Growth and yield of lowland tropical maize in Mexico

Abstract

SUMMARYThe growth and yield of three tropical varieties of maize were studied at two elevations in Mexico: Poza Rica (60m) and Tlaltizapan (940m). Grain yields were between 3·5 and 8·5 t/ha. The growing period was longer and the crop produced more dry weight and yield at Tlaltizapan than at Poza Rica. Crop growth rates (C) increased to a maximum of about 35 g/m2/day at both sites and then declined. Grain growth rates (maximum 35 g/m2/day) exceeded current C during most of the grain filling period. After silking when C exceeded grain growth, dry matter accumulated in the stem. Later as grain growth increased and exceeded C, some of the accumulated material was incorporated into the grain and stem weight decreased. The dry weight increase after flowering was similar at the two sites, but the grain yield at Tlaltiapan was larger because a larger proportion of the dry weight increase was incorporated into the grain than at Poza Rica. The results indicate that at both sites grain ‘sink’ capacity was limiting yield.