Academic literature on the topic 'Crop canopy modification'
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Journal articles on the topic "Crop canopy modification"
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McDonald, Mary Ruth, Bruce D. Gossen, Cezarina Kora, Monica Parker, and Greg Boland. "Using crop canopy modification to manage plant diseases." European Journal of Plant Pathology 135, no. 3 (January 17, 2013): 581–93. http://dx.doi.org/10.1007/s10658-012-0133-z.
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Sandhu, Sarabjot Kaur, and L. K. Dhaliwal. "Role of agronomic manipulations in modification of wheat microclimate under central Punjab." Journal of Applied and Natural Science 8, no. 4 (December 1, 2016): 1905–11. http://dx.doi.org/10.31018/jans.v8i4.1060.
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Wheat crop is influenced by different microclimatic parameters like solar radiation, canopy temperature etc. Agronomic manipulation like change in row spacing and row direction can be used as a strategy to modify the microclimate of crop. Keeping these facts in view, field trials were conducted during rabi 2012-13 and 2013-14 under two experiments in first experiment wheat varieties HD 2967, PBW 550 and PBW 343 were sown under three row spacing viz. 15 cm, 22.5 cm and 30 cm. In second experiment, wheat varieties HD 2967, PBW 550 and PBW 343 were sown under two row direction viz. North-South (N-S) and East-West (E-W). Short wave radiation interception and canopy temperature was recorded under different treatments at 15 days interval. Among different row spacing, short wave radiation interception and canopy temperature was maximum at 30 cm row spacing (77.7% and 25.1oC) followed by 22.5 cm (75.7% and 24.2oC) and 15 cm row spacing (73.9% and 23.2oC), whereas under row directions short wave radiation interception and canopy temperature was more (76.5% and 23.9oC) in E-W row direction as compared to N-S row direction (75% and 23.2oC). Relationships were developed between dry matter accumulation and canopy temperature. Polynomial relationships gave significant R2 value (0.66 & 0.69) under different treatments. This two year study indicated that agronomic manipulations play an important role in microclimate modification and canopy temperature significantly influence dry matter accumulation under different crop geometry.
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Thakur, P., and Sonam Singh. "Impact of tree management on growth and production behaviour of intercrops under rainfed agroforestry." Indian Journal of Forestry 31, no. 1 (March 1, 2008): 37–46. http://dx.doi.org/10.54207/bsmps1000-2008-5213m3.
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This investigation was aimed to evaluate the impact of changes in incident radiation through crown modification on crop performance. Different shade intensities created through tree crown management significantly affected growth, physiological attributes and yield related parameters in Vigna mungo (syn. Phaseolus mungo) and Pisum sativum grown as understorey field crops with Morus alba under rainfed conditions. The crown management treatments namely, no crown removal, 25, 50 and 75% crown removal resulted in 91, 85, 63 and 47% shade, respectively. Plant height, number of flowers, leaf area of crops was reduced significantly with the increase in shade intensities and decrease in distance from the tree trunk. Higher pods per plant, grains per pod, grain yield and harvest index were observed at lower shade intensities. Growth and yield were maximum in open control (without tree); while unmanaged canopy of Morus trees caused overall yield reduction of 42% beneath canopy up to 3 m distance from the tree trunk. The crown management regulated physiological attributes in the field crops. The maximum photosynthetic rate was recorded for open plot plants, which declined in plants beneath dense canopy. The amount of water transpired from the crop plants decreased with increase in shade intensity. The conversion efficiency was maximum for plants growing as sole crop which decreased with increasing shade intensities. Based on the results of present investigation, it can be recommended that out of the four tree canopy management options tried i.e. 0, 25, 50 and 75% crown removal; 75% crown removal causing least negative effects on crop growth and yield may be adopted as a compromised crown management practice.
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Jambhulkar, Prashant P., M. L. Meghwal, and G. S. Ameta. "Microclimatic Modification of Tomato Crop Canopy to Alter Conidial Dispersal ofAlternaria solani." Vegetos- An International Journal of Plant Research 28, no. 4 (2015): 155. http://dx.doi.org/10.5958/2229-4473.2015.00098.1.
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Bravetti, B., V. Lanari, E. Manni, and O. Silvestroni. "CANOPY DENSITY MODIFICATION AND CROP CONTROL STRATEGIES ON 'MONTEPULCIANO' (VITIS VINIFERA L.)." Acta Horticulturae, no. 931 (March 2012): 331–37. http://dx.doi.org/10.17660/actahortic.2012.931.37.
