Development Of A Fruit Tree

Press, Volume CX, Issue 32351, 17 July 1970, Page 6

Development Of A Fruit Tree

When the seed of any (fruit tree germinates in the (soil the initial growth is downwards to form the first roots. Coincident with the development of the root another portion raises itself upwards to the light and air. This is the original stem or trunk, carrying a pair of leaves and the first root is recognised at the tap root. This however rarely remains prominent unless the tree is allowed to develop in its original position. When shifted, within the first year or two of its life, the tap root is broken and on resettlement of the tree elsewhere it does not continue to develop, instead secondary rooting is induced and these then predominate. As the stem ascends more leaves are developed and as the terminal point continues to grow they are left stationary at fairly regular intervals along the stem. In each axil where the leaf stalk is attached to the stem a bud is developed. The position of

'(the bud is known as a node . and the region between two . buds or nodes is called the ’ internode. 1 Uninterrupted growth ' throughout the season will ; mean that most of these may remain dormant, even obscure. ; If, however, the terminal bud ( is checked, such as by pruning, some of these buds will ' start into growth and show ; all the potentialities of a ( branch. After the check has ’’been received by the ter'lminal bud irrespective of ’ I how whether by natural (i process of suspended growth ’’in autumn or by some exter(l nal means such as suggested ' I—there is an increased flow Hof sap to some of the lower (buds. 1 ’ When growth begins again •in the following spring these ((specially favoured buds (j usually those at closest ’ proximity to the terminal—) ' break into growth simul-i taneously with it. The shoots i ( arising therefrom will bej ( known as the main arms. ' These branches will repeat in i their growing season the, same processes of extension, with leaf and axillary bud formation noted on the main stem from which they arise. The following season’s development sees repetitions of that of previous summers. The more favourably .situated buds formed last year upon the main arms will break into growth and form secondary arms. At the same time the i increasing number of buds (forming on the various 'shoots will see an uneven

i utilisation of food supplied i to them, which will be clearly : visible by the different progress they each make. This i will be further influenced by I their position on the tree, ■ the lower elevation resulting . in less sunlight and air. The I result is weaker growth, much - of which is tending to a more horizontal than upright plane. ' They are called lateral i shoots. Following on from the ; development of the secondary ■ arms a third set of shoots ' will arise which are someI times called wood shoots or i leaders. Leader is a generally ■ more widely accepted term I for each of the main limbs ' forming the framework of a ■ fruit tree. When the buds upon the i laterals start into growth ■(they are still further -restricted by unsuitability Hof position or insufficient (nourishment. They are con(sequently transformed into : .short stubby growth called i (spurs. Various influences . I often cause direct spur fori (mation of some lower buds. /Also it should be noted that

on the laterals of some kin of trees, particularly thu of apricot, peach and ne< tarine, the flower buds ar' directly developed during th first summer. This briefly describes th' development of the branches of a fruit tree and give* some indication of how the effects of pruning can influence this development in one way or another. Attention must be drawn to the fact that development of a fruit tree has been traced here from that of a seedling Today, of course, varieties are budded and even grafted on to selected root stocks which are chosen for such desirable characteristics as suitability for a particular soil, for ultimate size of tree, freedom from a particular disease or perhaps earliness of fruiting. However, the growth pattern is still the same whether the tree is a seedling, has been grafted or budded or even double worked which means that the tree includes more than one variety on the same rootstock.