EFFECT OF CEREAL APHID INFESTATION ON GRAIN YIELD AND PERCENTAGE PROTEIN OF BARLEY, WHEAT, AND OATS IN SOUTHWESTERN QUEBEC

1980 ◽  
Vol 112 (7) ◽  
pp. 681-686 ◽  
Author(s):  
S. A. Ba-Angood ◽  
R. K. Stewart

AbstractNatural infestations of cereal aphids caused significant reductions in grain yield in field plots of early and late cultivars of barley, wheat, and oats in southwestern Quebec. Severely reduced grain yields resulted when caged plants of wheat and late cultivars of barley and oats were artificially infested, but early cultivars of barley and oats were less affected. The percentage protein of grain was significantly reduced in all crops, but wheat and late oats were most affected.

1978 ◽  
Vol 90 (2) ◽  
pp. 283-289
Author(s):  
B. F. Pain ◽  
S. J. Richardsonf ◽  
Rosemary J. Fulford

SummaryIn experiments over 3 years (1974–6) cow slurry in the range 0–112·5 t/ha and ammonium nitrate in the range 0–120 kg N/ha were applied to field plots factorially to test the effects on the yield and quality of spring barley grain.In 1974 slurry application markedly improved the grain yield (cv. Golden Promise) at each rate of inorganic N and increased grain size. Applying N fertilizer with more than 37·5 t slurry/ha reduced grain yield below the maximum. Grain with the highest crude protein content (15·1 %) was obtained from a combination of slurry and inorganic N. The residual effects of the slurry treatments gave satisfactory grain yields in 1975 without additional fertilizer.Grain yields (cvs Julia and Abacus) in other experiments carried out on a different soil type in 1975 and 1976 were approximately half those obtained in 1974, due in part to drought conditions. The pattern of the results was similar. Heaviest grain yields were harvested from plots receiving 70 t slurry/ha with no additional N.


1980 ◽  
Vol 112 (8) ◽  
pp. 759-764 ◽  
Author(s):  
S. A. Ba-Angood ◽  
R. K. Stewart

AbstractArtificial infestations of cereal aphids in caged plants were made at different growth stages of barley in the field in 1978 and 1979. Forty, 80, 160, and 200 aphids/tiller reduced grain yield significantly (P < 0.01) when introduced into caged plants at flowering and milky stages for 2 weeks. Only the 150 and 200 aphids/tiller-treatments gave significant reductions in yield when introduction was at the mealy ripe stage. Twenty aphids/tiller gave a significant reduction in yield only when they were introduced at the beginning of ear emergence and flowering, but not at the milky ripe stage. Significant reduction in percentage protein was obtained only when 160 and 200 aphids/tiller were introduced at flowering and milky ripe stages. The economic injury and threshold levels were calculated as 10–18 and 8–16 aphids/tiller, respectively, depending on rate of increase of aphids, costs of chemical control, and the value of the crop in 1978 and 1979.


2006 ◽  
Vol 61 (9-10) ◽  
pp. 704-708 ◽  
Author(s):  
Herman Silva ◽  
Sylvia V. Copaja ◽  
Héctor R. Bravo ◽  
Victor H. Argandoña

AbstractFifteen wheat genotypes were grown under water deficit to ascertain the role of osmotic adjustment (OA) and the concentration of benzoxazinones in sustaining grain yield. A positive correlation between osmotic adjustment capacity and yield was observed in wheat genotypes cultivated under field conditions. The weight gain of plants exposed to drought was in agreement with the OA values (R2 = 0.93). However, when wheat plants were infested by cereal aphids, this correlation was not found. The benzoxazinones 2,4-dihydroxy-1,4-benzoxazin- 3-one (DIBOA) and 2,4-dihydroxy-7-methoxy-1,4 benzoxazin-3-one (DIMBOA) are defensive secondary metabolites present in wheat and others cereals. The content of these compounds varied in wheat genotypes and increased with drought and aphid infestation. A positive correlation between weight gain of irrigated-infested plants and drought-infested plants and the contents of benzoxazinones was observed. These results suggest that plants with better OA capacity and high benzoxazinone content should have better field yields.


