Effect of intercropping maize (Zea mays) and potato (Solanum tuberosum L.) on yield and incidence of major potato pests

A study to investigate the effect of intercropping maize and potato on crop yield and the incidence of potato aphids and leafhoppers was conducted at Namulonge Agricultural and Animal Production Research Institute (NAARI), during the 1994 to 1995 growing seasons. Three potato varieties and one maize variety were intercropped in six spatial arrangements; 2:1, 2:2, 1:1, 1:2 potato: maize row arrangements and one additive mixture. Potato varieties showed significant differences in most growth parameters including branching, canopy heights (at 60 DAP), stem length and stems per plant. Kisoro had the highest number of branches, longest stems and lowest canopy. The reverse was true for sangema while Victoria had an immediate position. Crop growth rates, canopy heights and tuber initiation times appeared to be the most important potato attributes in intercropping with maize because they were more closely related to yield. Intercropping influenced some growth parameters of potato but not of maize. The rate of potato stem extension and leaf formulation rates were hastened by intercropping. Plant heights and main stems were not significantly influenced though the tendency was for intercropped potato to grow taller than the sole crop. Branching in potato influenced the amount of leaf area produced especially in the second rains where the additive mixture had the least of both characters. Potato yield differed significantly among the spatial arrangements with the highest potato yield in the sole crop followed closely by the 2:1 and 2:2 potato: maize mixtures. These yield differences however varied with potato variety; Kisoro being the most affected variety. Generally potato yield components decreased in the intercrops except tuber number per plant that was not influenced by intercropping.