by Judy Biss | Feb 3, 2016
Corn tassels at the top provide the pollen needed to produce the perfect ear of corn on the stalk below. UF/IFAS Photo by Tyler Jones.
It won’t be long until row crops and vegetable gardens are planted and thriving once again next spring. A sometimes taken for granted, yet critical element of any prosperous crop is successful pollination. Most of us know what “text book” pollination means, but did you know in cucurbit plants, (squash, melon, pumpkin) at least 1,000 grains of pollen must be evenly deposited in each bloom to produce a uniform marketable fruit? Or, to grow our favorite summer delight, each watermelon flower must be visited by a honeybee a minimum of 8 times? And how about the fact that each silk in a corn flower is connected to one kernel on the ear of corn, and for the kernel to develop properly pollen must travel down the silk through a pollen tube to the waiting kernel? Add to these facts the dizzying variety of pollen and flowers, bloom times, pollination dynamics, weather conditions, plant growth, and availability of pollinator insects, then one can begin to see how amazing pollination is, and how critical it is to our food supply.
What are the basics of pollination?
The first step of fruit or vegetable reproduction takes place when flowers emerge. Plant flowers can be male, female, or perfect flowers. The male flowers produce pollen. The female flowers have ovaries which, when fertilized, become the fruit or vegetable. “Perfect” flowers have both male and female parts within a single flower. Most garden vegetables such as beans, peppers, and tomatoes have perfect flowers, whereas cucurbits like squash, pumpkins and watermelon, have separate male and female flowers on the same vine. For successful pollination to occur, the male pollen must reach the female ovaries in order for the fruit or vegetable to be produced.
Methods of Pollinating
Transfer of pollen to the plant ovaries for fruit and vegetable production, whether in the same “perfect” flower, or in another separate female flower, occurs in several ways. Some plants, like corn, depend on wind to transfer pollen to the silk, and ultimately ovaries, of the female flower. Other plants, like squash depend on the help of pollinators like insects to deliver the pollen to the ovaries. Plants that produce perfect flowers can self-pollinate, but still benefit from contact with pollinators. In small backyard gardens, many crops in the cucurbit family (squash, melons, etc.) or those that have separate male and female flowers, can be pollinated by the gardener by hand. In the absence of insect pollinators in dooryard gardens, hand pollination will increase yields.
The Importance of Bees
Obviously, in production agriculture, hand pollination of crops is not feasible, and although some crops are wind pollinated, most crops need insect or animal pollinators to accomplish the job. As we know, bees are one of the most important pollinating insects, and it is well documented that yields of many fruit and vegetable crops increase in both quality and quantity when pollinated by honey bees. According to the UF/IFAS publication Minimizing Honey Bee Exposure to Pesticides:
The Business of Pollination
Because they are so critical to increased quality and quantity yields, managed honey bee colonies are used across the country in a thriving contractual pollination industry. According to the UF/IFAS publication Sample Pollination agreement,
The business of pollination is crucial to the agricultural industry in the United States. In Florida, the major need for pollination is in fruit and vegetable production.
And according to the UF/IFAS publication Minimizing Honey Bee Exposure to Pesticides,
Rental of honey bee colonies for pollination purposes is a highly demanded service and a viable component of commercial beekeeping and agriculture. Bee colonies are moved extensively across the country for use in multiple crops every year. There are also over 3,000 registered beekeepers in Florida, managing a total of more than 400,000 honey bee colonies and producing between 10–20 million pounds of honey annually.
Cotton is largely self-pollinating, but attractive to bees. In some cotton varieties, pollination by bees can increase seed set per boll. Source: University of Georgia Pollination: Crop Pollination Requirements. Photo by Judy Biss
Crop Pollination Requirements
The dynamic of pollination is a fascinating and critical component of both dooryard and production agriculture. Research on plant health, varieties, growth, and potential, as well as research on honey bee colony health and management, all play a role in producing sustainable food yields. The University of Georgia has summarized pertinent literature related to common fruit and vegetable crop pollination requirements (Apple, Blueberry, Cantaloupe, Cucumber, Squash, Watermelon, Other Crops). This comprehensive resource provides the recommended number of beehives per acre for each crop, plus additional information on plant variety characteristics, and other useful information related to maximizing pollination and yield. Check it out: Pollination: Crop Pollination Requirements
So whether you have a dooryard garden or a large farm, it will benefit you to learn all there is to know about your crop’s pollination requirements to maximize yield and quality potential.
