Effect of Ascochyta blight on the grain yield of field peas (Pisum sativum L.) grown in southern Australia

1995 ◽  
Vol 35 (4) ◽  
pp. 531 ◽  
Author(s):  
TW Bretag ◽  
PJ Keane ◽  
TV Price
Keyword(s):  
Grain Yield ◽  
Disease Severity ◽  
Field Experiments ◽  
Ascochyta Blight ◽  
Crop Loss ◽  
Yield Losses ◽  
Crop Losses ◽  
Effective Strategies ◽  
Percentage Yield ◽  
Loss Models

Field experiments were conducted to determine the crop losses caused by ascochyta blight in different pea varieties grown in Victoria. For each variety, the reduction in yield associated with disease was determined by comparing grain yields in plots not sprayed with fungicide (disease present) and plots where the disease was controlled with fungicide sprays (no disease). There was considerable variation between pea varieties and lines in disease severity and crop losses. Individual varieties had different levels of tolerance to disease, and there were large differences between varieties in the percentage yield loss caused by the same level of disease. Disease severity was closely correlated with reductions in grain yield, and for most varieties there was a 5-6% reduction in grain yield for every 10% of stem area affected by disease (first 10 internodes on the main branch). Ascochyta blight caused substantial reductions in grain yield of all commercial pea varieties grown in Victoria but was usually most severe on the early-maturing varieties. For 15 varieties, empirical crop loss models to predict the relationship between disease severity and reduction in yield were developed. A disease survey of commercial crops was then conducted and estimates made of yield losses caused by ascochyta blight using the previously developed crop loss models. The estimated yield losses caused by ascochyta blight in commercial crops in Victoria in 1986 ranged from 3.1 to 26.4% and exceeded 15% in over three-quarters of crops surveyed. The results suggest that field pea production in Victoria is seriously retarded by ascochyta blight and that the development of effective strategies to control the disease should be given a high priority.

scholarly journals The impact of cultivar resistance and fungicide treatment on mycotoxin content in grain and yield losses caused by Fusarium head blight in wheat

2010 ◽  
Vol 46 (No. 1) ◽  
pp. 21-26 ◽  
Author(s):  
V. Šíp ◽  
J. Chrpová ◽  
O. Veškrna ◽  
L. Bobková
Keyword(s):  
Grain Yield ◽  
Fusarium Head Blight ◽  
Field Experiments ◽  
Yield Loss ◽  
Joint Effect ◽  
Yield Losses ◽  
Cultivar Resistance ◽  
Head Blight ◽  
Fungicide Treatment ◽  
The Impact

Reactions to artificial infection with Fusarium graminearum isolates and a new fungicide Swing Top were studied in nine winter wheat cultivars evaluated in field experiments at two sites for three years for expression of symptoms, deoxynivalenol (DON) content in grain and grain yield. The results demonstrate a pronounced and relatively stable effect of cultivar resistance on reducing head blight, grain yield losses and contamination of grain by the mycotoxin DON. It is advantageous that the moderate level of resistance to Fusarium head blight (FHB) was detected also in two commonly grown Czech cultivars Sakura and Simila. Average fungicide efficacy for DON was 49.5% and 63.9% for a reduction in yield loss, however, it was found highly variable in different years and sites. The joint effect of cultivar resistance and fungicide treatment was 86.5% for DON and even 95.4% for reducing the yield loss. A very high risk was documented for susceptible cultivars and also the effects of medium responsive cultivars were found to be highly variable in different environments and therefore not guaranteeing sufficient protection against FHB under different conditions.

scholarly journals Relationships Between Early Wheat Streak Mosaic Severity Levels and Grain Yield: Implications for Management Decisions

Plant Disease ◽  
2017 ◽  
Vol 101 (9) ◽  
pp. 1621-1626 ◽  
Author(s):  
F. Workneh ◽  
S. O’Shaughnessy ◽  
S. Evett ◽  
C. M. Rush
Keyword(s):  
Grain Yield ◽  
Disease Severity ◽  
Water Conservation ◽  
Field Experiments ◽  
Regression Function ◽  
High Plains ◽  
Management Decisions ◽  
Texas High Plains ◽  
Severity Levels ◽  
The Impact

