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Title:Effects of Cercospora Sojina and Phomopsis Spp. On Soybean Seed Quality and Yield, and of Production Systems On Diseases and Yield of Soybean
Author(s):Bisht, Vikram Singh
Department / Program:Plant Pathology
Discipline:Plant Pathology
Degree Granting Institution:University of Illinois at Urbana-Champaign
Degree:Ph.D.
Genre:Dissertation
Subject(s):Agriculture, Plant Pathology
Abstract:Cercospora sojina (C) and Phomopsis (P) causing frogeye leafspot and pod and stem blight, respectively, were field inoculated alone or in combination (CP) on Corsoy-79 and Wells soybeans in 1981 and 1982. The recovery of C or P from stems, pods and seeds was independent of the presence of the other. In 1981, C and P interacted negatively, resulting in higher yields and seed weight than either C or P alone; but not in 1982, probably due to a higher brown stem rot incidence C and P had an additive affect in reducing seed germination and clean seeds.
Production systems: Soybeans in continuous cropping yielded lower, had more weeds and lodging than those in rotation with corn. In continuous cropping, Corsoy-79 seeds had higher germination, less vigorous seedlings and higher yield than Cumberland. Soybeans in wide-rows had fewer weeds, less lodging and higher yields than in narrow-rows. Seed germination, weight and seedling vigor were unaffected by row-spacing. Conventional tillage resulted in higher seedling emergence, plant stand and yields, but lower seed germination and vigorous seedlings. Increased tillage shortened crop duration and increased yields; seed weight was unaffected. Continuous soybeans had more brown spot (BS), brown stem rot (BSR) and pod and stem blight (PSB) than those in rotation. Corsoy-79 had more bacterial pustule (BP), BS, charcoal rot (CR) and PSB, while Cumberland had more bacterial blight (BB). BB was negatively correlated to BP and BS. Wide-row soybeans had more BS than narrow-row; but row-spacing did not affect BB, BP, BSR, CR and PSB. Tillage systems did not influence BB, BP, BSR and CR. In rotation cropping, BS PSB tended to increase with increased tillage. Diseases in general reduced seed weight. Soybeans in continuous cropping produced poorer quality seeds than those in rotation; greater lodging, poor plant vigor and accumulation of inoculum were implicated. In continuous cropping, seed germination was not affected by cultivar, row-spacing or tillage. Seed health of Corsoy-79 was better than that of Cumberland. Wide-rows produced better quality seeds than narrow-rows. Tillage had no consistent influence on seed health.
Issue Date:1983
Type:Text
Description:315 p.
Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1983.
URI:http://hdl.handle.net/2142/70594
Other Identifier(s):(UMI)AAI8409863
Date Available in IDEALS:2014-12-15
Date Deposited:1983


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