Views: 4 Author: Site Editor Publish Time: 2018-04-19 Origin: Site
Most apple cultivars are self-sterile and completely dependent on cross-pollination from a different cultivar in order to set fruit. Only the bee net and bumble bees can improve apple production.
Although various insects may be pollinators, but the main one is the honey bee. However, despite the advantages of the honey bee as pollinator of many plants, it is a relatively inefficient pollinator of apple flowers. The main reason for this is the tendency of honey bees to visit the apple flower from the side, thus "stealing" nectar without touching the flower's reproductive organs – stamens and stigma.
In contrast, a bee that visits the flower from the top contacts the flower's reproductive organs, which results in better pollination. Due to the low pollination efficiency, few seeds are formed, and often the resulting fruit is too small to be of commercial value.
Increasing Size of Pears and Number of Seeds
Experiments conducted in the Galilee and in the Golan over the last few years have shown for the first time that adding bumble bees into pear orchards improved cross-pollination, thus increasing the number of seeds and subsequently fruit size.
The main advantages of bumble bees are that they are active at ambient temperatures below 15° C and limited space in plastic mesh, which is the threshold for honey bees, their fast flight, which allows them to visit more flowers per time, their high efficiency as pollinators due their large body that does not allow them to be side workers, and their limited communication system, which retains bees in the orchard even if nest mates have found a highly attractive competing bloom elsewhere.
Increasing Size of Apples and Number of Seeds
The goal of the present work was to test the hypothesis that adding bumble bees to apple orchards may improve cross-pollination, not only due to an additive effect from the addition of pollinators, especially those that are active at lower ambient temperatures and bee nets, but also due to a possible synergistic effect on honey bees.
Such an effect would increase the activity and efficiency of the honey bees as top worker pollinators, thereby increasing the number of seeds and fruit size.
It appears that the addition of bumble bees did not only increase the number of pollinating insects in the orchard that could perform cross-pollination, including in adverse weather conditions and plastic bee net, but that it also changed honey bee foraging behavior, which resulted in improved cross-pollination and increased efficiency, and subsequently more seeds and larger fruit.