scholarly journals Effect of Septoria brown spot on soybean yield in Illinois

2019 ◽  
Author(s):  
Heng-An Lin ◽  
María B. Villamil ◽  
Santiago X. Mideros
Keyword(s):  
Disease Severity ◽  
Critical Factor ◽  
Brown Spot ◽  
Linear Predictor ◽  
Soybean Yield ◽  
Best Linear Predictor ◽  
Effect On Yield ◽  
Yield Responses ◽  
Production Areas ◽  
Different Levels

AbstractBrown spot caused by Septoria glycines is a prevalent foliar disease in all soybean production areas. Application of foliar fungicides after bloom reduces the disease severity, yet yield responses are not consistent among locations and years. Our research goal was to determine the effect of different levels of Septoria brown spot on yield. Different levels of disease severity were effectively obtained in the field by weekly application of chlorothalonil for three, six, and nine times after disease inoculation at V3/V4 stage. Fungicide treatments had a significant effect on vertical progress and chlorotic area with no statistically significant effect on yield. Soybean yield was negatively correlated with vertical progress of the disease (r = −0.36). The vertical progress was the best linear predictor of yield. Based on this model, when the vertical progress of brown spot at R6 increased by 10%, the yield decreased by 142.13 kg/ha (3.4%). A variance component analyses of our data showed that location was the most critical factor, illustrating the significant effect of local environmental conditions on the disease. Power analyses indicated that at least eight locations are needed to detect an effect of 269 kg/ha. Our results provide useful information to improve the experimental design for future experiments addressing the yield constrain by late season diseases of soybean.

Effect of Pleiochaeta setosa on field responses of Lupinus angustifolius and L. luteus to applications of phosphorus

2001 ◽  
Vol 41 (4) ◽  
pp. 549 ◽  
Author(s):  
M. D. A. Bolland ◽  
M. W. Sweetingham ◽  
R. J. Jarvis
Keyword(s):  
Grain Yield ◽  
Lupinus Angustifolius ◽  
Brown Spot ◽  
Triple Superphosphate ◽  
Resting Spores ◽  
P Application ◽  
Effect On Yield ◽  
Yield Responses ◽  
Moderately Resistant ◽  
P Addition

The effect of the fungus Pleiochaeta setosa on grain yield responses of lupins to applications of phosphorus (P) fertiliser (0–40 kg P/ha as triple superphosphate banded 80 mm below seed while sowing at 40 mm) was measured for 4 lupin cultivars that differed in reaction to the pathogen: Lupinus angustifolius cv. Merrit (susceptible), cv. Tallerack (moderately resistant), cv. Myallie (resistant) and L. luteus cv. Teo (very resistant). Variable levels of P. setosa inoculum (as resting spores in the soil) were generated by different rotations. Disease levels of lupin foliage were manipulated by either burning or retention of the previous wheat (Triticum aestivum) stubble. The severity of brown spot (caused by P. setosa infecting the foliage) was influenced by the previous rotation, by the stubble treatment, and by the susceptibility of each lupin cultivar to the disease. Pleiochaeta setosa was least in and had little or no effect on yield of the very resitant Teo, but P. setosawas greatest and decreased yields most in the susceptible Merrit. Where grain yields were affected by P. setosa, there were increases in grain yield with increasing amounts of P applied. For Merrit, Tallerack and Myallie, grain yield responses to P addition tended to increase with increasing disease. Grain yield increases to P application were greatest for Merrit with the highest P. setosa level, and were least for L. luteus cv. Teo with the lowest P. setosa level.

Efficacy of Different Level of Systemic Fungicides on Management of Rice Blast at Baitadi, Nepal

2020 ◽  
Vol 7 ◽  
pp. 33-42
Author(s):  
Ashok Acharya ◽  
Prabin Ghimire ◽  
Dhurba Raj Joshi ◽  
Kishor Shrestha ◽  
Govinda Sijapati ◽  
...  
Keyword(s):  
Disease Severity ◽  
Rice Blast ◽  
Fungal Pathogens ◽  
Block Design ◽  
Rice Variety ◽  
Disease Suppression ◽  
Systemic Fungicide ◽  
Disease Development ◽  
Systemic Fungicides ◽  
Different Levels

