were only 54 percent of the conventional yield. However, the organic plots yielded only 17 percent culls whereas the IPM plots yielded 37 percent culls. Fifty-two percent of the organic tomatoes were U.S. Number Ones, while only one third of the produce from the other two systems were U.S. Number One grade. Organic plots had lower chemical costs, but substantially higher labor costs than the other two systems.
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French, RJ, i MA Ewing. "Soil type influences the relative yields of different cereals and crop legumes in the Western Australian wheatbelt". Australian Journal of Experimental Agriculture 29, nr 6 (1989): 829. http://dx.doi.org/10.1071/ea9890829.
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Crop choice depends on the relative yields of different species, and will vary according to soil type and seasonal conditions. Crop legumes are a relatively new component of agriculture in southern Australia, especially on the drier fringe of the agricultural areas. In this study wheat, barley, field peas and narrow-leafed lupin were compared at Merredin, Western Australia (mean annual rainfall 310 mm) from 1984 to 1986 on a red brown earth, a solonised brown soil, a solodic soil and, in 1984 and 1985, on an acid earthy sand. Oats, cereal rye and triticale were included in 1984, and chickpeas in 1984 and 1986. Highest mean seed yields were produced on the red brown earth and solonised brown soil, although the red brown earth produced very low yields in a dry season. Lowest yields were produced on the earthy sand. Triticale, oats and cereal rye yielded less seed than wheat or barley on all soils except the earthy sand where triticale yielded more than wheat. Legumes yielded less seed than cereals, although the yield for peas was close to that for wheat on the red brown earth. Peas yielded more than lupins or chickpeas on all soils. Lupin yield was closest to pea yield on the solodic soil and earthy sand. A separate series of experiments comparing peas and lupins in different seasonal conditions but on similar soils showed that lupins yielded more than peas when growing season rainfall was high. Peas are the most suitable crop legume for the Merredin area on all fine-textured soils. Lupins remain the choice on coarse-textured soils until pea stubbles can be managed to minimise erosion. In wetter areas lupins are a better choice on coarse-textured soils.
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Thompson, Paul G. "Multiple-harvest Yield Prediction from Once-over Harvests of Cowpeas". HortScience 21, nr 6 (grudzień 1986): 1340–44. http://dx.doi.org/10.21273/hortsci.21.6.1340.
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Abstract The relationship between yields of eowpea [Vigna unguiculata (L.) Walp.] cultivars multiple-harvested (MH) at the mature-green stage and once-over harvested (OH) at two later stages of maturity was linear. Coefficients of determination of 0.82 and 0.86 showed that OH yields at later stages of maturity accounted for a high percentage of the variability in MH yield. Once-over harvested yields were consistent predictors of MH yields among planting dates and cultivars. Once-over harvested, shelled yields were as accurate as OH in-pod yields in determining MH yield rankings. Dry weight yields were not useful in predicting mature-green yields.
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Talebpour, Babak, Maksut Barış Eminoğlu, Uğur Yegül i Ufuk Türker. "Spatial and Temporal Variation in an Apple Orchard". HortScience 54, nr 12 (grudzień 2019): 2182–87. http://dx.doi.org/10.21273/hortsci14447-19.
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One important goal of precision horticulture (PH), as well as precision agriculture (PA), is to measure and manage spatial and temporal variation in orchards. In this study, temporal and spatial analysis of yields were carried out over 2 years for a 0.5-ha apple orchard (at the Haymana Research Station of Ankara University, Turkey, from 2017 to 2018) to determine the variability of yields over time and included seven apple varieties: ‘Royal Gala’, ‘Red Chief’, ‘Braeburn’, ‘Mondial Gala’, ‘Jonagold’, ‘Fuji’, and ‘Mitch Gala’. To achieve this, yield data for two different years were analyzed for mean yield, temporal variance, and cv in terms of spatial and temporal stability, and their yield maps were produced. The results showed that ‘Jonagold’, ‘Braeburn’, and ‘Red Chief’ varieties yielded less than the average yield, whereas the other varieties produced average yields when the yield from 2 years was taken into account. Calculation of the values for determining temporal stability over time resulted in all existing varieties being identified as stable over time. For example, the ‘Jonagold’ and ‘Red Chief’ varieties showed 100% stability in terms of temporal variance. Results also showed that the ‘Gala’ varieties were stable for 2 years and produced high yields, whereas the other varieties were specified as stable and low yielding when spatial and temporal variability was considered in combination.
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Guldan, Steven J., Charles A. Martin, Jose Cueto-Wong i Robert L. Steiner. "Dry-matter and Nitrogen Yields of Legumes Interseeded into Sweet Corn". HortScience 31, nr 2 (kwiecień 1996): 206–8. http://dx.doi.org/10.21273/hortsci.31.2.206.
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Five legumes [hairy vetch (Vicia villosa Roth.), barrel medic (Medicago truncatula Gaerth.), alfalfa (Medicago sativa L.), black lentil (Lens culinaris Medik.), and red clover (Trifolium pratense L.)] were interseeded into sweet corn (Zea mays L.) at last cultivation when sweet corn was at about the V9 (early) or blister (late) stage. The effect of legume interseeding on sweet corn yield, and late-season dry-matter and N yields of aboveground portions of the legumes was determined. Sweet corn yield was not affected by legume interseeding. In 1993, legume dry-matter yields were 1420 kg·ha–1 interseeded early and 852 kg·ha–1 interseeded late. Nitrogen yields were 49 kg·ha–1 interseeded early and 33 kg·ha–1 interseeded late. In 1994, dry-matter yields were 2760 kg·ha–1 interseeded early and 1600 kg·ha–1 interseeded late. Nitrogen yields were 83 kg·ha–1 interseeded early and 50 kg·ha–1 interseeded late. In 1993, barrel medic was the highest-yielding legume with dry matter at 2420 kg·ha–1 and N at 72 kg·ha–1 interseeded early, while red clover yielded the lowest with dry matter at 340 kg·ha–1 and N at 12 kg·ha–1 interseeded late. In 1994, dry-matter and N yields ranged from 4500 and 131 kg·ha–1, respectively, for early interseeded barrel medic to 594 kg·ha–1 and 16 kg·ha–1, respectively, for late interseeded red clover.
