Articles
POLLINATION NEEDS OF THE SELF-COMPATIBLE ALMOND CULTIVAR “LAURANNE”
Our objectives were therefore to (1) check whether the level of self- compatibility of "Lauranne" was satisfactory to establish mono-cultivar orchards, and (2) determine whether insect pollinators were still needed in such orchards to produce a good crop.
Trials were conducted over 2 years in an isolated orchard of 72 trees planted in 1985 and located nearby a large apiary.
In 1991, fruit set at harvest was similar with open-pollination and hand-pollination (HP) with self-pollen (22% et 24%, respectively). Furthermore, the average kernel weight was also similar (1.37 g), which confirmed that the orchard was well isolated and also indicated that such an orchard could give a satisfactory crop.
With self-pollination (insectproof sleeves), fruit set reached only 18% with a kernel weight of 1.26 g.
These values were significantly less than those of other treatments, indicating that bees were necessary to get a satisfactory crop of good quality kernels.
HP with compatible "Texas" pollen gave the highest fruit set (33%) and heaviest kernels (1.48 g), suggesting that the crop of "Lauranne" trees could be improved with optimal conditions of cross-pollination.
1992 results were not as clear as those of 1991, perhaps because blooms were scarce and the fruit set much higher (up to 60%). An HP assay with self-pollen gave a fruit set of 20%% with a single pollen load, 35% with 2 loads, 45% with 3 loads, and 50% with a thorough pollen covering of the stigma.
Kernel weight showed a similar positive relationship with pollination intensity and it went from 1.24 g with a single pollen load to 1.72 g with a maximum load.
These results confirm the importance of insect pollinators to get adequate pollination in almond orchards of self-compatible cultivars.