Rice blast (Pyriculariaoryzae Cavara) is one of the most devastating diseases affecting the rice crop in across the world. Systemic fungicides are used for the suppression of blast diseases caused by fungal pathogens. Propiconazole and Carbendazim are commercial chemical control products available in markets for the control of the fungal pathogen. An experiment was conducted to examine the effectiveness of systemic fungicide on suppression of rice blast incidence in farmers' field during wet seasons in 2016. The treatments consisted of the use of different levels of propiconazole and Carbendazim on ‘Rato Basmati’ a landrace rice variety. The experiments were arranged in a randomized complete block design with three replications. The disease was scored according to the standard scale developed by the International Rice Research Institute (IRRI). Disease severity and Area under Disease Progressive curve (AUDPC) was computed based on that scale score. Propiconazole and Carbendazim at different levels reduce disease development than no treatment (control). But its efficacy was not consistent. The magnitude of disease suppression by Propiconazole was high as compared to Carbendazim. The application of propiconazole at the rate of 1.5 ml effectively reduced disease severity and AUDPC at different dates. So propiconazole at the rate of 1.5 ml thrice at weekly intervals is effective to reduce the disease development

scholarly journals Summer Heat and Low Soil Organic Matter Influence Severity of Hazelnut Cytospora Canker

2014 ◽  
Vol 104 (4) ◽  
pp. 387-395 ◽  
Author(s):  
Jay Ram Lamichhane ◽  
Alfredo Fabi ◽  
Leonardo Varvaro
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Disease Severity ◽  
Severity Index ◽  
Stress Factors ◽  
Disease Severity Index ◽  
Positive Correlation ◽  
Summer Heat ◽  
Production Areas ◽  
Cytospora Canker

Cytospora canker, caused by the fungus Cytospora corylicola, is present in hazelnut production areas worldwide. The disease is widespread throughout the main production areas of Italy. The causal agent is considered to be a secondary invader of damaged tissue that attacks mainly stressed plants. However, little is known of disease severity and stress factors that predispose plants to infection. In particular, the role of pedoclimatic factors was investigated. Direct survey indicated that disease severity varied across several study sites. Geostatistics showed a strong positive correlation between disease severity index and summer heat (r = 0.80 and 0.91 for July and August, respectively) and strong negative correlation between disease severity index and soil organic matter (r = –0.78). A moderate positive correlation between disease severity index and magnesium/potassium ratio (r = 0.58) and moderate negative correlations between disease severity index and total soil nitrogen (r = –0.53), thermal shock (r = –0.46), and rainfall (r = –0.53) were determined. No significant correlation between disease severity index and soil aluminum (r = –0.35), soil pH (r = –0.01), and plant age (r = –0.38) was found.

scholarly journals Brown spot disease severity, yield and yield loss relationships in pigmented upland rice cultivars from East Nusa Tenggara, Indonesia

2020 ◽  
Vol 21 (4) ◽  
Author(s):  
Yosep S. Mau ◽  
Antonius Ndiwa ◽  
Shirly Oematan
Keyword(s):  
Disease Severity ◽  
Yield Loss ◽  
Upland Rice ◽  
Brown Spot ◽  
Yield Reduction ◽  
Rice Cultivars ◽  
Rice Varieties ◽  
Resistance Level ◽  
Spot Disease ◽  
Brown Spot Disease

Abstract. Mau YS, Ndiwa ASS, Oematan SS. 2020. Brown spot disease severity, yield and yield loss relationships in pigmented upland rice cultivars from East Nusa Tenggara, Indonesia. Biodiversitas 21: 1625-1634. Brown spot is one of the most devastating diseases of rice, which could lead to total yield loss. The disease has a worldwide distribution, more specifically in areas where water supply is scarce, most specifically in the dry upland areas. Almost all stages of rice are affected by the disease, where leaves and grains are mostly affected. Considerable differences exist in susceptibility to brown spot among rice varieties, which may cause a large variation in yield loss caused by the disease. Therefore, the resistance level of rice varieties and their yield reduction has to be regularly evaluated and updated. There are only a few reports on the relationship between brown spot severity with yield and yield loss of upland rice, and is even lacking in pigmented upland rice. The objectives of the present study were to assess the brown spot severity and resistance level in pigmented upland rice cultivars from East Nusa Tenggara Province, Indonesia, and to elucidate their relationships with yield and yield reduction. Twenty four pigmented upland rice genotypes were evaluated in the field during May to October 2019, and their disease responses and yields were recorded. Disease severity was observed weekly and used to calculate Area Under the Disease Progress Curve (AUDPC) for comparison among the genotypes. The relationships between disease severity and AUDPC with yield and yield loss were also examined. The results showed significant variation in brown spot severity and AUDPC, ranging from, respectively, 11.11% to 40.70% and 398.42%-days to 1081.30%-days. Yields and yield losses of test genotypes also varied substantially. Yields under diseased-free and diseased plots ranged from, respectively, 2.34 t ha-1 to 6.13 t ha-1 and 1.68 t ha-1 to 3.74 t ha-1 while yield loss was between 10.46% and 56.15%. Six genotypes were moderately resistant, four genotypes were moderately susceptible and 14 genotypes were susceptible to brown spot. Neither disease severity nor AUDPC had a linear relationship with yield but both exhibited positive and linear relationships with yield loss.