For more information on this topic, please see the following publications used as resources for this article:
by Mary Salinas | Sep 24, 2015
Native Lanceleaf Coreopsis. UF/IFAS Photo: Thomas Wright.
In our demonstration garden we are enjoying the small but vibrant blooms of our state wildflower Coreopsis, also commonly known as tickseed. After many years of its use in the Florida highways beautification program, Coreopsis was adopted as Florida’s official state wildflower in 1991.
Florida can boast of 16 different species of Coreopsis that occur in the state with most blooming in the spring but some species blooming in the summer to later in the fall. Some of those species are rare, endangered or only found in very limited areas of the state, while others are quite common throughout the state.
Photo credit: Mary Derrick, UF/IFAS.
Many lovely new cultivars have been introduced for our enjoyment by plant breeders through cross-breeding and selection. Some you can see in the accompanying photographs in this article.
Photo credit: Mary Derrick, UF/IFAS.
Coreopsis is an annual or short-lived perennial that makes a great addition to your garden beds. And the bees and butterflies will enjoy them! The numerous flowers readily produce seed for naturalizing in the landscape. Plant them in a sunny spot in the landscape in evenly watered but well-drained soil. Removing the dead blooms will encourage plants to prolong their blooming; you can also save the seed for replanting in new areas of your landscape.
For more information:
History of Coreopsis as Florida State Wildflower
Gardening Solutions: Coreopsis
Florida Wildflower Foundation
by Sheila Dunning | May 22, 2015
Everyone with a landscape can make a difference for pollinators. Simply Having Areas Reserved for the Environment enables homeowners, land managers, farmers, individuals, corporations, schools, roadside managers, and golf courses to increase the number of pollinators in the area by making conscious choices to include plants that provide essential habitat for bees, bats, birds, butterflies, moths, beetles, and hummingbirds. What better time than during National Pollinator Week, June 15-21, 2015.
Initiated and managed by the North American Pollinator Protection Campaign, National Pollinator Week was unanimously approved and designated by the U.S. Senate in 2007. Each year since, the U.S. Secretary of Agriculture has signed the proclamation in an effort to address the urgent issue of declining pollinator populations.
Worldwide there is evidence that pollinating animals have suffered from loss of habitat, pesticide misuse, competition from invasive species, disease, and parasites. Many pollinators are federally “listed species”, meaning that there is documented information confirming the disappearance and/or significant population reduction in natural areas. The United States has lost over 50% of its managed honeybee colonies over the past ten years. The European Union has been so concerned that they invested over $20 million investigating the status of pollinators in Europe.
Pollinator health affects everyone. Worldwide, roughly 1,000 plants grown for food, beverages, fibers, spices, and medicines need to be pollinated by animals in order to produce the goods on which we depend. Food and beverages produced with the help of pollinators include: apples, blueberries, chocolate, coffee, melons, peaches, potatoes, pumpkins, vanilla, almonds, and tequila. In the U.S., pollination by honey bees, native bees, and other insects produces $40 billion worth of products annually.
The native plants that can be identified and preserved or introduced include trees, shrubs, vines and perennials. Some of them include: Eastern Redbud (Cercis canadensis), Highbush Blueberry (Vaccinium spp.), Passionflower (Passiflora spp.), Coreopsis (Coreopsis spp.), Goldenrod (Solidago spp.), Black-eyed Susan (Rudbeckia hirta), and Butterfly Milkweed (Asclepias tuberosa). Simply identifying and avoiding damaging many of the existing native plants will allow anyone to provide important homes and food for many different pollinating animals. During National Pollinator Week S.H.A.R.E. your space.
