Occurrence, distribution and severity of finger millet blast caused by Magnaporthe oryzae in Kenya

Abstract

Finger millet is a food crop that provides nutritional security and is climatically resilient for farming and agricultural diversification. However, its quality and yield remain low due to biotic and abiotic factors, the greatest of which is blast disease caused by Magnaporthe oryzae. We surveyed the occurrence, distribution and severity of finger millet blast in five counties, namely, Busia, Bungoma, Kisii, Machakos and Makueni, in Kenya. Blast disease occurrence was determined by observing disease symptoms of different plant parts on each farm, and symptoms were recorded as either present or absent. Severity was evaluated based on the disease symptoms on plant fingers, leaves and necks and generally at the whole farm scale. Distribution was assessed based on the number of farms sampled for blast per county, and global positioning systems coordinates were recorded. Blast occurrence was 100%, with a uniform distribution pattern on all the farms surveyed across all the counties. Busia County had the highest disease severity at 82.3%, while Makueni had the lowest severity at 61%. Pearson’s correlation test revealed no statistically significant correlation between blast severity and plant parts infected (p< 0.05), with Busia (74.2%) having the highest number of plants showing symptoms of blast on fingers, followed by Bungoma (57.1%), Makueni (57%), Machakos (56%) and Kisii, 53.3%. This study reveals that finger millet blast is rampant in all the counties surveyed and is widely distributed in Kenya. This information is helpful in understanding the geographical distribution, occurrence and severity of M. oryzae. Key