The effects of short and long shading, applied during different stages of growth, on the development, productivity and quality of forage maize (Zea mays L.).

Abstract

In 2 field experiments, shading which differed in duration and date of initiation was applied to normal stands of forage maize cv. LG11. Short shading during vegetative development affected leaf area, plant ht., stem thickness and reproductive development but final effects on DM yield and quality were small. Short shading during silking drastically reduced ear size and final ear yield. Although the deleterious effect on ear yield was partly compensated for by higher stover yield, productivity was low after the shading tents were removed. Digestibility was also greatly reduced because production of total DM was affected more than production of partly indigestible cell walls. Short shading soon after silking curtailed cell-wall formation more than DM production and crop digestibility was not adversely affected. Reduction in DM production remained large especially in the ear because of grain abortion. Shading after grain set stimulated the depletion of short carbohydrates in the stover and slowed down the decrease in the cell wall content of the whole crop. Crops shaded for long periods yielded more than expected on the basis of the short treatments. Long shading treatments lasted until final sampling and the earlier a long treatment was initiated, the greater the reduction in yield. The same was true for whole-crop digestibility, except in the earliest shading treatment in which poor vegetative development accompanied poor ear development. (Abstract retrieved from CAB Abstracts by CABI’s permission)