There is considerable interest among cotton growers in developing a hybrid seed industry, which, of course, would make insect pollinators mandatory.

Honey bees visit cotton flowers for nectar only, but when the flowers are not too wide open, the nectar-gathering bees transfer pollen satisfactorily. Many of the bees visit extra floral nectaries, and often it is necessary to "saturate" the field with bees to force enough of them to visit the blossoms.

THE TOMATO FLOWER is unattractive to most domestic species of pollinators and has structural adaptations to insure self-pollination. Consequently seed of first-generation hybrid tomato is produced by emasculating and hand Pollinating the flowers.

Suitable male-sterile lines of tomatoes have been developed, but pollinators are not attracted to them in sufficient numbers to set much seed. In their Peruvian homeland, tomatoes are attractive to their natural pollinators, and native varieties of tomato are structurally adapted for cross-pollination.

Male-sterile lines probably could be used for the production of first-generation hybrid seed if they were grown in the country of origin or if the natural species of pollinators could be established in this country. The problems involved may be difficult to overcome, but when we consider that hybrid tomato seed produced in California by hand pollination cost 200 to 300 dollars a pound in 1961, the effort seems to be justified.

THE HONEY BEE can be considered as a tool in the grower's hands for increasing seed production. Natural pollination is like natural soil moisture and fertility it is there for the using, but it usually requires supplementation.

"How many colonies do I need?" is the question most often asked by growers of seed.

A reasonable answer is almost impossible to give for growers who have little control over the total acreage in bloom or the total number of colonies within flight range of their fields.

A more practical question is, "How many bees per square yard do I need?"

Before the research worker can give an answer for the crop in question, he must determine four things: The number of flowers per day requiring pollination; the number of visits required per flower; the working speed of honey bees; and the seed-setting capacity of the plants. The efficiency and abundance of the wild pollinators present should be included in the calculation of the number of honey bees needed for a particular field.

The grower can work toward the calculated optimum population on the field by continually increasing the number of colonies, reducing competing sources of bloom, and making his field more attractive to bees.

Some seed crops give a clear indication of the adequacy of pollination by the speed with which the flowers wilt. For crops like alfalfa, in which flowers appear progressively along the stems and racemes, an appearance of full bloom is a sign of inadequate pollination.

Colonies should be distributed throughout the field if the acreage is large. Although honey bees sometimes fly long distances to forage, most of them range within a few hundred feet of their colonies if plenty of attractive bloom is available within that radius.

Furthermore, if colonies are placed within the field, flight to other fields is lessened, and the bees conserve time and energy. Very likely two-tenths of a mile is a good spacing for groups of colonies in large seed fields.

Strong colonies should be used for pollination. The percentage of field bees available for pollination and the possibility of obtaining surplus honey are better with strong colonies than weak ones.

Progressive movement of colonies into a field insures that some bees will be present to pollinate the first flowers and reduces the danger of mass orientation to other sources. If the full number of colonies is brought to the field when it begins to bloom, many of the bees are likely to locate other sources of bloom and remain faithful to them for long periods. The introduction of colonies to the field should be scheduled to the blossoming cycle of the crop.

COOPERATION among beekeepers and seedgrowers and community action are the twin keys to the pollination of seed crops by honey bees.

Cooperation by the grower usually takes the form of providing locations for apiaries and exercising care in the use of insecticides.

If the number of colonies needed exceeds that which the beekeeper considers best from the standpoint of a honey crop, he will expect supplemental income in the form of rental or a percentage of the seed crop.

The success of a grower's relationship with the beekeeper usually hinges upon cooperation throughout the community. Honey bees range far from their colonies sometimes several miles. If the neighbors use insecticides carelessly, the bees and their pollination services suffer, to the detriment of both parties in the cooperative agreement.

If the neighbors raise seed and do not enter into cooperative agreements with beekeepers, they benefit from pollination provided by the cooperating parties and provide nothing in return. That obviously is economically unsound.

Growers of alfalfa seed in California have formed what amounts to pollination districts, in which the seedgrowers in an area deal with a pollination coordinator, who contracts for a specific number of colonies to be placed in the fields according to a predetermined time and space schedule. Applications of insecticides follow a careful program supervised by entomologists working for the growers under the guidance of the California Agricultural Experiment Station.

This arrangement, which approaches the ideal, seems to be working out to the satisfaction of all concerned. In other areas where only a few members of the farming community have participated, little progress has been made toward consistently good pollination by honey bees.

GEORGE E. BOHART and FRANK E. TODD are members of the Entomology Research Division, Agricultural Research Service. The former is in charge of the Bee Culture Laboratory at Logan, Utah, and the latter of the Bee Culture Laboratory at Tucson, Ariz. The research work of these stations is carried on with the cooperation of the agricultural experiment stations of Utah and Arizona, respectively.