Суровые морозы и болезни citrus: фермеры Алабамы ищут новые методы защиты урожая

Along Alabama's Gulf Coast, citrus producers face cold snaps, disease, and invasive pests. Alabama Extension Commercial Horticulture Agent at Auburn University Jacob Kelley supports growers in the southwest corner of the state, working with researchers and the Alabama Agricultural Experiment Station. Citrus production began in Baldwin and Mobile counties in the early 20th century. Today, the sector includes a handful of nursery stock growers and approximately 100 commercial fruit producers. Variable weather is one of the biggest challenges. Winter temperatures can swing from 70 to 80 degrees in one week to below 32 the next, causing stress to citrus trees. Warm spells can push moisture into buds, and when freezing temperatures follow, expanding fluid can split the bark and damage the tree. Cold injury can also kill cells in developing flower buds, preventing blooms. © Auburn University In January 2025, a snowstorm brought as much as 12 inches of snow to parts of Mobile and Baldwin counties, severely damaging citrus acreage. Growers can reduce cold-related losses through careful management. Jay Spiers, associate professor in the Department of Horticulture, said greenhouses and cold frames can protect citrus, while grafting satsumas onto trifoliate orange rootstock enhances cold tolerance. He also recommends micro sprinklers targeting the graft union and canopy for active protection of field-grown satsumas. During the 2025 snowstorm, growers using irrigation techniques properly suffered the least damage, according to Kelley. Irrigating before freezing helps moist soil retain heat. Frost cloths, row covers, and lightweight breathable materials can also trap radiant heat under the canopy. Alabama growers favor satsumas because of their hardiness, with most commercial producers using the 'Owari' variety. Disease is another challenge. Citrus canker was confirmed in plant material from Mobile and Baldwin counties in 2025. Because it spreads through rain and wind drift, Kelley recommends thorough equipment sanitation, particularly between orchard blocks. Symptoms include raised, corky lesions with watery margins and yellow halos on leaves and fruit. Citrus greening, spread by the Asian citrus psyllid, causes blotchy yellow leaves and misshapen, green fruit. Mobile and Baldwin counties also have quarantines for citrus greening. Kelley said he remains hopeful because the detection was residential rather than on a commercial property. Kelley plans to continue working with the Alabama Agricultural Experiment Station on variety trials and demonstrations to support citrus growers. For more information: Auburn University Tel: +1 334 844 4000 www.wire.auburn.edu