Data shown are averaged across 3 years and 2 sites. unifoliate), and (B) variety type (kabuli vs desi). 2: Severity of ascochyta blight in relation to (A) leaf type (pinnate vs. Planting less susceptible (also known as partially resistant) varieties can improve control efficiency by disrupting the infection cycles of the disease during a growing season. Similarly, desi types (all with pinnate leaves) are less susceptible to ascochyta blight than kabuli types (Fig. 2b). CDC Diva, Sanford) at all growth stages (Fig. 2a). CDC Orion, CDC Leader, Amit, CDC Chico, CDC Frontier) show consistently lower susceptibility to ascochyta blight than varieties with unifoliate leaves (i.e. Under similar disease pressure, varieties with pinnate (fern-like) leaves (i.e. Select less susceptible varietiesĬhickpea varieties differ in their susceptibility to ascochyta blight. However, in areas where the infection is through long distance dispersal of pathogen via winds, crop rotation may be of limited benefit. The pathogen may be present in the field even four years after the initial chickpea crop, but the amount of fungal inoculum declines substantially after the first two intervening crops. Thus, a 3- to 4-year rotation cycle with non-host crops is required between successive chickpea crops. In western Canada, ascochyta pathogen can be persistent on infected crop resides for 3 to 4 years. Rotate chickpea every three to four years New plantings should be at least 500 meters away from fields that had chickpea crops the previous season, especially if the crop might have been infected. Select fields with no or less ascochyta historyĬhickpea should be grown in an area with a non-host crop surrounding it. Use of granular inoculants instead of seed-applied inoculants will increase Rhizobium viability. It is essential that Rhizobium inoculants are compatible with the fungicides and that the fungicide is applied first and dried before Rhizobium inoculants are to be applied. Damaged seeds are highly vulnerable to infection by soil-borne pathogens. Also, planting machinery needs to be equipped with a seed-feeding mechanism capable of handling large sized seeds to avoid physical damage. Producers should be aware that Saskatchewan Crop Insurance requires seeds with ascochyta-infection at or below 0.3% for coverage. Kabuli chickpea are more sensitive to seedling blight than desi varieties. Metalaxyl containing products can also provide protection against seedling blight caused by Oomycetes. Treating seeds with a product registered for Ascochyta rabiei with multiple modes of action will help minimize seed-borne disease in both kabuli and desi varieties. Using certified, disease-free seed is key to a successful ascochyta blight management program. How to prevent disease before it strikes? Use disease-free and treated seeds 1: Symptoms of ascochyta blight disease on (A) leaves, (B), stems and (C) pods of chickpea plants and (D) total crop failure caused from severe disease. Ascochyta blight causes low yields with poor seed quality and can result in up to 100% yield loss, especially in susceptible varieties (Fig. 1d). The fungus attacks all above-ground plant parts and infection can occur on leaves, stems and pods at any stage of plant growth (Fig. 1A-C), but plants are most susceptible to disease during flowering. The disease occurs in nearly all chickpea growing areas. Sustainable Crop Protection Results from the Pesticide Risk Reduction ProgramĪscochyta blight, caused by the pathogenic fungus Ascochyta rabiei, is the most important challenge limiting chickpea production in western Canada.

Ascochyta leaf blight treatment