Growth and Development of Horticultural Crops (1+1)

Physiological basis of pruning

• Pruning is a tool to regulate size and shape of plants to achieve desired architecture of canopy and also reduce foliage density by removal of unproductive branches.
• Commonly, trees are pruned annually in two ways. A few shoots or branches that are considered undesirable are removed entirely without leaving any stub. This operation is known as ‘thinning out’. The other method which involves removal of terminal portion of the shoots, branches or limb, leaving its basal portion intact, is called ‘heading back’. Thinning out involving large limbs as in old and diseased trees is called ‘bulk pruning’.
• These operations are carried out to divert a part of the plant energy from one part to another. As trees grow older, they should receive relatively more of thinning out and less of heading back. Heading back tends to make trees more compact than thinning out. If a few of the several branches growing close together on the same parent limb are entirely removed or thinned out, the rest of the branches would grow more vigorously. Thinning out results in lesser new shoot growth but more new spurs and fruit bud formation than corresponding severe heading back. Pruning is done with the following specific objectives.
1. To remove surplus branches
2. To open the trees – maximum sun light interception, so that the fruits will colour more satisfactorily
3. To train it to some desired form
4. To remove the dead and diseased limbs,
5. To remove the water sprouts and
6. To improve fruiting wood and to regulate production of floral buds.
7. Source sink relation