Abstract:
Field experiments were conducted in three seasons (1998/99, 1999/00 and 2000/01) to determine the effects of removing the male flower (detasselling) or oldest leaves (leaf stripping) on grain yield of maize. Detasselling increased yield by 11.2-12.2% in the first two seasons and by 32.3% in the third. The effect of leaf stripping on grain yield depended on timing; leaf stripping at anthesis (50% silking) increased yield by 16.6% in the first season and by 28% in the second, whereas leaf stripping at three to four weeks before or after anthesis had no significant effect on yield. In the third season, ear growth rate was measured over a seven week period, two weeks after leaf stripping and/or detasselling, from 12 to 18 WAE. Coefficients of linear regression of ear dry weight over the seven week period were 18.29 ± 1.564, 20.10 ±.1.264, 20.43 ± 1.329 and 25.02 ± 1.528 for the intact, leaf stripped, leaf stripped and detasselled and detasselled treatments, respectively. Detasselling increased radiation interception (RI) by sub-tassel leaves and by the cob leaf by 10-28% and 5-27%, respectively. Moreover, detasseling may have reduced apical dominance, allowing greater rates of kernel filling. The results indicate that detasseling and leaf stripping may offer small holders feasible methods for maximizing maize grain yield.
