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.

STUDIES OF RECOVERY FROM ARTIFICIALLY INDUCED LODGING IN SEVERAL SIX-ROW BARLEY CULTIVARS

1990 ◽  
Vol 70 (1) ◽  
pp. 173-181 ◽  
Author(s):  
K. G. BRIGGS
Keyword(s):  
Grain Yield ◽  
Kernel Weight ◽  
Yield Reduction ◽  
Growth Stages ◽  
Research Station ◽  
Hordeum Vulgare L ◽  
Lodging Resistance ◽  
Thousand Kernel Weight ◽  
University Of Alberta ◽  
Barley Cultivars

Artificial lodging treatments were applied to several six-row barley cultivars (Hordeum vulgare L.) in 1985 and 1986 in field plots at the University of Alberta Research Station, Edmonton, to determine the effects of lodging from the milk stage to maturity. For all cultivars the largest significant reduction in grain yield was obtained from lodging induced at the milk stage (average 21% yield reduction), with later lodging resulting in relatively less yield reduction (4% at preharvest). Significant effects of lodging treatments on thousand-kernel weight and hectoliter weight followed the same pattern. Incidence of disease (mainly scald) was significantly increased by the induction of lodging in one of the two years. Final lodging scores at maturity were significantly higher the later that lodging was induced, associated with generally reduced ability to recover from lodging. In 1 year of testing, the semidwarf cultivar Duke was found to be superior to the semidwarf cultivar Samson for lodging resistance, for ability to recover from lodging applied at all stages, for grain yield, thousand-kernel weight, and for disease resistance. In both years the cultivar Johnston had very poor lodging resistance and almost no ability to recover from lodging, whereas Leduc and Klondike were intermediate for these traits. A simple artificial lodging test is proposed for obtaining improved data on the lodging resistance and lodging recoverability of new cultivars.Key words: Lodging recovery, cultivar evaluation, disease level, grade reduction, growth stages, yield

Response of wheat to single short-term waterlogging during and after stem elongation

1988 ◽  
Vol 39 (1) ◽  
pp. 11 ◽  
Author(s):  
WS Meyer ◽  
HD Barrs
Keyword(s):  
Grain Yield ◽  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Root Length ◽  
Stem Elongation ◽  
Stem Growth ◽  
Yield Reduction ◽  
Growth Stages ◽  
Short Term

Transient waterlogging associated with spring irrigations on slowly draining soils causes yield reduction in irrigated wheat. Physiological responses to short-term flooding are not well understood. The aim of this experiment was to monitor above- and below-ground responses of wheat to single waterlogging events during and after stem elongation and to assess the sensitivity of the crop at these growth stages to flooding. Wheat (cv. Bindawarra) was grown in drainage lysimeters of undisturbed cores of Marah clay loam soil. A control treatment (F0) was well-watered throughout the season without surface flooding, while three others were flooded for 96 h at stem elongation (Fl), flag leaf emergence (F2) and anthesis (F3), respectively. Soil water content, soil O2, root length density, leaf and stem growth, apparent photosynthesis (APS), plant nutrient status and grain yield were measured. Soil water content increased and soil O2 levels decreased following flooding; the rate of soil O2 depletion increasing with crop age and root length. Leaf and stem growth and APS increased immediately following flooding, the magnitude of the increases was in the order F1 >F2>F3. A similar order existed in the effect of flooding which decreased the number of roots. Subsequently, leaf and stem growth decreased below that of F0 plants in F1, and briefly in F2. Decreases in APS of treated plants compared to F0 plants appeared to be due to their greater sensitivity to soil water deficit. There was no effect of flooding on grain yield. It is suggested that, while plant sensitivity to flooding decreased with age, flooding at stem elongation had no lasting detrimental effect on yield when post-flood watering was well controlled.

Influence of number and timing of fungicide applications on the yield and quality of early and later-sown spring malting barley grown in the south-east of Ireland

2001 ◽  
Vol 136 (2) ◽  
pp. 159-167 ◽  
Author(s):  
M. J. CONRY ◽  
B. DUNNE
Keyword(s):  
Grain Yield ◽  
Disease Severity ◽  
Sowing Date ◽  
Major Effect ◽  
The Other ◽  
Growth Stages ◽  
Malting Barley ◽  
Barley Powdery Mildew ◽  
Dominant Disease

