Texas crop, weather Armyworm onsets intense after tropical-storm rains Entomologist Armyworm onsets intense after tropical-storm rains

COLLEGE STATION — Intense armyworm infestations continue to consume pastures and hay meadows, but there’s no indication that population counts are any larger than in previous years, according to a Texas AgriLife Extension Service expert.

“I don’t think they’re worse, but it’s probably more intense (sudden) onset,” said Dr. Allen Knutson, AgriLife Extension entomologist.

Substantial rains, like those much of the state has recently had from hurricanes and tropical storms, often trigger armyworm outbreaks, he said. The perception that armyworms are worse this year is probably because dry weather seems to inhibit their reproduction.

“There was a long period of time when it was dry and there was no armyworm activity. Then all of sudden, here they are in large numbers,” he said.

Knutson said no one really knows why armyworms burst forth in large numbers when it rains following a dry period. But the theory is that eggs and small larvae survive when the humidity is high and plant growth is lush.

“We know that the (armyworm) moths are moving up from South Texas all summer long and no doubt laying eggs, but the eggs and small larvae just don’t survive when it’s hot and dry,” he said.

Now that conditions are ripe for their survival, armyworms will be active and require spraying until the first cold weather comes in, Knutson said.

“It’ll take a freeze to actually kill them because they’re not cold-tolerant, but certainly cooler weather will slow their development,” he said. “We still are weeks and weeks away from that, so there’s lots of time for armyworms to do damage. It’s too early to hope that weather is going to slow down the infestations.”

Armyworms are not only damaging existing pastures, they are also delaying planting wheat for grazing and small grains for winter pastures, according to AgriLife Extension agent reports.

Armyworms can strip a field of newly emerged small grains overnight, Knutson said.

“Wheat producers are considering sowing early for grazing, but most are worried about armyworms,” said Steven Sparkman, AgriLife Extension agent for Hardeman County, west of Wichita falls. “I think it is unsafe to sow at this time.”

“Some producers have begun sowing wheat, but most are holding off another week or two due to reports of armyworms to the north, especially in Oklahoma,” said Heath Lusty, AgriLife Extension agent for Jack County, northwest of Fort Worth.

“What the armyworms hadn’t gotten last week, they are getting this week,” said Josh Blanek, AgriLife Extension agent for Somervell County, south of Dallas. “But if the armyworms aren’t eating your grass, you’re probably in pretty good shape after the good rains.”

AgriLife Extension district reporters compiled the following summaries:

CENTRAL: Fields greened up due to recent rains. Armyworm pressure remained high, and many producers were spraying. Soil-moisture levels were adequate for planting small grains. Cotton looked better than earlier expected. Much of the high-aflatoxin corn harvested was dumped in turn-rows.

COASTAL BEND: The cotton harvest was put on hold because of 1 inch to 6 inches of rain brought by tropical storm Karl. Producers expected to begin fall planting the first of October.

EAST: No significant rainfall and above-average temperatures stressed pastures and crops throughout the region. Producers in some counties continued to cut hay, while others looked for more to buy. Grasshopper and armyworm infestations were sporadic to severe. Livestock were in fair to good condition with some producers beginning to provide supplemental feed.

FAR WEST: The region had widely scattered showers, but there was no significant accumulation. Pecans were entering the gel stage. Chiles were turning red. Cotton bolls were opening. Some producers were applying defoliates to cotton. Cotton producers were happy they have never seen prices this high. The sorghum harvest was ongoing. The corn harvest began, and winter wheat was being planted. The cantaloupe harvest was finished. Melons were small but sweet.

