ศูนย์นวัตกรรมเทคโนโลยีหลังการเก็บเกี่ยว

Field trial using paclobutrazol foliar sprays on Hass avocado trees.

Symons, P. R. R.; Wolstenholme, B. N.;

Yearbook - South African Avocado Growers' Association Year: 1990 Vol: 13 Pages: 35-36 Ref: 17 ref.

1990

บทคัดย่อ

Six-year-old trees of cv. Hass on clonal Duke 7 rootstock were sprayed with paclobutrazol at 0, 500, 1000 or 2000 mg/litre plus 1% Reverseal sticker, at about 5 litres of spray/tree. Three application times were compared, viz. (a) early spring flush elongation, (b) estimated full bloom, and (c) 3 weeks after full bloom. At harvest, individual tree yields were determined and fruits were sampled before the remainder were stored at 6 deg C for 5 weeks. After ripening at ambient temperature, fruits were cut open to assess postharvest physiological disorders. Trees that were sprayed latest showed the lowest increase in canopy area. There were no significant differences in trunk circumference between trees treated with different concentrations of paclobutrazol or at different times; the average increase was 11.8 cm. Fruits from paclobutrazol-sprayed trees were significantly rounder than control fruits but length was unaffected. Yields were not significantly different, but for each of the 3 spraying times the highest yield corresponded to the highest concentration applied. Spraying at flush elongation was associated with yields that appeared generally higher than those of control trees. Spraying resulted in a reduction in the mass of undersized fruits present at the time of harvest; although results were not significant, the highest concentration appeared to be associated with the lowest mass of undersized fruits. Pulp spot was entirely absent from the fruits and the other postharvest disorders assessed, vascular browning and grey pulp, showed no significant incidence for any treatment. The results are discussed.