Wet conditions late in the season, provides ideal conditions for pod infection which can result in seed discolouration.Īscochyta blight is a common disease in all areas of Victoria where lentils are grown and is favoured by cool, wet conditions. Infection can occur at any stage of plant growth. The development of ascochyta blight epidemics is largely determined by the prevailing environmental conditions, especially the presence of moisture. Further spread from plant to plant within crops then occurs through rain splash. Spores are produced on old stubble and are spread to plants by rain splash. Previously infected stubble is an important source of fungal inoculum. Sowing infected seed can give rise to infected seedlings, and the appearance of symptoms at the seedling stage. Seed can remain infected for several years. The fungal pathogen Ascochyta lentis that causes ascochyta blight can survive in infected seed, and in previously infected lentil stubble. Compared to healthy seed, heavily infected seed is purplish-brown, shrivelled and reduced in size. Infected seed generally has brown patches on the seed surface, but may show no symptoms at all. Pod infection can lead to seed infection and discolouration of the seed. Heavy infestations of ascochyta blight will cause premature leaflet drop and stem dieback at the growing tips giving plants a blighted appearance. The presence of pycnidia is the best way of identifying ascochyta blight lesions from those caused by other diseases such as botrytis grey mould or stemphylium blight. The centres of lesions become speckled with pycnidia (tiny, dark fruiting bodies). The disease appears as spot-like lesions which are initially light grey, but become tan with a dark brown margin. Symptoms may appear on plants from the seedling to mature stages. What to look forĪll above ground plant parts of lentil plants can be affected by ascochyta blight. While the disease can cause leaf abscission, it may also discolour seed which can result in the downgrading of seed quality and a reduction in their market value. ![]() Note the dark pycnidia within the centre of the lesion. The disease is favoured by high spring rainfall and prolonged wet periods. Temperate pulse viruses: subterranean clover stunt virusĪscochyta blight is a serious disease of Victorian lentil crops. Temperate pulse viruses: pea seed-borne mosaic virus Temperate pulse viruses: bean yellow mosaic virus Temperate pulse viruses: bean leafroll virus ![]() ![]() For more information about this disease and questions and answers, please refer to the Iowa Turf Blog in the link below.Temperate pulse viruses: cucumber mosaic virus Several lawns where the disease was observed have already shown quick recovery aided by the recent rainfalls that followed the weather events that incited the disease. Turf may look dead from a distance, but the blight does not affect bluegrass crowns and roots, so grass will recover in a matter of weeks depending on weather conditions. Maintain grass height at 2.5 and 3 inches and reduce mowing frequency. Manage the disease by reducing thatch by annual core aeration to allow better water penetration. ![]() Some leaves may have uniform lesions affecting the entire leaf blade.Īscochyta blight occurs on drought-stressed turf and also during periods of hot weather preceded by wet conditions. Infected leaves present a bleached tip dieback and the margin between healthy and disease shows a slightly pinched appearance. Ascochyta symptoms can appear as quickly as overnight. From a distance the symptoms resemble drought stress. It causes large irregular patches of turf to quickly turn straw-brown in color and appear dead. During early June we received several photos of dying lawns while neighboring lawns looked healthy and green.Īscochyta leaf blight is the disease causing these problems.
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