scholarly journals Experimental Assessment of the Economic Injury Level of the Cereal Leaf Beetle (Coleoptera: Chrysomelidae) in Winter Wheat

2020 ◽  
Vol 113 (4) ◽  
pp. 1823-1830
Author(s):  
Thomas Steinger ◽  
Françoise Klötzli ◽  
Hans Ramseier
Keyword(s):  
Winter Wheat ◽  
Yield Loss ◽  
Crop Yields ◽  
Flag Leaf ◽  
Field Trials ◽  
Leaf Beetle ◽  
Pest Species ◽  
Cereal Leaf Beetle ◽  
Economic Injury ◽  
The Impact

Abstract The cereal leaf beetle, Oulema melanopus L., is an economically important pest species, reducing crop yields in many cereal growing parts of the world. Available studies on yield depression in winter wheat in relation to the density of O. melanopus revealed inconsistent results, creating uncertainty about economic thresholds for pest control. We present results from a series of controlled field trials over a 4-yr period (2014–2017) in Switzerland to examine the impact of artificial defoliation (0, 20, 40, and 60% of flag leaf area removed in 1-m2 field plots) on yield and yield components in winter wheat. The applied defoliation treatments correspond to field infestations levels of approximately 2–6 larvae per stem. Analysis of the combined data from 11 location-years revealed a significant linear decrease in yield per ear with increasing defoliation intensity. Yield per ear declined at a rate of 1.14% (SE = 0.28) per 10 percentage-point increase in defoliation. Similar results were found in a parallel series of field trials in which a 40% defoliation treatment was applied to eight common wheat cultivars. Interestingly, however, three cultivars showed complete tolerance in yield to defoliation. Data from two trials with natural defoliation by larvae revealed equally low levels of yield loss by feeding of O. melanopus. Based on the experimentally derived yield loss function, we calculated economic injury levels for a range of crop values. These will serve as benchmarks in the development of IPM decision-support tools for managing cereal leaf beetles in winter wheat.

scholarly journals The Pitfalls of Relating Weeds, Herbicide Use, and Crop Yield: Don't Fall Into the Trap! A Critical Review

2020 ◽  
Vol 2 ◽  
Author(s):  
Nathalie Colbach ◽  
Sandrine Petit ◽  
Bruno Chauvel ◽  
Violaine Deytieux ◽  
Martin Lechenet ◽  
...  
Keyword(s):  
Crop Yield ◽  
Weed Management ◽  
Crop Production ◽  
Yield Loss ◽  
Crop Yields ◽  
Cropping Systems ◽  
Crop Productivity ◽  
Arable Farming ◽  
Herbicide Use ◽  
The Impact

The growing recognition of the environmental and health issues associated to pesticide use requires to investigate how to manage weeds with less or no herbicides in arable farming while maintaining crop productivity. The questions of weed harmfulness, herbicide efficacy, the effects of herbicide use on crop yields, and the effect of reducing herbicides on crop production have been addressed over the years but results and interpretations often appear contradictory. In this paper, we critically analyze studies that have focused on the herbicide use, weeds and crop yield nexus. We identified many inconsistencies in the published results and demonstrate that these often stem from differences in the methodologies used and in the choice of the conceptual model that links the three items. Our main findings are: (1) although our review confirms that herbicide reduction increases weed infestation if not compensated by other cultural techniques, there are many shortcomings in the different methods used to assess the impact of weeds on crop production; (2) Reducing herbicide use rarely results in increased crop yield loss due to weeds if farmers compensate low herbicide use by other efficient cultural practices; (3) There is a need for comprehensive studies describing the effect of cropping systems on crop production that explicitly include weeds and disentangle the impact of herbicides from the effect of other practices on weeds and on crop production. We propose a framework that presents all the links and feed-backs that must be considered when analyzing the herbicide-weed-crop yield nexus. We then provide a number of methodological recommendations for future studies. We conclude that, since weeds are causing yield loss, reduced herbicide use and maintained crop productivity necessarily requires a redesign of cropping systems. These new systems should include both agronomic and biodiversity-based levers acting in concert to deliver sustainable weed management.

