Saturation pollination
Encyclopedia
Saturation pollination is a pollination
technique for agricultural
crops
in areas dominated by non-crop plant species that are preferred by pollinators. The technique involves keeping a larger number of bee colonies than normally maintained for honey production so as to exhaust the preferred plants and ensure visitation of the crop plants by the bees. The technique is applied in areas that are normally avoided by beekeepers because of poor honey yields.
Saturation pollination is especially important for those with special pollination problems, such as crops with flower
s that are unattractive to Western honey bees (kiwifruit
, for example), that have nectar that is low in sugar
s, or crops that have been moved from their native areas without the corresponding movement of their normal pollinators. The keel of alfalfa
flowers knock young honey bees on the head when they attempt to take the nectar and the bees soon learn to come in from the side to avoid getting hit with the keel's pollen bearing structure while still getting the nectar. Thus only young, inexperienced bees are doused with pollen and able to pollinate alfalfa. Saturation pollination is becoming increasingly required for many crops due to decline of wild pollinators and monoculture
d crops.
entomologist
George H. Vansell in conjunction with alfalfa seed production.
Though fruit
growers and beekeepers were well acquainted with the vital role of Western honey bees in pollinating fruit blossoms, the role of these bees in alfalfa
seed
production was poorly understood. In the 1920s California beekeepers began migrating into Utah
during the alfalfa bloom; at that time Utah being the largest alfalfa seed producing state in the US
. When alfalfa first comes into bloom the flowers are bluish-purple and the fields have a bright cast. As the blossoms are pollinated the flowers fade and take on a grayish cast, making the field appear dull colored. Utah farmers were convinced that the bees were somehow damaging the blossoms, and persuaded the state legislature
in 1930 to enact an embargo
against bees entering the state from other states. Alfalfa seed yields from the fields declined so precipitously that the farmers were going bankrupt. The error was realized and the embargo rescinded in 1934; however Utah had forever lost its pre-eminent position as an alfalfa seed growing state, and California took the lead. After World War II
, demand for alfalfa seed reached an all-time high. Normally alfalfa is planted in rotation with other crops, because, as a legume, it replenishes nitrogen
in the soil. However, wartime needs had caused many alfalfa fields to be converted to vegetable
s and other crops thought to be more necessary to the war effort. Now, the farmers were trying to repair the damage done to soils by replanting alfalfa. While the demand was the highest in history, seed production was steadily declining. Increasing pesticide
use and the increased utilization of fallow land and hedgerows was depleting wild pollinators
to near the
vanishing point. California beekeepers produced a high quality honey from alfalfa, and were willing to move bees to the alfalfa seed fields at a rate of one and a half hives
per acre. Experience had shown this the maximum rate at which bees could be stocked without damaging the honey yield per hive. Vansell and Whitcombe had become convinced by their observations that the optimum rate for honey production for beekeepers was not sufficient for optimum pollination and seed production. Whitcombe notes that he always observed the heaviest seed set in the plants that were nearest the stands of bees.
Vansell was finally able to convince Luther G Jones, the alfalfa seed specialist at the agricultural college at Davis
, that further experiments in this area would be profitable. The plan was to stock some test fields at four to six hives per acre and see if the yield responded. It was called saturation pollination. But beekeepers were not willing to stock hives at a more concentrated rate, because they would lose money. At the same time, even though fruit growers had long been accustomed to paying pollination fees, no alfalfa seed grower was willing to pay for pollination service.
In 1948 the three were able to find a grower who was willing to risk a contingent deal. Stan Good, of Woodland, California
, was a progressive farmer who was willing to experiment. But he would not risk any money. The deal was that Good would raise 150 acre (0.607029 km²) of alfalfa for seed production, using the best cultivation techniques known, and Whitcombe would supply the bees at the rate of five hives per acre, again using the best management practices. For every pound of alfalfa seed produced above the rate of 400 pounds per acre (which was well above the area's normal average), Whitcombe would receive one cent per hive. And for all seed produced above 750 pounds per acre, one third of the seed would belong to the beekeeper.