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Reddy, Belum V. S., N. Seetharama i L. R. House. "Sorghums in the Post-Rainy Season. I. Effect of Irrigation and Date of Sowing on the Grain and Stover Yields of Diverse Cultivars". Experimental Agriculture 24, nr 1 (styczeń 1988): 31–36. http://dx.doi.org/10.1017/s0014479700015672.
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SUMMARYIn India, sorghum is grown during the post-rainy season on Vertisols with stored soil moisture. As water stress towards the end of the growing season is believed to be a major cause of poor yields in these crops, an experiment was carried out involving five sorghum genotypes and four sowing dates with and without irrigation.Supplementary irrigation with 40 mm of water in the earliest sown crop increased grain yields by 24 and 26% in 1979 and 1982, respectively, while irrigation with a total of 120mm water in the latest sown crop increased yields by 87 and 60% compared with the corresponding dryland crops. Early sowings always resulted in better stover and grain yields irrespective of irrigation treatment. Grain yields of hybrids were similar to those of the cultivars but their stover yields were less. The post-rainy season cultivar SPY 86 gave the best grain yield across sowing dates. The widely grown post-rainy season cultivar M 35–1 yielded less but produced more stover and its yields were more stable. The importance of the stability of grain and stover yields and of evaluating the materials for more than one date of sowing in selecting sorghums for the post-rainy season is discussed.
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Kravchenko, Alexandra N., Sieglinde S. Snapp i G. Philip Robertson. "Field-scale experiments reveal persistent yield gaps in low-input and organic cropping systems". Proceedings of the National Academy of Sciences 114, nr 5 (17.01.2017): 926–31. http://dx.doi.org/10.1073/pnas.1612311114.
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Knowledge of production-system performance is largely based on observations at the experimental plot scale. Although yield gaps between plot-scale and field-scale research are widely acknowledged, their extent and persistence have not been experimentally examined in a systematic manner. At a site in southwest Michigan, we conducted a 6-y experiment to test the accuracy with which plot-scale crop-yield results can inform field-scale conclusions. We compared conventional versus alternative, that is, reduced-input and biologically based–organic, management practices for a corn–soybean–wheat rotation in a randomized complete block-design experiment, using 27 commercial-size agricultural fields. Nearby plot-scale experiments (0.02-ha to 1.0-ha plots) provided a comparison of plot versus field performance. We found that plot-scale yields well matched field-scale yields for conventional management but not for alternative systems. For all three crops, at the plot scale, reduced-input and conventional managements produced similar yields; at the field scale, reduced-input yields were lower than conventional. For soybeans at the plot scale, biological and conventional managements produced similar yields; at the field scale, biological yielded less than conventional. For corn, biological management produced lower yields than conventional in both plot- and field-scale experiments. Wheat yields appeared to be less affected by the experimental scale than corn and soybean. Conventional management was more resilient to field-scale challenges than alternative practices, which were more dependent on timely management interventions; in particular, mechanical weed control. Results underscore the need for much wider adoption of field-scale experimentation when assessing new technologies and production-system performance, especially as related to closing yield gaps in organic farming and in low-resourced systems typical of much of the developing world.
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Yoder, Keith S. "Effect of Powdery Mildew on Apple Yield and Economic Benefits of Its Management in Virginia". Plant Disease 84, nr 11 (listopad 2000): 1171–76. http://dx.doi.org/10.1094/pdis.2000.84.11.1171.
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Plots were established in a ‘Ginger Gold’ apple orchard to test the effects of different powdery mildew levels on cumulative yields. Disease pressure was heaviest in 1997 but yield effects were detected each year. Primary infection in 1997 and 1998 was correlated to previous foliar mildew incidence. Five myclobutanil applications followed by three of triadimefon (M5-T3) reduced primary infections in 1997 to 19% of those on trees not receiving a mildewcide (Ck). M5-T3 gave the most reduction in mildew incidence and severity but a schedule with two less applications (M3-T3) than M5-T3 gave the highest yield. Yields were lowest on trees not receiving a mildewcide. In 1998, the weakest and the strongest treatments had two and four times more flower clusters per tree, respectively, than Ck trees. Yield of the weakest mildew treatment (six applications of sulfur, S6), was about twice that of the Ck trees; several treatments yielded more than 2× S6. Increasing the number of sulfur applications from six to eight increased mildew control and yield. Most of the treatments resulted in yields higher than the nontreated control over a 3-year period. The M3-T3 treatment regime resulted in the highest 3-year yield, whereas a slightly more effective M5-T3 regime yielded slightly less. An economic analysis of cumulative treatment benefits, using local price inputs, is included.
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Korkmaz, Ahmet, i Robert J. Dufault. "Influence of Short-term Cyclic Cold Temperature Stress on Muskmelon and Honeydew Yield". HortTechnology 13, nr 1 (styczeń 2003): 67–70. http://dx.doi.org/10.21273/horttech.13.1.0067.
