Annals of Botany 39: 423-432, 1975
© 1975 Annals of Botany Company
RESEARCH-ARTICLE |
Productivity of Peach Trees: Factors Affecting Dry-weight Distribution During Tree Growth
Horticultural Research Station, Department of Agriculture Tatura, Victoria, Australia
Received: 8 July 1974
The distribution of d.wt in peach trees varies greatly with increasing tree size or age. The growth of the fruit, roots and tree frame is competitively inter-related throughout the life of the tree while the growth of leaves and the annual shoots that support them is independent and increases in direct proportion to tree size. The proportion of the annual increment of d.wt directed into fruit growth increases from less than 30 per cent in a young tree of about 16 cm butt-circumference to almost 70 per cent in a mature tree of about 55 cm butt-circumference. Thereafter the proportion of d.wt allocated to fruit growth did not increase, although the total yield of d.wt continued to increase exponentially. Conversely the proportion of d.wt allocated to the frame and roots declined from just under 40 and 20 per cent respectively to less than 10 and 1 per cent respectively. In these organs also, the proportions did not change further for larger trees.
The ratio of vegetative growth made by the top of the tree compared to root growth increased from 1 in a young tree to 4 in the oldest trees but there was a strong allometric relation (r=0·99) between the growth of both systems. The physiological implications of these data and their relation to horticultural productivity are discussed.