Infestations of damaging pests are increasing on corn, sorghum and cotton crops in the South Plains and Panhandle, according to a Texas A&M AgriLife Extension Service entomologist.
Producers are monitoring crops, but Dr. Ed Bynum, AgriLife Extension entomologist, Amarillo, said they should remain vigilant in scouting and be prepared to act with pesticide treatments if infestations reach damage thresholds to avoid yield losses.
Bynum said damages vary depending on the pest and crop, but that producers have seen increased numbers of spider mites, bollworms and sugarcane aphids over the last few weeks.
Spider mite infestations are primarily in corn, but have been noted in sorghum as well, Bynum said.
“Corn is in the ear development growth stages,” he said. “Feeding by spider mites kill individual plant cells, and the accumulation of feeding will kill leaves. When you have enough leaves killed during ear and grain development, it will ultimately reduce yields.”
Producers were scouting fields on a regular basis and treating based on pest numbers. Some fields have not needed to be treated because beneficial predator populations are present.
The primary mite predators that help control spider mite populations are six-spotted thrips, predatory mites, minute pirate bugs and “spider mite destroyer beetles” – small lady beetles or stethrou, which occur naturally in fields and can keep spider mite populations in check, he said.
“Natural infestations of predators will build as spider mite populations increase,” he said. “Good populations of beneficials can mean producers may not have to spray their fields.”
Bynum said producers were beginning to see cotton bollworms as the crop enters the flowering period and boll development stage. Bollworms feed on bolls and small squares.
“We’ve seen an increase in moth activity and egg lays,” Bynum said. “Producers are watching closely because we are starting to see some damaging infestations in a few fields.”
Second – Bollgard II, WideStrike and TwinLink – and third generation Bt cotton varieties with the Vip3A trait have held up against pests on the High Plains. However, farmers still need to monitor their Bt cotton fields for damage because in other cotton-growing areas there have been issues with bollworms in the second generation Bt cotton varieties.
Sugarcane aphid numbers were beginning to increase as well, Bynum said.
“Producers should be monitoring for sugarcane aphids because they are in the area, and their numbers can build rapidly,” he said. “They’ve arrived later this year in the South Plains. Producers have done a good job managing them the last few years, but sugarcane aphids can do damage to an individual’s field in a hurry.”
Bynum said tolerant sorghum varieties have helped delay sugarcane aphid build up, but damaging populations can still build to the point producers should make timely pesticide applications and use spray rates to get good plant coverage.
AgriLife Extension district reporters compiled the following summaries:
CENTRAL: High daytime temperatures reached into the upper 90s with heat index well over 100. Hot temperatures evaporated any moisture that was received. Pastures and rangelands were in decent condition, but more rain was needed. Sorghum and corn were being harvested, but yields were not very good. Sorghum harvest in some areas was complete. Fires were occurring. Forecasts called for chances of rain and lower temperatures. Hay and grass were becoming scarce. Many cattle were being sold. Cotton was struggling to open or hang any bolls due to high temperatures and dry weather. Some supplemental feeding was needed for livestock. Three-quarters of the district’s counties reported poor soil moisture and rangeland and pasture conditions. Most counties reported fair crop conditions, and poor overall livestock conditions.
ROLLING PLAINS: Record high temperatures were taking a toll on crops and livestock. Little field work was done other than irrigating cotton and peanuts. Dryland cotton was mostly poor and starting to flower. Irrigated cotton was fair to good and was beginning to square more and more each day. Producers said more than 1-2 inches of rainfall was needed to get cotton to its typical progress. Concerns remained that any rains may be too little too late for a majority of fields. Pasture conditions were mostly very poor, and livestock were being moved around and supplemental hay was being fed. Ranchers were beginning to search for hay to feed livestock in hopes of keeping herd numbers up. Cattle were being given cake and mineral blocks to keep them steady, while ranchers waited for rain to improve grazing conditions. Some cattle were being culled. Fire danger remained high.
COASTAL BEND: Hot, dry conditions continued to deplete soil moisture. Grain sorghum was being harvested, but producers were challenged with the presence of honeydew from sugarcane aphids. Corn harvest was also in full swing. Cotton defoliation was occurring daily, and cotton began accumulating on the area gin yards with facilities running around the clock. Hay baling was in full swing, and hay producers made a fair to good mid-summer harvest. Livestock were in good condition.
EAST: Temperatures were over 100 degrees with little to no rainfall, which continued to deplete area soil moisture levels. Pond water levels were a problem for many producers in Anderson and Cherokee counties. Some Gregg and Sabine county producers continued hay harvests with Cherokee County reporting 25-50 percent less than normal for their second cutting. The list of producers looking for hay continued to grow in Trinity, Houston and Anderson counties. Pasture and rangeland conditions were poor to very poor across the district with a few exceptions. Sabine County reported good pasture and rangeland conditions, and Jasper and Gregg counties reported fair conditions. Counties reported short to very short subsoil conditions in all but Sabine, Jasper and Gregg counties. Topsoil conditions were also short to very short in all but Sabine and Jasper counties, which reported adequate conditions. Anderson County cotton was good to excellent, while grain sorghum, corn and soybean fields were burning up or were too far gone to recover. Watermelon and peach season slowed down. Most gardeners in Marion County were watering more than once a day to keep their gardens growing, and a large number of producers had given up. Marion County was added to the ever-growing burn ban list. In Marion County, cows were holding their weight, and calves were growing well even with grass drying out. Gregg and Shelby counties reported local cattle prices were lower for the most part. Houston County cattle sale numbers were up due to grass shortage, and slaughter prices were down, but calves were steady to higher. Armyworm infestations were reported in pastures and hay meadows in Cherokee, Gregg and Wood counties. Feral hogs continued to cause problems for producers and homeowners in Anderson, Shelby, Wood and Trinity counties.