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Muskmelon (Cucumis melo) seedlings are transplanted in late winter or early spring before last frost date to ensure early yields; however, this makes them very vulnerable to temperatures cycling between almost freezing and optimal temperatures. To simulate temperature alternations that may occur after field transplanting, `Athena', `Sugar Bowl', `Eclipse' muskmelon, and `Tesorro Dulce' honeydew (C. melo) transplants were subjected to 2 ± 1 °C (35.6 ± 1.8 °F) in a walk-in cooler and then to 29 ± 5 °C (84.2 ± 9.0 °F) in a greenhouse before field planting. In 1998, transplants were exposed to 2 °C for 9 to 54 hours, and for 9 to 81 hours in 1999. `Athena' and `Sugar Bowl' yielded less early melons in both years, whereas `Eclipse' and `Tesoro Dulce' early yields were only reduced in 1999. Total yields of `Athena' decreased linearly in both years with 10% yield reduction occurring with 12 to 21 hours of cold stress. Total yields of `Sugar Bowl' decreased linearly in both years with 11 to 18 hours of cold stress causing 10% yield reduction in 1998 and 1999, respectively. Therefore, early planting before last frosts of all these muskmelon and honeydew cultivars should be done with caution since reductions in early yields are highly probable.
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HUCL, P., i R. J. BAKER. "SEEDING RATE EFFECTS ON LOW-TILLERING SPRING WHEATS IN A SEMIARID ENVIRONMENT". Canadian Journal of Plant Science 70, nr 1 (1.01.1990): 9–17. http://dx.doi.org/10.4141/cjps90-002.
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To determine if increased seeding rates would alter relative yields of traditional and low-tillering genotypes, a high-tillering (Neepawa), a low-tillering (Siete Cerros), and an oligoculm (M1417) spring wheat (Triticum aestivum L.) genotype were seeded in replicated field trials at two locations in 1984 and 1985. A four-replication split-plot design, with genotypes assigned to main plots and seeding rates (40, 80 160, 320 and 640 seeds m−2) to subplots, was used for each experiment. Grain yield and its components were measured on individual plots or on main stems of five plants in each plot. All three genotypes expressed maximum yield at the same seeding rate (640 seeds m−2 in 1984 and 320 seeds m−2 in 1985) in the semiarid conditions of these experiments. Despite diverse tillering habits, the relative yields of these three genotypes could not be altered by changing seeding rates. On average, Siete Cerros (low-tillering) yielded 15% more than Neepawa and 17% more than M1417. Neepawa had lower grain yields than M1417 at all seeding rates in 1984, but higher grain yields in 1985. A similar change in relative performance of these two genotypes was observed for harvest index of the main stem but not for main stem grain yield kernels spike −1 on the main stem or kernel weight.Key words: Wheat (spring), oligoculm, yield components, genotype-environmental interaction.
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White, Ethel M. "Straw and grain production in spring barley cultivars". Journal of Agricultural Science 108, nr 2 (kwiecień 1987): 293–98. http://dx.doi.org/10.1017/s0021859600079284.
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SummaryGrain and straw yields of a range of spring barley cultivars were assessed in field experiments conducted from 1981 to 1983 in Northern Ireland. Mean straw yields varied between 2·75 t/ha in Inga and 1·94 t/ha in Golden Promise over the 3-year period. Both grain and straw yields varied from year to year, with straw production being more consistent for individual cultivars than grain yield. High grain yields were not associated with high straw yields, straw to grain ratios varying between 0·72 in Midas and 0·51 in Corgi. Neither grain yield nor straw length were good predictors of straw yield of cultivars. The role for and assessment of straw yield in cultivar evaluation is discussed.
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Potts, M. J., E. Biranguza i C. Bweyo. "Evaluation of Alternative Legumes for Green Manure and Grain under African Highland Conditions". Experimental Agriculture 25, nr 1 (styczeń 1989): 109–18. http://dx.doi.org/10.1017/s0014479700016495.
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SUMMARYThree species of lupin, three vetches and a soyabean were evaluated as green manures under tropical highland conditions. With moderate soil fertility and 150 days of rain, all lupin types and a locally obtained vetch gave yields of about 80 t ha−1 fresh material. Under less favourable conditions, low soil pH and high aluminium saturation, only Lupinus luteus achieved these yields. During the short season, with about 60 days of rain, the yield of L. luteus was reduced to 30 t ha−1 and establishment of the vetches was slow and they yielded poorly. Growth of soyabean was poor under cool conditions. Under fertile conditions, lupin grain yields of up to 5.2 t ha−1 were obtained in the long season but in the short season, yields were less than 1 t ha−1. Rhizoctonia solani was the major disease encountered.
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Moustafa, Ehab S. A., El-Sayed E. A. El-Sobky, Hossam I. A. Farag, Mohamed A. T. Yasin, Ahmed Attia, Mohamed O. A. Rady, Mohamed F. Awad i Elsayed Mansour. "Sowing Date and Genotype Influence on Yield and Quality of Dual-Purpose Barley in a Salt-Affected Arid Region". Agronomy 11, nr 4 (9.04.2021): 717. http://dx.doi.org/10.3390/agronomy11040717.
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Dual-purpose barley is an alternative approach to producing high-quality forage yield plus an acceptable grain yield in marginal environments of arid regions that are characterized by lack of forage. Field experiment was performed in two consecutive growing seasons at an arid region affected by salinity in irrigation water and soil at Western Sinai Peninsula in Egypt. The study aimed to optimize sowing date and screen salt-tolerant barley genotypes that perform better in terms of forage yield and quality as well as grain and biomass yield production in salt-affected environment. Sowing dates, genotypes, and their interaction significantly impacted most of the studied variables such as forage yield, crude protein yield, and grain and biomass yields. The early sowing in late October yielded higher than intermediate sowing in mid-November and late sowing in early December. Some of the tested genotypes performed better than others as indicated by about 50% higher forage yield, 6% crude protein content, 39% grain and 21% biological yields (total aboveground dry matter), suggesting higher adaptation capacity. Interestingly, grain and biological yields did not differ significantly between dual-purpose approach and grain-only pattern. In conclusion, dual-purpose barley was found favorable for producing grain and forage production in similar environments under early sowing date.