Wheat streak mosaic (WSM) caused by Wheat streak mosaic virus, which is transmitted by the wheat curl mite (Aceria tosichella), is a major yield-limiting disease in the Texas High Plains. In addition to its impact on grain production, the disease reduces water-use efficiency by affecting root development. Because of the declining Ogallala Aquifer water level, water conservation has become one of the major pressing issues in the region. Thus, questions are often raised as to whether it is worthwhile to irrigate infected fields in light of the water conservation issues, associated energy costs, and current wheat prices. To address some of these questions, field experiments were conducted in 2013 and 2016 at two separate locations to determine whether grain yield could be predicted from disease severity levels, assessed early in the spring, for potential use as a decision tool for crop management, including irrigation. In both fields, disease severity assessments started in April, using a handheld hyperspectral radiometer with which reflectance measurements were taken weekly in multiple plots in arbitrarily selected locations across the fields. The relationship between WSM severity levels and grain yield for the different assessment dates were determined by fitting reflectance and yield values into the logistic regression function. The model predicted yield levels with r2 values ranging from 0.67 to 0.85 (P < 0.0001), indicating that the impact of WSM on grain yield could be fairly well predicted from early assessments of WSM severity levels. As the disease is normally progressive over time, this type of information will be useful for making management decisions of whether to continue irrigating infected fields, especially if combined with an economic threshold for WSM severity levels.

Response of four annual broadleaf crops to simulated imazamethabenz spray drift

1995 ◽  
Vol 75 (3) ◽  
pp. 751-757 ◽  
Author(s):  
David A. Wall
Keyword(s):  
Field Experiments ◽  
Field Pea ◽  
Spray Drift ◽  
Wild Oat ◽  
Yield Losses ◽  
Area Index ◽  
Application Rates ◽  
Percentage Yield ◽  
Index 2 ◽  
Growing Conditions

Field experiments were conducted from 1992 to 1994 in southern Manitoba to investigate the tolerance of buckwheat, canola, field pea and lentil to simulated imazamethabenz spray drift. Imazamethabenz was applied at 0, 7.5, 15, 30, 60 and 120 g a.i. ha−1 2 wk after crop emergence when buckwheat and canola were in the two- to three-leaf stage and lentil and field pea vine length was 10 cm. Application rates corresponded to 0, 1.6, 3.1, 6.3, 12.5 and 25% of the recommended field rate for control of wild oat (482 g a.i. ha−1). At the dosages examined, buckwheat and canola leaf area index 2 and 4 wk after treatment, seed yield and thousand seed weight were unaffected. Lentil and field pea were severely injured by 60–120 g a.i. ha−1 of imazamethabenz. Injury consisted of foliar chlorosis, stunting, increased basal branching and delayed maturity. Field pea and lentil yields were reduced only at 60–120 a.i. ha−1 of imazamethabenz. At these rates, yield losses were 27–59% and 25–76% for lentil and field pea, respectively. Yield losses differed among years, with the highest percentage yield losses occurring under cold, wet growing conditions. Key words: Buckwheat (tame), canola, pea (field), lentil, spray drift, sublethal rates

scholarly journals Yields Losses Caused by Basal Plate Rot (Fusarium oxysporum f.sp. cepae) in Some Shallot Varieties

2020 ◽  
Vol 35 (2) ◽  
pp. 250
Author(s):  
Hadiwiyono Hadiwiyono ◽  
Kumala Sari ◽  
Susilo Hambeg Poromarto
Keyword(s):  
Correlation Analysis ◽  
Fusarium Oxysporum ◽  
Disease Severity ◽  
Basal Plate ◽  
Yield Losses ◽  
Crop Losses ◽  
Independent Variables ◽  
Randomized Design ◽  
Completely Randomized Design ◽  
Important Disease

