Effect of Seeding Date of Winter Wheat on Incidence, Severity, and Yield Loss Caused by Cephalosporium Stripe in Kansas

Plant Disease ◽  
1984 ◽  
Vol 68 (8) ◽  
pp. 665 ◽  
Author(s):  
Peter J. Raymond
Keyword(s):  
Winter Wheat ◽  
Yield Loss ◽  
Seeding Date

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.

scholarly journals Environmental Conditions Associated with Stripe Rust in Kansas Winter Wheat

Plant Disease ◽  
2016 ◽  
Vol 100 (11) ◽  
pp. 2306-2312 ◽  
Author(s):  
B. S. Grabow ◽  
D. A. Shah ◽  
E. D. DeWolf
Keyword(s):  
Soil Moisture ◽  
Winter Wheat ◽  
Stripe Rust ◽  
Yield Loss ◽  
Initial Step ◽  
Disease Forecasting ◽  
Estimation Equations ◽  
Forecasting System ◽  
Moisture Conditions ◽  
General Estimation

Stripe rust has reemerged as a problematic disease in Kansas wheat. However, there are no stripe rust forecasting models specific to Kansas wheat production. Our objective was to identify environmental variables associated with stripe rust epidemics in Kansas winter wheat as an initial step in the longer-term goal of developing predictive models for stripe rust to be used within the state. Mean yield loss due to stripe rust on susceptible varieties was estimated from 1999 to 2012 for each of the nine Kansas crop reporting districts (CRD). A CRD was classified as having experienced a stripe rust epidemic when yield loss due to the disease equaled or exceeded 1%, and a nonepidemic otherwise. Epidemics were further classified as having been moderate or severe if yield loss was 1 to 14% or greater than 14%, respectively. The binary epidemic categorizations were linked to a matrix of 847 variables representing monthly meteorological and soil moisture conditions. Classification trees were used to select variables associated with stripe rust epidemic occurrence and severity (conditional on an epidemic having occurred). Selected variables were evaluated as predictors of stripe rust epidemics within a general estimation equations framework. The occurrence of epidemics within CRD was linked to soil moisture during the fall and winter months. In the spring, severe epidemics were linked to optimal (7 to 12°C) temperatures. Simple environmentally based stripe rust models at the CRD level may be combined with field-level disease observations and an understanding of varietal reaction to stripe rust as part of an operational disease forecasting system in Kansas.

Downy Brome (Bromus tectorum) Interference and Economic Thresholds in Winter Wheat (Triticum aestivum)

Weed Science ◽  
1990 ◽  
Vol 38 (3) ◽  
pp. 224-228 ◽  
Author(s):  
Phillip W. Stahlman ◽  
Stephen D. Miller
Keyword(s):  
Winter Wheat ◽  
Bromus Tectorum ◽  
Yield Loss ◽  
Wheat Yield ◽  
Dry Weight ◽  
Quadratic Equation ◽  
Downy Brome ◽  
Economic Threshold ◽  
Weed Density ◽  
Economic Thresholds

Densities up to 100 downy brome m2were established in winter wheat in southeastern Wyoming and west-central Kansas to quantify wheat yield loss from downy brome interference and to approximate economic threshold levels. A quadratic equation best described wheat yield loss as a function of weed density when downy brome emerged within 14 days after wheat emergence. Densities of 24, 40, and 65 downy brome m2reduced wheat yield by 10, 15, and 20%, respectively. Wheat yield was not reduced when downy brome emerged 21 or more days later than wheat. Economic thresholds varied with changes in downy brome density, cost of control, wheat price, and potential wheat yield. In a greenhouse experiment, dry weight of 72-day-old wheat plants grown in association with downy brome was not affected by the distance between the weeds and wheat, whereas downy brome plant dry weight increased with increasing distance between the weeds and wheat.

