Stem borers on young corn and sorghum plants can be controlled relatively easily with crushed neem seeds (the powder normally used to mix with water). A small amount of powder mixed with sawdust or dry clay at a ration of 1:1 is placed in the funnel. 1 kg powder should be sufficient for 1500 – 2000 plants.
In this method, rainwater dissolves the substances in the neem seeds as it gathers in the funnel and washes out the powder. Where rainfall is irregular a liquid neem seed extract can be sprayed into the funnel.
This treatment should be repeated every 8 to 10 days during the sensitive growing phase. Thus, roughly three treatments are sufficient for protection against stem borers. This recommendation applies only for young plants before flowering and not for older plants.