SOUTH PLAINS: Recent rains improved topsoil and subsoil moisture levels. Cotton development ranged from small squares to near hard-cutout with only one to two nodes above white flower. Insects were starting to show up in area crops – mainly different types of worms. Bollworms and armyworms were in cotton, as well as pockets of aphids. In sorghum and corn, the hot, dry weather led to spider mites. Fall armyworms were damaging whorl-stage sorghum plants, and headworms were feeding on filling grain. Peanuts did not take the last round of 100-plus degree weather very well. Heat stress caused many fields to stop flowering, or the flowers were desiccated by the heat. Either way, flowering should start back soon with the latest weather pattern. Pastures and rangelands improved with recent moisture levels. Cattle were in good condition.
PANHANDLE: Hot and windy conditions were reported. Temperatures were near-normal before a cool front at the end of the reporting period. Some moisture was received. Amounts ranged from a trace to 3 inches. Soil moisture was mostly short. Cattle and crops needed moisture to progress in the triple-digit temperatures. Pasture and rangeland conditions should improve in areas that received significant rain.
NORTH: Conditions were dry. Topsoil and subsoil moisture levels were very short across the district. Most counties reported hot and dry conditions were negatively affecting hay production yields. Some soybean farmers were cutting beans for hay. All crops were in bad need of water. According to the U.S. Drought Monitor, district counties were in moderate to severe drought. Some signs of heat stress in livestock were reported.
FAR WEST: Conditions were windy, and temperatures averaged highs in the upper 90s to mid 100s and lows in the 60s. Scattered showers in eastern parts of the district averaged an inch of recorded rainfall. Extreme temperatures made it hard to keep cotton or rangeland from burning up. A good general rain was desperately needed to keep irrigated cotton acres from shedding bolls. Plants were loading up nicely but showing stress from lack of moisture. Corn was drying down, but yields were well below normal. Sorghum harvest was nearing as well, and yields were expected to be decent. There were no reports of sugarcane aphids. Watermelon harvest was basically complete. The watermelon season started well, but the market became flooded with melons. Mesquite trees were dropping beans. Pecan trees needed water for nut growth. Pastures were drying up, and grass was becoming nonexistent.
WEST CENTRAL: Very hot and dry conditions continued. Cotton fields were in mostly fair to poor condition. Many acres failed due to drought conditions. About 35-40 percent of planted acres remained in production. Rangeland and pasture conditions were in poor to fair condition, but conditions were deteriorating daily. Forage and hay crops were struggling, and drought stress was very apparent. Few hay cuttings occurred so far, with marginal yields. Hay supplies were looking very short. Some producers began to sell livestock. Stocker steers, feeder heifers and heifers were selling steady. Feeder steers sold steady to $3 lower per hundredweight. Packer cows and bulls were steady with the top cows at $66, and bulls at $87, per hundredweight. Pairs and bred cows were steady in limited numbers. Wildfire danger remained moderate.
SOUTHEAST: Moisture levels were rapidly dropping in some areas due to the heat. Livestock were in good condition. Pastures and forages were in fair to good condition but could use rain. Sorghum harvest was mostly complete with corn harvest following. Sorghum yields ranged from 2,000-6,000 pounds per acre, with an average of approximately 3,500-4,000 pounds. Corn yields ranged from 30-100 bushels per acre, with an average of around 50-70 bushels. Cotton could use rain. Producers were working to get a late hay cutting completed. Rangeland and pasture ratings were excellent to very poor with fair ratings being most common. Soil moisture levels ranged from adequate to short with adequate being most common.
SOUTHWEST: Moisture conditions continued to decline with higher and higher temperatures. Rangeland and pasture conditions worsened as well. Rivers and creeks were rapidly drying. Livestock conditions remained good throughout the counties.
SOUTH: Conditions were hot and dry with short to very short soil moisture levels. Temperatures were over 100 degrees in most areas. Hot and dry conditions took a toll on soil moisture and pasture conditions. Rangeland and pasture conditions remained fair but were declining in some areas. A little hay was cut and baled, but hay and other supplements were being fed in some areas due to drought. Some producers hauled water for livestock and wildlife. Cattle and livestock conditions were fair. Producers in some areas continued to reduce herd numbers, selling off weaned calves as soon as possible. Acquiring good, quality hay at reasonable prices was beginning to become more difficult. Corn harvest was complete in some areas, continued in other areas and continued to dry down in others. Peanuts and cotton were under irrigation. All irrigated fields looked to be in good condition. Cotton bolls were opening, and some fields were being defoliated. Cotton yields were expected to be lower than expected, according to visual inspections of fields. Irrigated Bermuda grass hay was cut and baled. Horn fly numbers increased.
Source: AgriLife Today