Pollination of Vegetable Crops – Maximize Your Crop’s Potential

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:

• Florida Crop/Pest Management Profile: Watermelon
• University of Georgia, Pollination: Crop Pollination Requirements
• Sample Pollination agreement
• Home Vegetable Garden Techniques: Hand Pollination of Squash and Corn in Small Gardens
• Minimizing Honey Bee Exposure to Pesticides
• Pollination in the Garden