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Yang, Yubin, Livia Paleari, Lloyd T. Wilson, Roberto Confalonieri, Adriano Z. Astaldi, Mirko Buratti, Zongbu Yan, Eric Christensen, Jing Wang, and Stanley Omar P. B. Samonte. "Characterizing Genotype-Specific Rice Architectural Traits Using Smart Mobile App and Data Modeling." Agronomy 11, no. 12 (November 28, 2021): 2428. http://dx.doi.org/10.3390/agronomy11122428.
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The quantity and quality of light captured by a plant’s canopy control many of its growth and development processes. However, light quality-related processes are not very well represented in most traditional and functional–structural crop models, which has been a major barrier to furthering crop model improvement and to better capturing the genetic control and environment modification of plant growth and development. A main challenge is the difficulty in obtaining dynamic data on plant canopy architectural characteristics. Current approaches on the measurement of 3D traits often relies on technologies that are either costly, excessively complicated, or impractical for field use. This study presents a methodology to estimate plant 3D traits using smart mobile app and data modeling. Leaf architecture data on 16 genotypes of rice were collected during two crop seasons using the smart-app PocketPlant3D. Quadratic Bézier curves were fitted to leaf lamina for estimation of insertion angle, elevation angle, and curve height. Leaf azimuth angle distribution, leaf phyllotaxis, canopy leaf angle distribution, and light extinction coefficients were also analyzed. The results could be used for breeding line selection or for parameterizing or evaluating rice 3D architectural models. The methodology opens new opportunities for strengthening the integration of plant 3D architectural traits in crop modeling, better capturing the genetic control and environment modification of plant growth and development, and for improving ideotype-based plant breeding.
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Nur Arina, I., M. Y. Martini, S. Surdiana, R. Mohd Fauzi, and S. Zulkefly. "Radiation Dynamics on Crop Productivity in Different Cropping Systems." International Journal of Agronomy 2021 (March 13, 2021): 1–8. http://dx.doi.org/10.1155/2021/4570616.
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Global demand for food has always been on the increase due to the increase of the population in this world. Intercropping is one of the alternatives of agronomic practices that is widely practiced in ensuring food security and enhancing yield stability. Strip, mixed, and relay intercropping can be practiced to increase crop production. In addition to achieving a successful intercropping system, factors such as suitable crops, time of sowing, maturity of the crop, and plant density need to be considered before and during planting. Besides, practiced intercropping becomes a useful cropping system to increase efficient resource utilization, enhance biodiversity, promote soil health, enhance soil fertility, erosion control, yield advantage, weed, pest, and disease control, insurance against crop failure, ecosystem and modification of microclimate, market instability, and increase farmers income. Crop productivity in any types of cropping system implemented relies primarily on the interception of photosynthetically active radiation (PAR) of crop canopy and conversion of intercepted radiation into biomass or known as radiation use efficiency (RUE). Both PAR and RUE are important measurements that have significant roles in crop growth and development in which the accessibility of these radiation dynamics is connected with the leaf area index and crop canopy characteristics in maximizing yield as well as total productivity of the crop component in intercropping systems.
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Hlaváčiková, Hana, and Viliam Novák. "Comparison of daily potential evapotranspiration calculated by two procedures based on Penman-Monteith type equation." Journal of Hydrology and Hydromechanics 61, no. 2 (June 1, 2013): 173–76. http://dx.doi.org/10.2478/johh-2013-0022.
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Abstract Paper presents comparison of the daily reference crop (grass vegetation cover) potential evapotranspiration results calculated by the two modifications of the Penman-Monteith type equation. The first modification was published in FAO recommendation (Allen at al., 1998), PM-FAO, the second is modification according to Budagovskiy (1964) and Novák (1995), PM-BN. Both are used in soil water simulation models HYDRUS-1D and GLOBAL. Calculations were performed for frost-free seasons of the years 2000-2009, using the meteorological station Gabčíkovo (South Slovakia) meteorological data and canopy characteristics. The results indicate significant differences in daily and seasonal potential evapotranspiration. Reasons for those differences are discussed; they should be in different net radiation and aerodynamic resistance estimation methods.
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Jiménez-Pérez, Alfredo, Manuel J. Cach-Pérez, Mirna Valdez-Hernández, and Edilia De la Rosa-Manzano. "Effect of canopy management in the water status of cacao (Theobroma cacao) and the microclimate within the crop area." Botanical Sciences 97, no. 4 (December 19, 2019): 701–10. http://dx.doi.org/10.17129/botsci.2256.
