Tokinashi was treated with GA at various concentrations, numbers and growth stages and also with IAA and IAA+GA. On the other hand, Seoul-bommoo was treated with growth retardants such as Ethephon, B-9 and MH, respectively. And their responses on bolting and flowering in each treatment were investigated.
1. GA promoted the bolting and flowering of Tokinashi. The most effective treatment, thrice applications with 100 ppm, promoted bolting and flowering by 8 days, respectively.
2. Promoting effect of GA treatment at each growth stage was remarkable in seed treatment and April 2. and April 12. (almost the end of seedling stage) treatment, while in other growth stage the effect was a little.
3. IAA treatment delayed the bolting of Tokinashi by 4 days, but had no effect on flowering. IAA+GA treatment promoted the bolting and flowering by 3 days, respectively.
4. 200ppm of Ethephon and 1500ppm of B-9 treatment had no effect on bolting and flowering of Seoul-bommoo, while once or twice treatments of 0.25% MH-30 delayed its bolting and flowering by 3 and 8 days, respectively. But MH-30 treatment caused serious chemical injury.
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