Yield Losses in Maturing Spring Wheat Caused by Cereal Aphids (Homoptera: Aphididae) under Laboratory Conditions

1997 ◽  
Vol 90 (5) ◽  
pp. 1346-1350 ◽  
Author(s):  
Todd S. Voss ◽  
Robert W. Kieckhefer ◽  
Billy W. Fuller ◽  
Murdick J. McLeod ◽  
David A. Beck
Keyword(s):  
Spring Wheat ◽  
Cereal Aphids ◽  
Yield Losses ◽  
Laboratory Conditions

scholarly journals THE LINK BETWEEN AGRICULTURAL CROPS AND THE OIL CONCENTRATION OF POLLUTED SOIL

1970 ◽  
Vol 63 ◽  
Author(s):  
N. C. Sabău
Keyword(s):  
Spring Wheat ◽  
Agricultural Research ◽  
Latin Square ◽  
Random Order ◽  
Polluted Soil ◽  
Agricultural Crops ◽  
Yield Losses ◽  
Polluted Soils ◽  
Oil Concentration ◽  
Agricultural Research And Development

The paper presents the results of researches regarding oil polluted soils, that took place at the Agricultural Research and Development Station in Oradea, from 1993 to 2002. The experimental device was made out of 1 m² micro parcels, spread out in a random order in a Latin square; these parcels were polluted under control with petroleum from Suplacu de Barcău, Bihor County, with the following concentrations: 0, 1, 3, 5 and 10 % petroleum on the ploughed layer, with 4 repetitions. The experience was set out on a luvosoil and the soil was cultivated with millet, a plant which is considered to be tolerant to soil pollution, in the first 3 years, and with spring wheat in the last 7 years of research. The results of the research have shown that the yield losses are proportional with the petroleum concentration, and had a descending evolution. For instance, in the case of the 1% pollution, losses are insignificant after 7 years of crops.

Trophic interactions between three species of cereal aphid (Hemiptera: Aphididae) and spring wheat (Poaceae): implications for pest management

2007 ◽  
Vol 139 (6) ◽  
pp. 850-863 ◽  
Author(s):  
Samuel M. Migui ◽  
Robert J. Lamb
Keyword(s):  
Spring Wheat ◽  
Trophic Interactions ◽  
Plant Biomass ◽  
Rhopalosiphum Padi ◽  
Aphid Species ◽  
Economic Damage ◽  
Cereal Aphids ◽  
Cereal Aphid ◽  
Economic Thresholds ◽  
Specific Impact

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.

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

Weed Science ◽  
1995 ◽  
Vol 43 (3) ◽  
pp. 381-388 ◽  
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.

Tolerances of wheat cultivars to pre-emergence herbicides

1985 ◽  
Vol 25 (4) ◽  
pp. 922 ◽  
Author(s):  
D Lemerle ◽  
AR Leys ◽  
RB Hinkley ◽  
JA Fisher
Keyword(s):  
Grain Yield ◽  
Spring Wheat ◽  
Yield Loss ◽  
New South ◽  
New South Wales ◽  
Yield Reduction ◽  
Wheat Cultivars ◽  
Yield Losses ◽  
South Wales

Twelve spring wheat cultivars were tested in southern New South Wales for their tolerances to the recommended rates and three times the recommended rates of trifluralin, pendimethalin, tri-allate and chlorsulfuron. Recommended rates of these herbicides did not affect the emergence or grain yield of any cultivar. However, differences between cultivars in their tolerances to trifluralin, pendimethalin and chlorsulfuron at three times the recommended rate were identified. The extent of the reduction in emergence and/or grain yield varied with herbicide and season, and there was also a herbicidexseason interaction. Durati, Songlen and Tincurrin were the most susceptible cultivars to trifluralin, and Teal was the most tolerant. Yield losses from trifluralin were more severe in 1979 than in 1980 or 1981. The differential between cultivars treated with pendimethalin was smaller and more variable; Tincurrin was the only cultivar with a yield reduction in more than one season. Durati, Songlen and Shortim were the only cultivars affected by chlorsulfuron. A reduction in crop emergence of a cultivar treated with trifluralin or pendimethalin did not correlate consistently with any grain yield loss, and reductions in emergence were always greater than yield loss.

MONITORING OF ENTOMOСOMPLEXES OF SOFT SPRING WHEAT IN THE FOREST-STEPPE OF SAMARA AREA

2016 ◽  
Vol 1 (4) ◽  
pp. 3-9
Author(s):  
Каплин ◽  
Vladimir Kaplin
Keyword(s):  
Seedling Growth ◽  
Spring Wheat ◽  
Negative Impact ◽  
Stem Elongation ◽  
High Density ◽  
Forest Steppe ◽  
Cereal Aphids ◽  
Competitive Relations ◽  
Hippodamia Variegata ◽  
Pre Treatment

The purpose of research is creation of conditions for the formation of self-regulating entomocomplexes in agrocenoses with a significant competitive relations in the cultivation of spring wheat in the non-use of insecticides against pests. Insects was collected with an entomological net for 25-50 flaps in triple repeated in period of vegetation of wheat. In the conditions of the non-use of insecticides of entomokomplexes included insects-phytophagous which are potential vectors of viruses, phytoplasmas; suctorial and gnawing phytofagous; insects are developing inwardly wheat stems; entomophagous. Entomophagous regulating the density of phytophagous were represented by predators and parasites. In 2013-2016 Phyllotreta vittula, Oscinella pusilla, O. frit had a high density in the stage of seedling growth, Haplothrips tritici – in the stage of stem elongation of spring wheat. Against pests of seedlings in terms of their high density recommended for pre-treatment of seeds of spring wheat before sowing by system insecticide Cruiser, KC, without a negative impact on useful entomofauna of the agro-ecosystems. To the head emergence stage of spring wheat and the beginning of oviposition of Haplothrips tritici, its population was effectively reduced by Aeolothrips pascidutus. Development of cereal aphids was annualy kept Hippodamia variegata (Coccinellidae).