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Background: Cacao is an umbrophile species and therefore the handling of shade by producers can cause a microclimatic modification that influences the physiology of the plant.
Questions: Can canopy management influence the microclimate of the crop area and the water content of cacao?
Species of study: Theobroma cacao L. (Malvaceae).
Study site: Comalcalco, Tabasco, Mexico; dry and rainy season 2018.
Methods: Three sites were selected with an open canopy (OC) and three with a closed canopy (CC), where we determined air temperature and humidity, soil temperature, vapor pressure deficit, photosynthetically active radiation, soil water potential and leaf water potential in 15 cacao trees and the sap flow density in 12 trees, by canopy condition and by season.
Results: Higher values of solar radiation, air and soil temperature, vapor pressure deficit and lower relative humidity were recorded under OC compared to CC, in both seasons. Differences in soil water potential between 10 and 60 cm depth in CC were recorded during the dry season. There was a lower sap flow density and daily water use in OC. The leaf water potential was similar between canopy conditions, in both seasons.
Conclusions: Changes in canopy coverage significantly modify the microclimate of the crop area, a less stressful environment being generated under closed canopy conditions, influencing the sap flow density of cacao trees.
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FAYAZ AHMED BAHAR and K.N. SINGH. "Modification of crop ecology in maize (Zea mays) through fertility levels and weed control measures under temperate conditions of Kashmir." Indian Journal of Agronomy 58, no. 3 (October 10, 2001): 349–53. http://dx.doi.org/10.59797/ija.v58i3.4198.
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A field experiment was conducted during kharif seasons of 2008 and 2009 at Sher-e-Kashmir University of Ag- ricultural Sciences and Technology Kashmir to study the effect of fertility levels, mulching and weed management practices on the microclimate of crop, soil temperature, phenological changes and yield of maize (Zea mays L.). The experiment was conducted in a split-plot design with three replications and consisted of four treatments viz; N , N + Azotobacter, N , and N + Azotobacter in main plots and five treatments viz; polyethylene mulch, 90 90 120 120 straw mulch @ 1.0 tonne/ha, hand weeding at 30 and 60 DAS, atrazine @1.0 kg a.i./ha and weedy check in sub- plots. Results revealed that N + Azotobacter produced grain yields at par with N , resulting in saving of 30 kg N/ 90 120 ha. Highest grain yield 5.14 t/ha, stover and biological yield with concomitant increase in yield attributes viz; num- ber of cobs/plant, number of rows/cob, number of grains/row, cob length, cob diameter, 1,000-grains weight was obtained with polyethylene mulch. Polyethylene mulch also helped plants to reach phenological stages two to four days earlier as compared to unweeded check. Percentage of light interception by crop at the middle of the canopy was maximum with N + Azotobacter, more than other fertility levels. However, N treatment recorded the high- 120 90 est percentage of light interception among all the fertility levels, when recorded at the bottom of the canopy. Light interception was most with polyethylene mulch among all the weed control treatments when recorded at the middle of the canopy, whereas it was most with weedy check treatment when recorded at the bottom of the canopy. The peak values for the interception of radiation were observed at 90 DAS. The soil temperature in the polyethylene mulched plots was 680C higher as compared to un-mulched plots. Modification of crop ecology through polyethylene mulch and straw mulch resulted in 73.4% and 72.6% more grain yield, respectively, as com- pared to uncontrolled weedy check. Benefit cost ratio was the highest with N + Azotobacter and atrazine @ 1.0 120 kg/ha, respectively.
Book chapters on the topic "Crop canopy modification"
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Long, S. P. "Rubisco, the Key to Improved Crop Production for a World Population of More Than Eight Billion People?" In Feeding a World Population of More Than Eight Billion People. Oxford University Press, 1998. http://dx.doi.org/10.1093/oso/9780195113129.003.0016.
