PLANTING STOCK QUALITY ACCORDING TO THE METHOD OF APPLE TREE CROWN FORMATION IN THE FRUIT NURSERY

Abstract

One of the main factors of modern orchard foundation, including that of apple trees, is the superior quality of the planting material: superior genetically (clonal), phytosanitary healthy (virus free), physiologically well-developed (licensed). These superior qualities of the planting material contribute to an early entering of fruit trees on fructification and an increase of the plantation’s productivity with about 20-25 % than the ordinary one. At present in the superintensive apple tree orchard from the Republic of Moldova there are planted grafted apple trees on the rootstock M 9 having the form of rods without ramifications. The crown formation is made after the plantation of the apple trees in the orchard according to actual recommendations. From the experience of the countries with a developed pomology, the superintensive apple trees orchards are planted with trees produced during 2 years with a formed crown of “knip baum” type. The researches were made during the period of 2005-2007 in the fruit nursery of the firm “Fruit Nurseries” Ltd. As a rootstock was used the M 9 type and as a graft – the variety Idared, Golden Reinders and Jonagored. For grafting were used marcottes with a diameter of 10,0 mm and graft virus free branches imported from Holland. The bench-grafting was made in March. The plantation in the first field was made in the second part of April. The distance of plantation is 90x35cm. The aerial part was palisated on a bamboo support. In the second field, in spring the annual stems were shortened at a height of 50-60 cm from the grafting’s place. With the appearance of the sylleptic shoots, these shoots are removed and it is left only the terminal shoot. In order to stimulate the shoots ramification and growth in the crown zone, there were applied three methods: V1 – knip-baum with free growth (control variant); V2 – knip-baum with periodical remove of apical leaves at the axle; V3 – knip-baum with application of biological active substances. As a biologic active substance in order to stimulate the growth, it was used the preparation Ecostim with a concentration of 0,25 ml to 1 liter of water. The investigations were made in the field and laboratory conditions according to the required methods of doing experiments with fruit-growing plants. On the basis of the investigations made, it came out that the striking degree of the planted bench graftings in the first field of the fruit nursery constituted in average 93,0-99,3 %. What greatly influenced on the measures on annual growth the biological features of the soil, the plant height varying between the limits of 106 cm (Idared), and 122 cm (Jonagored); the leaf surface of the grafted apple trees under the study was 5,39-6,34 thousand m2/ha. In the second field the development best indicators of the apple trees of “knip baum” type were registered at the formation of the crown basis by periodical remove of apical leaves on the axle where the trees height is 153,7-181,1 cm, the trunk diameter is 15,2-1,0 mm, the number of branches in the crown zone is 6,4-12,7 pieces/tree with an average length of 34,2-55,4 cm, the leaf surface is 0,41- 0,67 m2/tree. The standard apple tree productivity for the varieties taken into the study is between the limits of 29, 11-31,19 thousand pieces/tree.