Crop Yield Losses Reduction at Harvest, from Research to Adoption

ABSTRACTInadequate herbicide application can result in failures in weed control and/or poisoning of the crops, resulting in yield losses. In this research were assessed the effects of the sprayer nozzle boom height in the distribution of the spray solution for weed control, influencing intoxication of beans and crop yield. Experiments were conducted in laboratory and field conditions. In laboratory, the performance of flat spray tip TT 11002 was assessed at heights 0.20, 0.30, 0.40 and 0.50 meters with respect to the target surface. In the field the same heights were assessed in applications of herbicides fomesafen, fluazifop-P-butyl and fomesafen + fluazifop-P-butyl. There was an inverse relationship between the height of the spray boom and the coefficients of variation of the patterns. The mixture better efficiency in a tank of fluazifop-P-butyl + fomesafen was obtained with the height of 0.50 m from the target. This treatment resulted in better weed control, lower poisoning of the bean plants and better crop yield rates.

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Round-leaved Mallow (Malva pusilla) Interference in Spring Wheat (Triticum aestivum) and Lentil (Lens culinaris) in Saskatchewan

Weed Science ◽

10.1017/s0043174500081364 ◽

1995 ◽

Vol 43 (3) ◽

pp. 381-388 ◽

Cited By ~ 1

Author(s):

Roberte M. D. Makowski

Keyword(s):

Crop Yield ◽

Spring Wheat ◽

Lens Culinaris ◽

Yield Loss ◽

Yield Losses ◽

Variable Model ◽

Early Season ◽

Crop Density ◽

Density And Biomass ◽

Tiller Density

The competitive ability of annual round-leaved mallow was determined in spring wheat and lentil at Indian Head and Regina, Saskatchewan, in 1985 and 1986 using paired quadrats. Significant biomass and seed yield loss occurred in three of four tests in lentil and two of three tests in spring wheat. Differences in numbers of wheat tillers produced between weedy and weed-free plots were found in three of four tests. A two-variable model comprised of early season crop density loss and round-leaved mallow biomass best accounted for the majority of variation in crop yield loss for both lentil and wheat, and tiller density loss in wheat. In 1985 at Indian Head, where no yield loss occurred for either wheat or lentil, round-leaved mallow had been seeded immediately before the crop. Greater yield losses occurred at Regina, in the presence of an older, well-established infestation. In the years and locations with the greatest crop yield losses, round-leaved mallow emerged before the crop causing poor crop emergence. At Regina in 1986, crop yield losses were more than 60% in wheat and 90 to 100% in lentil because of large differences in crop density between weed-free and weedy subplots. Round-leaved mallow exhibited great variability in growth, producing more biomass per plant, more capsules per plant, and more capsules per gram of biomass in the less competitive crop, lentil, than in wheat. Density and biomass of round-leaved mallow were not correlated; with a density of 200 plants m−2, round-leaved mallow biomass in wheat ranged from 100 to 500 g m−2; while in lentil, from 200 to as high as 1000 g m−2, approximately double the range found in wheat. The type of round-leaved mallow infestation (newly seeded or well-established) and environmental conditions (mainly early season precipitation) account for differences between sites and between years.

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Estimating yield losses in wheat resulting from infestation by doublegee (Emex australis)

Australian Journal of Experimental Agriculture ◽

10.1071/ea9740656 ◽

1974 ◽

Vol 14 (70) ◽

pp. 656 ◽

Cited By ~ 5

Author(s):

DJ Gilbey

Keyword(s):

Crop Yield ◽

Field Trial ◽

Yield Loss ◽

Wheat Yield ◽

Yield Reduction ◽

Yield Losses ◽

Seedling Mortality ◽

Emex Australis ◽

Percentage Yield

The effect of doublegee (Emex australis) density on wheat yield was studied in a field trial. Percentage yield reduction (y) was related to doublegee plants m-2 at 1 week (x1) and 8 weeks (x2) after seeding thus: y = 10.3 + 0.24 x1 r = 0.78*** y = 5.6 + 0.44 x2 r = 0.86*** showing that estimates of doublegee density could be used for forecasting crop yield losses before it is too late to spray. No further yield loss occurred when x1 was greater than 120 plants metre-2. Doublegee seedling mortality that occurred during the seven weeks between plant counts was strongly related to the initial counts (x1) thus: r = 0.88***.