The result was that the plants set so heavy a seed crop that they could not support the seed head. True to his word, Good began irrigating, a practice not normally done, so that the plants would continue to grow and strengthen to support the seed heads. The plants began to grow again and put out more bloom, which promptly set more seed. At harvest time, the results of the experiment were so phenomenal that it almost ruined the experiment. The crop yield was so heavy that the harvesting equipment choked up and broke down. It had to be reworked by the agricultural mechanic
s at Davis to give heavier bearings and increased capacity. With seasonal rains threatening the crop was finished just in time to be measured.
The total yield was almost 1000 pounds to the acre - well above the 220 average California yield at that time. Both beekeeper and farmer were rewarded handsomely by the results. The word spread quickly and in four seasons California tripled its alfalfa seed production.
The saturation pollination technique was also applied to ladino
and alsike clover
seed production with corresponding increases. With California running three times the national average per acre for forage legume seeds, other states began to pick up California's techniques. By the 1970s and 1980s large scale saturation pollination had become the norm
in US agriculture for many more crops which require bee pollination.
for alfalfa seed pollination.
Pollination management
Pollination Management is the label for horticultural practices that accomplish or enhance pollination of a crop, to improve yield or quality, by understanding of the particular crop's pollination needs, and by knowledgeable management of pollenizers, pollinators, and pollination...
technique for agricultural
Agriculture
Agriculture is the cultivation of animals, plants, fungi and other life forms for food, fiber, and other products used to sustain life. Agriculture was the key implement in the rise of sedentary human civilization, whereby farming of domesticated species created food surpluses that nurtured the...
crops
Crop (agriculture)
A crop is a non-animal species or variety that is grown to be harvested as food, livestock fodder, fuel or for any other economic purpose. Major world crops include maize , wheat, rice, soybeans, hay, potatoes and cotton. While the term "crop" most commonly refers to plants, it can also include...
in areas dominated by non-crop plant species that are preferred by pollinators. The technique involves keeping a larger number of bee colonies than normally maintained for honey production so as to exhaust the preferred plants and ensure visitation of the crop plants by the bees. The technique is applied in areas that are normally avoided by beekeepers because of poor honey yields.
Saturation pollination is especially important for those with special pollination problems, such as crops with flower
Flower
A flower, sometimes known as a bloom or blossom, is the reproductive structure found in flowering plants . The biological function of a flower is to effect reproduction, usually by providing a mechanism for the union of sperm with eggs...
s that are unattractive to Western honey bees (kiwifruit
Kiwifruit
The kiwifruit, often shortened to kiwi in many parts of the world, is the edible berry of a cultivar group of the woody vine Actinidia deliciosa and hybrids between this and other species in the genus Actinidia....
, for example), that have nectar that is low in sugar
Sugar
Sugar is a class of edible crystalline carbohydrates, mainly sucrose, lactose, and fructose, characterized by a sweet flavor.Sucrose in its refined form primarily comes from sugar cane and sugar beet...
s, or crops that have been moved from their native areas without the corresponding movement of their normal pollinators. The keel of alfalfa
Alfalfa
Alfalfa is a flowering plant in the pea family Fabaceae cultivated as an important forage crop in the US, Canada, Argentina, France, Australia, the Middle East, South Africa, and many other countries. It is known as lucerne in the UK, France, Australia, South Africa and New Zealand, and known as...
flowers knock young honey bees on the head when they attempt to take the nectar and the bees soon learn to come in from the side to avoid getting hit with the keel's pollen bearing structure while still getting the nectar. Thus only young, inexperienced bees are doused with pollen and able to pollinate alfalfa. Saturation pollination is becoming increasingly required for many crops due to decline of wild pollinators and monoculture
Monoculture
Monoculture is the agricultural practice of producing or growing one single crop over a wide area. It is also known as a way of farming practice of growing large stands of a single species. It is widely used in modern industrial agriculture and its implementation has allowed for large harvests from...
d crops.
History of the technique
The concept was developed by commercial California beekeeper Harry J. Whitcombe and University of CaliforniaUniversity of California
The University of California is a public university system in the U.S. state of California. Under the California Master Plan for Higher Education, the University of California is a part of the state's three-tier public higher education system, which also includes the California State University...
entomologist
Entomology
Entomology is the scientific study of insects, a branch of arthropodology...