2017 ◽  
Vol 155 (9) ◽  
pp. 1394-1406 ◽  
Author(s):  
X. M. MAO ◽  
W. W. ZHONG ◽  
X. Y. WANG ◽  
X. B. ZHOU

SUMMARYThe production of winter wheat (Triticum aestivum L.) is affected by crop population structures and field microclimates. This 3-year study assessed the effect of different precision planting patterns and irrigation conditions on relative humidity (RH), air and soil temperature within the canopy, intercepted photosynthetically active radiation (iPAR), evapotranspiration (ET), water productivity (WP) and grain yields. Field experiments were conducted from 2011 to 2014 on a two-factor split-plot design with three replicates. The experiments involved three precision planting patterns (single row, alternating single and twin rows [hereafter ‘single–twin’] and twin row) and three irrigation treatments (0 mm (I0), 90 mm (I90) and 180 mm (I180)). Planting patterns and irrigation treatments exerted a significant effect on RH, air and soil temperature, iPAR, ET, WP and grain yield. The lowest RH and iPAR levels were detected in the single row pattern. When the irrigation treatment was identical, the highest soil and air temperatures were detected in the single row pattern, followed by the single–twin row and twin row patterns. Compared with the single row, the single–twin and twin row patterns increased ET by 0·3 and 1·4, WP by 4·7 and 5·7% and yields by 6·0 and 7·9%, respectively. Compared with I0, the I90 and I180 irrigation treatments increased ET by 0·3 and 1·4%, and WP by 4·7 and 5·7%, respectively. The grain yields of the twin row pattern were 5·8 and 1·7% higher than those of the single row and single–twin row patterns, respectively. Compared with I0, I90 increased yield by 19·3%. The twin row pattern improved crop structure and farmland microclimate by increasing RH and iPAR, and reducing soil and air temperatures, thus increasing grain yield. These results indicated that a twin row pattern effectively improved grain yield at I0. On the basis of iPAR, WP and grain yield, it was concluded that a twin row pattern combined with an I90 irrigation treatment provided optimal cropping conditions for the North China plain.


2014 ◽  
Vol 6 (4) ◽  
pp. 188 ◽  
Author(s):  
Joseph Adigun ◽  
A. O. Osipitan ◽  
Segun Toyosi Lagoke ◽  
Raphael Olusegun Adeyemi ◽  
Stephen Olaoluwa Afolami

Weed problem appears to be the most deleterious factor causing between 25 and 60% reduction in potential yield of cowpea. Field trials were therefore conducted to study the effect of inter-row spacing and period of weed interference on growth and yield of cowpea (Vigna unguiculata (L) Walp) at the Teaching and Research Farm of the Federal University of Agriculture, Abeokuta (07° 15'; 03° 25' E) in South Western Nigeria during the early and late wet seasons of 2009. The experiment consisted of eight main plots of weed interference which included initial weed removal for 3, 6, 9, and 12 weeks after sowing (WAS) and subsequently weed –infested until harvest as well as initial weed infestation for corresponding periods and thereafter kept weed free until harvest. There were also sub-plot treatments of three inter-row spacing of 60, 75, and 90 cm. All treatments in different combinations were laid out in a split-plot design with three replications. In both trials, the use of inter-row spacing of 60 cm resulted in significant reduction in weed growth as evident in lower weed dry matter production and subsequent higher cowpea pod and grain yields than those of 75 and 90 cm inter-row spacing. Initial weed infestation of up to 3 WAS did not have any adverse effect on crop growth and cowpea grain yields provided the weeds were subsequently removed. On the other hand, cowpea grain yield loss was not significantly averted by keeping the crop weed free for only 3 WAS without subsequent weed removal. In this study, initial weed-infestation for 6 WAS and beyond significantly depressed various crop growth parameter and cowpea grain yield compared with the crop kept weed free throughout its life cycle. In order to obtain optimum yields similar to that of the weed free cowpea field, it was required to keep the crop weed free for 6 WAS and beyond. However, frequent weeding beyond 9 weeks after sowing did not improve cowpea yield significantly and as a matter of fact it may even result in reduction of cowpea grain yield due to mechanical damage of hoe weeding. The practical implication of this finding is that early weeding starting from 3 WAS is very crucial for cowpea production while the critical period of weed removal for optimum yield in cowpea is between 3 and 9 WAS in the forest-savannah transitional zone of south Western Nigeria.


2021 ◽  
Vol 13 (17) ◽  
pp. 3482
Author(s):  
Malini Roy Choudhury ◽  
Sumanta Das ◽  
Jack Christopher ◽  
Armando Apan ◽  
Scott Chapman ◽  
...  

