Study on damages caused by cassava mosaic disease in Thua Thien Hue

Abstract

Cassava is an important crop in Thua Thien Hue. Cassava mosaic disease has invaded and caused large damage in the province since the end of 2019, but so far there has been no assessment of the level of damage caused by this disease. Investigation of cassava leaf mosaic disease showed that the KM94 was the main variety, accounting for over 90%. Mosaic disease infected most of the area of KM94 variety from scale 2 to scale 5 depending on the seed source used by farmers. The damaged area was recorded in Thua Thien Hue about 670 ha (14.9%) and lost up to 484 ha (12.6%). The remaining areas yield decreased depending on the severity of the disease, the higher the disease severity and the earlier infection, the greater the damage. Plants infected early at sprouting yield greatly reduced, infected at the stages of leaf and tuber development, yield decreased insignificantly. Cassava mosaic disease correlated with crop yield (R² = 1). The higher the disease severity, the greater the decrease in yield. KM94 variety with disease severity over 90% reduced yield from 61.5 - 62.1% yield and 18.1 - 20.1% starch content.