To improve fruit set in ＂Carmel＂ almond （Prunus dulcis） trees grown in the 6th region of Chile, seven different growth regulators （GRs） were sprayed onto flowering branches： gibberellic acid （GA3）, Promalin, ...To improve fruit set in ＂Carmel＂ almond （Prunus dulcis） trees grown in the 6th region of Chile, seven different growth regulators （GRs） were sprayed onto flowering branches： gibberellic acid （GA3）, Promalin, naphthaleneacetic acid （NAA）, Thidiazuron, Kinetin, Point-tomatomone and Brassinolide. The percentage of fruit set was determined by comparing the initial number of flowers present on each treated branch with the total number of almonds on the branches 50 days after anthesis. In comparison to the controls, Brassinolide, Point-tomatomone and Promalin achieved increases in fruit set of 19.4%, 14.5% and 12.9%, respectively. A parallel experiment was done in vitro, on the effects of these GRs on pollen germination and pollen tube growth. The greatest pollen germination （4 hours at 20 ~C） occurred with Brassinolide and GA3, which were significantly higher than the control, while NAA and Promalin significantly reduced germination. For pollen tube growth （24 hours at 20 ~C）, the greatest lengths were observed with Point-tomatomone and Brassinolide, which were significantly longer than the control, while NAA, Thidiazuron and Promalin were significantly shorter than the control, and the least growth was observed with Kinetin.展开更多
The almond （Prunus dulcis） is a self-incompatible species that requires various orchard management techniques to encourage pollination and achieve a good fruit set. Fungicides are commonly applied to almond flowers ...The almond （Prunus dulcis） is a self-incompatible species that requires various orchard management techniques to encourage pollination and achieve a good fruit set. Fungicides are commonly applied to almond flowers to control fungaI infections, such as ＂blossom blight＂ and ＇brown rot＂ that damage the flowers and developing fruits. However there is evidence that the application of some of these products may adversely affect pollination and fruit set. The effects of the fungicides captan, chlorothalonyl, propiconazole, mancozeb and dichloran on fruit set were studied in an orchard using ＂Nonpareil＂ and ＂Carmel＂ almond trees. The effects on in vitro pollen germination and pollen tube elongation were studied using ＂Carmel＂ pollen. With respect to Non Pareil fruit set, all fungicidal treatments were statistically similar to the control （11.5%） but being propiconazole （13.1%） and chlorotalonil （5.6%） different between them. Fruit set for ＂Carmel＂ was significantly lower than the control （26.1%） with all fungicidal treatments. After 24 hours, in vitro ＂Carmel＂ pollen germination was significantly higher in the control （90.5%） compared with the fungicidal treatments, with the exception of chlorothalonyl （70.2%）. Pollen tube growth in the control was four times greater than in the fungicide treatments at 24 hours, none of which were significantly different from the other treatments. It can be concluded that the application of certain fungicides has a clearly detrimental effect on fruit set in ＂Nonpareil＂ and ＂Carmel＂ almond trees and on ＂Carmel＂ pollen activity.展开更多
文摘To improve fruit set in ＂Carmel＂ almond （Prunus dulcis） trees grown in the 6th region of Chile, seven different growth regulators （GRs） were sprayed onto flowering branches： gibberellic acid （GA3）, Promalin, naphthaleneacetic acid （NAA）, Thidiazuron, Kinetin, Point-tomatomone and Brassinolide. The percentage of fruit set was determined by comparing the initial number of flowers present on each treated branch with the total number of almonds on the branches 50 days after anthesis. In comparison to the controls, Brassinolide, Point-tomatomone and Promalin achieved increases in fruit set of 19.4%, 14.5% and 12.9%, respectively. A parallel experiment was done in vitro, on the effects of these GRs on pollen germination and pollen tube growth. The greatest pollen germination （4 hours at 20 ~C） occurred with Brassinolide and GA3, which were significantly higher than the control, while NAA and Promalin significantly reduced germination. For pollen tube growth （24 hours at 20 ~C）, the greatest lengths were observed with Point-tomatomone and Brassinolide, which were significantly longer than the control, while NAA, Thidiazuron and Promalin were significantly shorter than the control, and the least growth was observed with Kinetin.
文摘The almond （Prunus dulcis） is a self-incompatible species that requires various orchard management techniques to encourage pollination and achieve a good fruit set. Fungicides are commonly applied to almond flowers to control fungaI infections, such as ＂blossom blight＂ and ＇brown rot＂ that damage the flowers and developing fruits. However there is evidence that the application of some of these products may adversely affect pollination and fruit set. The effects of the fungicides captan, chlorothalonyl, propiconazole, mancozeb and dichloran on fruit set were studied in an orchard using ＂Nonpareil＂ and ＂Carmel＂ almond trees. The effects on in vitro pollen germination and pollen tube elongation were studied using ＂Carmel＂ pollen. With respect to Non Pareil fruit set, all fungicidal treatments were statistically similar to the control （11.5%） but being propiconazole （13.1%） and chlorotalonil （5.6%） different between them. Fruit set for ＂Carmel＂ was significantly lower than the control （26.1%） with all fungicidal treatments. After 24 hours, in vitro ＂Carmel＂ pollen germination was significantly higher in the control （90.5%） compared with the fungicidal treatments, with the exception of chlorothalonyl （70.2%）. Pollen tube growth in the control was four times greater than in the fungicide treatments at 24 hours, none of which were significantly different from the other treatments. It can be concluded that the application of certain fungicides has a clearly detrimental effect on fruit set in ＂Nonpareil＂ and ＂Carmel＂ almond trees and on ＂Carmel＂ pollen activity.