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Wadl, Phillip A., Livy H. Williams, Matthew I. Horry i Brian K. Ward. "Evaluation of 12 Sweetpotato Clones in Coastal South Carolina for Yield and Insect Resistance Using Organic and Conventional Cultural Practices". HortTechnology 32, nr 3 (czerwiec 2022): 253–62. http://dx.doi.org/10.21273/horttech04979-21.
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The yield and insect resistance of 12 sweetpotato (Ipomoea batatas) clones grown in two different production systems (organic black plastic mulch and conventional bare ground) were evaluated in 2016 and 2017 in coastal South Carolina. Significant differences in total storage root yield, marketable storage root yield, U.S. No. 1 storage root yield, and percent of U.S. No. 1 storage roots in all trials were found, except for percent of U.S. No. 1 storage roots in 2017 for the organic black plastic mulch trial. In the organic black plastic mulch trials, ‘Bonita’ and USDA-04-136 consistently produced high marketable yields, whereas ‘Ruddy’ and USDA-W388 consistently produced the lowest marketable yields. ‘Averre’, ‘Beauregard’, ‘Covington’, and USDA-09-130 exhibited variable performance, with marketable yields among the highest in a single year. For the conventional trials, USDA-04-136 consistently produced high marketable yields, whereas ‘Ruddy’ and USDA-W-388 consistently produced the lowest marketable yields. ‘Averre’, ‘Bonita’, ‘Covington’, and USDA-09-130 exhibited variable performance, with marketable yields among the highest in a single year. For the organic black plastic mulch, significant differences were detected in the percent of uninjured roots and percent white grub (primarily Plectris aliena) damage in 2016 and in wireworm (Elateridae)-cucumber beetle (Diabrotica)-flea beetle (Systena) severity index (WDS severity index) in 2016 and 2017. USDA-04-136 and USDA-W-388 consistently had the lowest WDS severity index, whereas ‘Covington’ consistently had the highest WDS severity index. For the conventional trials, significant differences were found among clones in both years for all insect rating variables, except for percent sweetpotato weevil (Cylas formicarius elegantulus) damage. ‘Ruddy’, USDA-04-136, and USDA-W-388 consistently yielded the highest percent of uninjured roots, whereas ‘Averre’, ‘Bonita’, SC-1149-19, and USDA-09-130 consistently had the lowest percent of uninjured roots. The research reported here for yield and insect resistance under conventional and organic production systems will be useful for producers in the selection of cultivars suitable for growth in South Carolina.
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Ntare, Bonny R. "Intercropping Morphologically Different Cowpeas With Pearl Millet in a Short Season Environment in the Sahel". Experimental Agriculture 26, nr 1 (styczeń 1990): 41–47. http://dx.doi.org/10.1017/s0014479700015386.
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SUMMARYThe effects on yield of varying the planting date and planting pattern of morphologically different cowpea cultivars intercropped with pearl millet were studied in two field trials. The interaction between cowpea cultivars and planting date was highly significant. There was a sharp reduction in cowpea yields with late planting. Millet yields were reduced less when sown simultaneously with early cowpea cultivars than when sown with a late maturing local cultivar. Early maturing cowpea cultivars planted in closely spaced hills had less effect on millet yields than a late maturing cultivar sown in widely spaced hills. An appropriate cowpea cultivar for intercropping with peal millet would be one that was weakly competitive and that yielded both grain and fodder.
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Morgan, C. L., R. B. Austin, Margaret A. Ford, J. Bingham, W. J. Angus i S. Chowdhury. "An evaluation of F1 hybrid winter wheat genotypes produced using a chemical hybridizing agent". Journal of Agricultural Science 112, nr 2 (kwiecień 1989): 143–49. http://dx.doi.org/10.1017/s0021859600085038.
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SummaryIn experiments harvested in 1985 and 1986 the grain yields of 61 F1 hybrids among winter wheat varieties and advanced breeding lines were 5·9% greater than the yields of the best parents. In a trial with 430 hybrids in 1986, the hybrids yielded 3·6% more grain than the best parents. Among these 430 hybrids heterosis for yield was greatest for those from the lowest yielding parents. This result is taken to indicate that among these genotypes most genes for high yield have been fixed in the highest yielding parents.The hybrids had slightly fewer ears/m2, but more grains per ear and heavier grains than the highest yielding parents. They yielded more straw as well as more grain.The results are compared with those from other studies and it is concluded that yield advantage of F1 hybrids so far tested is not generally sufficient to justify their introduction into U.K. agriculture.
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Challinor, A. J., T. R. Wheeler, J. M. Slingo, P. Q. Craufurd i D. I. F. Grimes. "Simulation of Crop Yields Using ERA-40: Limits to Skill and Nonstationarity in Weather–Yield Relationships". Journal of Applied Meteorology 44, nr 4 (1.04.2005): 516–31. http://dx.doi.org/10.1175/jam2212.1.