Eighteen experiments were carried out over a 6-year period (1989–94) on three different soil types to compare the effects of a broad-spectrum fungicide, applied as 1-, 2- or 3-spray programmes at different growth stages, to control foliar diseases on early and later-sown Blenheim malting barley. Powdery mildew, caused by Erysiphe graminis (Blumeria graminis) f. sp. hordei, was the dominant disease in all 6 years. Sowing date had a major effect on grain yield and ex-farm quality of the malting barley. The earlier-sown treatments gave significantly greater yield than the later-sown in 13 of the experiments, and significantly lower grain N concentrations and screenings (small grains <2·2mm) in 14 and 16 of them, respectively.Early and more frequent fungicide applications improved grain yield and reduced grain screenings but had no significant effect on grain N. Early-applied fungicide (i.e. before GS 33) was generally the most effective in controlling disease, increasing yield and reducing screenings. The magnitude of the response depended on disease severity. In those years when disease was low on the early-sown crops (1989,1991 and 1994), the early-applied 1-spray programme and 2-spray programmes increased grain yields by relatively small amounts in both early and late-sown crops. In the other 3 years (1990,1992 and 1993), when disease severity was greater, the early-applied 1-spray programme and 2-spray programmes gave much greater grain yield increments on both early and late sowings. The 3-spray fungicide programme gave the greatest yields in most of the experiments but they were not significantly greater than the best of all the other treatments. Grain screenings were reduced by fungicide applications in both early and late-sown crops, but the early-applied 1-spray programme and 2-spray programmes were generally the most effective in reducing screenings.

scholarly journals Estimating grain yield losses caused by septoria leaf blotch on durum wheat in Tunisia

2014 ◽  
Vol 74 (4) ◽  
pp. 432-437 ◽  
Author(s):  
Samia Berraies ◽  
Mohamed Salah Gharbi ◽  
Salah Rezgui ◽  
Amor Yahyaoui
Keyword(s):  
Grain Yield ◽  
Durum Wheat ◽  
Yield Losses ◽  
Septoria Leaf Blotch ◽  
Leaf Blotch

scholarly journals Fungicides against diseases of lawn grass leaves

2019 ◽  
pp. 7-9
Author(s):  
S. Retman ◽  
O. Nychyporuk ◽  
О. Shevchuk
Keyword(s):  
Powdery Mildew ◽  
Technical Efficiency ◽  
Disease Severity ◽  
Growing Season ◽  
Disease Spread ◽  
Septoria Leaf Blotch ◽  
Leaf Blotch ◽  
Chemical Groups ◽  
Positive Effect

Goal. To evaluate the effectiveness of the use of fungicides of various chemical groups against the leaf diseases turfgrass. Methods. The research was carried out in 2015—2017 on the lawn mixture «Universal» in the zone of the Polissya of Ukraine. The effect of fungicides of various chemical groups was investigated (Impact T, SC; Bumper Super, EC; Amistar Extra 280 SC, SC; Alto Super 300 EC, EC; Maxim 025 FS, FS; Horus 75 WG, WG). Fungicides were applied twice. The first spraying was carried out when development of diseases in control plot reached 3—5%, the second — in 30 days. The assessments were performed according to generally accepted methods, disease spread, disease severity and technical efficiency of pesticides were determined. Results. During the period of research, the most common leaf diseases of turfgrass, which eveloped annually and had a significant severity during the growing season, were powdery mildew and septoria leaf blotch. After two-time spraying, the technical efficiency of fungicides against powdery mildew reached 82.2—92.2%, against septoria leaf blotch up to 80.2%. The most effective against powdery mildew was the use of Alto Super 330 EC, EC (0.5 l / ha), Amistar Extra 280 SC, SC (0.75 l / ha) and tank mixture of Maxim 025 FS, FS (0.75 l / ha and 1.0 l / ha) with Horus 75 WG, VH (0.6 kg / ha). Against the septoria leaf blotch, the highest efficiency was shown by Alto Super 330 EC, EC (0.5 l / ha), Bumper Super, EC (0.8 l / ha) and Maxim 025 FS, FS (1.0 l / ha) + Horus 75 WG, WG (0.6 kg / ha). In addition, due to the reduction of disease severity, a positive effect of fungicides on the quality of the lawn was achieved and the projective coating increased to 92—93%. Conclusion. The use of fungicides contributes to the reduction of disease and the formation of quality herbs. The best indicators against flour dew and septoriosis of leaves were obtained for the treatment of Alto Super 330 EC, CE (0.5 l / ha) and tank Maxim 025 FS, tc.s. (1.0 l / ha) + Horus 75 WG, VH (0.6 kg / ha).

scholarly journals Control of speckled leaf blotch of wheat with fungicides

2000 ◽  
Vol 53 ◽  
pp. 103-108
Author(s):  
M.G. Cromey ◽  
M. Braithwaite ◽  
B.J.R. Alexander ◽  
S. Ganev ◽  
T.R. Cookson
Keyword(s):  
Disease Severity ◽  
Total Yield ◽  
Field Trials ◽  
Growth Stages ◽  
The South ◽  
Leaf Blotch ◽  
Fungicide Application ◽  
Low Levels ◽  
Disease Pressure

Two field trials were conducted in autumnsown wheat cv Domino which is highly susceptible to speckled leaf blotch in Central and South Canterbury Eighteen fungicide treatments were applied at two growth stages (tillering and ear emergence) at the manufacturers recommended rates Severity of speckled leaf blotch and other diseases was assessed on several occasions Speckled leaf blotch was severe in the South Canterbury trial but only low levels of the disease were recorded in the central Canterbury trial Most fungicides reduced disease severity and increased yield especially in the South Canterbury trial where disease pressure was highest and yield increases greater than 30 were recorded The second fungicide application appeared to provide most of the increase in yield The increases in thousand grain weights following fungicide applications contributed approximately onethird of the total yield increases in the South Canterbury trial and half in the Central Canterbury trial

