Crop pollination and weed control highlight Cross Timbers Melon meeting

By MANDY JOHN | Central Texas Edition

January 30, 2003 -- The Cross Timbers Melon Shortcourse that was held Jan. 23 in Comanche, gave participants the opportunity to learn more about crop production. Dr. Tanya Pankiw, research entomologist, discussed bee pollination and pheromones and Dr. Russ Wallace, Extension horticulturist, talked about weed control in melons.

"There are 130 agricultural crops in the United States that are pollinated by bees," explained Pankiw. "The value of honeybees, and any other bee for that matter, is significant in the United States."

She stated that the rationale for pollination research is that the demand for colonies has increased due to the high consumption of bee pollinated crops and the reduced number of colonies due to parasites and disease.

"Bees take three days to three weeks to go from emergence, which is coming out of their cell in the hive, to becoming a forager. It is during that time that they become adapted to most of the forage dangers that they will face.

"When bees become foragers, they de-cide their forage choice.

"That means they either de-liver nectar, pollen, or both nectar and pol-len."

Pankiw said that the intra-colony environment affects the foraging behavior, such as the amount of stored pollen and the amount of larvae. The forage environment outside the colony, such as the nectar and the pollen quality, also affects their forage behavior.

"The effects of the stored pollen amount changes the proportion of pollen forages. More stored pollen results in less pollen foraging. The effects of larvae also changes the proportion of pollen forages in that more larvae results in more pollen foraging.

"Pollen, larvae, and empty space interact with each other, affecting pollen foraging. Larvae has a positive effect on pollen foraging. Larvae and empty space also have a positive effect, but pollen has a negative effect."

She concluded that the load of pollen that a bee carries represents the number of flowers that the bee has visited. The greater the load, the more flowers that the bee is going to.

Wallace began his presentation by stating that good pre-emergence broadleaf weed control is essential in melon and squash production. "There are currently few herbicide options with a good pre-emergence weed control."

He discussed a new weed control option called Sandea. "At the time of application, the growth of the actual plant will be stabilized, but then it will start growing again. Good weed control creates temporary crop stunting, such as on nutgrass.

"Using Sandea on watermelons initially has crop injury, but it will be low after the initial use. Same as when you use it on tank mixes, which means mixing herbicides together. "

He gave a few tips when dealing with herbicide residual from rotational crops:

• Always read the label carefully

• Plan ahead for rotational crops with the choice of herbicide in mind

• Understand conditions that would likely occur causing residual, such as environment, application, or soil type.

"The first two tips that were mentioned before also apply when dealing with herbicide residual to rotation crops."

Wallace ended his presentation by explaining the USDA funded program IR-4. "IR-4 is a program that provides pest management solutions to growers of fruits, vegetables, and other minor crops. IR-4 is the only publicly funded program in the U.S. that conducts research and submits petitions to the EPA for registration of pesticides on minor crops. People who benefit are crop growers, food processors, and consumers."