SINGLE DEFOLIATION HAD LITTLE INFLUENCE ON GROWTH AND DRY MATTER ATTRIBUTES OF SHEA (VITELLARIA PARADOXA C. F. GAERTN.) SEEDLINGS

Abstract

ABSTRACT Seedlings of Vitellaria paradoxa are normally subjected to annual environmental hazards within the savanna environment that tends to constitute serious impediment to their growth. A field and nursery experiment was conducted in July 2009 to July 2010 to test seedling recovery when subjected to 3 defoliation times (22, 26 and 30 weeks after planting) and levels (0, 50 and 100%). Factorial combinations of this were laid out in randomized blocks and replicated three and four times respectively in the field and nursery experiments. Results of analysis of variance indicated container raised seedlings showed significant response only to defoliation time in which case leaf removal 30 weeks after planting resulted to seedlings with significantly lower values of leaf width and leaf area. Field grown seedlings did not respond significantly in any of the growth parameters to treatment but showed a tendency towards lower values when defoliated 30 weeks after planting. Generally, seedlings defoliated 30 weeks after planting showed a tendency towards reduced fresh/dry weight and dry matter attributes except dry matter partitioning to the root where the reverse was the case. Degree of defoliation did not significantly affect seedling growth and dry matter attributes although the most severe defoliation treatment (100%) tended to have the lowest values for most parameters. Generally, single defoliation, or one year disturbance in the field, only marginally affects seedling growth.