For additional information:
UF Native Buzz
Gardening for Pollinators
Minimizing Honey Bee Exposure to Pesticides
The Xerces Society
by Sheila Dunning | Apr 28, 2015
Bees have been disappearing at an alarming rate and continue to vanish without a trace. Why should anyone care? Well, they matter a lot more than most people think. Bees are the overwhelmingly dominant pollinator for most food crops. Native bees in the United States are responsible for pollinating over $15 billion worth of agricultural commodities annually. However, native bee populations are in decline due to habitat loss. At the same time, managed colonies of European honey bees have suffered a 50% decline over the past few decades. Numerous other pollinating insects are facing the same fate.
European honey bee. Photo credit: UF/IFAS.
As the spring planting season is upon us, it’s exciting to think about all the wonderful produce we will have this summer. But, without pollinators many of these crops would not be available. The majority of fruit and vegetable food sources we eat are dependent on insect pollinators. One of every three bites of food Americans consume comes from a plant visited by bees or other pollinators.
As declining numbers of farmers work to meets the need of increasing populations, they are forced to make choices on alternative to chemicals for pest control. “Good bug blends” of flowers can help attract pollinators as well as beneficial insects that suppress harmful pests. Establishment of these meadows can be done on a small or large scale and in any habitat. One approach to “bring back the pollinators” is to intercrop with blooming plants that attract insects. Selecting a diversity of plants with different flower sizes, shapes and colors, as well as various plant heights and growth habits, will encourage the greatest numbers of pollinators. It is important to provide a continuous source of pollen and nectar throughout the growing season. At minimum, strive for three species to be blooming at any one time; the greater the diversity the better.
To enhance the garden, choose flowering plants that also provide shelter for beneficial insects. Many companion plants are suitable habitat for predators and parasitoids. Research in Florida has demonstrated that predatory minute pirate bugs can build to high numbers in sunflowers. The favorite food of minute pirate bugs is Western flower thrips. So, planting sunflowers on the perimeter of vegetable crops, such as peppers, can greatly reduce the damage caused by the thrips. Similar results were found with the planting of sorghum to attract beneficial mites and intercropping with buckwheat to house syrphid flies and parasitoid wasps. The garden vegetables experienced fewer spider mite, whitefly and aphid problems. Crimson clover, Hairy vetch and cosmos are other annual seed crops that can aid in attracting pollinators and harboring beneficial insects.
Blue Mistflower. Photo Credit Mary Derrick, UF / IFAS Extension.
Insectary meadows can be created in the landscape and along roadways, not just in the garden. For more permanently planted areas, native wildflowers, grasses and woody plants serve as larval host plants for butterflies, and also provide nesting and overwintering sites for bumble bees, predacious beetles and other beneficial insects. Native perennial wildflowers such as blanketflower, tickseed, black-eyed Susan, partridge pea, narrowleaf sunflower, milkweed, beebalm, goldenrod and silkgrass can be installed in the spring as potted plants or seeded in the fall. Seeds require exposure to cold temperatures and damp conditions before germination can occur. In Florida, the best time is November to February.
Though grasses do not offer nectar or high-quality pollen, it is often useful to include at least one native bunch grass or sedge. Short, clump-forming grasses are preferable to large, spreading grasses. Hedgerow planting of woody species is a way to provide winter-blooming plants vital for supporting pollinators. Woody plants and grasses provide more than forage for pollinators, as many native bee species nest in the stems of plants or in the undisturbed ground underneath plantings. Suitable grasses include: beaked panicgrass, purple lovegrass, Muhly grass, broomsedge,little bluestem, wiregrass and toothache grass. Favored woody species that make good “beetle banks” include: fetterbush, American beautyberry, saw palmetto, Chickasaw plum, red maple, sparkleberry, Dahoon holly, redbud, blackgum, magnolia, buttonwood and sourwood.
Regardless of whether the objective is to establish herbaceous or woody vegetation, the time and effort spent on eradicating undesirable plants prior to planting will result in higher success rates in establishing the targeted plant community. Choose level, open sites that receive full sunlight and have limited weed populations. If perennial weeds are a problem, the use of herbicides that have no soil residual (e.g. glyphosate) may be necessary.
For more information on establishing planting for pollinators visit: www.xerces.org/pollinator.
