Incidence of Aphid-Transmitted Viruses in Farmer-Based Seed Potato Production in Kenya
Field studies were carried out in farmer-based seed
potato production to determine the incidence of potato aphids and potato
aphid-transmitted viruses in two potato-producing areas of Kenya. Parameters
determined included aphid population, virus disease incidence and tuber
yield. Aphid population was monitored on leaves and in water-pan traps.
Virus infection was determined based on symptoms and the viruses were
identified in tubers sprouts by DAS-ELISA. Tuber yield was determined
for plants showing virus symptoms and healthy-looking plants. Five aphid
species were identified, with the most abundant being M. euphorbiae
and A. gossypii on leaves and M. persicae and A. gossypii
in water traps. The average aphid population was between 1.4 and 4.2 aphids
per three leaves and 4.68 and 9.64 aphids per water pan trap. Farms with
higher population of M. persicae had higher virus disease incidence.
The most prevalent viruses were PVS, PLRV and PVM. Healthy looking plants
had a latent infection rate 57.2% compared to 76.6% for symptomatic plants.
Virus infection reduced the number and weight of tubers by 74 and 62.7%,
respectively. However, virus infection increased the number and weight
of the chats grade. The results indicated that aphid infestation and virus
disease incidence were higher than the recommended for seed potato production.
Therefore, there is need to create awareness among the farmers on aphid
and virus symptom recognition and use of clean certified seed potato.
Cited References Fulltext