插穗狀態、氣候以及殺菌劑、IBA、乙烯和1-MCP處理對番木瓜扦插成活之影響

Abstract

The papaya cutting survival rate was effect by internal factors and external environmental factors. Therefore, this experiment used from 15 to 20 cm of softwood cuttings, which were taken from 3-month-old 'ML × PPI' papaya seedlings. Papaya cutting with leaves had higher formation of adventitious roots than non-leaf cutting. During summer, 15-20 cm of papaya cuttings only need 15-21 days for root formation. In spring and autumn was longer than summer about 7 days, and papaya cutting was difficult to rooting between 32 and 36 days in winter. Shorter cutting length between 3-12 cm had lower survival rate and root development. However, above 30 cm had less root than 20 cm cutting. Shorter cutting length (less than 10 cm) had high rot rate about 20%, but cutting treated with 800x Streptomyces can effectively reduce the rot rate. Cuttings were treated with 2000x 9.4% cyazofamid on adventitious root formation and growth of cuttings was better than 3000x 50% dimethomorph and 800x Streptomyces treatment. 1000x 23% azoxystrobin treatment was no effect. Cutting treated with 6000 ppm IBA on adventitious roots formation was better than 4000 ppm IBA treatment. 20 ℃ treatment of cuttings did not show adventitious root formation, compared with cutting treated at 25-35℃. In the variable temperature treatment, cutting were treated under 35/30℃, 30/25℃ and 25/20℃ showed root formation at 15, 18 and 27 days, respectively. When treated with 6000 ppm IBA rooting happened at 9, 12 and 15 days. Cutting respiration rate increased significantly after cut from field-grown plants, and then gradually decreased. IBA treatment and control cutting’s leaves defoliate in the first three days, which 1-MCP and ethylene treatment in the first five days. All treatment respiration rate increased significantly before defoliation. Cuttings treated with ethylene, IBA, and 1-MCP of ethylene production rate increased after cutting. 1-MCP decline rapidly and maintained balance till 3th weeks, but ethylene treatment of cuttings achieve the peak after 2 days, and then gradually decreased maintained balance till 5th week. IBA treatment maintained high ethylene production rate for long days. Control cutting no significant increase after harvested. Cutting treated with Ethylene on leaf percentage are higher than the control group and IBA treatment, but only ethylene treatment and control group promoted adventitious root formation and development. Cutting treated with ethylene after 3 days had higher base of sugar and starch than 1-MCP treatment in the stem base.