Colonization of soybean roots by Macrophomina phaseolina.

Reference Report for GUA85006173

Title:	Colonization of soybean roots by Macrophomina phaseolina.
Authors:	Pearson, C.A.S., Schwenk, F.W., Crow, F.J., Kelley, K.
Source:	Plant Dis. 1984, 68(12):1086-1088
Abstract:	Nine soybean [Glycine max] cultivars, representing groups III, IV and V, were monitored for root colonization by M. phaseolina in naturally infested, fumigated and fumigated-infested soils. Fumigation reduced initial soil populations by 80% but did not significantly reduce subsequent disease incidence. Cultivars differed in the rate at which they were colonized. On the basis of colonization rates calculated using time after planting and host ontogeny, cultivars can be better evaluated at specific growth stages than at specific times after planting. 'Bay', 'Essex', and 'Forrest' (group V cultivars) had the slowest rates of colonization. 'Sprite' (a group III cultivar) had a rate similar to the group V cultivars and yielded like 'Essex'. Fungal population in root systems of soybean at growth stage R8 (harvest maturity) was negatively correlated with yield.

Funded by the USDA-ARS. Developed by the USDA-ARS SoyBase and Legume Clade Database group at the Iowa State University, Ames, IA

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