Chickpea variety evaluation and intercropping for disease management and yield

Abstract

Chickpea (Cicer arietinum L.) is an important food grain legume, but production is constrained by the soilborne pathogen complex, Ascochyta rabiei, and the development of fungicide resistance. Cultivar resistance is one of the most efficient strategies in disease management. However, chickpea cultivars with resistance to soilborne pathogens or complete resistance to A. rabiei have not been developed. Intercropping chickpea-flax has the potential for Ascochyta blight management. To minimize the impact of soilborne disease and Ascochyta blight on chickpea production, refining of integrated pest management practices is essential. To evaluate the effect of cultivar selection in combination with seed treatment on soilborne disease control, twenty-five cultivars/lines were planted with or without fluxapyroxad, pyraclostrobin, and metalaxyl under field conditions. The area under disease progress curve (AUDPC), seed yield, and protein content were assessed. Fusarium solani was isolated and identified in the late season, and the disease severity of root rot was evaluated. The results showed that seed treatment effectively suppressed damping-off and improved chickpea yield but only slightly reduced late-season root rot. The AUDPC of NDC160166 and NDC 160236 was not significantly reduced by seed treatment, which could be a future resource of resistance. To assess the effects of configurations and resistant cultivar on yield and Ascochyta blight management in intercropping chickpea-flax, two chickpea cultivars (CDC Leader and Royal) were planted with flax under six configurations (monocrop chickpea, 70% chickpea-30% flax in mixture, 50% chickpea-50% flax in mixture, 50% chickpea-50% flax in alternate rows, 30% chickpea-70 flax in mixture, monocrop flax). Yield and nutrient content of component crops and Ascochyta blight infection were evaluated. Chickpea yield decreased as flax proportion increased in the mixture. Chickpea yielded higher in the alternate row design than in the mixture at the same seeding rate due to less interspecies competition in the alternate rows. Intercrop increased 2%-23% land productivity. Chickpea-flax intercrop effectively reduced Ascochyta blight under higher disease pressure. The configuration of 50% chickpea and 50% flax in the mixture was more effective in suppressing Ascochyta blight than in the alternate row configuration. Integrated resistant cultivar and intercropping configuration was most effective in disease suppression.