| Popis: |
This study was conducted to elucidate the influence of prohexadione-calcium (Pro-Ca) application on shoot growth and fruit quality in 'Fuji'/M.9 mature apple trees. Pro-Ca was applied at concentrations ranging from 100 to 400 mg·L -1 one time at petal fall (PF; 5-10 cm terminal shoot growth) to the whole canopy of the tree, or at 100, 125, 150 mg·L -1 concentrations two times, at PF and then 4-8 weeks after PF. Pro-Ca treatment generally reduced mean shoot growth, with its effect being proportional to the application rate. Pro-Ca at 400 mg·L -1 significantly reduced the shoot growth by 15-22% compared to the control, while its effect was not significantly different from Pro-Ca 200 mg·L -1 . Pro-Ca treatments induced higher occurrence of secondary growth compared to the control. Pro-Ca treatment increased the photosynthetic rate by 5-10% relative to the control, and also increased soluble solid concentration and fruit red color. However, fruit weight was significantly reduced by 400 mg·L -1 Pro-Ca, which was attributable to the greater secondary growth caused Pro-Ca 400 mg·L -1 treatment compared to the control and Pro-Ca 200 mg·L -1 treatment. |