Sodic soils adversely affect crop production over extensive areas of rain-fed cropping worldwide, with particularly large areas in Australia. Crop phenotyping may assist in identifying cultivars tolerant to soil sodicity. However, studies to identify the most appropriate traits and reliable tools to assist crop phenotyping on sodic soil are limited. Hence, this study evaluated the ability of multispectral, hyperspectral, 3D point cloud, and machine learning techniques to improve estimation of biomass and grain yield of wheat genotypes grown on a moderately sodic (MS) and highly sodic (HS) soil sites in northeastern Australia. While a number of studies have reported using different remote sensing approaches and crop traits to quantify crop growth, stress, and yield variation, studies are limited using the combination of these techniques including machine learning to improve estimation of genotypic biomass and yield, especially in constrained sodic soil environments. At close to flowering, unmanned aerial vehicle (UAV) and ground-based proximal sensing was used to obtain remote and/or proximal sensing data, while biomass yield and crop heights were also manually measured in the field. Grain yield was machine-harvested at maturity. UAV remote and/or proximal sensing-derived spectral vegetation indices (VIs), such as normalized difference vegetation index, optimized soil adjusted vegetation index, and enhanced vegetation index and crop height were closely corresponded to wheat genotypic biomass and grain yields. UAV multispectral VIs more closely associated with biomass and grain yields compared to proximal sensing data. The red-green-blue (RGB) 3D point cloud technique was effective in determining crop height, which was slightly better correlated with genotypic biomass and grain yield than ground-measured crop height data. These remote sensing-derived crop traits (VIs and crop height) and wheat biomass and grain yields were further simulated using machine learning algorithms (multitarget linear regression, support vector machine regression, Gaussian process regression, and artificial neural network) with different kernels to improve estimation of biomass and grain yield. The artificial neural network predicted biomass yield (R2 = 0.89; RMSE = 34.8 g/m2 for the MS and R2 = 0.82; RMSE = 26.4 g/m2 for the HS site) and grain yield (R2 = 0.88; RMSE = 11.8 g/m2 for the MS and R2 = 0.74; RMSE = 16.1 g/m2 for the HS site) with slightly less error than the others. Wheat genotypes Mitch, Corack, Mace, Trojan, Lancer, and Bremer were identified as more tolerant to sodic soil constraints than Emu Rock, Janz, Flanker, and Gladius. The study improves our ability to select appropriate traits and techniques in accurate estimation of wheat genotypic biomass and grain yields on sodic soils. This will also assist farmers in identifying cultivars tolerant to sodic soil constraints.


2016 ◽  
Vol 8 (1) ◽  
pp. 59
Author(s):  
Valentín A. Esqueda ◽  
Arturo Durán ◽  
Ernesto López

Three experiments were carried out in the central area of the state of Veracruz, Mexico, during the Fall-Winter seasons of 1989-90, 1991-92 and 1992-93. The main objective was to determine the effect of the time and type of weeding on the yield of residual moisture growing beans. Twelve treatments, arranged in a CRBD with four replications were evaluated. Treatments consisted in hoeing at different times. In some treatments, hoeing was complemented with hand-weeding. The highest grain yields were obtained when the weeds were eliminated at least in two ocations during the early stages of development of the crop. The yield of these treatments was significantly higher than that obtained with the traditional weeding practice (hoeing at 25 days after emergence).Handweeding after hoeing increased grain yields at high weed densities,but when the weed density was not very high, handweeding after hoeing made no difference. The increase in grain yield obtained when two weeding operations were performed instead of one, was sufficient to cover for the expenses of this additional practice and to generate economic profits.


2021 ◽  
Vol 1 ◽  
Author(s):  
Rechiatu Asei ◽  
Robert Clement Abaidoo ◽  
Andrews Opoku ◽  
Samuel Adjei-Nsiah ◽  
Philip Antwi-Agyei