Basal plate rot or moler caused by <em>Fusarium oxysporum</em> f. sp. <em>cepae</em> (FOCe) is the most important disease of shallot. However, the information of crop losses attributed to the pathogen is still limited, especially related to resistance of shallot. This paper discusses the correlation between disease severity and resistance of some shallot varieties to yield losses. The experiment was arranged by Completely Randomized Design (CRD) with six varieties of shallot as treatments, each of which consisted of 20 shallots, with three times of replications. The independent variables were the disease severity of twisting leaf and rotting of shallot bulb. The association of disease severity versus yield losses in different varieties was based on the correlation analysis. The results showed that both variables were positively correlated to yield losses, which were significantly affected by the level of resistance. Yield losses in resistant and moderate varieties were at the ranges of 2.13-4.38 and 15, 27.26-40.04, respectively.

Effects of hybrid susceptibility and inoculation timing on Goss’s bacterial wilt and leaf blight severity and corn yield

Plant Disease ◽  
2021 ◽  
Author(s):  
Elizabeth C Bauske ◽  
Andrew J Friskop
Keyword(s):  
Disease Severity ◽  
Bacterial Wilt ◽  
Field Experiments ◽  
Yield Loss ◽  
Leaf Blight ◽  
Corn Yield ◽  
Yield Losses ◽  
Sequential Combination ◽  
High Level ◽  
Growing Region

Goss’s bacterial wilt and leaf blight (Goss’s wilt) of corn is the most important corn disease in North Dakota (ND), and yield loss due to the disease has not been reliably quantified in northern corn growing regions. To help quantify the amount of yield loss caused by Goss’s wilt, a total of six field experiments were conducted from 2015 to 2017. Experiments were designed in a randomized complete block with a split plot arrangement. Hybrids served as main plots and Clavibacter nebraskensis (Cn) inoculation timings as sub-plots. Three hybrids were used and classified as a susceptible, moderately susceptible, and resistant. Inoculation timings included a non-inoculated control, six to ten leaf collars (V6 to V10), reproductive silk stage (R1), or a sequential combination of V6 to V10 and R1. A high level of disease (greater than 50% on susceptible hybrid) occurred in three experiments, a low level of disease (less than 5% on susceptible hybrid) in one experiment, and no disease was reported in two experiments. A combined analysis of the high disease experiments indicated yield losses of 34 to 41% on the susceptible hybrid when Cn inoculation occurred at V6 to V10. Yield losses of 22 to 25% occurred on the moderately susceptible hybrid when C. nebraskensis inoculation occurred at V6 to V10, and statistical differences in yield loss were not found among inoculations timings on the resistant hybrid. Correlation analyses suggest that for every 1% increase in R1 disease severity on the susceptible hybrid, yield was reduced by 117 kg/ha (1.9 bu/A). The current study further demonstrates the importance of hybrid resistance and provides updated yield loss information on Goss’s wilt in a northern corn growing region.

Agronomic Evaluation of Performance of Sesame Varieties in Maize-based Intercropping System in the Southern Guinean Savanna of Nigeria

2019 ◽  
pp. 1-10
Author(s):  
A. T. Ajibola ◽  
G. O. Kolawole
Keyword(s):  
Grain Yield ◽  
Field Experiments ◽  
Block Design ◽  
Yield Reduction ◽  
K Value ◽  
Land Equivalent Ratio ◽  
Sesame Seeds ◽  
Evaluation Of Performance ◽  
Percentage Yield ◽  
Cropping Seasons