George H. Vansell in conjunction with alfalfa seed production.
Though fruit
Fruit
In broad terms, a fruit is a structure of a plant that contains its seeds.The term has different meanings dependent on context. In non-technical usage, such as food preparation, fruit normally means the fleshy seed-associated structures of certain plants that are sweet and edible in the raw state,...
growers and beekeepers were well acquainted with the vital role of Western honey bees in pollinating fruit blossoms, the role of these bees in alfalfa
Alfalfa
Alfalfa is a flowering plant in the pea family Fabaceae cultivated as an important forage crop in the US, Canada, Argentina, France, Australia, the Middle East, South Africa, and many other countries. It is known as lucerne in the UK, France, Australia, South Africa and New Zealand, and known as...
seed
Seed
A seed is a small embryonic plant enclosed in a covering called the seed coat, usually with some stored food. It is the product of the ripened ovule of gymnosperm and angiosperm plants which occurs after fertilization and some growth within the mother plant...
production was poorly understood. In the 1920s California beekeepers began migrating into Utah
Utah
Utah is a state in the Western United States. It was the 45th state to join the Union, on January 4, 1896. Approximately 80% of Utah's 2,763,885 people live along the Wasatch Front, centering on Salt Lake City. This leaves vast expanses of the state nearly uninhabited, making the population the...
during the alfalfa bloom; at that time Utah being the largest alfalfa seed producing state in the US
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
. When alfalfa first comes into bloom the flowers are bluish-purple and the fields have a bright cast. As the blossoms are pollinated the flowers fade and take on a grayish cast, making the field appear dull colored. Utah farmers were convinced that the bees were somehow damaging the blossoms, and persuaded the state legislature
Legislature
A legislature is a kind of deliberative assembly with the power to pass, amend, and repeal laws. The law created by a legislature is called legislation or statutory law. In addition to enacting laws, legislatures usually have exclusive authority to raise or lower taxes and adopt the budget and...
in 1930 to enact an embargo
Embargo
An embargo is the partial or complete prohibition of commerce and trade with a particular country, in order to isolate it. Embargoes are considered strong diplomatic measures imposed in an effort, by the imposing country, to elicit a given national-interest result from the country on which it is...
against bees entering the state from other states. Alfalfa seed yields from the fields declined so precipitously that the farmers were going bankrupt. The error was realized and the embargo rescinded in 1934; however Utah had forever lost its pre-eminent position as an alfalfa seed growing state, and California took the lead. After World War II
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...
, demand for alfalfa seed reached an all-time high. Normally alfalfa is planted in rotation with other crops, because, as a legume, it replenishes nitrogen
Nitrogen
Nitrogen is a chemical element that has the symbol N, atomic number of 7 and atomic mass 14.00674 u. Elemental nitrogen is a colorless, odorless, tasteless, and mostly inert diatomic gas at standard conditions, constituting 78.08% by volume of Earth's atmosphere...
in the soil. However, wartime needs had caused many alfalfa fields to be converted to vegetable
Vegetable
The noun vegetable usually means an edible plant or part of a plant other than a sweet fruit or seed. This typically means the leaf, stem, or root of a plant....
s and other crops thought to be more necessary to the war effort. Now, the farmers were trying to repair the damage done to soils by replanting alfalfa. While the demand was the highest in history, seed production was steadily declining. Increasing pesticide
Pesticide
Pesticides are substances or mixture of substances intended for preventing, destroying, repelling or mitigating any pest.A pesticide may be a chemical unicycle, biological agent , antimicrobial, disinfectant or device used against any pest...
use and the increased utilization of fallow land and hedgerows was depleting wild pollinators
Pollinator decline
The term pollinator decline refers to the reduction in abundance of pollinators in many ecosystems worldwide during the end of the twentieth century....
to near the
vanishing point. California beekeepers produced a high quality honey from alfalfa, and were willing to move bees to the alfalfa seed fields at a rate of one and a half hives
Beehive (beekeeping)
A beehive is an enclosed structure in which some honey bee species of the subgenus Apis live and raise their young. Natural beehives are naturally occurring structures occupied by honeybee colonies, while domesticated honeybees live in man-made beehives, often in an apiary. These man-made...
per acre. Experience had shown this the maximum rate at which bees could be stocked without damaging the honey yield per hive. Vansell and Whitcombe had become convinced by their observations that the optimum rate for honey production for beekeepers was not sufficient for optimum pollination and seed production. Whitcombe notes that he always observed the heaviest seed set in the plants that were nearest the stands of bees.
