By Clint Thompson
Poor fruit set in tomatoes is a bi-product of the heat and humidity felt across Alabama this time of year; when daytime temperatures exceed 85 degrees Fahrenheit (F) or nighttime temperatures exceed 70 F.
Wade Hummer, Alabama Extension agent, discussed poor fruit set during a webinar on Facebook.
“Once you start seeing the nighttime temps above 70 F, daytime temps above 85 F, you really start to see the pollen viability go down. And same with that humidity too. If it gets way out of whack, the pollen can get either too sticky or too dry,” Hummer said.
He talked about a few of the methods to increase fruit set in a follow-up interview with AgNet Media.
“I would say probably one of the most successful ways I’d say would be to plant a few cherry tomatoes. Just because that way, if you don’t do the shade cloth or anything else, they’re still a little more heat tolerant,” Hummer said. “Also working with some varieties that work well in the area. So, if you start with your recommended varieties with that research of Auburn, that’s a good start.”
Hummer highlighted other tactics that growers can implement to increase their tomato fruit.
“First thing would be some shade cloth, so that will decrease your temperature just a little bit. The next step would be having some sort of integrated pest management program. Using that and also frequently scouting for pests and diseases. Say, for example, I had a problem last year with tomato spotted wilt virus, I’d recommend trying to find a variety that’s resistant to that next year,” Hummer said.
“If you’re in a greenhouse, you can either shake or tap the stem. Consistent watering would be another step. “Avoiding excessive nitrogen; so an excess of nitrogen tends to cause a lot of vegetative growth. And what you really want is reproductive growth than flowers and fruits. If you are using bumblebees, you want to limit your pesticide exposure. So, a good way to do that would be to spray pesticides about an hour before it gets dark.”