EFFECT OF PACLOBUTRAZOL ON VEGETATIVE GROWTH, FLOWERING, FRUIT SET, FRUIT DROP, FRUIT QUALITY AND YIELD OF LYCHEE CV. HONG HUAY

T. Chaitrakulsub, R. Ogata, S. Subhadrabandhu, T. Powsung, H. Gemma
In the first trial : the effect of paclobutrazol applied as soil drench (at the trunk soil line) at 2, 4, 8 and 16 gm ai /tree were compared to the single spray at the concentration of 125, 250, 500 ppm. and the untreated control. Using the 12 years old lychee cv. Hong Huay in Hung-Dong district, Chiang Mai, Thailand, as one-tree plots, the chemical was applied on September, 15, 1988. It was found that, soil drench treatment did not affect vegetative growth but spraying increased the diameter of internode greater than soil drench and untreated control. The treatments did not affect flowering, while soil drench reduced panicle length to be shorter than spraying and control, whereas fruit set, fruit drop, fruit quality and yield were not affected. In the second trial, effect of soil drench paclobutrazol on vegetative growth of the four months old lychee cv. Hong Huay were studied from April to September, 1989, compared to the untreated control. It was found that the vegetative growth of plants treated with 8, 16, 32 and 64 gm. ai./cm. of stem O/plant were storong refuced more than the plsnts treated with 2 and 4 gm. ai./cm. of stem O/plant, whereas plants treated with 1 gm. ai./cm. of stem O/plant showed slighter effect. There was no different among chemical treated for yellow leaf symptom, while paclobutrazol did not show neither phytotoxicity nor lethal effect.
Chaitrakulsub, T., Ogata, R., Subhadrabandhu, S., Powsung, T. and Gemma, H. (1992). EFFECT OF PACLOBUTRAZOL ON VEGETATIVE GROWTH, FLOWERING, FRUIT SET, FRUIT DROP, FRUIT QUALITY AND YIELD OF LYCHEE CV. HONG HUAY. Acta Hortic. 321, 291-299
DOI: 10.17660/ActaHortic.1992.321.29
https://doi.org/10.17660/ActaHortic.1992.321.29

Acta Horticulturae