First Results on Growth and Cropping of Pear Trees Budded at Different Heights

Abstract

Pear trees cv 'Agua de Aranjuez' A-840 (VT) clon, budded in the nursery at 15 and 50 cm from the soil were planted with the union at 10 and 50 cm high, and growth and cropping during the first two years recorded. Scion trunk-cross-sectional area was smaller on the high-worked trees from the time of planting, and stock area at soil level was also smaller on the high-budded trees from the first year after planting. Almost all the high-worked trees carried a crop on the second year of growth, while a few (20%) of the low-budded carried some fruits, which were smaller in size. Differences in size of both scion and stock were greater by the end of the second year. -Introduction'Agua de Aranjuez' is a very vigorous pear variety (P y r u s c o m m u n i s L.) usually grown in Spain on pear seedling rootstocks, for wich the adult tree attains a very large size. The need for a growth control has led to the use of quince rootstocks, and first reports are showing that 'Agua de Aranjuez' A-840 (VT) clon grafted on Quince C (EM) results in a tree of small size and early cropping, but which needs staking because of poor anchorage and twisting down of the aerial part of the stock.Van Oosten (1978) and Parry (1986) have shown that in apple, high working increases the dwarfing effect of the rootstock, allowing the use of more vigorous rootstocks. To test this effect on pear trees, a preliminary trial has been carried out and the results on growth and cropping during the first two years after planting are presented here. -Materials and MethodsQuince A rootstocks were grafted in the nursery in 1981 at two different heights: 15 and 50 cm from the ground with 'Agua de Aranjuez'A-840 buds. Ten trees of each height of budding were chosen as uniform as possible and of the best quality, in terms of tree height and number of feathers. The trees were planted in a row at 3.5 m apart,