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Fruit growing in the tropics - Part 10

10 Layout and establishment of the orchard This is usually one of the first subjects in books on fruit growing, but in fact all the other subjects should be clear in your mind before you start planning the layout of an orchard. You should take into account: ? Differences in vigour between cultivars ? Measures to control tree vigour (drought, root pruning, girdling, etc.) ? Requirements with regard to cross-pollination. | 10 Layout and establishment of the orchard This is usually one of the first subjects in books on fruit growing but in fact all the other subjects should be clear in your mind before you start planning the layout of an orchard. You should take into account Differences in vigour between cultivars Measures to control tree vigour drought root pruning girdling etc. Requirements with regard to cross-pollination. 10.1 Tree spacing Orchards are traditionally planted on the square e.g. 10 x 10 m for mango. This is all right for large seedling trees with their immense canopies. If smaller tree size allows doubling the number of trees per ha to 200 approx. 7 x 7 m other planting patterns may not be advantageous. But if 400 trees or more can be planted per ha the trees should remain so small that you can allow them to form a closed row or hedge. This means that at 400 trees per ha instead of a spacing of 5 x 5 m on the square a spacing of 6 x 4 m i.e. ROW CROPPING becomes attractive. Sufficient light should penetrate the hedge to produce good quality fruit even on the lowest limbs. The square planting pattern is based on the notion that all trees grow equally well and that you can fairly accurately predict the size of the mature trees. Both notions are false. There is usually much variation in tree size even in a single cultivar. Also it is quite common for trees to remain much smaller or to grow much larger than anticipated. A succession of a few good crops as soon as the tree comes into bearing greatly helps to limit tree size. As shown in figure 19 the open fringe around each tree planted on the square has become an open alley in the row-cropping model. The closer spacing in the row means that a more vigorous tree can make Layout and establishment of the orchard 69 up for a weaker neighbour. If growth is disappointing the trees should still fill the rows and intercropping in the alleyways can be continued for a few more years. If tree vigour is excessive the alleyways serve