NORTH: Soil-moisture levels were mostly in the adequate range with only a couple counties reporting theirs to be below adequate. Areas that received substantial rainfall from Hermine also received additional rain this past Tuesday. Because of wet field conditions, corn yet unharvested may not be harvested this year. The grain sorghum harvest was mostly completed before the rains. The soybeans harvest was completed. Both soybean and sorghum yields were about average. Cotton was in fair condition and growers resumed harvesting. The rains made a big difference in the pastures and hay meadow conditions, and some producers expected to get another cutting of hay. With improved soil-moisture levels, a few farmers and ranchers began planting small grains for winter pastures. (Small grains planted for grain will not be planted until later in the fall.) Some producers were waiting to plant winter pastures because of armyworms, the reports of which increased ten-fold. In addition to the armyworms, feral hogs continued to pose a major problem to new plantings and crops.

PANHANDLE: Temperatures were mostly above average with soil-moisture levels rated mostly short. Corn harvest was under way in some areas. Cotton was in fair to good condition. Producers began spraying defoliants on cotton that was mature, and expectations were that the harvest will begin in two to three weeks. Sorghum was mostly in fair condition. Soybeans were rated mostly good. Growers continued planting wheat, but some areas needed a good rain before planting could be resumed. Rangeland and pastures were very poor to fair, with most reporting poor. Cattle were in good condition.

ROLLING PLAINS: Soil-moisture levels were adequate, and the warmer weather helped green up pastures and finish the cotton crop. Bolls were beginning to open, and producers expected to begin harvest about mid-October. Some farmers were getting ready to defoliate cotton while others were waiting for the crop to further mature. Some producers began sowing wheat but most were holding off due to reports of armyworms to the north. Armyworms were a threat to Bermuda grass pastures and recently emerged small grains. Some growers were spraying for armyworms. Many stands of winter wheat that were planted about a week ago were already showing substantial growth. Peanut producers began harvesting and were expecting a good crop. Pastures were in good to excellent shape, as were livestock. Ranchers were receiving cattle and were turning them out on grass until their wheat is ready to graze. Stock-water tanks were full.

SOUTH: From 2 to 5 five inches of rain were reported throughout the northern, eastern and western counties, and 5 to 9 inches in the southern counties. Overall, soil-moisture levels were adequate to surplus. In the eastern part of the region, the cotton harvest was ongoing and peanuts were developing well. Hay cutting and baling could also be seen throughout that area as well as other parts of the region. Some remaining cotton was being harvested in the western part of the region. In the southern part of the region, there was not much field activity as pastures were completely saturated. However, rangeland and pastures were in excellent condition, allowing livestock producers to reduce supplemental feeding. Stock-tank water levels rose significantly, and cattle body-condition scores were good.

SOUTH PLAINS: The region received scattered showers with accumulations ranging from 0.1 to 1 inch. Soil-moisture levels were short to adequate. The corn harvest was ongoing with yields ranging from 7,000 to 13,000 pounds per acre. Cotton was in good condition. Sorghum and sunflower harvests continued. Producers were planting wheat. Pastures and rangeland were in fair to good condition but needed more rain. Cattle were in good condition.

SOUTHEAST: Rains in many parts of the region last week prompted forage growth, but armyworms and grasshoppers continued consume fields. Liberty County crops and pastures continued to worsen due to the prolonged lack of substantial rain. The ratoon rice crop looked good.

SOUTHWEST: The region received another 0.5 to 1.0 inch of rain. Overall, good rains in September and cooler temperatures improved the agricultural situation substantially. However, about 10 percent of the cotton crop was not yet harvested and may suffer reduced yields and quality because of the rains. The harvesting of sesame, sweet corn and peanuts was ongoing. Lima beans, cabbage and green beans were making excellent progress. The pecan harvest was expected to start near the end of September. Forage availability improved from the recent rains and cooler temperatures.

WEST CENTRAL: Conditions were warm and humid this week. Cotton was maturing on schedule, and growers expected to begin harvesting soon. Oat planting was under way in some areas, and producers were preparing fields for fall plantings. Hay producers were cutting and baling hay. Encouraged by the extra moisture from tropical Hermine, hay producers were fertilizing more. Armyworm problems were reported in a few locations. Rangeland and pastures looked very good in areas that received moisture. Livestock were in good condition, and ranchers reduced supplemental feeding. Pecan growers were irrigating what promised to be a good crop in most areas.

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