Aims: Field experiments were conducted to determine compatibility of sesame varieties for intercropping with maize. Study Design: The experiment was a randomized complete block design with three replications. Place and Duration of Study: Teaching and Research Farm, LAUTECH, Ogbomoso, southern guinea savanna area of Nigeria during the 2010 and 2011 cropping seasons. Methodology: The treatments included Sole maize (Oba Super 1 variety), five sole sesame varieties (E-8, O3l, O1m, O2 m, Exotic-Sudan) and their intercrops, making a total of eleven treatments.  Sole maize was planted at a spacing of 75 cm x 25 cm. For intercrops, maize was planted at a spacing of 100 cm x 25  cm and sesame seeds were planted at a spacing of 100 cm x 10 cm such that sesame row alternated maize row. Maize was planted first and sesame was introduced two weeks after. Results: Intercropping maize with sesame varieties significantly (P = 0.05) reduced number of pods and grain yield of sesame varieties in both years. However, variety O2m produced grain yield in the intercrop similar to the mono crop. Generally, Intercropping sesame with maize significantly reduced the grain yield of maize by 36% compared to the sole crop. Exotic-Sudan varieties caused the highest percentage yield reduction (52%). Sesame varieties O2m and O3l were the only varieties whose yield advantage in intercropping with maize had land equivalent ratio (LER) of 1.28 and 1.18 while other varieties had values less than 1 indicating yield advantage of O2m and O3l with maize. The relative crowding coefficient (K) value of maize (4.98) was higher than sesame (0.44) thus indicating its dominance in the mixture. Conclusion: It is concluded that the prospective sesame farmers could grow varieties O2m and O3l in place of the popular E-8 because intercropping with maize did not affect their performances in both years.

Relationship between scald (Rhynchosporium secalis) and losses in grain yield of barley in Western Australia

1985 ◽  
Vol 36 (5) ◽  
pp. 655 ◽  
Author(s):  
TN Khan ◽  
MF D'Antuono
Keyword(s):  
Grain Yield ◽  
Critical Point ◽  
Western Australia ◽  
Field Experiments ◽  
Yield Loss ◽  
Growth Stages ◽  
Point Model ◽  
Percentage Yield ◽  
The Mean ◽  
Ripe Stage

The three commonly used techniques, viz. critical point model, area under the curve and multiple linear regression, were applied to study the relationship between scald infection and grain yield in field experiments conducted during 1979-1983 in Western Australia. In the preliminary analysis leaf three from the top and the mean of the top three leaves were found to be best correlated with yield. The three models did not dilfer greatly, presumably owing to the high correlations between scald at the milky ripe stage and at the earlier growth stages. The critical point model was chosen because of its simplicity. Percentage yield loss in combined data from all experiments showed a significant correlation (P < 0.001) with scald at the milky ripe stage and defined percentage yield loss in cultivars Clipper and Stirling to be about one-third of the mean scald damage on leaves 1 (flag), 2 and 3 at g.s. 75. Due to the range of trials in this analysis, it was suggested that this relationship may be applied to estimate yield loss from survey data in other parts of southern Australia, where scald is endemic.

Yield losses in canola in response to blackleg disease

2020 ◽  
Vol 100 (5) ◽  
pp. 488-494
Author(s):  
Yixiao Wang ◽  
Stephen E. Strelkov ◽  
Sheau-Fang Hwang
Keyword(s):  
Disease Severity ◽  
Field Experiments ◽  
Leptosphaeria Maculans ◽  
Economic Benefits ◽  
Control Measures ◽  
Yield Losses ◽  
Blackleg Disease ◽  
Brassica Napus L ◽  
Moderately Resistant ◽  
The Relationship

Blackleg, caused by Leptosphaeria maculans (Desm.) Ces. & De Not., is an important disease of canola (Brassica napus L.) worldwide. In Canada, blackleg is managed mainly by the cultivation of resistant or moderately resistant canola hybrids. Field experiments were conducted in Edmonton, AB, Canada, in 2017 and 2018 to determine the relationship between blackleg disease severity and yield in the moderately resistant canola hybrids ‘73-15RR’ and ‘1950RR’. Blackleg severity was rated on a 0–5 scale, where 0 = no disease and 5 = plant death. Regression analysis showed that relationships between disease severity and pod number and seed yield were best explained by second-degree quadratic equations in all site-years for both cultivars. Percentage yield loss increased by 18%–99% and 26%–86% in plants of ‘73-15RR’ and ‘1950RR’, respectively, with disease severities of 2–5 compared with plants with severities of 0–1. An improved knowledge of the relationship between blackleg severity and yield losses is important for a more accurate evaluation of the agronomic efficacy and economic benefits of control measures.

