Rejuvenating indigenous trees in agroforestry parkland systems for better fruit production using crown pruning.

摘要

The effects of crown pruning of mature indigenous fruit trees of Vitellaria paradoxa (commonly known as karite) and Parkia biglobosa (commonly known as nere) on recovery of crown size and fruit yield were assessed during 6 years in an agroforestry parkland system in Burkina Faso. Three treatments of crown pruning (total-pruning, half-pruning and a control of no-pruning) were applied to karite and nere. Each treatment comprised ten individuals of each species or a total of 60 trees of both species. Six years after pruning, higher recovery (81%) of crown diameter was achieved in total-pruned trees of nere as opposed to karite which recovered by only 73%. On the contrary, fruit production in total-pruned trees of karite recovered by 83% 5 years after pruning and fully (100%) 6 years after pruning as opposed to nere which recovered by only 57% 5 years after pruning but declined to 16% on the sixth year probably due to interannual variability. Fruit yields did not differ significantly between unpruned and half-pruned trees of both species throughout the experiment period. Total pruning may, therefore, be recommended to farmers to rejuvenate old trees of karite in parklands on the basis of fast recovery of fruit and slow recovery of crown in the species. Slow recovery of crown in pruned trees is the most desirable characteristic in parklands in order to avoid the negative effect of tree shade on adjacent crop.