Screening of chickpea (Cicer arietinum L.) germplasm accessions for tolerance against post-emergence herbicide imazethapyr

In the present study, 200 chickpea genotypes including accessions from the ICRISAT chickpea core collection, ICAR-IARI advanced breeding lines and varieties were screened against imazethapyr (an Acetolactate Synthase inhibiting broad-spectrum herbicide) to identify the source of resistance to the post-emergence herbicide. Wide genetic variations were observed among chickpea genotypes. A total of eight genotypes, viz. ICC 1710, ICC-14061, GL 14054, IPC 10-134, ICCX 130012-B-B-B-B-25, ICC17255, ICCX110067-B-B-B-B 76-B-B, and ICCX110066-B-B-B-B-59-B-B showed tolerance to imazethapyr; hence, they were considered promising. The application of imazethapyr significantly reduced plant height, and 100 seed weight and increased days to 50% flowering and maturity. Plant biomass under herbicide treatment increased most likely due to an increase in the number of secondary branches. Weed control efficiency was 78.58% when imazethapyr applied at 80 g a.i. per ha at 40 days after sowing. Among the tolerant genotypes, IPC 06-77 and ICC 14061 gave the most consistent positive performance for yield and yield attributes under herbicide treatment. The herbicide-tolerant lines identified can be useful resources for undertaking genetic and physiological studies on herbicide tolerance and for the development of herbicide-tolerant cultivars of chickpea.