Sunday, August 10, 2014

Cotton Crop Is Looking Good; But It’s No Time to Relax




Lygys bug - UC IPM photo.
While the drought has put a damper on cotton plantings this season, the plants themselves are developing well. Fruit set is very good.

Field scout Carlos Silva sees good fruit retention rates, generally at 60 percent. As a rule, growers figure on a 40 percent retention rate by harvest time.

Overall, growers are concentrating on seeing through the development of their crop and then preparing for the cotton picking time – from cutout to defoliation to harvest. It sometimes seems like an eternity getting to the day when the harvesters finally fire up.

The reason is simple: There’s still a lot to worry about and all kinds of things can happen in the field to hamper yield or the fiber quality, says Dr. Pete Goodell of the UC Integrated Pest Management program. “The issue is just finishing off the crop,” he says.

At the moment, lygus remains Public Enemy No. 1. Make sure lygus is under control and not hurting fruit set. “Be in the fields scouting at least twice a week,” Pete says.

Carlos Silva snags aphics in his sweep net.
August and September are big months to watch out for aphids and white flies.  “White flies and aphids will jump out on you when you least expect it,” Pete says. “Make sure these pest populations don’t build up where you can’t control them once the cotton lint opens up. Sticky cotton has become an issue and you want to make sure you prevent it.”

So far this season, some growers have treated their fields for lygus and even aphids. But Pete points out the pest problems are scattered across the Valley and usually vary from field to field.
White flies populate the back of a cotton plant leaf.
Carlos says some fields were experiencing an uptick in lygus counts in the past week, approaching the UC IPM threshold for treatment. Other pests are in check right now. 

Clean cotton, left, and sticky cotton.
You can check out the UC IPM website for more information about dealing with lygus as well as managing white fly and aphid in cotton.

Pete offers this final advice to growers: “Don’t go to sleep thinking that you’ve defoliated your cotton and it’s ready to go. Watch that crop through until it gets into the picker basket.”
 
 It’s safe to assume cotton growers can expect a couple more months of sleepless nights.

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