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Despite great advances in understanding of photosynthesis in crops, photosynthesis research has contributed little to improvement of crop production in the past. Does it have a future role in the task of feeding a world of 8 billion? In this chapter I argue that modification of the primary carboxylase of photosynthesis (Rubisco) promises very significant increases in potential crop yields. Plant breeding over the past three decades has produced remarkable worldwide increases in the potential yields of many crops, most notably improvements in the small grain cereals of the “green revolution” (Beadle and Long, 1985; Evans, 1993). Potential yield is defined as the yield that a genotype can achieve under optimal cultivation practice and in the absence of pests and diseases. What are the physiological bases of these increases? Following the principles of Monteith (1977), the potential yield (Y) of a crop at a given location is determined by . . . y = St- εi- εe- η/k (1) . . . where St is the integral of incident solar radiation (MJ m-2), εi the efficiency with which that radiation is intercepted by the crop; εe the efficiency with which the intercepted radiation is converted into biomass; η the harvest index or the efficiency with which biomass is partitioned into the harvested product; and k the energy content of the biomass (MJ g-1). St is determined by the site and year, while k varies very little across higher plant species (Roberts et al., 1993). Potential yield is therefore determined by the combined product of three efficiencies, each describing broad physiological properties of the crop: εi, εe, and η. εi is determined by the speed of canopy development and closure, and by canopy longevity and architecture. εe is a function of the combined photosynthetic rate of all leaves within the canopy less crop respiratory losses. In the context of equation 1, increase in potential yield over the past 30 years has resulted almost entirely from large increases in η.
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Singh, Bijay, R. J. Buresh, and S. Peng. "Synchronizing nitrogen fertilizer application to crop nitrogen needs." In Improving nitrogen use efficiency in crop production, 167–200. Burleigh Dodds Science Publishing, 2024. http://dx.doi.org/10.19103/as.2024.0135.10.
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Nitrogen synchrony refers to nitrogen (N) availability in the soil being closely aligned in space and time with the N requirements of crop plants. However, due to large temporal and spatial variability in the availability of soil N across regions, there is considerable potential for asynchrony between N supply and crop N demand. Synchronizing fertilizer N application to crop N requirements involves managing fertilizer N using strategies that lead to ‘just-in-time N supply’, i.e., the quantity is not excessive or deficient throughout the cropping season. Whether using split applications of fertilizer N, precision agriculture tools such as chlorophyll meters and canopy reflectance sensors, or fertilizer source modification, these strategies have been formulated over the last 20 to 30 years to concomitantly increase crop yield and the efficiency of fertilizer N use. This chapter explores the causes of N asynchrony and evaluates the strategies that have been developed to synchronize fertilizer N application to crop N requirements.
Conference papers on the topic "Crop canopy modification"
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Grushcow, J., and M. A. Smith. "Next Generation Feedstocks From New Frontiers in Oilseed Engineering." In World Tribology Congress III. ASMEDC, 2005. http://dx.doi.org/10.1115/wtc2005-63523.
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Recent advances in molecular breeding techniques along with developing tools for Genomics and Proteomics are delivering new oil seed profiles for industrial applications. Ultra high Oleic, Erucic and blends including Hydroxy fatty acids are now, or will be shortly, available in a variety of oilseed crops including Soybean and Canola as well as Flax. As a result, vegetable oils need to be re-examined by industry for specific applications. Feedstocks and base oils derived from oil seeds are renewable as well as biodegradable. A brief summary of recent progress is presented together with a description of new research into the development of an alternative source of Hydroxy fatty acids to replace castor oil and an overview of an enzyme engineering approach to create new enzymes for seed oil modification.
Reports on the topic "Crop canopy modification"
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Tanny, Josef, Gabriel Katul, Shabtai Cohen, and Meir Teitel. Application of Turbulent Transport Techniques for Quantifying Whole Canopy Evapotranspiration in Large Agricultural Structures: Measurement and Theory. United States Department of Agriculture, January 2011. http://dx.doi.org/10.32747/2011.7592121.bard.
