Intercropping chickpea-flax for yield and disease management

Abstract

Ascochyta blight (caused by Ascochyta rabiei) is a primary concern of chickpea production worldwide. Intercropping chickpea with a non-host crop has the potential to suppress this disease and improve resource use efficiency for enhanced crop yield. This study aimed to evaluate the effects of seeding rate and row configuration of chickpea (Cicer arietinum, L.)-flax (Linum usitatissimum, L) intercropping on 1) yield and seed quality, 2) disease incidence and severity of Ascochyta blight of chickpea, and 3) land productivity of this intercropping system. Field trials were conducted at the Eastern Agricultural Research Center (EARC), Sidney, MT, and the Southern Agricultural Research Center (SARC), Huntley, MT, in 2020 and 2021. Chickpea was planted with flax in 4 intercropping configurations (70% chickpea – 30% flax in mixed rows, 50% chickpea – 50% flax in alternate rows, 50% chickpea – 50% flax in mixed rows, and 30% chickpea – 70% flax in mixed rows). Chickpea yield decreased with increased flax proportion in the mixed rows intercrop. Flax displayed higher competitiveness than chickpea, resulting in decreased yield and protein concentration in chickpea but increased yield and protein content in flax. Land equivalent ratio (LER) of intercropping was greater than 1, showing improved land productivity (2% -23% greater than monocropping). Intercropping reduced Ascochyta blight disease incidence and severity; the 50% chickpea – 50% flax and 30% chickpea – 70% flax intercropping configurations could reduce the disease severity to 50% (in Hunley) and 67% (in Sidney) of that in the monocropping. These results indicated that seed ratio and planting configurations of chickpea-flax intercropping may be manipulated to increase land use efficiency and reduce Ascochyta blight in chickpea. CDC Leader yielded greater than Royal in the higher disease pressure environment in Huntley indicated that selection of disease resistant cultivar is important for managing Ascochyta blight on chickpea.