Vansell was finally able to convince Luther G Jones, the alfalfa seed specialist at the agricultural college at Davis
University of California, Davis
The University of California, Davis is a public teaching and research university established in 1905 and located in Davis, California, USA. Spanning over , the campus is the largest within the University of California system and third largest by enrollment...
, that further experiments in this area would be profitable. The plan was to stock some test fields at four to six hives per acre and see if the yield responded. It was called saturation pollination. But beekeepers were not willing to stock hives at a more concentrated rate, because they would lose money. At the same time, even though fruit growers had long been accustomed to paying pollination fees, no alfalfa seed grower was willing to pay for pollination service.
In 1948 the three were able to find a grower who was willing to risk a contingent deal. Stan Good, of Woodland, California
Woodland, California
Woodland is the county seat of Yolo County, California, located approximately northwest of Sacramento, and is a part of the Sacramento - Arden-Arcade - Roseville Metropolitan Statistical Area. The population was 55,468 at the 2010 census.Woodland's origins trace back to 1850 when California...
, was a progressive farmer who was willing to experiment. But he would not risk any money. The deal was that Good would raise 150 acre (0.607029 km²) of alfalfa for seed production, using the best cultivation techniques known, and Whitcombe would supply the bees at the rate of five hives per acre, again using the best management practices. For every pound of alfalfa seed produced above the rate of 400 pounds per acre (which was well above the area's normal average), Whitcombe would receive one cent per hive. And for all seed produced above 750 pounds per acre, one third of the seed would belong to the beekeeper.
The result was that the plants set so heavy a seed crop that they could not support the seed head. True to his word, Good began irrigating, a practice not normally done, so that the plants would continue to grow and strengthen to support the seed heads. The plants began to grow again and put out more bloom, which promptly set more seed. At harvest time, the results of the experiment were so phenomenal that it almost ruined the experiment. The crop yield was so heavy that the harvesting equipment choked up and broke down. It had to be reworked by the agricultural mechanic
Mechanic
A mechanic is a craftsman or technician who uses tools to build or repair machinery.Many mechanics are specialized in a particular field such as auto mechanics, bicycle mechanics, motorcycle mechanics, boiler mechanics, general mechanics, industrial maintenance mechanics , air conditioning and...
s at Davis to give heavier bearings and increased capacity. With seasonal rains threatening the crop was finished just in time to be measured.
The total yield was almost 1000 pounds to the acre - well above the 220 average California yield at that time. Both beekeeper and farmer were rewarded handsomely by the results. The word spread quickly and in four seasons California tripled its alfalfa seed production.
The saturation pollination technique was also applied to ladino
White clover
Trifolium repens, the white clover , is a species of clover native to Europe, North Africa, and West Asia...
and alsike clover
Clover
Clover , or trefoil, is a genus of about 300 species of plants in the leguminous pea family Fabaceae. The genus has a cosmopolitan distribution; the highest diversity is found in the temperate Northern Hemisphere, but many species also occur in South America and Africa, including at high altitudes...
seed production with corresponding increases. With California running three times the national average per acre for forage legume seeds, other states began to pick up California's techniques. By the 1970s and 1980s large scale saturation pollination had become the norm
in US agriculture for many more crops which require bee pollination.
A supplement or alternative to honeybees
Today, research is ongoing in the use of an alternative pollinator, the alfalfa leafcutter beeAlfalfa leafcutter bee
Megachile rotundata, the alfalfa leafcutter bee or lucerne leafcutter bee is a European bee that has been introduced to other regions...
for alfalfa seed pollination.