scholarly journals Measuring and Modeling Crop Loss of Wheat Caused by Septoria Leaf Blotch in Seven Cultivars and Lines in Iran

2009 ◽  
Vol 49 (3) ◽  
pp. 257-262 ◽  
Author(s):  
Shideh Mojerlou ◽  
Naser Safaie ◽  
Azizollah Alizadeh ◽  
Fatemeh Khelghatibana
Keyword(s):  
Grain Yield ◽  
Disease Severity ◽  
Integral Model ◽  
Yield Reduction ◽  
Multiple Point ◽  
Growth Stages ◽  
Research Station ◽  
Crop Loss ◽  
Septoria Leaf Blotch ◽  
Leaf Blotch

Measuring and Modeling Crop Loss of Wheat Caused by Septoria Leaf Blotch in Seven Cultivars and Lines in IranSeptoria leaf blotch caused bySeptoria tritici, is one of the most important diseases of wheat worldwide including Iran. To determine yield reduction caused by this disease in Golestan province, field experiments were carried out in randomized complete block design with four replications and five wheat cvs. Tajan, Zagros, Shiroodi, Koohdasht, Shanghai and two lines N-80-6 and N-80-19 at Gorgan Research Station. Artificial inoculation was performed using spore suspension at three growth stages (Zadoks scale) including tillering (GS 37), stem elongation (GS 45) and flag leaf opening (GS 53). Control plots were sprayed with water. In this study, the 1 000 kernel weight (TKW), grain yield and area under disease progress curve (AUDPC) during growth season were measured. Statistical analysis showed that the levels of yield reduction was different in various studied wheat cultivars and lines and was reduced by 30 to 50%. The highest losses were observed for cvs. Zagros and Tajan with 48.86% and 47.41% of grain yield reduction, respectively. There was a positive correlation between grain yield reduction and AUDPC. The results of crop loss modelling using integral and multiple point regression models showed that the integral model (L = 1230.91+1.37AUDPC) in which AUDPC and crop loss percentages were independent and dependent variables, respectively, could explain more than 95% of AUDPC variations in relation to crop loss in all cultivars in two years. In the study of integral model for each cultivar, cv. Shiroodi showed the highest fitness. In multiple point models, disease severity at various dates was considered as independent variables and crop loss percentage as dependent variable. This model with the highest coefficient of determination had the best fitness for crop loss estimation. Besides, the results showed that the disease severity at GS37, GS53 and GS91 stages (Zadok's scale) was more important for crop loss prediction than that in other phenological stages.

scholarly journals EFFECT OF BOTANICALS FOR MANAGEMENT OF LEAF BLAST AND ENHANCING YIELD TRAITS IN RICE

2018 ◽  
pp. 17-21
Author(s):  
SANDEEP PANDEY
Keyword(s):  
Grain Yield ◽  
Disease Severity ◽  
Field Experiments ◽  
Disease Incidence ◽  
Grain Weight ◽  
Panicle Length ◽  
Leaf Blast ◽  
Yield Attributes ◽  
Pooled Data ◽  
Cent Disease

Field experiments were undertaken during kharif 2012 and 2013 under irrigated ecosystem to evaluate the efficacy of botanicals along with standard fungicides for assessing per cent disease incidence, plant height, number of tiller per plant, number of spikelet per panicle, panicle length, 100-grain weight and grain yield against blast of rice. Pooled data of two years suggest that neem based commercial biopesticides with azadiractin as active ingredients were found effective in reducing disease severity and improving the yield attribute of the crop and proves promising products when compared to standard fungicides. Among the botanicals the spraying of Achook, Neem Azal T/S, Neem gold and Tricure shows significant reduction in disease severity, along with improving yield attributes, increasing the 100-grain weight and grain yield.

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