A better understanding of soil fertility factors that constraint positive crop response to fertilizer inputs will facilitate the improvement of soil nutrient management. In this study, a nutrient omission trial was carried out in a greenhouse condition to identify soil chemical properties limiting in non-responsive soils and to ascertain their effect on soybean (Glycine max) production. The treatments evaluated were control (distilled water), complete nutrient solution (all nutrients), and complete solution with the omission of each of N, P, K, Ca, Mg, and S and micronutrients (Fe, Zn, Cu, Mn, B, and Mo) arranged in a completely randomized design with three replications. After the greenhouse study, the identified limiting nutrients were tested with or without FertiSoil (commercial compost) in a 3 year field experiment. Results of the soil analyses showed low fertility status of the non-responsive soils. The sufficiency quotient index revealed non-responsive soils in all the sites to be predominantly limiting in P and K. The occurrence of other limiting nutrients was also identified: Pishegu (Zn, B), Serekpere (Mg, S), Daffiama Saapare (Ca, Mg, S), and Naaga (Mg, S, Zn, B). The nutrient inputs positively influenced soybean yield response in all the locations. The application of PKZnB with FertiSoil and FertiSoil alone significantly increased soybean grain yields by 585 and 477 kg ha−1, respectively, at Pishegu. Soybean grain yields also increased by 585, 573, and 364 kg ha−1 under the FertiSoil, PKMgS + FertiSoil, and PKMgS applications at Serekpere, respectively. At Daffiama Saapare, the highest (103%) percent increase in soybean grain yield was recorded from the combined application of PKMgSCa and FertiSoil. However, the application of FertiSoil and PKMgSCa singly equally increased soybean grain yield by 77%. Percent soybean grain yield increases of 86, 84, and 74% were observed when PKMgSZnB + FertiSoil, PKMgSZnB, and FertiSoil were applied, respectively, at Naaga. In absolute terms, 83% of the fields had a positive response to mineral fertilizer and 93% to FertiSoil and mineral fertilizer + FertiSoil applications. Organic amendment and/or site-specific fertilizer applications are the best options for alleviating poor or no crop responses to inputs and improve productivity on non-responsive soils.


2020 ◽  
Vol 13 (1) ◽  
pp. 147
Author(s):  
Gabriel Bressiani Melo ◽  
Alessandro Guerra da Silva ◽  
Adriano Perin ◽  
Guilherme Braga Pereira Braz ◽  
Christiano Lima Lobo de Andrade

The use of biostimulants in the treatment of soybean seeds can provide beneficial effects on the crop due to the synergism between the organic components present in products from natural compounds. Due to the scarcity of results of research on biostimulants in the treatment of soybean seeds, the objective of this study was to evaluate the effects of doses of a biostimulant in the treatment of seeds, on agronomic characteristics, productivity components and profitability of soybean culture. Therefore, two experiments were carried out in the field in the 2016/17 and 2017/18 harvests, using a randomized block design with six replications and four treatments referring to doses of 0.00; 0.05; 0.10; and 0.15 L 100 kg seeds-1. The agronomic characteristics of soybeans, grain yield and profitability of using the biostimulant were evaluated. From the obtained results, it can be seen that the dose of 0.15 L 100 kg seeds-1 provided greater profitability in both harvests. In addition, doses above 0.12 L 100 kg seed-1 provide higher grain yields and a higher grain mass, in addition to other productivity components.


2007 ◽  
Vol 139 (6) ◽  
pp. 850-863 ◽  
Author(s):  
Samuel M. Migui ◽  
Robert J. Lamb

AbstractThe susceptibilities of genetically diverse Canadian spring wheats, Triticum aestivum L. and Triticum durum Desf., to three aphid species, Rhopalosiphum padi (L.), Sitobion avenae (Fabricius), and Schizaphis graminum (Rondani), were investigated. Trophic interactions measured as changes in biomass of aphids and wheat plants were used to quantify levels of resistance, components of resistance, and impact of aphids on yield. Plants in field cages were infested with small numbers of aphids for 21 days at heading. These plants were usually more suitable for the development of S. avenae and S. graminum than of R. padi. Partial resistance, measured as seed production by infested plants as a proportion of that by a control, varied from 11% to 59% for different aphid species and wheat classes when all wheat plants were infested at the same stage. Cultivars within wheat classes responded similarly to each of the aphid species. None of the wheat cultivars showed agriculturally effective levels of antibiosis. The specific impact of each aphid species and wheat class varied from 5 to 15 mg of plant biomass lost for each milligram of biomass gained by the aphids. Canadian Western Red Spring wheat had a lower specific impact and therefore was more tolerant to aphids than the other two classes, but not tolerant enough to avoid economic damage at the aphid densities observed. Plants did not compensate for feeding damage after aphid feeding ceased, based on the higher specific impacts observed for mature plants than for plants that were heading. The interactions between aphids and plants show that current economic thresholds probably underestimate the damage caused by cereal aphids to Canadian spring wheat.


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