Honey bee pollinating necatarine. Honey bees are important pollinators of apricots. They visit flowers to collect both nectar and pollen. However, because apricots flower early in the spring mid August , the weather is often cool and rainy and will often not be suitable for honey bee foraging, which makes pollination difficult. The flowers are also often not very attractive to honey bees, as their nectar has very low concentrations of sugar, which will cause bees to move onto more attractive crops if they are available in the vicinity.
Pollen foragers are reported to visit apricot flowers faster than nectar foragers and are also more likely to touch the stigma while foraging and are therefore better pollinators. It has been suggested that for adequate pollination, a minimum of two bees need to be seen in a s search of a tree.
It is recommended that five hives are used per ha, however, in high density orchards this may need to be increased. Using colonies with a high demand for pollen will increase pollen collecting, as will trapping pollen and feeding sugar syrup. Honey bee and hover fly pollinating plum flowers. The most important plums Prunus sp. They produce clusters of white flowers that have five petals, one style and a ring of anthers.
Species range from those that are self-fertile through to those that are completely self-infertile. When planting plums it is therefore important to find out if the variety needs cross pollination and if so, also to plant the variety required for pollination. Plums are commonly planted in a distribution. Many problems with plum pollination occur because the necessary pollinisers are absent at flowering. Honey bees are the most important pollinators of plums because they can be introduced for pollination.
In a study on Japanese plums in the Goulburn Valley area of Victoria, Australia, 19 per cent of insect visitors were honey bees. The study concluded that other insect visitors lacked the behavioural traits to be effective pollinators. Honey bees visit flowers to collect both pollen and nectar. Many self- sterile cultivars have been largely or completely eliminated from the market, regardless of their other good qualities, because interplanting of cultivars and insect pollination are necessary in their production.
Hale', 'June Elberta', 'Mikado', and a few others. Unfortunately, the references to the self-sterility of such cultivars has tended to draw attention away from the "self-fertile" cultivars and the possibility that they might not be capable of fertilizing themselves without the aid of an outside agency. Conners b, reported that peaches in a glasshouse failed to set unless pollinated by hand or bees because of a lack of air currents to sway the blossoms and cause the stamens to come in contact with the stigma.
Coote also showed that when trees were grown in the greenhouse with bees to visit the flowers a heavy set resulted. Vermeulen and Pelerents obtained 84 fruits per tree in a glasshouse with bees but only five per tree with bees absent. Thompson reported on the value of bees to peaches in greenhouses in England. Later, he a mentioned the 'Susquehanna' as being self-sterile and that he discarded three other selections for that reason. Crandall found that more than twice as man: bagged flowers set fruit if they were hand pollinated than if bagged only.
Detjen performed a similar experiment with similar results, that is, flowers bagged and hand pollinated set more fruit than did open flowers, but flowers bagged only, without additional pollination, set fewer flowers. He felt that buffeting of the flowers by wind was sufficient to dislodge the pollen and transfer it to the stigma.
Sharma reported that while bagged peach flowers "gave a commercial set without pollination insects," the set was higher on unbagged branches. Kerr bagged branches of 27 cultivars and found that 19 were "sufficiently self fruitful, 5 did not set enough and 2 were unfruitful". For example, MacDaniels and Heinecke stated: "Most peach varieties are self-fertile and present no pollination difficulties except that attributable to lack of sufficient insects at blooming time to accomplish self-pollination.
Bulatovic and Konstantinovic obtained better set on various species with exposed flowers than with selfed flowers, and they concluded that there was slightly more fruit set on all cultivars when visited by bees. Rather thorough studies were conducted by Marsha et al. Jorgense and Drage listed peaches as "largely self-fruitful, but "bees are necessary" in their pollination. Khan also concluded that cross-pollination is necessary to obtain good yields and that bees are the chief agent for cross-pollination.
Boller stated that "Some pollination occurs' without the help of bees, probably by shaking of the flowers by the wind. Whether we get enough self-pollination by this means is unknown. We do know that a small number of bees can do a lot of self-pollinating since almost every visit to a flower results in self- pollination.
Fogle personal commun. These references indicate that, although the actual data are sparse, pollinating insects are of value even for the self-fertile cultivars of peaches.
Some growers consider thinning of a heavy set of fruit to be a greater problem than pollination Snyder et al. Pollinators: The degree of pollination actually accomplished by wind as compared to insects is unknown. Also, if, as some references indicate, wind alone is insufficient and insects are needed, the number of visitors is unknown. If the weather is clear and mild, the bees will visit the flowers throughout much of the day; however, if the weather is cold or wet, bees may be absent.
In visiting the nectaries in the base of the flower, the bee either pushes one or more anthers against the stigma or rubs against it.
A guide to managing bees for crop pollination. Slingerland, K. Peach and nectarine cultivars. Pollination Basics What is Pollination? References Kevan, P. Pollination, crops and bees.
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