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Abstract Reanalysis data provide an excellent test bed for impacts prediction systems, because they represent an upper limit on the skill of climate models. Indian groundnut (Arachis hypogaea L.) yields have been simulated using the General Large-Area Model (GLAM) for annual crops and the European Centre for Medium-Range Weather Forecasts (ECMWF) 40-yr reanalysis (ERA-40). The ability of ERA-40 to represent the Indian summer monsoon has been examined. The ability of GLAM, when driven with daily ERA-40 data, to model both observed yields and observed relationships between subseasonal weather and yield has been assessed. Mean yields were simulated well across much of India. Correlations between observed and modeled yields, where these are significant, are comparable to correlations between observed yields and ERA-40 rainfall. Uncertainties due to the input planting window, crop duration, and weather data have been examined. A reduction in the root-mean-square error of simulated yields was achieved by applying bias correction techniques to the precipitation. The stability of the relationship between weather and yield over time has been examined. Weather–yield correlations vary on decadal time scales, and this has direct implications for the accuracy of yield simulations. Analysis of the skewness of both detrended yields and precipitation suggest that nonclimatic factors are partly responsible for this nonstationarity. Evidence from other studies, including data on cereal and pulse yields, indicates that this result is not particular to groundnut yield. The detection and modeling of nonstationary weather–yield relationships emerges from this study as an important part of the process of understanding and predicting the impacts of climate variability and change on crop yields.
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Bekele, Bewket Getachew. "Review on Yield Gap Analysis: Modeling of Achievable Yields at Farm Level". European Journal of Agriculture and Forestry Research 10, nr 2 (15.02.2022): 21–27. http://dx.doi.org/10.37745/ejafr.2013/vol9n22127.
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In the present context, ‘model’ is expressed as a computer program that can be repeatedly run several times for computing several designed mathematical or statistical expressions (equations) governing crop growth-environment relations, given appropriate input data. The experiment station yields obtained under a rainfed situation without any nutrient deficiency mostly considered as the potential yields of rainfed crops. Actual yields are obtained by recording crop yields of farmers in the region under investigation and achievable yield is between actual and potential yield. Actual yields are compared with the potential yields to estimate yield gaps of crops for that area and others which have the same agro-ecology. Achievable yield is determined by factors like availability of moisture and nutrients, Precipitation and irrigation as input, Soil profile water holding characteristics, Plant water balance (transpiration, water uptake), Soil water balance (evaporation, infiltration, runoff, flow, drainage) and Nitrogen fertilizer applications as input, Soil nitrogen conditions, Plant nitrogen balance (uptake, fixation, mobilization), Soil nitrogen balance (mineralization, immobilization, nitrification, denitrification). Generally, modeling Achievable yield of farm depend on water and nutrient data of the area and Actual yield is determined by factors like weeds, insect pests, diseases and pollutants.
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Huňady, I., i M. Hochman. "Potential of legume-cereal intercropping for increasing yields and yield stability for self-sufficiency with animal fodder in organic farming". Czech Journal of Genetics and Plant Breeding 50, No. 2 (12.06.2014): 185–94. http://dx.doi.org/10.17221/242/2013-cjgpb.
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Intercropping of grain legumes and cereals is a promising theme in organic farming for its potential for increasing and stabilizing yields, reducing weed pressure and sustaining plant health. On animal husbandry farms, pea-cereal mixtures may be an interesting crop harvested for green fodder as well as for feed concentrates. Increasing self-sufficiency with fodder is in agreement with the principles of organic agriculture, and it reduces the risks related to the import of soy protein that may be admixed with GM soya. In 2008–2011, plot trials (PT) with intercropped peas and spring cereals (wheat, barley) were conducted. Varieties and pea-cereal combinations were examined to find suitable varieties for intercropping, and the best pea to cereal ratio in the seed intercrop (pea to cereal ratios 80:20, 60:40, 40:60, 20:80). Results show that intercropping peas and spring cereals may be advantageous compared to monocultures. Pea-cereal intercrops produce high yields of green matter and concentrates especially when intercropped at the pea to cereal ratio of 60:40 and 40:60. In 2009, on five certified organic farms, controlled field trials (FT) were conducted with field pea (leaf type), spring barley and spring wheat in monocultures and intercrops (pea to cereal ratio 60:40). Forage yields were evaluated at pea growth phases BBCH-scale 79 and 83. Fresh yields of monocultures and intercrops were evaluated at grain harvest.
34
Hannah, MC, i GJ O'Leary. "Wheat yield response to rainfall in a long-term multi-rotation experiment in the Victorian Wimmera". Australian Journal of Experimental Agriculture 35, nr 7 (1995): 951. http://dx.doi.org/10.1071/ea9950951.
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Seventy-six years of wheat yield data from a long-term rotation experiment at Dooen in the Victorian Wimmera were analysed to describe the response of wheat yield to seasonal rainfall, crop sequence, and time. Wheat yields from 7 different 1- to 4-course rotations involving wheat, barley, oat, field pea, grass pasture and fallow were compared as a function of growing-season (May-November) rainfall. The field layout had no within-year replication, but each phase of each rotation was represented once in each year. An approximate quadratic response of wheat yield to both current year and previous year May-November rainfall was observed for each rotation. Previous year May-November rainfall boosted wheat yields grown on fallow, but decreased the yield of wheat grown on field pea or wheat stubble. Highest wheat yields followed fallow preceded by pasture, high yields followed fallow preceded by a cereal, moderate yields followed field pea, and low yields occurred for continuous wheat. Long-term trends in wheat yields adjusted for rainfall depended on crop sequence and fluctuated more in the non-fallow, 3-course rotations. Over the 76 years, average yield declined in all rotations except the continuous wheat, which was always low, but there was evidence that yield of all continuous cropped rotations had increased during the last 2 decades.
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Dahniya, M. T., S. K. Hahn i C. O. Oputa. "Effect of Shoot Removal on Shoot and Root Yields of Sweet Potato". Experimental Agriculture 21, nr 2 (kwiecień 1985): 183–86. http://dx.doi.org/10.1017/s0014479700012461.