On dispersion of stable random vectors and its application in the prediction of multivariate stable processes

1994 ◽  
Vol 31 (3) ◽  
pp. 691-699 ◽  
Author(s):  
A. Reza Soltani ◽  
R. Moeanaddin
Keyword(s):  
Stable Process ◽  
Stable Processes ◽  
Random Vectors ◽  
Linear Predictor ◽  
Error Vector ◽  
Best Linear Predictor ◽  
Definition Of ◽  
Stable Random Vectors

Our aim in this article is to derive an expression for the best linear predictor of a multivariate symmetric α stable process based on many past values. For this purpose we introduce a definition of dispersion for symmetric α stable random vectors and choose the linear predictor which minimizes the dispersion of the error vector.

scholarly journals Evaluation of Foliar Diseases for Soybean Entries in the Pan-African Trials in Malawi and Zambia

Plant Disease ◽  
2020 ◽  
Vol 104 (8) ◽  
pp. 2068-2073
Author(s):  
Christabell Nachilima ◽  
Godfree Chigeza ◽  
Mwila Chibanda ◽  
Hapson Mushoriwa ◽  
Brian D. Diers ◽  
...  
Keyword(s):  
Disease Severity ◽  
The United States ◽  
Sub Saharan Africa ◽  
Brown Spot ◽  
Soybean Rust ◽  
Growth Stages ◽  
Foliar Diseases ◽  
Pan African ◽  
Private And Public ◽  
Sub Saharan

Soybean production has expanded worldwide including countries in sub-Saharan Africa. Several national and international agencies and research groups have partnered to improve overall performance of soybean breeding stocks and have introduced new germplasm from Brazil and the United States with the goal of developing new high-yielding cultivars. Part of this effort has been to test improved soybean lines/cultivars accumulated from private and public sources in multilocational trials in sub-Saharan Africa. These trials are known as the Pan-African Soybean Variety Trials, and the entries come from both private and public breeding programs. The objective of this research was to evaluate entries in the trials that include commercial cultivars or advanced experimental lines for the incidence and severity of foliar diseases. All trials were planted in December 2018 with six located in Zambia and one in Malawi. Plants were evaluated during the reproductive growth stages using a visual pretransformed severity rating scale. Foliar disease ratings were recorded for three bacterial diseases, six fungal diseases, one oomycete, and viruses. The overall occurrence of most of the diseases was high except for soybean rust and target spot, which were only found at two and one location, respectively. However, disease severity was generally low, although there were differences in disease severity ratings among the entries at some of the locations for brown spot, downy mildew, frogeye leaf spot, red leaf blotch, and soybean rust.

scholarly journals Effects of BAU- biofungicide and Proud on disease severity, seed quality, vigour index and health status of seed against brown spot disease of rice

2016 ◽  
Vol 11 (50) ◽  
pp. 5092-5099
Author(s):  
Mahmud Hyat ◽  
Hossain Ismail ◽  
Dey Purnima ◽  
K. M. Kamal Hasan A. ◽  
Afsar Uddin Sheikh
Keyword(s):  
Health Status ◽  
Disease Severity ◽  
Seed Quality ◽  
Brown Spot ◽  
Spot Disease ◽  
Brown Spot Disease ◽  
Vigour Index
Sign in / Sign up

Export Citation Format

Share Document