Response of chickpea cultivars to foliar, seed and soil inoculations with <I>Botrytis cinerea</I>

Abstract

Twenty-four cultivars of chickpea were evaluated for their susceptibility to the grey mould fungus Botrytis cinerea using foliar, seed and soil inoculation at 2, 4 and 8 g fungus per plant, per kg seed or per kg soil. At 8 g the inoculum caused necrotic lesions to all 24 cultivars with foliar inoculation, to 23 cultivars except cv. CH-2007-22 with seed inoculation and to 17 cultivars with soil inoculation, and reduced yield by 7–43% (foliar inoculation), 3–34% (seed inoculation) and 3–26% (soil inoculation). Foliar or seed inoculation with 4 g of the fungus significantly reduced the yield of all cultivars tested except CH-2007-22 with foliar inoculation, and 4 cultivars with seed inoculation. Soil inoculation at 4 g fungus kg^-1 soil, significantly reduced the yield of eight cultivars. Foliar and seed inoculations at 2 g of the fungus significantly reduced the yield of 16 and 7 cultivars of chickpea respectively; but soil inoculation at this concentration, did not significantly reduce yield in any cultivar. The greatest significant decline in yield was recorded with foliar inoculation in the cv. BG-256, 43% at 8 g, 40% at 4 g and 26% at 2 g inoculum level. The cv. CH-2007-22 was tolerant to B. cinerea as it exhibited only 3–7% yield loss at 8 g inoculum. The fungal population, especially that on the phylloplane, increased exponentially from January to March and declined drastically in April. At the high inoculum level of 8 g fungus kg^-1 soil, B. cinerea may initiate infection through the soil. There was a positive correlation between disease severity and yield decline, and a disease severity above 2 significantly reduced yield.