INFLUENCE OF SOIL-MOISTURE ON ROOT-ROT AND WILT OF CHICKPEA

This study was conducted to determine the effects of soil moisture on wilt and root rot of chickpea (Cicer arietinum), caused by Fusarium oxysporum f. sp. ciceri, F. solani f. sp. pisi, Pythium ultimum, and Thielaviopsis basicola. Three soil matric potential regimes (high = -40 to -20 kPa, medium = -260 to -40 kPa, low = -1,060 to -260 kPa) were used. Wilt and root rot increased with decreased soil matric potential, as did rhizosphere populations of each pathogen when present in soil alone or in various pathogen combinations. Chickpeas grown in soil infested with equal inoculum densities of two pathogens usually had as much or more disease as plants grown in soil infested with a single pathogen. However, wilt severity was significantly less when plants were grown in soil infested with F. o. ciceri and P. ultimum than with either pathogen alone. Rhizosphere populations of F. o. ciceri were higher than populations of other pathogens at the conclusion of each test.