GENERAL CODITIONS:
Peanut planting for most producers is complete, and peanuts are cracking and forming uniform stands. Thrips are present in peanut fields where drying winter grains are in close proximity to fields, but the fields I have scouted are well below the population of needing to be sprayed. I have also observed wireworms in some fields in Gaines County. Cotton planting is just starting for some producers. Cotton is starting to emerge in some fields around the area, and as our winter grain crops are starting to dry down we need to be cautious of thrips. If rain chances materialize next week, and the weather stays warm the meteorologist are predicting thrips may not be a big issue, but is still an insect we need to keep our eye on.
COTTON:
Cotton planting is still well underway, with some producers just getting started. Now is the time we need to be on the look out for thrips in cotton, as our winter grain crops are starting to dry down or being baled for hay. Thrips are small straw colored insects that are shaped like small cigars (Figure 1). Thrips damage can be easily confused with wind/sand damage, and common sings are crinkling of leaves, silvering of leaves, and dead terminals. Their damage can cause a delay of maturity, loss of apical dominance leading to crazy cotton, and in some cases death of the plant. Thrips damage can be magnified when growing conditions are suboptimal, such as cool wet conditions. Our insecticidal seed treatments should last for up to about 30 days, and can provide effective control of thrips. Current economic thresholds for thrips are 1 thrips per a true leaf (Table 1). When needed there are numerous insecticides that can be used to manage thrips populations in cotton, these include the active ingredients Acephate, Dicrotophos, and Dimethoate.
PEANUTS:
Peanut planting is pretty much complete with the exception of a few producers that tried to wait for rains. A majority of the peanut fields I am looking at this year are up and making really good stands. As I started scouting peanuts this week I have found a few pest occurring around the area. The first pest are thrips, which alone pose little economic importance to peanut production, but their ability to transmit the Tomato Spotted Wilt Virus makes them worth keeping an eye on. Thrips damage in peanuts can be seen as silvering of leaves, cupping and curling of leaves. Tomato Spotted Wilt symptoms include chlorotic spots, mottling, as well as necrotic and chlorotic rings/streaks (Figure 2). Management of thrips and TSWV starts when you purchase your seed. Planting a high quality seed that has the right seed treatment and resistance to TSWV is the first step in managing the virus and its vector. At plant systemic insecticides may provide some control for thrips in peanuts, but past research has not found a yield benefit when they are used. Additionally, there are numerous insecticides labeled for thrips management in peanuts, including Dimethoate and Acephate.
The last insect pest I have observed in area peanut fields are wireworms and false wire worm. These insect are soil inhabiting insects that early in the season feed on the hypocotyl and developing roots. Their damage can lead to decreased stands from plants being chewed off below the ground, a decrease in the amount of water and nutrients taken up by the plant, and in some cases infection of soil borne diseases. After bloom, during pegging and pod maturation, these insect feed on pegs and developing pods. Feeding on pegs will lead to a loss of the pod, where pod feeding als leads to a decrease in pods and also a greater potential of seeing pod rotting diseases. Wireworms enter the pod by chewing small jagged edged hole in the side of the pod, and consume some to all of the kernels within a pod (Figure 3). Wireworms are slender hard worm like insects that are a tannish brown color (Figure 3), where false wireworms have a hard slender body that looks like wireworms but are a reddish brown color. Currently the only management options include application of Chlorpyrifos for suppression, or digging heavily infested fields early to avoid Segregation III peanuts.
Thank You to the sponsors of the Gaines, Terry, Yoakum Integrated Pest Management Program. Sponsors of the program sponsors include:
Platinum Sponsors:
Gold Sponsors: Doyle Fincher Farms, Golden Peanut & Tree Nuts
Silver Sponsors: Birdsong Peanuts
Bronze Sponsors: Crop Production Services of Brownfield; New-Tex Gin, Inc.
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