ศูนย์นวัตกรรมเทคโนโลยีหลังการเก็บเกี่ยว

Fruit set regulation and quality.

Schumacher, R.; Stadler, W.;

Acta Horticulturae Year: 1993 Issue: No. 326 Pages: 49-57 Ref: 3 ref.

1993

บทคัดย่อ

Defoliation and thinning experiments were carried out in order to investigate their effects on transport of assimilates, natural fruit fall, flower bud formation and fruit quality of young apple trees. Defoliation (0, 1/3, 2/3 or all leaves removed) was carried out on fruit spurs at 4 different stages (just after full bloom, or 10, 20 or 30 days after bloom cessation) with or without 2 thinning treatments (fruit thinning on adjoining secondary branches or blossom removal on adjoining secondary branches). The extent of June drop depended not only on the leaf:fruit ratio of a fruit branch but also on fruit set in the adjoining part of the tree. With defoliation at flowering, fruit Ca content decreased linearly with increasing defoliation and was not influenced by fruit thinning on adjoining fruiting branches. In further experiments, different thinning methods were evaluated in order to achieve a more balanced yield in the biennial apple cultivar Elstar. Results are tabulated for yield and quality and graphically presented for fruit size at harvest, sugar content and titratable acidity, colour and organoleptic tests. Thinning after June drop reduced the yield of quality fruit. More regular bearing could be achieved with one-sided manual removal of blossom.