Are some pollinators really better than others? Results of a three-year study on almond

Fruit set from the cross-pollination of the 100% of the flowers of the self-incompatible almond cultivars Ne Plus Ultra and Ferragnes was not influenced by any of the 12 pollens used from 1988 to 1990. The results indicate that for optimum fruit set of self-incompatible almonds some pollinators may not be better than others and that each pollen, when viable and fully or partially compatible, can be effectively used provided that cross-pollination is optimized. The pattern of the monofactorial gametophytic sterility affecting the almond as well as any other fruit tree species is the same: therefore it cannot be ruled out that the usual differences in fruit set found with current methods to detect pollinators of self-incompatible cultivars may be due not to a really different fertilizing power among pollens but rather to faulty techniques. It is indeed questionable whether current methods account for the real number of flowers usefully cross-pollinated in comparison to the number of blossoms initially counted for each intervarietal combination.