The 2011 cotton season is on the move: The long-awaited warm weather arrived, and San Joaquin Valley cotton fields have taken off toward harvest.
University California cotton experts say some fields will be as much as two weeks later than normal getting to harvest, while others have a shot at a traditional harvest date.
With a prolonged planting season due to cool, wet conditions, there is considerable variability between fields.
This is one of those years, says University of California IPM specialist Pete Goodell, that best pest management practices begin with human shadows in fields.
This isn’t a cookie cutter season, he says.
Bob Hutmacher, University of California Cooperative Extension cotton specialist, and Fresno County farm advisor Dan Munk say this year is much like last season — when they told growers and PCAs to not count on top crop to pay the bills.
Protecting the early set will be critical to making this a successful year.
Fortunately, unlike 2010, San Joaquin Valley cotton growers have plenty of irrigation water for this crop, so water stress shouldn’t be a factor.
But, this above normal moisture year is bringing plenty of weedy vegetation that is host to lygus.
“Weeds have held on longer than normal into summer, but with the heat we saw early in July, expect those weeds to dry down and send lygus in search of cotton,” says Munk.
Safflower, a perfect sink for lygus, also began to dry down as temperatures soared above 100 in late June and early July.
“We’re also not too far away from the beginning of tomato harvest,” warns Munk. Tomatoes are another source of lygus to move into cotton.
Lygus have definitely been active, says Hutmacher. “I’m getting a fair number of calls from growers and PCAs, although lygus aren’t spiking as quickly as you might expect.”
Lygus move from harvested alfalfa to cotton, and UC entomologists suggest strip cutting alfalfa to give the pest a host in the alfalfa rather than having it move out at harvest in search of cotton.
But, this practice may be a challenge this year with the high price of alfalfa hay.
“There are cotton fields fairly well along, while in other places fields are solidly two weeks behind,” says Hutmacher. Some plantings are struggling, especially those that were “beat up by thrips” early. “Those fields have a lot of small nodes,” he says.
Because of the cool start, fruiting nodes are also generally higher on the plant, which puts a premium on setting the crop early.
“Now is the key time period when growers and PCAs need to pay attention to any kind of stress in order to hold squares,” says Hutmacher. “With the price of cotton, I think most growers are paying attention and are willing to spend the money to spray for lygus control.
“My concern is that some growers may be a little more forgiving with early season lygus and tolerate too much damage. Fruit loss early on can cause problems at the end of the season.
“There is a nice population of beneficials this year, and I would hope growers use softer materials for lygus control to preserve those beneficials.“
Hutmacher is encouraging growers to “strike some kind of balance” by paying attention to damaging levels, then doing something about them early enough.
This is definitely one of those “screwball years” where growers and PCAs will be making many field-by-field decisions. “It has not been an easy calendar year,” he says.
Munk warns that other late years have demonstrated that growers cannot make up for lost time with Pima cotton, the predominant species in Valley cotton fields.
“With Acala, you can lose a few squares and maybe make up for them later. You can’t do that with Pima — we say, ‘With Pima, fruit early and fruit often.’”