Author : Cach Thi Nguyen

Summary : The effect of intercropping maize on growth and yield of groundnut at different row ratios were determined. Suitable intercropping patterns and the advantages of intercrop over monocrop were also assessed. BPI-Pn2 groundnut variety and IPB var 7 maize variety with similar growth duration were grown at different row ratios in a replacement intercrop. Growth and yield of groundnut were adversely affected by intercrop. Groundnuts were taller, less-branched, and lower in total dry matter weight (TDW), leaf area index (LAI), net assimilation rate (NAR), crop growth rate (CGR), and plant yield (PY) than in sole groundnut. In contrast, intercropping benefited maize as indicated by its increased TDW, LAI, CGR, and PY. Seed yield per groundnut plant was reduced by intercropping as a result of reduced number of pods per plant. On the other hand seed yield of maize increased in all intercrop treatments. Harvest index and shelling percentage of the two crops were slightly affected by intercropping. Chlorophyll content of groundnut was also affected by maize shading. Increases in total chlorophyll content and ratio of Ca/Cb were observed. Land equivalent ratio (LER) was greater than one in all intercropping treatments. The highest value of 1.40 was obtained from T6 (3:1 groundnut: maize row ratio), followed by T7. These two treatments also had higher marginal rate of return (MRR) and return on investment (ROI) than the others. These results showed that this groundnut variety can be intercropped with maize. However, only 3:1 and 3:2 row ratio are recommended under dry season conditions based on LER and MRR.