Ascochyta seedling blight

Reduced yield and quality may cause economic losses up to 70 percent in susceptible cultivars.

Plants are susceptible from the seedling stage right through to maturity. Spot-like lesions (grey to tan to dark brown) develop on leaflets, petioles, stems, peduncles and pods (darkest lesions on pods). Rainfall in late summer may cause renewed flowering, delaying maturity or causing uneven maturity. Pod infection may lead to seed infection, discolouration and downgrading. Difficult to distinguish from Septoria leaf spot; Septoria lesions contain concentric markings and are mainly confined to lower leaflets.

Scouting

Test seed for disease. In early season, check for lesions on all parts of young growth. Prior to flowering, monitor crops carefully and prepare to apply foliar fungicide to reduce abortion and seed infection. In later season, patches of discoloured diseased plants appear in ripening crop. At harvest, check seed for shriveled, purplish brown surfaces and if severely affected, seed will contain whitish patches of mycelia and pycnidia and will be severely downgraded.

Control

Resistant cultivars have been developed. Grow lentils no more than once every four years and avoid fields adjacent to lentil residues of the previous year. Plant disease-free seed – lab testing available.