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 Physiochemical Changes of Mung Bean [Vigna radiata (L.) R. Wilczek] in Responses to Varying Irrigation Regimes

Horticulturae ◽  
2021 ◽  
Vol 7 (12) ◽  
pp. 565
Author(s):  
Mohammad Rafiqul Islam ◽  
Mohd. Mostofa Kamal ◽  
Mohammad Ashraful Alam ◽  
Jamil Hossain ◽  
Walid Soufan ◽  
...  
Keyword(s):  
Water Stress ◽  
Seed Yield ◽  
Mung Bean ◽  
Agricultural Research ◽  
Photosynthetic Pigment ◽  
Yield Reduction ◽  
Growth Stages ◽  
Research Station ◽  
Flowering Stage ◽  
Drought Tolerant

Mungbean is one of the most powerful pulses providing substantial protein for human diets and fixing N to the soil, improving nutritional food security and agricultural sustainability. The production of summer mungbean in the tropics and subtropics is adversely affected by drought due to water scarcity caused by various factors as well as lack of rainfall. Irrigation at different growth phases is not a suitable solution. An environmentally friendly and economically viable answer is a convenient irrigation management option that will be available to farmers together with drought-tolerant genotypes. The study considered to determine the effect of differences between drought-tolerant and drought susceptible genotypes on water productivity response and physiological traits in mung beans. To quantify seed yield-related to irrigation at different growth stages eventually to quickly determine the most appropriate irrigation stage. One water stress tolerant mung bean genotype (BMX-08010-2) and one sensitive genotype (BARI Mung-1) were grown in the field with four different irrigation schedules along with water stress conditions (no irrigation) under rain shelter at Regional Agricultural Research Station, BARI, Ishwardi, Pabna, Bangladesh. The experiment was laid out in split plots with three replications, with irrigation schedules assigned in the main plot and mung bean genotypes assigned in the side plots. Water use efficiency ranged from 3.79 to 4.68 kg ha−1 mm−1 depending on irrigation regime, and mung bean seed yield of mung bean Water stress decreased plant water status, photosynthetic pigment and membrane stability index, and increased proline soluble sugar content. Treatments that received irrigation during two or three phases (I3 or I4) gave significantly higher yields than those that received irrigation during only one stage (I1 and I2) with the lowest yield. While the yield obtained ranged between 1145.44 kg ha−1 with seasonal irrigation of 277 mm (I4) and 555.14 kg ha−1 without irrigation (I0). The flowering stage (I3) was recorded as the most sensitive growth stage with an 18.15% yield reduction compared to the treatment with triple irrigation (I4). Also, depending on the irrigation sources, at least two irrigation phases should be provided at the triple leaf stage (I2, i.e., 20 DAS) and at the flowering stage (I3, i.e., 35 DAS) to achieve the highest yield. Genotypes that maintained the higher performance of physicochemical traits under water stress provided higher seed yield and promoted drought tolerance. Therefore, these parameters can be used as physiological and biochemical markers to identify and develop superior genotypes suitable for drought-prone environments.

scholarly journals Effect of nitrogen fertilizer application timing on nitrogen use efficiency and grain yield of winter wheat in Ireland

2016 ◽  
Vol 55 (1) ◽  
pp. 63-73 ◽  
Author(s):  
A. Efretuei ◽  
M. Gooding ◽  
E. White ◽  
J. Spink ◽  
R. Hackett
Keyword(s):  
Winter Wheat ◽  
Grain Yield ◽  
Plant Density ◽  
Fertilizer Application ◽  
Yield Reduction ◽  
Growth Stages ◽  
Fertilizer N ◽  
N Application ◽  
Application Timing ◽  
Use Efficiency

Abstract The objectives of this work were to determine the effects of initiating application of fertilizer nitrogen (N) to winter wheat at different growth stages (GSs) on grain yield and N use efficiency (NUE). A factorial experiment was carried out in two growing seasons (2011 and 2012) with five timings of first N application (GS 24/26 [tillering], GS 30, GS 31, GS 32 or GS 37) and an unfertilized control, two sowing densities (100 and 400 seeds/m2) and a cattle slurry treatment (with or without slurry). The latter was included to simulate variation in soil N supply (SNS). Delaying the first application of N from the tillering stage until GS 30 had no significant effect on grain yield in either year. Further delaying the initial N application until GS 31 caused a significant yield reduction in 2011, in comparison to GS 30 application, but not in 2012. Differences in efficiency of recovery and use of fertilizer N by the crop among the first three application timings were small. There was no evidence to support alteration in the timing of the first application of N in response to low plant density. Slurry application did not influence SNS, so the interaction between SNS and fertilizer N application timing could not be determined. It is concluded that in order to maximise yield and NUE, the first N application should be applied to winter wheat between late tillering and GS 30 and that delaying the first N until GS 31 can lead to yield reductions compared to the yield obtained with earlier application.

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