Comparison of the climate indices based on the relationship between yield loss of rain-fed winter wheat and changes of climate indices using GEE model

Abstract Cereal yield loss from eyespot directly depends on the severity of the disease. The aim of this study was to establish the relationship between eyespot damage in winter wheat and components of yield of winter wheat cultivars Ada, Mulan and Tukan in Lithuania in the 2011/2012 cropping season. Several eyespot did not decrease the grain number per ear cv. of Tukan while for cvs. Ada and Mulan the decrease was 14 and 15%, respectively; however, the grain number per ear of moderately eyespot-affected stems of cv. Ada did not differ from that of visually healthy stems. For cv. Ada, the grain weight per ear of moderately affected stems was 5.8% less and that of severely affected stems was 12.8% less than that of healthy stems, while for cv. Mulan the decrease in grain weight per ear was 40.3 and 35.5%, respectively and for cv. Tukan it was 59.0 and 63.2%, respectively for moderately and severely affected stems. The decrease in thousand grain weight of moderately eyespot-affected stems of cv. Ada was less (6.5%) compared with that of cv. Mulan (31.3%) and cv. Tukan (55.8%). Thousand grain weight of severely eyespot-affected stems of cvs. Ada, Mulan and Tukan was 22.2, 26.0, and 65.0%, respectively, less than that of healthy stems. Screening of healthy, moderately and severely affected plants of the winter wheat varieties Ada, Mulan and Tukan for grain number per ear, grain weight per ear and TGW revealed that these varieties differed in tolerance to eyespot

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Yield Loss Caused by Bacterial Streak in Winter Wheat

Plant Disease ◽

10.1094/pdis.1999.83.7.609 ◽

1999 ◽

Vol 83 (7) ◽

pp. 609-614 ◽

Cited By ~ 6

Author(s):

B. L. Tillman ◽

W. S. Kursell ◽

S. A. Harrison ◽

J. S. Russin

Keyword(s):

Winter Wheat ◽

Yield Loss ◽

Regression Line ◽

Weather Conditions ◽

Grain Weight ◽

Disease Development ◽

Susceptible Cultivar ◽

Field Plot ◽

The Relationship ◽

Field Plots

The relationship between severity of bacterial streak and yield in winter wheat was studied in field plots and using a single-tiller method. Regression analysis from single-tiller studies showed that the grain weight per spike decreased as bacterial streak severity increased in cvs. Florida 304 and Savannah. The number of kernels per spike decreased as bacterial streak severity increased in Savannah but not in Florida 304. There was no difference in slope of the regression line between different years, locations, or cultivars for grain weight per spike. However, grain weight per spike at 0% bacterial streak (intercept) was different for different years, locations, and cultivars. The average reduction in grain weight per spike was 0.012 g for every 1% increase in bacterial streak severity. Using this relationship for cv. Savannah, average bacterial streak severity of 10% would result in about a 9% reduction in the grain weight per spike. In Florida 304, bacterial streak severity of 10% would result in about a 7% reduction in the grain weight per spike. During 1993-94, the largest difference in bacterial streak severity between inoculated and noninoculated plots was 4% in cv. Pioneer 2548, and the smallest difference was less than 1% in cvs. Terral 101 and Florida 304. There were no yield differences between inoculated and noninoculated treatments for any genotype. In field plot studies at two locations during 1989-90, bacterial streak severity did not differ between inoculated and noninoculated plots in Alexandria, Louisiana; but in Winnsboro, Louisiana, bacterial streak severity was 18 to 40% in inoculated plots and less than 5% in noninoculated plots. Differences in yield between inoculated and noninoculated plots ranged from 1,370 kg/ha (24% loss) to -121 kg/ha in Winns-boro. During the three seasons in which these studies were conducted, bacterial streak severity averaged about 10% or less in susceptible cultivars in all experiments except one. Based on the relationships derived from single-tiller studies, this suggests that yield loss is likely to be low most years. As indicated by the experiment in Winnsboro, however, more severe yield reductions could occur in a susceptible cultivar if weather conditions are favorable for disease development.