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SUMMARYExperiments on harvesting sweet potato as a green vegetable and as a root crop are described. Whole shoots yielded 62% more than shoot tips. Similar total shoot yields were harvested whether tip removal was at two, three or four week intervals. Root yield was decreased by 31 to 48% by removing shoot tips, while removing whole shoots led to root yield decreases of 48 to 62%. Harvesting shoots at two week intervals gave 72% reduction in root yield, compared with 50% with four week intervals. There were fewer and smaller tubers as the frequency of shoot harvests increased. There were varietal differences in response to shoot removal For reasonable yields of both shoot tips and tuberous roots harvesting shoot tips at four week intervals is recommended.
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CAI CHENG-ZHI, LIAO CONG-JIAN, XIAO DAN, ZENG XIAO-SHAN i ZUO JIN. "Global warming and world soybean yields". Journal of Agrometeorology 23, nr 4 (11.11.2021): 367–74. http://dx.doi.org/10.54386/jam.v23i4.139.
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The crop yield potential of world soybean from 2019 to 2028 has been projected using ARIMA model based on the yields from 1961 to 2018. Both annual global mean temperature and the yields of world soybean have been projected to rise during the ensuing decade 2019-2028. Projected average yields of world soybean varies from 2841 to 3276 kg ha-1 while 4324 to 4807 kg ha-1 in the case of top (national) yields of world soybean. Annual global mean temperatures may vary from 15.0 to 15.3oC and likely to exert positive impact on average yield (R squared = 0.80) while negative on top yield (R squared = 0.40) of world soybean. It may be concluded that for world soybean yields in 2019 to 2028, the opportunities for improving production should be dependent on both high and low-yielding countries as the yield remained between 30 and 70 per cent of potential limit i.e. in middle place around the turn-point of S-shaped curve in long-term trend partly affected by global warming.
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Pomp, Stephan, Andrea Mattera, Vasileios Rakopoulos, Ali Al-Adili, Mattias Lantz, Andreas Solders, Kaj Jansson i in. "Measurement of fission yields and isomeric yield ratios at IGISOL". EPJ Web of Conferences 169 (2018): 00017. http://dx.doi.org/10.1051/epjconf/201816900017.
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Data on fission yields and isomeric yield ratios (IYR) are tools to study the fission process, in particular the generation of angular momentum. We use the IGISOL facility with the Penning trap JYFLTRAP in Jyväskylä, Finland, for such measurements on 232Th and natU targets. Previously published fission yield data from IGISOL concern the 232Th(p,f) and 238U(p,f) reactions at 25 and 50 MeV. Recently, a neutron source, using the Be(p,n) reaction, has been developed, installed and tested. We summarize the results for (p,f) focusing on the first measurement of IYR by direct ion counting. We also present first results for IYR and relative yields for Sn and Sb isotopes in the 128-133 mass range from natU(n,f) based on γ-spectrometry. We find a staggering behaviour in the cumulative yields for Sn and a shift in the independent fission yields for Sb as compared to current evaluations. Plans for the future experimental program on fission yields and IYR measurements are discussed.
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Rayburn, Edward B., i Tom Basden. "Comparison of Crop Yield Estimates Obtained from an Historic Expert System to the Physical Characteristics of the Soil Components—A Project Report". Agronomy 12, nr 4 (22.03.2022): 765. http://dx.doi.org/10.3390/agronomy12040765.
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Crop yields vary due to soil type. Expected crop yields are reported in published soil surveys based on the knowledge of local conservation and extension professionals. Crop yields have increased over the years due to improved genetics and management. The objective of this project was to compare historic expected crop yields to soil physical characteristics and to update expected yields for West Virginia soils in the United States National Soils Information System (NASIS). Regression analysis found that soil physical characteristics explained 57 to 65% of the variation in corn and hay yields. Corn and hay yield regressions calculated from a regression data set predicted yields for crops on soils in a test data set without bias and with residual errors of 10 to 15%. Updated crop yields under good management on more productive soils were obtained by surveying farmers and variety trials conducted in West Virginia and surrounding states. The updated yields and relative historic yields were used proportionally to update expected crop yields by soil series. The updated yields were reviewed by local conservation professionals and adjusted as needed based on local experience. These updated yields are now being used as the expected crop yield for the West Virginia soil series in the NASIS.
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Hodges, Laurie, Douglas C. Sanders, Katharine B. Perry, Kent M. Eskridge, K. M. `Dean' Batal, Darbie M. Granberry, Wayne J. McLaurin i in. "Adaptability and Reliability of Yield for Four Bell Pepper Cultivars Across Three Southeastern States". HortScience 30, nr 6 (październik 1995): 1205–10. http://dx.doi.org/10.21273/hortsci.30.6.1205.
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Four bell pepper (Capsicum annuum L.) cultivars were evaluated for yield (total weight of marketable fruit) performance over 41 environments as combinations of 3 years, three planting dates, and seven locations across North Carolina, South Carolina, and Georgia. Cultural practices, including trickle irrigation and double rows planted on black-plastic-covered beds, were uniform across all environments, except for fertilization, which was adjusted at each location based on soil tests. Comparing production over 3 years between the mountain location and the Coastal Plain location in North Carolina, yields were lower on the Coastal Plain. Spring plantings provided higher yields than summer plantings at both locations. Yield increases were obtained from hybrid cultivars over that of the open-pollinated (OP) standard [`Keystone Resistant Giant #3' (KRG#3)] in the summer planting in the mountains compared to the Tidewater Coastal Plain. Across the three-state region, hybrid cultivar yields were higher than those of the OP cultivar for the second spring planting date in 1986 and 1987. Although the hybrid yields were higher than that of the OP standard, the hybrid `Skipper' yielded less than the other hybrids (`Gator Belle' and `Hybelle'). `Gator Belle' generally out-yielded `Hybelle' at all locations, except in Fletcher, N.C. This difference may be related to the relative sensitivity of these two cultivars to temperature extremes, rather than soil or geographic factors, because there was a tendency for `Hybelle' yields to exceed `Gator Belle' in the earliest planting date. Based on the reliability index, the chance of outperforming KRG#3 (the standard) was 85% for `Hybelle', 80% for `Gator Belle', but only 67% for `Skipper'.