Seeding Date, Seeding Rate, and Row Spacing Affect Wheat (Triticum aestivum) and Cheat (Bromus secalinus)

1991 ◽  
Vol 5 (4) ◽  
pp. 707-712 ◽  
Author(s):  
Jeffrey A. Koscelny ◽  
Thomas F. Peeper ◽  
John B. Solie ◽  
Stanley G. Solomon
Keyword(s):  
Triticum Aestivum ◽  
Winter Wheat ◽  
Field Experiments ◽  
Wheat Yield ◽  
Row Spacing ◽  
Infestation Level ◽  
Seeding Rate ◽  
Seeding Date ◽  
Bromus Secalinus ◽  
Winter Wheat Yield

Field experiments were conducted in Oklahoma to determine the effects of winter wheat seeding date and cheat infestation level on cultural cheat control obtained by increasing winter wheat seeding rates and decreasing row spacing. Seeding rate and row spacing interactions influenced cheat density, biomass, or seed in harvested wheat (dockage) at two of three locations. Suppressive effects on cheat of increasing wheat seeding rates and reduced row spacings were greater in wheat seeded in September than later. At two other locations, increasing seeding rate from 67 to 101 kg ha–1or reducing row spacings from 22.5 to 15 cm increased winter wheat yield over a range of cheat infestation levels.

INFLUENCE OF SPRING SEEDING DATE ON YIELD LOSS FROM ROOT ROT OF BARLEY

1976 ◽  
Vol 56 (3) ◽  
pp. 741-743 ◽  
Author(s):  
H. W. JOHNSTON
Keyword(s):  
Root Rot ◽  
Yield Loss ◽  
Seeding Date

not available

Economic Returns from Cheat (Bromus secalinus) Control in Winter Wheat (Triticum aestivum)

1990 ◽  
Vol 4 (2) ◽  
pp. 306-313 ◽  
Author(s):  
Kenneth L. Ferreira ◽  
Thomas F. Peeper ◽  
Francis M. Epplin
Keyword(s):  
Triticum Aestivum ◽  
Economic Analysis ◽  
Winter Wheat ◽  
Field Experiments ◽  
Control Strategies ◽  
Economic Returns ◽  
Forage Production ◽  
Net Returns ◽  
Seeding Date ◽  
Bromus Secalinus

Field experiments were conducted to determine the influence of winter wheat seeding date and forage removal on the efficacy of cheat control herbicides, forage and grain yields, and net returns to land, overhead, risk, and management for the various cheat control strategies. Economic analysis showed that net returns were higher when wheat was seeded during the traditional seeding period (October) than when either seeded early (September) for increased forage production or delayed (November) for cultural cheat control. Some herbicides were economically beneficial at two of three locations where the initial cheat population exceeded 170 plants/m2.

CEPHUS PYGMAEUS INFLUENCE FOR SOFT WINTER WHEAT ELEMENTS YIELD IN THE FOREST SAMARA REGION

2016 ◽  
Vol 1 (1) ◽  
pp. 57-60
Author(s):  
Лысиков ◽  
Pavel Lysikov
Keyword(s):  
Winter Wheat ◽  
Yield Loss ◽  
Weather Conditions ◽  
Science Research ◽  
Stem Borer ◽  
Stem Length ◽  
Sawfly Larvae ◽  
Grain Productivity ◽  
Meso Form ◽  
Soft Winter Wheat

The purpose of the study is to reduce yield loss of winter wheat crops infested with stem borer. The studies were conducted in the forest of the Samara region in the vicinity of st. Ust-Kinelsky in 2011, 2012 and 2014. in the fields of the Povolzsje Science Research Institute of selection and seeds production of P. N. Konstantinov with the meso form of the relief at the landscape profile length of about 8 m to 4 varieties of soft winter wheat: Povolgskaya 86, Kinelskay 8, Kinelskay 4 and Konstantinovskaya (Erythrospermum). The damage of productive stalks of wheat sawfly larvae was 0.5-1.2%, peaking at an average of weather conditions in 2012, the minimum – in a relatively arid 2014 and depended on the plant population, sawflies favored more sparse crops with a correlation coefficient In 2011, 2012 –0,472- –0.480, –0.734 – in 2014. Under the influence of the sawfly larvae damaged ear stem length was reduced by no more than 5.2, the number of grains per ear – 14.4, the weight of grain in the ear – 14.4, weight of 1000 seeds – 15,2%. The largest decrease in the length of the spike observed in average weather conditions for 2012, the number and grains weight per ear – in a wet 2011, the mass of 1000 grains – in the dry 2014 from wet to dry years, the harmfulness of the sawfly increased from an average to the bottom of the slope. The smallest decrease in all indicators of productivity observed in the upper part of the slope. The number of adults cephus pygmaeus in all parts of the slopes were almost equally low (0.2-0.4 ind./100 net sweeps). The cephus pygmaeus loss of of wheat grain productivity were minor and were 3-35 kg/h.

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