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Quantification of the relationship between the environment and Fusarium head blight, Fusarium pathogen density, and mycotoxins in winter wheat in Europe

European Journal of Plant Pathology ◽

10.1007/s10658-012-9968-6 ◽

2012 ◽

Vol 133 (4) ◽

pp. 975-993 ◽

Cited By ~ 23

Author(s):

Alissa B. Kriss ◽

Pierce A. Paul ◽

Xiangming Xu ◽

Paul Nicholson ◽

Fiona M. Doohan ◽

...

Keyword(s):

Winter Wheat ◽

Fusarium Head Blight ◽

Head Blight ◽

The Relationship

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

Plant Health Progress ◽

10.1094/php-rs-14-0039 ◽

2015 ◽

Vol 16 (1) ◽

pp. 1-6 ◽

Cited By ~ 9

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.

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Relationship between the precipitation variability in Montenegro and the Mediterranean oscillation

Glasnik srpskog geografskog drustva ◽

10.2298/gsgd1404109b ◽

2014 ◽

Vol 94 (4) ◽

pp. 109-120 ◽

Cited By ~ 1

Author(s):

Dragan Buric ◽

Vladan Ducic ◽

Jovan Mihajlovic ◽

Jelena Lukovic ◽

Jovan Dragojlovic

Keyword(s):

Human Factor ◽

General Idea ◽

Climate Indices ◽

Intensity Increase ◽

Negative Consequences ◽

Teleconnection Patterns ◽

The Mediterranean ◽

Mediterranean Oscillation ◽

The Relationship ◽

The Mediterranean Basin

This study investigates the influence of atmospheric circulation in the Mediterranean region on the precipitation in Montenegro. Nine precipitation parameters have been used in the analysis and the relationship has been investigated by the Mediterranean and West Mediterranean Oscillation change index (MO and WeMO). According to a 60 - year observed period (1951-2010), the research results show that nothing characteristic happens with seasonal and annual precipitation sums because the trend is mainly insignificant. However, precipitation extremes are getting more extreme, which corresponds with a general idea of global warming. Negative consequences of daily intensity increase and frequency of precipitation days above fixed and percentile thresholds have been recorded recently in the form of torrents, floods, intensive erosive processes, etc., but it should be pointed out that human factor is partly a cause of such events. The estimate of the influence of teleconnection patterns primarily related to the Mediterranean Basin has shown that their variability affects the observed precipitation parameters on the territory of Montenegro regarding both seasonal and annual sums and frequency and intensity of extreme events shown by climate indices.

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Growth and clorophyll content dynamics of winter wheat (Triticum aestivum L.) in different cropyear

Acta Agraria Debreceniensis ◽

10.34101/actaagrar/53/2137 ◽

2013 ◽

pp. 101-105

Author(s):

Enikő Vári

Keyword(s):

Winter Wheat ◽

Grain Filling ◽

Triticum Aestivum L ◽

Area Index ◽

Rotation System ◽

Crop Rotation System ◽

Two Parameters ◽

The University ◽

The Relationship

The experiments were carried out at the Látókép experimental station of the University of Debrecen on chernozem soil in a long term winter wheat experiment in the season of 2011 and 2012 in triculture (pea-wheat-maize) and biculture (wheat-maize) at three fertilisation levels (control, N50+P35K40, N150+P105K120). Two different cropyears were compared (2011 and 2012). The research focused on the effects of forecrop and fertilisation on the Leaf Area Index, SPAD values and the amount of yield in two different cropyears. We wanted to find out how the examined parameters were affected by the cropyear and what the relationship was between these two parameters and the changes of the amount of yield. Examining the effects of growing doses of fertilizers applied, results showed that yields increased significantly in both rotations until the N150+PK level in 2011 and 2012. By comparing the two years, results show that in 2011 there was a greater difference in yields between the rotations (7742 kg ha-1 at N150+PK in the biculture and 9830 kg ha-1 at N150+PK in the triculture). Though wheat yields following peas were greater in 2012, results equalized later on at N150+PK levels (8109–8203 kg ha-1). Due to the favorable agrotechnical factors, the leaf and the effects of the treatments grown to a great extent in 2011, while in 2012 the differences between treatments were moderate. Until the N150+PK level, nitrogen fertilisation had a notable effect on the maximum amount of SPAD values (59.1 in the case of the biculture and 54.0 in the triculture). The highest SPAD values were measured at the end of May (during the time of flowering and grain filling) in the biculture. In the triculture, showed high SPAD values from the beginning. The same tendency could be observed in the 2012 cropyear, although increasing doses of fertilizers resulted in higher SPAD values until N150+PK level only from the second measurement. Maximum SPAD values were reached at the end of May in both crop rotation system

