Mid-Coast Grain Sorghum Update

Grain sorghum maturity ranges from boot to soft dough.Sorghum field 5-25-16  Some fields are turning color. We are finding varying populations of Sorghum Midge in fields ranging from 0-5 per head.  Treatment thresholds are 0.5-1 midge per head depending on the number of flowering heads per acre.

We are finding headworms in Refugio County sorghum fields ranging from 0-4 per head.  Many of these are fall armyworms.  The economic threshold for headworms ranges from 0.15 to 1 large worm (> 0.5 inch) per head.  For medium worms (0.25-0.5 inch) the ET ranges 0.8 to 2 per head.  If application is by air, you can almost double the ET.

In fields with worms, we are also finding leLeaf-footed bugaf-footed bugs.  For management, consider a leaf-footed bug as a stink bug.  Rice stink bugs are still in low numbers.  The threshold for treating stink bugs is from 0.5 to 0.85 per head. (0.75-1.25 if treating by air).

Sugarcane aphids are being found in sorghum fields of the Mid-Coast.  Isolated fields toward Seadrift are seeing increasing numbers with spots in the field 50-60 feet across with excessive honeydew and aphids above 500 per leaf. SCA 5-12-16

Check all fields as often as possible.  Treat when aphid populations average 50-100 per leaf in post bloom sorghum.  Spraying parts of a field where aphids are found may be an effective strategy.

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