Setting the Final Stage for Developing Cotton Fruit

We’re almost halfway through summer and farms across the Valley are bustling with activity. As I travel around the fields, I see tomatoes being harvested, safflower drying nicely and cotton plants are almost finished setting their fruit.

The cotton plants are showing an average of 75 to 80 percent fruit retention with about 12 to 13 fruiting branches (some fields have 11 to 12 fruiting branches). The retention rate is very good, which is a credit to the work of growers and pest control advisors. You can refer to the University of California Statewide IPM web site for information about monitoring cotton plant growth.

Right now, cotton is about two weeks away from cut-out, which is the final stage of plant growth before the bolls start to open. As we head into hot August nights, I am telling growers to remember their WIGs. That’s short for:

• Water management. A lot of growers have completed their third or fourth irrigation. Some might want to cut off irrigation to push the plants to cut-out. However, there’s still time to get more fruit so continue reviewing your water management strategy to maximize fruit development.
• Insects. Lygus counts continue to increase in the cotton fields. In one field, I collected more than 50 adults and 50 nymphs in 25 passes of my sweep net. That’s high. The lygus are migrating from neighboring alfalfa and safflower fields. Remember to leave uncut strips of alfalfa to provide a home for lygus. You can treat for lygus in the safflower and alfalfa. Consider this: It’s more economic to treat five acres of an alfalfa strip than 150 acres of cotton.
• Growth regulators. Some growers might consider using a growth regulator product to enhance plant production such as boll and closed canopy development. Be aware a cooler than normal fall may make it difficult for late bolls to mature. It’s up to you to decide if you are willing to roll the dice, spend the money on regulators and go after late season bolls.

 It's still important to leave alfalfa strips to manage lygus.