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Simulation of Competition for Photosynthetically Active Radiation Between Common Ragweed (Ambrosia artemisiifolia) and Dry Bean (Phaseolus vulgaris)

Weed Science ◽

10.1017/s0043174500094315 ◽

1996 ◽

Vol 44 (3) ◽

pp. 545-554 ◽

Cited By ~ 11

Author(s):

David Chikoye ◽

Leslie A. Hunt ◽

Clarence J. Swanton

Keyword(s):

Leaf Area ◽

Crop Yield ◽

Photosynthetically Active Radiation ◽

Growth And Development ◽

Field Studies ◽

Weed Competition ◽

Yield Losses ◽

Dry Bean ◽

Common Ragweed ◽

Active Radiation

The influence of weeds on crop yield is not only dependent on weed-related factors such as density and time of emergence, but also on environmental and management factors that affect both the weed and crop through time. This study was undertaken to develop the first physiologically based dry bean model that would account for the influence of weed competition. The specific objective was to develop a model that would account for the influence of weed competition on crop yield, and to use this model to test the hypothesis that crop yield losses resulted from competition for photosynthetically active radiation (PAR). To this end, a model that simulated the growth and development of dry bean was developed. The model performed daily calculations and simulated the phenology, leaf area expansion, dry matter production and distribution, and grain yield of dry bean based on weather and management information, but assumed adequate water and nutrients. The model was calibrated without weed competition at two locations and yr, and for these situations, adequately described the growth and development of the crop. Simulations were then run for five common ragweed densities and two times of emergence. Common ragweed leaf area was read into the model from input files and used to simulate weed shading. Shading of the dry bean canopy by common ragweed accounted for about 50 to 70% of the yield losses observed in field studies when weeds emerged with the crop. Weed shading did not account for the yield reduction measured from weeds that emerged at the second trifoliate stage of crop growth. The agreement between model predictions and field studies was consistent with the hypothesis that competition for PAR was a principal factor in weed-crop interaction. The ability to account for differences in weed densities, management, and environmental conditions suggested that modeling was a useful tool for evaluating the interaction among weeds and crops.

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Wheat Crop Yield Losses Caused by the Aphids Infestation

Journal of Fertilizers & Pesticides ◽

10.4172/2155-6202.1000122 ◽

2012 ◽

Vol 03 (04) ◽

Cited By ~ 1

Author(s):

Arif Khan Muhammad

Keyword(s):

Crop Yield ◽

Wheat Crop ◽

Yield Losses

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Density and Time of Emergence of Yellow Nutsedge Affect Squash Yield

HortScience ◽

10.21273/hortsci.39.4.845d ◽

2004 ◽

Vol 39 (4) ◽

pp. 845D-846

Author(s):

J. Pablo Morales-Payan* ◽

William M. Stall

Keyword(s):

