Influence of harvest date on the germination and emergency of seeds of five olive cultivars.

摘要

The efficiency of an olive breeding program is directly related to the time between crossing and first bearing of the forthcoming seedlings, i.e. the length of the juvenile period. Harvesting the seeds as soon as possible is one of the factors that can contribute to shorten this period, if a high percentage of developing seeds is ensured. In the present work, seeds from open pollination of 'Arbequina', 'Empeltre', 'Koroneiki', 'Manzanilla de Sevilla' and 'Picual' cultivars were harvested at four different dates, from July to November, in order to determine the percentage of germination and subsequent emergency. The earliest harvest date for maximum number of germinating seeds varied among cultivars. This was not correlated with ripening date of the mother cultivars. In the optimal harvest date, 'Arbequina', 'Koroneiki' and 'Manzanilla de Sevilla' seeds reached 90% of germination and 'Empeltre' and 'Picual' 80%. Maximum emergency percentage was very variable and lower than the germination percentage (from 85% in 'Arbequina' to 40% in 'Picual'), which indicate that this technique could be improved. Harvest date for maximum germination and emergency were different. An additional experiment showed that the stratification period could be reduced to 30 days by increasing the temperature from 14 to 25 C 18 days after the beginning of stratification.