VIEW ARTICLE

Counteracting Bean Root Rot by Loosening the Soil. D. W. Burke, Research Plant Pathologist, Plant Science Research Division, Irrigated Agriculture Research and Extension Center, Prosser, Washington 99350; D. E. Miller(2), L. D. Holmes(3), and A. W. Barker(4). (2)(3)(4)Research Soil Scientist, Soil and Water Conservation Research Division, and Agricultural Research Technicians, ARS, USDA, respectively, Irrigated Agriculture Research and Extension Center, Prosser, Washington 99350. Phytopathology 62:306-309. Accepted for publication 1 October 1971. DOI: 10.1094/Phyto-62-306.

Subsoiling to reduce soil compaction after seedbed preparation in two sandy loam fields significantly increased yields of three bean cultivars whose roots were infected by Fusarium solani f. sp. phaseoli. Subsoiling under the drill row before planting was more effective than subsoiling between the rows before planting or after plant emergence. Subsoiling before plowing was ineffective. Yield increases appeared to result not from reduced infection but from counteraction of effects of the disease through increased rooting depth and volume, and through greater regeneration of roots as the season progressed. Response to subsoiling was greater in a bush bean highly sensitive to root rot than in two less sensitive Red Mexican cultivars. In fields containing the previous season’s barley crop residues, the soil was less uniformly compacted; subsoiling was therefore less beneficial than in adjacent fields where beans had grown the previous year. Subsoiling in Fusarium-infested or noninfested silt loam fields, where soil moisture was maintained near optimum for plant development, increased rooting depth and volume, but failed to affect seed yields.