Horticulture, Environment, and Biotechnology : HEB

Korean Society of Horticultural Science (한국원예학회)
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MaxCel$^{(R)}$ as a Postbloom Thinner for 'Hongro' and 'Fuji' Apples

Guak, Sung-Hee;Kim, Eun-Ju;Kook, Jung-Ryul;Choi, Dong-Geun

  • Published : 20090600
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Abstract

MaxCel$^{(R)}$, benzyladenine containing product developed for postbloom apple thinner, was tested to reduce the crop load of 'Hongro' and 'Fuji'/M.9 apple trees (Malus domestica) in Jangsu, Korea. In 2005, to determine the appropriate application rate, 75 or 100 mg.L$^{-1}$ a.i. MaxCel was applied to 'Hongro', while 100 or 125 mg.L$^{-1}$ to 'Fuji' apple. Carbaryl at 1,000 mg.L$^{-1}$ was involved for comparison. In 2006, the appropriate timing of application was determined by spraying the trees with MaxCel at 100 and 125 mg.L$^{-1}$ for 'Hongro' and 'Fuji' apple, respectively, at various times between 6- to 15-mm fruit size. In general, thinning response to MaxCel was proportional to rate. In 'Hongro', we found quite variable thinning activities year to year: MaxCel at 100 mg.L$^{-1}$ a.i. applied at around 10-mm fruit size reduced crop load by 25% in 2005, while the reduction was almost doubled in 2006. In 'Fuji', 125 mg.L$^{-1}$ MaxCel applied at around 10-mm fruit size reduced crop load about 26%. In both cultivars, MaxCel worked better than carbaryl that showed just a slight thinning activity. Tank mixed with carbaryl, the lower rate of MaxCel (75 mg.L$^{-1}$ for 'Hongro' and 100 mg.L$^{-1}$ for 'Fuji'), reduced the crop load to the level similar to their higher rate. The effect of MaxCel on fruit quality at harvest or after storage was found to be minimal in both cultivars, except for a slight reduction in fruit firmness of 'Hongro' apple by MaxCel treatment. As for timing of application, in general, similar thinning responses occurred regardless of the application timing (6- to 15-mm fruit size) on both cultivars.

Keywords

References

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