Timing of gibberellin(4+7) plus benzyladenine sprays influences efficacy against foliar chlorosis and plant height in easter lily

The effects of Promalin(R) [PROM; 100 mg.L-1 each of GA(4+7) and benzyladen ine (BA)] sprays on leaf chlorosis and plant height during greenhouse produ ction of ancymidol-treated (two 0.5-mg drenches per plant) Easter lilies (L ilium longiflorum Thunb, 'Nellie White') were investigated. Spraying with P ROM at early stages of growth [36 or 55 days after planting (DAP)] complete ly prevented leaf chlorosis until the puffy bud stage, and plants developed less severe postharvest leaf chlorosis after cold storage at 4 degrees C f or 2 weeks. When FROM was sprayed on plants in which leaf chlorosis had alr eady begun (80 DAP), further leaf chlorosis was prevented during the remain ing greenhouse phase and during the postharvest phase, FROM caused signific ant stem elongation (23% to 52% taller than controls) when applied 36 or 55 DAP, but not when applied at 80 DAP or later. The development of flower bu ds was not affected by PROM treatments. Although PROM sprays applied at 55 DAP or later increased postharvest flower longevity, earlier applications d id not, Chemical names used: N-(phenylmethyl)-1H-purine 6-amine (benzyladen ine, BA); alpha-cyclopropyl-alpha-(p-methoxyphenyl)-5-pyrimidinemethanol (a ncymidol).