You are looking at 1 - 4 of 4 items for
- Author or Editor: Miltiadis D. Vasilakakis x
Partial or complete removal of developing inflorescences from primocanes of ‘Heritage’ fall-bearing red raspberry had no effect on the number of inflorescences initiated. Inflorescence removal stimulated sucker initiation and increased fruit size.
Flower bud initiation in mature overwintering canes of ‘Heritage’ red raspberry (Rubus idaeus L.), a primocane-fruiting cultivar, began below the last inflorescence on the current year's growth in October and was completed by the end of December. Flower buds beyond the stage of initiation were not observed in noncold treated canes. However, in cold treated canes gradual basipetal flower bud development beyond initiation was observed. In non-cold treated overwintering canes of ‘Latham’, a June-bearing cultivar, flower bud induction and initiation occurred but no further development was observed.
The level of fruit set of ‘Truoito’ almond from hand self-pollination was high (47.7% and 56.8% in 1982 and 1983, respectively) and similar to the fruit set from hand cross-pollination. Fruit set in bagged branches excluding pollinators (honey bees and wind) was high and similar to that from open pollination (38.0% and 40.0%, respectively). Effective self-pollination occurred without pollinators because the stigmatic surface was adjacent to the anthers, in contrast to other cultivars examined in which the stigma was above the anthers. Pollen tube growth in self-pollinated styles was faster than in those cross-pollinated at 10° and 15°C, but similar at 20° and 25° and slower at 30°. Inhibition of pollen tube growth occurred at 30° in 45% of the selfpollinated styles. Optimum temperatures for ‘Truoito’ pollen tube growth in either selfed or crossed styles were between 20° to 25°, and 54 hr elapsed before tubes reached the base of the style after pollination. Pollen tube growth under field conditions was similar in both selfed and crossed styles.
Low temperature was not a requirement for flowering in ‘Heritage’, a primocane-fruiting red raspberry, as non-cold treated primocanes flowered at about 80 nodes. The amount of growth before flowering was inversely related to the amount of growth before cold exposure. Cold exposure (7°C) for 25 days at the 10-12 or 14-16 nodes stages of growth was followed by flowering at 32 and 28 nodes, respectively. Winter cold exposure until mid-December at the stage of adventitious buds on the root resulted in flowering at 41 nodes. Cold treatment did not influence the number of nodes that developed inflorescences on any one primocane.