Utilization Of Border Crops To Manage Aphid Colonization And PVY Incidence On Potato(Solanum tuberosum L)

Abstract

Sorghum (Sorghum bicolorL.), wheat (Triticum aestivumL.), maize(Zea MaysL.), common bean (Phaseolus vulgaris L.) and garden pea (Pisum sativumL.) were tested as border crops for their ability to reduce the number of colonizing aphids and Potato Virus Y (PVY) incidence in seed potatoes (Solanum tuberosumL.). The experiment was done at Tigoni, Central Kenya for two seasons, from 03 May 2002 and from 17 October 2002. Apterae aphids were monitored weekly by picking 15 leaves from 5 randomly selected plants per plot while alate aphids were collected using yellow sticky traps mounted 0.5 m from the ground level at the edge of border crops. Three aphid species were recorded: Aphis gossypii (Glover), Macrosiphum euphorbiae (Thomas) and Myzus persicae (Sulzer). PVY incidence in the inner rows of potatoes surrounded by fallow and the border crops was statistically insignificant (P>0.05) but outer rows in crop-bordered plots had significantly less PVY than outer rows of fallow-bordered plots. The DAS- ELISA test used to confirm presence of PVY showed that the disease had the highest and lowest incidence in fallow and wheat bordered plots, respectively. This study shows that the effective border-crops can be used to manage aphids and PVY disease in potatoes. In addition, since most Kenyan potato growers are low income earners, adoption of border cropping technology can improve immensely the production success of the crop