ISHS Acta Horticulturae 179: V International Symposium on Growth Regulators in Fruit Production
THE EFFECT OF GROWTH REGULATORS ON BUD DORMANCY AND WINTER INJURY IN RED RASPBERRY. |
| Author: | F. Maage |
| Abstract:
On August 8, 1984, primocanes of the red raspberry cultivar Veten were sprayed with either 100 ppm GA, 1500 ppm PP 333, or with both the substances in combination a few days after the last picking date. The experiment was performed in the southern part of Norway. Treatment with GA prolonged the vegetative growth in autumn, and leaf fall was late compared with untreated canes. PP 333 on the other hand, stopped vegetative growth, and the leaf fall was early. GA and PP 333 in combination lead to late leaf fall, but little new growth occurred after the spraying date. Bud dormancy, recorded by forcing stem pieces, showed late entering of dormancy in buds from canes treated with GA. This was expressed both by a higher number of burst buds in September and October, and by shorter time of forcing until the buds reached the stage defined as burst. Buds from canes treated with PP 333 entered dormancy earlier, while buds from the GA + PP 333 treatment, followed the same pattern as those treated with GA only. In November and December, forcing requirement in treated buds did not differ from the control. Buds on cuttings from untreated canes, forced with the base in solutions of 10 ppm GA, had reduced forcing requirement both before and after the deepest dormancy, but there was no effect in October. Concentrations from 6 to 100 ppm pp 333 in the forcing media, had no effect on forcing time. Canes sprayed with GA had more winter injury than unsprayed canes, while treatment with PP 333 had little or no effect on number of dead buds. | |
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