SPATIAL DISTRIBUTION AND SAMPLING PLANS WITH FIXED LEVELS OF PRECISION FOR CEREAL APHIDS (HOMOPTERA: APHIDIDAE) INFESTING SPRING WHEAT

1998 ◽  
Vol 130 (1) ◽  
pp. 67-77 ◽  
Author(s):  
Philip J. Boeve ◽  
Michael Weiss
Keyword(s):  
Spatial Distribution ◽  
Power Law ◽  
Spring Wheat ◽  
Rhopalosiphum Padi ◽  
Aphid Population ◽  
Management Decision ◽  
Cereal Aphids ◽  
Sampling Plans ◽  
Taylor’S Power Law ◽  
Taylor's Power Law

AbstractThree cereal aphids, Rhopalosiphum padi (L.), Schizaphis graminum (Rondani), and Sitobion avenae (F.), invade wheat fields in the northern Great Plains each spring, and populations occasionally reach economic levels. The first objective of this study was to describe the spatial distribution of three species of cereal aphids infesting hard red spring wheat (Triticum aestivum L.). The second objective was to develop two sampling plans for cereal aphids using individual stems as the sampling unit, a sampling plan with fixed levels of precision and a sequential sampling decision plan based on total numbers of aphids present. Aphid population estimates were collected from 47 eastern North Dakota spring wheat fields during 1993–1995. The number of aphids per stem were counted on 100–350 stems per field. Taylor’s power law and Iwao’s patchiness regression were used to analyze the spatial distribution of the aphids. Rhopalosiphum padi and S. avenae exhibited an aggregated distribution, whereas S. graminum was distributed randomly in the field. Taylor’s power law provided a better fit to the data than Iwao’s patchiness regression. Sample size requirements for precision levels of 0.10, 0.15, and 0.25 were estimated with Taylor’s regression coefficients. Required sample sizes increased with decreased aphid populations and increased levels of precision. The two sampling plans presented should be useful for research on cereal aphid population dynamics and pest management decision making in spring wheat.

Resistance to Hessian fly (Diptera: Cecidomyiidae) in a Canadian spring wheat cultivar

2006 ◽  
Vol 138 (5) ◽  
pp. 638-646 ◽  
Author(s):  
Ian L. Wise ◽  
Robert J. Lamb ◽  
Ronald I.H. McKenzie ◽  
Jay W. Whistlecraft
Keyword(s):  
Spring Wheat ◽  
Partial Resistance ◽  
Yield Loss ◽  
Wheat Cultivar ◽  
Hessian Fly ◽  
Seedling Stage ◽  
Susceptible Cultivar ◽  
Wheat Cultivars ◽  
Yield Losses ◽  
Spring Wheat Cultivar

AbstractThe Canadian spring wheat (Triticum aestivum L.; Poaceae) cultivar ‘Superb’ was less susceptible to damage by Hessian fly, Mayetiola destructor (Say), than the spring wheat cultivars ‘AC Barrie’, ‘AC Foremost’, ‘McKenzie’, ‘AC Domain’, and ‘Glenlea’ in Manitoba. The partial resistance of ‘Superb’ was similar, at the seedling stage, to that of ‘Guard’, which possesses the resistance gene H18. Females laid eggs readily on all cultivars, providing no evidence for antixenosis, but few larvae developed on seedlings of ‘Superb’ and ‘Guard’, showing that antibiosis against larvae is the mechanism of resistance in these seedlings. In the field, where infestation of spring wheat takes place about 4 weeks after the seedling stage, ‘Guard’ continued to show high levels of resistance, but ‘Superb’ was less resistant, although still more resistant than highly susceptible cultivars. Infested stems of ‘Superb’ and ‘Nordic’ were less likely to break than infested stems of other cultivars, showing that these two cultivars are partially tolerant to infestation. Infested stems of ‘Guard’ and other cultivars showed high levels of stem breakage and are intolerant. Yield losses due to infestation by Hessian fly were mostly caused by the breakage and falling over of infested stems, which prevented the seeds on these stems from being harvested. Infested stems of all susceptible cultivars that remained standing at harvest had lower seed masses and fewer seeds per spike than uninfested stems, which contributed to yield loss. ‘Grandin’, a parent of ‘Superb’, is the probable source of resistance in ‘Superb’, but the pedigree of ‘Grandin’ provides no clue as to the gene(s) involved. The partial antibiosis and tolerance expressed by ‘Superb’ is sufficient to reduce losses to Hessian fly by 65% in comparison with a susceptible cultivar such as ‘AC Barrie’. ‘Superb’ is the first Canadian spring wheat cultivar identified to have an agronomically useful level of resistance to Hessian fly.

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