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Rashwan, Emad, Ahmed Mousa, Ayman EL-Sabagh i Celaleddin Barutçular. "Yield and Quality Traits of Some Flax Cultivars as Influenced by Different Irrigation Intervals". Journal of Agricultural Science 8, nr 10 (7.09.2016): 226. http://dx.doi.org/10.5539/jas.v8n10p226.
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<p>Flax is a potential winter crop for Egypt that can be grown for both seed and fiber. The study was conducted during two successive winter seasons of 2013/14 and 2014/15 in the experimental farm of El-Gemmeiza Agricultural Research Station, Agriculture Research Centre, Egypt. The objective of this work was to evaluate the effect of irrigation intervals (25, 35 and 45) on the straw, seed, oil, fiber yields and quality of flax cultivars (Sakha1, Giza9 and Giza10). Irrigation intervals significantly influenced all studied traits except oil percentage. Irrigated flax plants every 35 days gave the maximum values for all traits, while irrigation every 45 days gave the minimum values. In respect to cultivars, significant differences were found in most yield and quality characters. Furthermore, the performance of Sakha 1 cultivar was superior in main stem diameter, biological, straw yields per faddan, seed index, seed, oil yields per faddan and oil percentage. Meanwhile, Giza 10 cultivar highly significantly out yielded Giza9 and Sakha1 in plant height, fiber fineness, fiber length, total fiber percentage and fiber yield per faddan. The interactions between irrigation intervals and flax cultivars were highly significant for all traits. Based on the results, Sakha1 cultivar recorded the maximum values for main stem diameter, biological, straw yields per faddan, seed, oil yields per faddan and oil percentage and Giza 10 recorded the maximum values for plant height, fiber fineness, fiber length, total fiber percentage and fiber yield per faddan under irrigation of plants every 35 days.</p>
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Qiao, Shengchao, Han Wang, I. Colin Prentice i Sandy P. Harrison. "Optimality-based modelling of climate impacts on global potential wheat yield". Environmental Research Letters 16, nr 11 (22.10.2021): 114013. http://dx.doi.org/10.1088/1748-9326/ac2e38.
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Abstract Evaluation of potential crop yields is important for global food security assessment because it represents the biophysical ‘ceiling’ determined by variety, climate and ambient CO2. Statistical approaches have limitations when assessing future potential yields, while large differences between results obtained using process-based models reflect uncertainties in model parameterisations. Here we simulate the potential yield of wheat across the present-day wheat-growing areas, using a new global model that couples a parameter-sparse, optimality-based representation of gross primary production (GPP) to empirical functions relating GPP, biomass production and yield. The model reconciles the transparency and parsimony of statistical models with a mechanistic grounding in the standard model of C3 photosynthesis, and seamlessly integrates photosynthetic acclimation and CO2 fertilization effects. The model accurately predicted the CO2 response observed in FACE experiments, and captured the magnitude and spatial pattern of EARTHSTAT ‘attainable yield’ data in 2000 CE better than process-based models in ISIMIP. Global simulations of potential yield during 1981–2016 were analysed in parallel with global historical data on actual yield, in order to test the hypothesis that environmental effects on modelled potential yields would also be shown in observed actual yields. Higher temperatures are thereby shown to have negatively affected (potential and actual) yields over much of the world. Greater solar radiation is associated with higher yields in humid regions, but lower yields in semi-arid regions. Greater precipitation is associated with higher yields in semi-arid regions. The effect of rising CO2 is reflected in increasing actual yield, but trends in actual yield are stronger than the CO2 effect in many regions, presumably because they also include effects of crop breeding and improved management. We present this hybrid modelling approach as a useful addition to the toolkit for assessing global environmental change impacts on the growth and yield of arable crops.
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Beckett, Thomas H., Edward W. Stoller i Loyd M. Wax. "Interference of Four Annual Weeds in Corn (Zea mays)". Weed Science 36, nr 6 (listopad 1988): 764–69. http://dx.doi.org/10.1017/s0043174500075792.
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Season-long interference of shattercane, giant foxtail, common cocklebur, and common lambsquarters in corn was evaluated in the field at weed densities from 0.4 to 13.1 plants or clumps/m of corn row during 1985, 1986, and 1987. Corn seed yields decreased linearly with increases in the density of clumps of 2 to 3 shattercane plants and 5 to 8 giant foxtail plants, reaching 22% yield loss at 6.6 shattercane clumps/m of row and 18% yield loss at 13.1 giant foxtail clumps/m of row. Increases in common cocklebur density caused corn yields to decrease curvilinearly in 1985 with a maximum predicted yield loss of 27% occurring at a density of 4.7 common cocklebur plants/m of row. In 1986 and 1987, yields decreased linearly as common cocklebur density increased to 6.6 plants/m of row, where a 10% yield loss was observed. Common lambsquarters reduced corn yields only in 1985. In this year, yields decreased curvilinearly with increasing weed density, resulting in a maximum yield loss of 12% at 4.9 common lambsquarters plants/m of row. Corn yields averaged 11600 kg/ha when grown without weed interference in these experiments.