Crop Yield ◽

Cucurbita Pepo ◽

Yield Loss ◽

Cyperus Esculentus ◽

Yield Losses ◽

Crop Season ◽

Yellow Nutsedge ◽

Live Oak ◽

Significant Yield ◽

Direct Seeded

A field experiment was conducted in Live Oak, Fla., to determine the effect of yellow nutsedge (Cyperus esculentus L.) (YN) density and time of emergence on the yield of direct-seeded squash (Cucurbita pepo L.). YN densities (0, 20, 40, 60, and 100 plants/m2) were established from tubers planted at different times onto polyethylene-mulched beds, so that YN would emerge the same day as the crop or 5, 15, or 25 days later than the crop (DLTC). YN was not controlled after its emergence. The extent of squash yield loss was affected by YN density and time of emergence. When YN emerged the same day as the crop, the yield of squash was reduced by ≈7% (20 YN/m2) to 20% (100 YN/m2). When YN emerged 15 DLTC, crop yield loss was ≈13% at the density of 100 YN/m2>. Regardless of density, YN emerging 25 DLTC did not significantly reduce crop yield as compared to weed-free squash. Thus, in soils with high YN densities (≈100 viable tubers/m2) herbicides and/or other means of YN suppression in squash should be effective for at least 25 days after crop emergence to prevent significant yield loss. If squash yield losses <5% were acceptable, YN control may not be necessary when densities <20 YN/m2 emerge at any time during the squash season or when <100 YN/m2 emerge >25 DLTC. However, YN emerging during the first 15 days of the squash season may produce tubers, which could increase the YN population at the beginning of the following crop season.

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Economy-Wide Effects of Climate Change in Benin: An Applied General Equilibrium Analysis

Sustainability ◽

10.3390/su11236569 ◽

2019 ◽

Vol 11 (23) ◽

pp. 6569 ◽

Cited By ~ 1

Author(s):

Femi E. Hounnou ◽

Houinsou Dedehouanou ◽

Afio Zannou ◽

Johanes Agbahey ◽

Gauthier Biaou

Keyword(s):

Climate Change ◽

General Equilibrium ◽

Crop Yield ◽

National Level ◽

Import Demand ◽

Equilibrium Analysis ◽

Household Welfare ◽

Climate Change Scenarios ◽

Yield Losses ◽

Poor Households

This research analyzes the economic effects of climate change-induced crop yield losses in Benin. As agriculture is a large sector in Benin, the climate change-induced crop yield losses are expected to affect the entire economy as well as household welfare in both rural and urban areas. The paper applies a dynamic general equilibrium model and simulates productivity shocks in the agricultural sector derived from climate change scenarios for Benin. The findings show that climate change-induced crop yield losses reduce domestic agricultural outputs by 4.4% and the nonagricultural output by 0.9% on average by 2025. While export supply decrease by 25.5%, import demand increases by 4.9% on average by 2025. As price of labour and capital decline, household income drop for all household groups by 2.5% on average. Ultimately, household welfare decline for all household groups by 2.7% on average. Rural and particularly poor households are projected to experience the worst adverse effects of climate change-induced crop yield losses. The results show that without adaptive strategies to cope with climate change, economic growth and household welfare will decline even further by 2035 and 2045. Subsequently, the paper suggests that adaptation strategies are needed not only at the national level to overcome the projected negative effects on macroeconomic indicators, but also at household level to enhance the adaptative capacity of households, especially the poor households living in rural areas.

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Control of volunteer soybean plants in sunflower crop1

Pesquisa Agropecuária Tropical ◽

10.1590/1983-40632015v4533999 ◽

2015 ◽

Vol 45 (3) ◽

pp. 274-281 ◽

Cited By ~ 1

Author(s):

Alexandre Magno Brighenti

Keyword(s):

Glycine Max ◽

Helianthus Annuus ◽

Crop Yield ◽

Dry Weight ◽

The Other ◽

Yield Losses ◽

Glufosinate Ammonium ◽

Total Death ◽

Sunflower Crop ◽

Soybean Plants

ABSTRACTSunflower (Helianthus annuus) sown offseason, after soybean crop (Glycine max), is affected by the competition imposed by volunteer plants. Two experiments were carried out to evaluate the control of volunteer soybean plants in sunflower crops. The sulfentrazone herbicide (75 g ha-1, 100 g ha-1 and 250 g ha-1) causes phytotoxicity to sunflower immediately after application, however, plants recover, with no yield losses. These doses do not cause the total death of volunteer soybean plants, but temporarily paralyzes their growth, avoiding the competition with the sunflower crop. The glufosinate ammonium and ametryn herbicides are effective in controlling volunteer soybean plants, however, symptoms of phytotoxicity in the sunflower crop are high, reflecting in losses of dry weight biomass and crop yield. The other treatments do not provide satisfactory control of volunteer soybean plants and even reduce the sunflower dry weight biomass and yield.

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