This study was carried out to determine the effect of 21 Citrus interstocks and the control Citrus macrophylla rootstock budded with Mexican lime （Citrus aurantifolia （Chistm.） Swingle） on growth and yield. Three ...This study was carried out to determine the effect of 21 Citrus interstocks and the control Citrus macrophylla rootstock budded with Mexican lime （Citrus aurantifolia （Chistm.） Swingle） on growth and yield. Three types of mandarin and 13 trifoliate types including ＂C-35＂ and ＂Benton＂ used as interstocks, developed vigorous trees similar or more productive than the control. ＂Morton＂ and ＂Benecke＂ citranges, ＂Pomeroy＂ trifoliate trifoliate orange and the ＂Severinia buxifolia＂ interstocks showed a moderated effect on tree growth. Flying dragon （FDT） and Hiryu trifoliate oranges performed as semi-dwarfing interstocks. These interstocks reduced the tree height, canopy volume and surface area covered by the foliage on 25%-35%, 20%-30% and 20%-30%, respectively, compared to the control. While most interstocks surpassed the assigned area of growth （24 m2） in the 7th year, ＂FDT＂ and ＂Hiryu＂ did that at the 10th year. These semi-dwarfing interstocks produced up to 80 kg/tree per year. Most treatments recorded the highest production from the 8th to 10th year, except FDT and Hiryu, which showed the highest yield （130 kg/tree） from the 5th to 7th year. This study provides useful results to face the huanglongbing （HLB） problem using moderate or semi-dwarfing interstocks for Mexican lime orchards in high density plantations.展开更多
Fruitlet abscission （cherelle wilt） is a major factor contributing to lower productivity of cacao plantation in Indonesia. An attempt was made to reduce such cherelle wilt by spraying plant growth retardants （PGRs...Fruitlet abscission （cherelle wilt） is a major factor contributing to lower productivity of cacao plantation in Indonesia. An attempt was made to reduce such cherelle wilt by spraying plant growth retardants （PGRs） on cacao trees at about 10 weeks before flowering session. The treatment was repeated every three weeks. Both the flowering initiation time and the number of flowers on the treated trees were improved significantly. With the most effective composition, flowers were initiated at 24 days after spraying （DAS）, where as the flowering initiation was 11-day later in the controls. At the 35 DAS, the chlorocholine chloride （CCC） 2,000 treatment induced about 20-80 folds more flowers than the controls. Extended observation was made to assess the treatment effect on the fruiting capacity. The treatments were found to improve fruiting ability by increasing the number of fruits set on the trees and shortening the time for fruit setting. At 20 weeks after the first spraying （WAS） there were on average 12.57 fruits per CCC 2,000-treated tree, as opposed to only 4.14 fruits per untreated tree. Analyses of the metabolites content in the flower cushions of the trees indicated that the reproductive growth is significantly correlated with the increased metabolites particularly the reduced sugar. Exogenous addition of sucrose to the PGR treatment gave greater improvement mainly in the fruiting. In conclusion, foliar spray of CCC induces flowering of cacao tress in the field that leads to improve the fruitlets productivity.展开更多
文摘This study was carried out to determine the effect of 21 Citrus interstocks and the control Citrus macrophylla rootstock budded with Mexican lime （Citrus aurantifolia （Chistm.） Swingle） on growth and yield. Three types of mandarin and 13 trifoliate types including ＂C-35＂ and ＂Benton＂ used as interstocks, developed vigorous trees similar or more productive than the control. ＂Morton＂ and ＂Benecke＂ citranges, ＂Pomeroy＂ trifoliate trifoliate orange and the ＂Severinia buxifolia＂ interstocks showed a moderated effect on tree growth. Flying dragon （FDT） and Hiryu trifoliate oranges performed as semi-dwarfing interstocks. These interstocks reduced the tree height, canopy volume and surface area covered by the foliage on 25%-35%, 20%-30% and 20%-30%, respectively, compared to the control. While most interstocks surpassed the assigned area of growth （24 m2） in the 7th year, ＂FDT＂ and ＂Hiryu＂ did that at the 10th year. These semi-dwarfing interstocks produced up to 80 kg/tree per year. Most treatments recorded the highest production from the 8th to 10th year, except FDT and Hiryu, which showed the highest yield （130 kg/tree） from the 5th to 7th year. This study provides useful results to face the huanglongbing （HLB） problem using moderate or semi-dwarfing interstocks for Mexican lime orchards in high density plantations.
文摘Fruitlet abscission （cherelle wilt） is a major factor contributing to lower productivity of cacao plantation in Indonesia. An attempt was made to reduce such cherelle wilt by spraying plant growth retardants （PGRs） on cacao trees at about 10 weeks before flowering session. The treatment was repeated every three weeks. Both the flowering initiation time and the number of flowers on the treated trees were improved significantly. With the most effective composition, flowers were initiated at 24 days after spraying （DAS）, where as the flowering initiation was 11-day later in the controls. At the 35 DAS, the chlorocholine chloride （CCC） 2,000 treatment induced about 20-80 folds more flowers than the controls. Extended observation was made to assess the treatment effect on the fruiting capacity. The treatments were found to improve fruiting ability by increasing the number of fruits set on the trees and shortening the time for fruit setting. At 20 weeks after the first spraying （WAS） there were on average 12.57 fruits per CCC 2,000-treated tree, as opposed to only 4.14 fruits per untreated tree. Analyses of the metabolites content in the flower cushions of the trees indicated that the reproductive growth is significantly correlated with the increased metabolites particularly the reduced sugar. Exogenous addition of sucrose to the PGR treatment gave greater improvement mainly in the fruiting. In conclusion, foliar spray of CCC induces flowering of cacao tress in the field that leads to improve the fruitlets productivity.
