Hello Tura; The number needed certainly varies with the crop of interest. If there is no research in your area, you might first try finding out what the local growers know. At least that would give you a value to start with. Best wishes, Jim Des Lauriers

Dear James Des Lauriers,

Yes, I know as the numbers needed are varied. However, I want to know the general formula to estimate the no. of honeybee colonies required to be placed per acres of crops for pollination.

Dear Tura,

The optimal number of honeybee colonies per acer is usually 1 - 2 colonies in the case of standard crops (oilseed rape, buckwheat or sunflowers). In the case of clover up to 2x more and in the case of alfalfa even ap to 4x more....

Additionally, it depends on the strength of the colony. My recommendations are based on the assumption that one colony has at least 30,000 worker bees...

Hi Tura,

This number is often defined in pollination contracts, that are mainly respected by the major farmers. I suggest you to collect some of these contracts among beekeepers or seed/fruit producers so you can make an estimation of the "economical need" for crop pollination.

If your question is about the "real" number of colonies necessary for crop pollination, you have to consider the landscape aroud the crops.

- if there is a largely diversified flora/fauna, and the global part of you crop in the landscape is small (

Dear Tura, your question is an important and basic one, since in many crops an adequate pollination is a mast term for achieving good yield.

The needed number of honeybee colonies for adequate pollination of a specific crop is depended on: a. The crop flowering properties; b. The size and the form of the crop plots; c. The competing nectar and pollen sources presenting around and within the crop field.

For many orchard crops, like apples and almonds, two strong and healthy honeybee colonies per acre are usually recommended. However, for large uniform plantations even one colony may be adequate, since that crop flowers are the main, or the only honeybee food source. Apple and almond bloom is attractive for honeybees, but avocado bloom, for instance, is much less so. Therefore, if a competing blooming plants are presenting in the vicinity, avocado orchard may demand 3-4 honeybee colonies per acre. Other crop species may have different needs, and should be studied specifically.

One colony is sufficient

Being a research worker I suggest that ,it is important to ist determine the available flora in the surroundings of the crop atleast 1 to 1.5 km.In one acre one bee hive with full 10 frames bees population is enough to cross pollinate the crop easily.however if the surrounding situation with respect to the flora is not at optimum level thn u need to place two bee hive colonies in one acre area tht will be sufficient for crop pollination and before the start of flowering period of respective crop the bees also fullfill their pollen and nectar requirement from the surroundings flora and supplimentary feed.

That is entirely dependent on the type of crop, and the variety of bee. For example, alfalfa is a difficult flower for bees to pollinate. However, most alfalfa will be cut before flowering and then regrown for a subsequent cut(s).

But if you are considering the cherry or almond crops in the Great Central Valley of California; they contract with moving pollinators. Large trucks move in a place dozens of hives while the trees are flowering. Most of them use the Carniolan or Russian variety of honeybee. Then they come in at night, close up the hives, and truck them out to pollinate another crop; say pears.

The hives do not stay at the orchards year-round. When orchards are sprayed with herbicides or insecticides, that is very detrimental to honeybees. Neonicotinides, a class of insecticide, has been shown to be a link between Colony Collapse disease.

So you see, the question has a lot of variables.