Abstract
Studies on peanuts (Arachis hypogaea L.) were made in Florida to examine genotype x cropping system interactions when cultivated as an intercrop with maize (Zea mays L.). The effects of different dates of sowing for maize were examined, as well as two different regimes of leafspot disease control (casual organisms- Cercospora arachidicola Hori and Cercosporidium personatum (Berk. & Curt.) Deighton) for peanuts. Peanut yields averaged 1870 kg ha-1 in the intercrop system and were the same whether the maize sowing was six weeks before the peanut sowing or the two crops were sown at the same time. Averaged over the two years of the study there was no significant interaction between peanut genotypes and cropping systems, although a significant interaction occurred in the first year of the study. Peanut yields in monocrop were highly correlated with yields in intercrop in both seasons (r = 0.97), while yield rank correlations between the two systems were inconsistent (r = 0.66). Fungicide applications at 14-day intervals increased peanut yields by 300 kg ha-1 when compared with applications at 28-day intervals, but the yield increase was less pronounced in the intercrop system. Genotype x spray interval genotype x spray interval x cropping system interactions were both significant. In this system peanut materials selected for high yield in monocrop were also suitable for intercropping with maize. The combination of the two crops had yield advantages for the entire system and improved peanut leafspot control compared with monocrop culture.
