عنوان
پدید آورنده
موضوع
رده
کتابخانه
محل استقرار
TLpq304295639
انگلیسی
Use of organic amendments and cropping sequences to manage peanut soilborne diseases and quantification of infection cushions formed by Sclerotinia minor
[Thesis]
R. K. Soufi
H. Melouk
Oklahoma State University
1996
69
Ph.D.
Oklahoma State University
1996
Scope of study. Sclerotinia blight (caused by Sclerotinia minor), southern blight (caused by Sclerotrium rolfsii), and pod rot (mainly caused by Pythium myriotylum) affect peanut yield and quality in Oklahoma. This study was conducted to investigate the effect of peanut cultivars, crop rotations, an organic amendment, and two green manure treatments on: (1) populations of the causal pathogens; (2) the resulting disease severity and (3) pod yield and quality. Another aspect of this study was to determine the utility of cellophane in studying formation of infection cushions by S. minor. The cellophane technique was used to evaluate the efficacy of two fungicides on formation of infection cushions and to compare infection cushion formation by six isolates of S. minor. Findings and conclusions. In the crop rotation experiment, planting Okrun (Sclerotinia susceptible peanut) for three years resulted in higher populations of S. minor and Pythium spp. than three years of Tamspan 90 (Sclerotinia resistant peanut) or any other rotation. Two-year rotations with sudan grass followed by Tamspan 90 had the lowest sclerotial populations of S. minor. Tamspan 90 had less sclerotinia blight and lower pod rot index than Okrun rotations. Two years of rotational crops (sorghum, wheat, or sudan) followed by Tamspan 90, or leaving the soil fallow had the lowest populations of Pythium spp. Peanut yield and grade were higher in Tamspan 90 than Okrun rotations. Using canola for three years as green manure reduced sclerotial populations of S. minor and Pythium spp. as well as sclerotinia blight incidence and pod rod index. The use of cellophane provided a method to quantify infection cushion formation by S. minor. Okrun supported more infection cushions, and resulted in formation of more sclerotia, per cm2 than Tamspan 90, Southwest Runner, other plant species, and a fallow treatment. The fungicide fluazinam reduced infection cushion formation in comparison to iprodione or water. Isolate N, non-pathogenic and non-sclerotia forming, produced fewer infection cushions per cm2 than all other tested isolates.
Agronomy
Biological sciences
Plant pathology
Pythium myriotylum
H. Melouk
R. K. Soufi
مطالعه متن کتاب p
[Thesis]
276903
a
Y