Estimating Yield Losses Due to Barley Yellow Dwarf on Winter Wheat in Kansas Using Disease Phenotypic Data

2015 ◽  
Vol 16 (1) ◽  
pp. 1-6 ◽  
Author(s):  
Genna M. Gaunce ◽  
William W. Bockus
Keyword(s):  
Winter Wheat ◽  
Yield Loss ◽  
Disease Incidence ◽  
Relative Yield ◽  
Yellow Dwarf ◽  
Wheat Cultivars ◽  
Grain Yields ◽  
Barley Yellow Dwarf ◽  
Winter Wheat Cultivars ◽  
The Impact

Barley yellow dwarf (BYD) is one of the most important wheat diseases in the state of Kansas. Despite the development of cultivars with improved resistance to BYD, little is known about the impact that this resistance has on yield loss from the disease. The intent of this research was to estimate yield loss in winter wheat cultivars in Kansas due to BYD and quantify the reduction in losses associated with resistant cultivars. During seven years, BYD incidence was visually assessed on numerous winter wheat cultivars in replicated field nurseries. When grain yields were regressed against BYD incidence scores, negative linear relationships significantly fit the data for each year and for the combined dataset covering all seven years. The models showed that, depending upon the year, 19–48% (average 33%) of the relative yields was explained by BYD incidence. For the combined dataset, 29% of the relative yield was explained by BYD incidence. The models indicated that cultivars showing the highest disease incidence that year had 25–86% (average 49%) lower yield than a hypothetical cultivar that showed zero incidence. Using the models, the moderate level of resistance in the cultivar Everest was calculated to reduce yield loss from BYD by about 73%. Therefore, utilizing visual BYD symptom evaluations in Kansas coupled with grain yields is useful to estimate yield loss from the disease. Accepted for publication 1 December 2014. Published 9 January 2015.

Damage Loss Assessment and Control of the Cereal Leaf Beetle (Coleoptera: Chrysomelidae) in Winter Wheat

2004 ◽  
Vol 97 (2) ◽  
pp. 374-382 ◽  
Author(s):  
G. David Buntin ◽  
Kathy L. Flanders ◽  
Robert W. Slaughter ◽  
Zandra D. Delamar
Keyword(s):  
Winter Wheat ◽  
Leaf Beetle ◽  
Loss Assessment ◽  
Cereal Leaf Beetle ◽  
And Control

scholarly journals The effect of No-till technology on the mineral nitrogen content in the Lower Don Chernozem

2020 ◽  
Vol 169 ◽  
pp. 02014
Author(s):  
Anna Medvedeva ◽  
Olga Buryukova ◽  
Yaroslav Ilchenko ◽  
Tatyana Minkina ◽  
Roman Kamenev ◽  
...  
Keyword(s):  
Winter Wheat ◽  
Crop Yields ◽  
Nitrate Nitrogen ◽  
Mineral Nitrogen ◽  
Zero Tillage ◽  
Resource Saving ◽  
Agricultural Technologies ◽  
Rostov Region ◽  
No Till ◽  
The Impact

The paper presents the results of a five-year study of the impact of various agricultural technologies (No-till, minimum and traditional using moldboard ploughing) on the content of mineral nitrogen in Haplic Chernozem in southern zone of Rostov Region. It has been revealed that the content of ammonium and nitrate nitrogen in the winter wheat areas cultivated by various agricultural technologies does not significantly change in samples collected both in spring and in summer. However, the content of nitrate nitrogen under resource-saving technologies (both minimum and Notill) has been higher than under ploughing throughout the whole period of study. The trend identified has not been mathematically confirmed. Nevertheless, the impact of No-till technology on the intensity of ammonification and nitrification should not be unequivocally denied, since a significant amount of mineral nitrogen is extracted by crops, and their crop yields under minimum and zero tillage was higher, than when ploughing was applied.

Effect of Cereal Leaf Beetle on the Yields of Resistant and Susceptible Winter Wheat 1

Crop Science ◽  
1982 ◽  
Vol 22 (4) ◽  
pp. 836-840 ◽  
Author(s):  
J. A. Webster ◽  
D. H. Smith ◽  
R. P. Hoxie
Keyword(s):  
Winter Wheat ◽  
Leaf Beetle ◽  
Cereal Leaf Beetle
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