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Peto, R. "Tar yields". Tobacco Control 1, nr 2 (1.06.1992): 139. http://dx.doi.org/10.1136/tc.1.2.139a.
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Eckstein, W. "Sputtering yields". Vacuum 82, nr 9 (maj 2008): 930–34. http://dx.doi.org/10.1016/j.vacuum.2007.12.004.
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THAYER, ANN M. "INTERACTION YIELDS". Chemical & Engineering News 86, nr 31 (4.08.2008): 12–20. http://dx.doi.org/10.1021/cen-v086n031.p012.
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Jarrow, Robert A. "Convenience yields". Review of Derivatives Research 13, nr 1 (18.08.2009): 25–43. http://dx.doi.org/10.1007/s11147-009-9042-5.
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van Binsbergen, Jules, Wouter Hueskes, Ralph Koijen i Evert Vrugt. "Equity yields". Journal of Financial Economics 110, nr 3 (grudzień 2013): 503–19. http://dx.doi.org/10.1016/j.jfineco.2013.08.017.
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Zymaroieva, Anastasiia, Tetiana Fedoniuk, Svitlana Matkovska, Olena Andreieva i Victor Pazych. "Agroecological Determinants of Potato Spatiotemporal Yield Variation at the Landscape Level in the Central and Northern Ukraine". Grassroots Journal of Natural Resources 4, nr 2 (30.05.2021): 34–47. http://dx.doi.org/10.33002/nr2581.6853.040203.
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Global food security largely depends on the crop yield increase, so the study of the yield-limiting factors of potato (the second bread) is a pressing issue today. This study determines the contribution of the agroecological factors, namely, bioclimatic variables, soil indicators, and factors of landscape diversity, to the variation in potato yields. Conducted in Polissya and Forest-steppe zones of Ukraine during 1991–2017, this study has not only addressed the relationship between ecological determinants and potato yields, but also considered crop yields as a dynamic system. The dynamics of potato yields from the mid-1990s to the present is described by a log-logistic model. There are statistically significant regression dependencies between potato yield parameters and agroecological factors. Potato yield is dependent on the diversity of landscape cover. The relationship between yield parameters and landscape-ecological diversity is non-linear, which determines the presence of optimal landscape structure for the highest potato yields. Among climatic factors, the continental climate is of the greatest importance for potato yield. The high sensitivity of potato yield parameters to soil indices was found, and mostly the soil texture components (silt content), which largely determines the potato yield spatial variation.
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Kumar, Ashok, Lalita Batra i R. Chhabra. "Forage Yield of Sorghum and Winter Clovers as Affected by Biological and Chemical Reclamation of a Highly Alkaline Soil". Experimental Agriculture 30, nr 3 (lipiec 1994): 343–48. http://dx.doi.org/10.1017/s0014479700024455.
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SUMMARYA field experiment was conducted on a highly alkaline soil (pH 10.6, exchangeable sodium 95%) to compare biological reclamation using Leptochloa fusca with chemical reclamation using gypsum. Rice gave satisfactory yields in the first year of gypsum application but sorghum and Sesbania gave extremely poor yields. The yield of Leptochloa was not affected by gypsum application. Trifolium resupinatum yielded more than T. alexandrinum when sown in the winter season. The green forage yield of sorghum was greatest when the sorghum followed Leptochloa grown for two years, with the harvested grass allowed to decompose on the site. The results show that biological reclamation with Leptochloa is a good substitute for chemical reclamation with gypsum.
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Gao, Yakun, Yinli Bi, Shaopeng Ma, Yanxu Zhang, Yun Guo, Yang Zhou, Shihao Xu i Peter Christie. "Yields of Buckwheat and Alfalfa in an Intercropping System Inoculated with Dark Septate Endophytes in a Coal Mining Subsidence Dryland Area". Agronomy 12, nr 11 (16.11.2022): 2860. http://dx.doi.org/10.3390/agronomy12112860.
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Coal mining subsidence areas in north Shaanxi province in north China are commonly low-fertility drylands, and intercropping is a popular method locally of maximizing crop yields. Inoculation with dark septate endophytes (DSE) can increase the yields of conventional crops grown in monoculture, but the effects of DSE on the growth and yield of intercropped plants are unknown. Here, a field experiment was conducted in a coal mining subsidence area on the loess plateau in 2020 and 2021. The two crops were buckwheat and alfalfa, with four treatments for each crop: sole cropping control, sole cropping with DSE inoculation, intercropping control, and intercropping with DSE inoculation. The yields, land equivalent ratios, DSE colonization rates, and yield components of buckwheat and alfalfa were compared in the different treatments. Stepwise regression and path analysis was conducted to identify the factors that determined crop yields. Yields of intercropped buckwheat and alfalfa with DSE inoculation increased in two consecutive years compared with sole cropping control, with yields increasing in 2020 by 117 and 86%, respectively. In 2021, the yield of buckwheat in intercropping with DSE inoculation did not increase significantly, but the yield of alfalfa increased by 120% compared with the sole cropping control. Buckwheat-alfalfa intercropping has the advantage of increasing the yield. DSE inoculation significantly increased the yield of buckwheat-alfalfa intercropping in 2020, but there was no yield advantage in 2021. The yield components of buckwheat and alfalfa showed inconsistent differences among experimental treatments. Stepwise regression and path analysis shows that the DSE colonization rate played an important role in the yield, which was an increased in buckwheat and alfalfa in 2020 and 2021. DSE affected the buckwheat yield indirectly by increasing the grain weight per plant, plant phosphorus uptake, and plant nitrogen content. DSE indirectly affected alfalfa yields by increasing plant nitrogen uptake and plant height. DSE may therefore have some potential to increase yields in buckwheat-alfalfa intercropping systems in coal mining subsidence areas.