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Biodiversity of Segetal Weed Communities when Chlorsulfuron-Based Weed Control is Being Used on Continuous Winter Wheat

Journal of Plant Protection Research ◽

10.2478/jppr-2014-0045 ◽

2014 ◽

Vol 54 (3) ◽

pp. 300-305

Author(s):

Zbigniew Pawlonka ◽

Katarzyna Rymuza ◽

Krzysztof Starczewski ◽

Antoni Bombik

Keyword(s):

Winter Wheat ◽

Initial Study ◽

Short Term ◽

Weed Communities ◽

The Status ◽

Weed Infestation ◽

Weedy Species ◽

The Relationship ◽

Experimental Plots ◽

Segetal Communities

Abstract The purpose of the study was to determine the relationship between herbicide rate and weed community biodiversity in continuous wheat. A six-year field experiment was conducted to examine the effect of four chlorsulfuron rates in comparison with untreated (the control) plots, on the status and severity of weed infestation - in successive study years of cultivating winter wheat in monoculture. In addition, the following indices were calculated: Shannon-Wiener and Simpson’s index of biodiversity, and Simpson’s index of domination. A total of 36 weedy species were identified in the experimental plots. The richest segetal communities were established in the control plots. An application of herbicide reduced the biodiversity of the agrophytocensosis. A short-term monoculture did not impoverish the species richness of the weed community established in winter wheat. The average number of species in the community was significantly greater in the second study year. In the initial study years of monoculture, the biodiversity of the segetal community increased markedly compared with rotation-based cultivation. The calculated indices of biodiversity were not significantly affected by herbicide rate or monoculture but the indices confirmed the trends outlined by an analysis of the status and level of weed infestation.

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Environmental Conditions Associated with Stripe Rust in Kansas Winter Wheat

Plant Disease ◽

10.1094/pdis-11-15-1321-re ◽

2016 ◽

Vol 100 (11) ◽

pp. 2306-2312 ◽

Cited By ~ 5

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.

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Pre-anthesis development of winter wheat and barley and relationships with grain yield

Plant Soil and Environment ◽

10.17221/202/2018-pse ◽

2018 ◽

Vol 64 (No. 7) ◽

pp. 310-316 ◽

Cited By ~ 1

Author(s):

Mirosavljevic Milan ◽

Momcolovic Vojislava ◽

Maksimovic Ivana ◽

Putnik-Delic Marina ◽

Pržulj Novo ◽

...

Keyword(s):

Winter Wheat ◽

Grain Yield ◽

Sowing Date ◽

Wheat Cultivars ◽

Growing Seasons ◽

Sowing Dates ◽

Winter Wheat Cultivars ◽

Leaf Appearance ◽

Relationship Of ◽

The Relationship

The aim of this study was to improve understanding of (1) the effect of genotypic and environmental factors on pre-anthesis development and leaf appearance traits of barley and wheat; (2) the relationship of these factors with grain yield, and (3) the differences between these two crops across different environments/sowing dates. Therefore, trials with six two-row winter barley and six winter wheat cultivars were carried out in two successive growing seasons on four sowing dates. Our study showed that the observed traits varied between species, cultivars and sowing dates. In both growing seasons, biomass at anthesis and grain yield declined almost linearly by delaying the sowing date. There was no clear advantage in grain yield of wheat over barley under conditions of later sowing dates. Generally, barley produced more leaf and had shorter phyllochron than wheat. Both wheat and barley showed a similar relationship between grain yield and different pre-anthesis traits.

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

Weed Science ◽

10.1017/s0043174500056447 ◽

1990 ◽

Vol 38 (3) ◽

pp. 224-228 ◽

Cited By ~ 40

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.

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