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Original objectives and revisions The original objectives of this research, as stated in the approved proposal were: 1. To establish guidelines for the use of turbulent transport techniques as accurate and reliable tool for continuous measurements of whole canopy ET and other scalar fluxes (e.g. heat and CO2) in large agricultural structures. 2. To conduct a detailed experimental study of flow patterns and turbulence characteristics in agricultural structures. 3. To derive theoretical models of air flow and scalar fluxes in agricultural structures that can guide the interpretation of TT measurements for a wide range of conditions. All the objectives have been successfully addressed within the project. The only modification was that the study focused on screenhouses only, while it was originally planned to study large greenhouses as well. This was decided due to the large amount of field and theoretical work required to meet the objectives within screenhouses. Background In agricultural structures such as screenhouses and greenhouses, evapotranspiration (ET) is currently measured using lysimeters or sap flow gauges. These measurements provide ET estimates at the single-plant scale that must then be extrapolated, often statistically or empirically, to the whole canopy for irrigation scheduling purposes. On the other hand, turbulent transport techniques, like the eddy covariance, have become the standard for measuring whole canopy evapotranspiration in the open, but their applicability to agricultural structures has not yet been established. The subject of this project is the application of turbulent transport techniques to estimate ET for irrigation scheduling within large agricultural structures. Major conclusions and achievements The major conclusions of this project are: (i) the eddy covariance technique is suitable for reliable measurements of scalar fluxes (e.g., evapotranspiration, sensible heat, CO2) in most types of large screenhouses under all climatic conditions tested. All studies resulted with fair energy balance closures; (ii) comparison between measurements and theory show that the model is capable in reliably predicting the turbulent flow characteristics and surface fluxes within screenhouses; (iii) flow characteristics within the screenhouse, like flux-variance similarity and turbulence intensity were valid for the application of the eddy covariance technique in screenhouses of relatively dilute screens used for moderate shading and wind breaking. In more dense screens, usually used for insect exclusions, development of turbulent conditions was marginal; (iv) installation of the sensors requires that the system’s footprint will be within the limits of the screenhouse under study, as is the case in the open. A footprint model available in the literature was found to be reliable in assessing the footprint under screenhouse conditions. Implications, both scientific and agricultural The study established for the first time, both experimentally and theoretically, the use of the eddy covariance technique for flux measurements within agricultural screenhouses. Such measurements, along with reliable theoretical models, will enable more accurate assessments of crop water use which may lead to improved crop water management and increased water use efficiency of screenhouse crops.
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Tanny, Josef, Gabriel Katul, Shabtai Cohen, and Meir Teitel. Micrometeorological methods for inferring whole canopy evapotranspiration in large agricultural structures: measurements and modeling. United States Department of Agriculture, October 2015. http://dx.doi.org/10.32747/2015.7594402.bard.
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Original objectives and revisions The original objectives as stated in the approved proposal were: (1) To establish guidelines for the use of micrometeorological techniques as accurate, reliable and low-cost tools for continuous monitoring of whole canopy ET of common crops grown in large agricultural structures. (2) To adapt existing methods for protected cultivation environments. (3) To combine previously derived theoretical models of air flow and scalar fluxes in large agricultural structures (an outcome of our previous BARD project) with ET data derived from application of turbulent transport techniques for different crops and structure types. All the objectives have been successfully addressed. The study was focused on both screenhouses and naturally ventilated greenhouses, and all proposed methods were examined. Background to the topic Our previous BARD project established that the eddy covariance (EC) technique is suitable for whole canopy evapotranspiration measurements in large agricultural screenhouses. Nevertheless, the eddy covariance technique remains difficult to apply in the farm due to costs, operational complexity, and post-processing of data – thereby inviting alternative techniques to be developed. The subject of this project was: 1) the evaluation of four turbulent transport (TT) techniques, namely, Surface Renewal (SR), Flux-Variance (FV), Half-order Time Derivative (HTD) and Bowen Ratio (BR), whose instrumentation needs and operational demands are not as elaborate as the EC, to estimate evapotranspiration within large agricultural structures; and 2) the development of mathematical models able to predict water savings and account for the external environmental conditions, physiological properties of the plant, and structure properties as well as to evaluate the necessary micrometeorological conditions for utilizing the above turbulent transfer methods in such protected environments. Major conclusions and achievements The major conclusions are: (i) the SR and FV techniques were suitable for reliable estimates of ET in shading and insect-proof screenhouses; (ii) The BR technique was reliable in shading screenhouses; (iii) HTD provided reasonable results in the shading and insect proof screenhouses; (iv) Quality control analysis of the EC method showed that conditions in the shading and insect proof screenhouses were reasonable for flux measurements. However, in the plastic covered greenhouse energy balance closure was poor. Therefore, the alternative methods could not be analyzed in the greenhouse; (v) A multi-layered flux footprint model was developed for a ‘generic’ crop canopy situated within a protected environment such as a large screenhouse. The new model accounts for the vertically distributed sources and sinks within the canopy volume as well as for modifications introduced by the screen on the flow field and microenvironment. The effect of the screen on fetch as a function of its relative height above the canopy is then studied for the first time and compared to the case where the screen is absent. The model calculations agreed with field experiments based on EC measurements from two screenhouse experiments. Implications, both scientific and agricultural The study established for the first time, both experimentally and theoretically, the use of four simple TT techniques for ET estimates within large agricultural screenhouses. Such measurements, along with reliable theoretical models, will enable the future development of lowcost ET monitoring system which will be attainable for day-to-day use by growers in improving irrigation management.