Texas citrus growers are adopting a planting system developed by scientists at Texas A&M University to address pest, water, and disease pressures. The system, first tested in 2013, was designed to control the Diaprepes root weevil, a pest damaging orchards in the Rio Grande Valley.
Dr. Mamoudou Setamou, professor and director of the Texas A&M Kingsville Citrus Center, and Dr. Olufemi Alabi, professor and extension specialist with the AgriLife Extension Service, began testing a black plastic mesh ground cover to interrupt the insect's life cycle. The barrier prevents larvae from entering the soil and stops adults from emerging.
Trees retrofitted with the barrier recovered from damage, leading researchers to test the method on new plantings combined with raised beds. "Within the space of one or two years, you see a dramatic difference in growth and foliage and everything," Alabi said. "Within three years, they actually produce a commercial-grade crop."
The ground cloth also reduces weed pressure and water loss. Setamou said growers using the system save 30–40% of water. Traditional flood irrigation became unsuitable under the barrier, and micro-sprinklers or drip irrigation are now recommended. Glen Martin of Lone Star Citrus Growers said drip systems allow precise control of water, nutrients, and insecticides. "Flood irrigation required two acre-feet of water to irrigate one acre of citrus grove," he said. "With a pressurized drip system, we only use 37% of an acre-foot now."
Healthier trees produced under the system show greater resilience to citrus greening, or Huanglongbing (HLB). Alabi said the disease reduces root hairs and uptake, but trees planted with the barrier system regenerate root growth. Setamou added that higher root mass allows infected trees to continue taking in water and nutrients, limiting collapse.
Nearly 5,000 acres in the Valley have already been planted with the barrier system. Growers in Florida, Mexico, Spain, and Morocco are also trialling the method. The research was funded by the HLB Multi-Agency Coordination Group and the USDA's Plant Health Inspection Service.
Dale Murden, president of Texas Citrus Mutual, said: "We're saving water, we're saving pesticide use, and we're keeping the trees healthier. I think that's key until some scientist can find a cure for some of these diseases like greening."
Murden noted that nearly all new citrus plantings in the Valley are now using the system, describing it as a step forward after years of hurricanes, drought, floods, and storms.
Source: myRGV