La Nina a Concern for Fruit, Vegetable Producers

Clint Thompson Alabama, Florida, Fruit, Georgia, Top Posts, Vegetables, Weather

Graphic from UGA Extension Blog.

A La Nina weather pattern is expected to last through early spring and bring warm and dry conditions to the Southeast.

According to the Climate and Agriculture in the Southeast blog, Pam Knox, University of Georgia Extension Agricultural Climatologist, said that the NOAA’s Climate Prediction Center predicts a 100% chance of a La Nina through the winter and better than 90% chance through early spring.

This scenario could be gloomy news for vegetable fruit farmers, especially peach growers in Alabama, Florida and Georgia who need chill hours to make a crop for the following year. It also means pests could linger longer than desired since the lack of cold temperatures will alive them to survive longer.

Pam Knox Comments


“In La Nina years, they’re much less likely to get the chill hours that they need. That’s going to be a problem for fruit producers,” Knox said.

“Another thing is when you have warm temperatures, it’s not cold enough to kill the bugs very effectively. So you have more overwintering of bugs like whiteflies and other things that will bring disease to the plants next year. They could get an earlier start, but they’re also going to be more numerous because they’ve been able to survive the winter because of the warmer temperatures.”

The lack of sufficient chill hours does not mean there will be zero cold weather. That’s still expected but will be overshadowed by the warmer temperatures to follow.

“Even in La Nina years, we have some outbreaks of cold weather. It’s still winter, so we’re still going to see some of those cold outbreaks. There’s a lot of variability over time. I would definitely expect to see some colder weather. We could have some pretty big outbreaks,” Knox said.

“It’s just that over the course of the whole winter, we’re likely to see those outbreaks punctuated by warmer spells. That’s not at all surprising. Winter is like that any way. It’s just that the whole average is a little higher. Those outbreaks come less frequently because the storm track is pushed to the north. The storm track is what controls whether we’re in the warmer air, because the warmer air is usually south of the storm track and also whether or not we’re getting rainfall because the rainfall usually happens along the storm track.”

Prolonged Dry Spell?

Winter is also a time when the soil moisture gets recharged due to rainfall. That’s not expected to happen this year amid La Nina, but it does appear the Southeast is in decent shape to withstand prolonged dry conditions.

“Temperatures are lower and evaporation is lower, and plants are dormant so they’re not using a lot of water. I think from a water standpoint, at least right now, it doesn’t look too bad,” Knox said.

According to the US Drought Monitor, southeastern counties in Georgia, as far south as Pierce and Ware, stretching as far north as Burke and Jefferson are classified as abnormally dry. The rest of Georgia, Alabama and Florida have sufficient moisture.