GA(4+7) plus benzyladenine reduce foliar chlorosis of Lilium longiflorum

The effectiveness of two commercial formulations of gibberellin (GA) and be nzyladenine (BA) for reducing foliar chlorosis on Easter lily (Lilium longi florum Thunb.) was compared. On a per liter basis, plants were sprayed with 0, 100, 200, or 400 mg (Bh equivalent) of Accel (GA(417):BA of 1:10) or Pr omalin (GA(417):BA of 1:1) when the crop leaf area index (LAI) = 3. One gro up of plants was sprayed with 100 mg of Accel or Promalin (BA equivalent) p er liter twice: once at LAI = 3 and again 3 weeks later. Plants were harves ted when the largest flower bud on each plant measured 13 cm in length, sto red for 0 or 3 weeks at 2.5 degreesC in the dark, and then moved into a pos t-harvest evaluation room at 21 degreesC, where foliar chlorosis was monito red for 3 weeks. Senescence of some lower leaves on plants in every treatme nt was evident at harvest, and incidence of senescence increased during the 21 days of post-harvest evaluation. Cold storage increased the number of l eaves senescing during the subsequent evaluation period. Application of Pro malin or Accel significantly reduced leaf senescence compared to that of un treated plants. At harvest, 21% of the leaves on untreated plants were sene scent, while plants treated with Promalin or Accel averaged 3 or 9% senesce nt leaves, respectively. Following 7 days of post-harvest evaluation, Proma lin was more effective in preventing chlorosis than Accel at the 400 mg l(- 1) (BA equivalent) level. Following 14 or 21 days of post-harvest evaluatio n, Promalin was more effective than Accel for the 100 mg l(-1) 2 x and 400 mg l(-1) (BA equivalent) treatments.