Publication Date:
1996-02-01
Description:
SUMMARYMaize (Zea mays L.) and common bean (Phaseolus vulgaris L.) were grown in five seasons, beginning in the long rains 1990 and ending in the short rains 1992, at Kiboko, Kenya under a range of different management conditions (N fertilization, irrigation, population density and intercropping). Seed weight was plotted against total dry weight to determine harvest index for both crops. For bean the intercept of this relationship for each experiment, with one exception, was not significantly different from zero, so that the slopes of the regressions were the harvest indices. Harvest indices for bean varied more between seasons (0·38–00·85) than from the effects of management practices (00·53–0·71). Over all seasons and treatments, the index for bean did not vary systematically with crop weight, and averaged 0·50. By contrast, a similar analysis for maize over all seasons and treatments, showed that the harvest index varied with crop dry weight, approaching an asymptotic value as dry weight increased. The regression intercepts for the different experiments were significantly different from each other, and in three cases differed significantly from zero. Therefore, although the slopes for the different experiments were parallel, they did not always represent the harvest index.
Print ISSN:
0021-8596
Electronic ISSN:
1469-5146
Topics:
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
