Texas Blacklands: Corn Planting Finished; Watch for Wheat Rust, Stink Bugs


Wheat is starting to head out with some hard-red wheat fields starting to flower. The soft red wheat fields in the scouting program are in the boot stage with some fields starting to have the head emerge out of the boot.

Insect pest have drop significantly since the last newsletter thanks to our beneficial insects, but as we move closer to harvest a new insect pest needs to be on our radar and is being observed at low levels in a handful of Hill County wheat fields. Rust is still hit or miss, and through an update on Monday with wheat specialist from across the state, we need to keep a keen eye out for rust in wheat.

Corn planting has finished, and most has emerged and looking good. The rain over last weekend and the potential for rain this weekend could lead to some disease issues that will be covered in this newsletter.

This wet weather pattern could lead to issues in our corn and cotton crop as well.


Aphid pest have dwindled down to almost nothing in fields in the scouting program, even in fields that were not sprayed. This can be attributed to our beneficial insect population that finally caught up to our aphid population.

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As we reach the head and flowering stage and move on toward harvest another pest we could see and being observed in a few fields are stink bugs. Stink bugs use their mouthparts to penetrate maturing wheat seeds to obtain the food. Their feeding can reduce germination, kernel weight and baking quality.

Wheat is most susceptible to stink bug damage between flowering through the milk stage. Multiple pest of stinkbugs can be found in wheat including rice stinkbug, brown stinkbugs, and southern green stinkbug. Threshold for stinkbugs in wheat are 1 or more stinkbugs per 10 head during the flowering to milk stage and 3 or more stinkbugs per 10 heads during the soft dough stage.

Rust is still around, and a few fields have reached a level of rust within a field that warranted a fungicide application. Some producers went out with a fungicide last week ahead of the rain, to keep rust from moving up the plant.

Both stripe rust and leaf rust are still present in area fields and based on reports from other wheat regions of Texas could become severe shortly depending on weather conditions. The rain over last weekend has led to favorable conditions for rust infections but will not be seen for seven days.

The rain has also caused dews to form on plants and last well into the afternoon hours which is also favorable conditions. Depending on what wheat variety planted some fields may not even need to be sprayed depending on the dominant rust species.

Fungicide selection is key at this time and not all fungicides work the same way. Most of our fungicides for wheat fall into one of two families strobilurins and triazoles. Our strobilurin encompass fungicide active ingredients like azoxystrobin, pyraclostrobin, and trifloxystrobin. These fungicides are excellent preventative fungicides but have little curative activity. When applied correctly strobilurin products can provide protection for 21 to 30 days.

The second family of fungicides is the triazoles, and include active ingredients such as tebuconazole, cyproconazole, and propiconazole. This family has both curative a preventative activity, but both the fungicide and fugus must be in the plant for triazoles to work.

Based on reports from the McGregor area and wheat regions further south, the best option would be to apply a fungicide that is a mix of a strobilurin and triazole. This would 1) manage what rust is already established within the plant and 2) prevent future infections for up to 30 days.

Premixes are available; however, some fungicides can be tank mixed with others as long as the label does not warn applicators against mixing with other pesticides.


The corn crop looks good, and this rain came as our soil was starting to dry out. The amount of rain received over last weekend (4/6 & 4/7) however could lead to stand issues in low lying regions of fields.

Ponding from the storms are were still visible Thursday afternoon in some areas which can lead to stunted plants, delayed maturity, loss of soil Nitrogen and in severe cases plant death. Waterlogged soil inhibits the absorption of Key nutrients such as Nitrogen, Phosphorus, Potassium, and Oxygen by the roots, this will lead to cell death in the roots that can eventually lead to root death.

Currently most of the corn fields I have seen are no farther along than the V3 or V4 growth stage, and the growing point is still below the soil surface, and need oxygen to respire, which impairs critical plant functions. Temperatures above 77 °F during waterlogged soil conditions decreases the chance for plant survival.

Checking for plant survival from waterlogged/flooding conditions can be done by checking the color of the growing point and mesocotyl of the plant. The mesocotyl of a healthy plant should be a creamy white color, and mesocotyls that are dark in color or soft leads to a sign of eventual plant death.

Another problem with waterlogged soils during early vegetative growth stages is the limitation of root growth. This leads to a shallow root system, this can lead to an increased sensitivity to drought, which can lead to decreased yield and an enhanced risk for aflatoxin contamination.


We are now taking acres for cotton, corn and sorghum for the Hill-McLennan Counties IPM Scouting Program. If you would like to sign up acres you can contact me through one of the number below or by email which is also in-cluded at the end of this newsletter. The cost per acre is $6.00 for all crops.

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