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Rhizoctonia Foliar Blight Reactions and Seed Yields in Soybean
Author(s) -
Harville B. G.,
Russin J. S.,
Habetz R. J.
Publication year - 1996
Publication title -
crop science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.76
H-Index - 147
eISSN - 1435-0653
pISSN - 0011-183X
DOI - 10.2135/cropsci1996.0011183x003600030005x
Subject(s) - biology , cultivar , rhizoctonia , rhizoctonia solani , agronomy , intraspecific competition , blight , horticulture , plant disease resistance , fungi imperfecti , botany , ecology , biochemistry , gene
Rhizoctonia foliar blight (RFB) is caused by the fungus Rhizoctonia solani Kühn anastomosis group 1, intraspecific groups IA and IB. The disease affects more than half of the soybean [ Glycine max (L.) Merr.] acreage in Louisiana. Although less‐susceptible cultivars are recommended, reliable estimates of cultivar susceptibility have been difficult to obtain because of several factors, including uneven distribution of RFB in fields, differences in plant developmental stage at time of infection, and the requirement for free moisture in RFD development. The objective of this study was to screen commercial soybean cultivars grown throughout the southern USA, as well as advanced breeding genotypes, for field reaction to RFB in south Louisiana. Ninety‐one soybean genotypes, representing Maturity Groups IV, V, VI, and VII, were evaluated at two locations in 1993 and 1994. Disease ratings were made with a severity scale that included pods as well as foliage. A range of reactions to RFB was observed among cultivars, but most were severely damaged. Significant negative correlations between RFB severity and yield occurred among cultivars in all Maturity Groups. Results identified several cultivars, notably Buckshot 66 and Pioneer variety 9593, with promising levels of resistance.