From the High Plains to the Lower Rio Grande Valley, farmers are, for the most part, rejoicing at recent rain showers that have, at least temporarily, interrupted a long-standing drought.

Some concerns come with rainfall, however, mostly from Valley cotton producers who have cotton open and vulnerable to rain damage.

Predicted rainfall in the Lower Rio Grande Valley, observers say, will not be enough to recharge soil moisture reserves but could damage some open cotton.

In other areas, farmers are happy to get any moisture they can.

Scott Russell, Texas AgriLife IPM agent for Terry and Yoakum counties, says “welcome rain has fallen…with accumulations since Sunday night at Brownfield of 1.66 inches to 3.97 inches at Plains.

Rainfall has been spotty, he says, “with some locations receiving much less. Producers should not be lulled into a false sense of relief with the rainfall. Area soils will dry quickly and once full sun and higher temperatures return, the crop demand for moisture will be high.”

Cotton at first bloom uses approximately 0.28 inches per day; peanuts beginning pod fill use about 0.27 inches per day.

Russell says soil type also makes a difference. “Typical fine sand to loamy sand soils only hold 0.75 to 1.2 inches per foot of soil, with only about half available to plants. Available water from these showers will be used by the crop (or lost to gravitational forces, excess water) in only a few days.”

Rainfall and overcast skies have also lowered temperatures and reduced heat unit accumulations. “However, totalheat unit accumulations (Growing Degree Days 60) remain above our 30-year average.This reduction could lead to cotton shedding some fruit; this will not be all bad. Cotton fields in the IPM Scouting Program remain at over 90 percent first position square retention. Every year we see cotton ‘load up’ early, and then in the heat of late July and August shed some fruit to compensate for the water, nutrient and carbohydrate demands.”

Back to the south, Clyde Crumley, IPM agent for Wharton, Jackson and Matagorda Counties, says the area has received significant rainfall.

“Tropical rainfall is occurring over this part of southeastern Texas this week with amounts that are varying from few tenths to over 1 inch,” he says.  Rain has slowed grain sorghum and corn harvest “with some seed sprouting in the sorghum heads and minor lodging in corn.”

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Crumley says most cotton is at physiological cutout. “The next hurdle will be protecting the bolls from insect damage, and we need to thinking about be timing harvest aids.

He says cotton “is a few days behind when it comes to average heat units for this year, and you should consider that when thinking about preparing for harvest.”

Crumley says adverse weather has caused some premature senescence “in a handful of cotton fields locally. This condition is generally thought to be caused by insufficient potassium in plant leaf tissue which predisposes the foliage to secondary pathogen infection. Now in 2005, Dr. Robert Lemon, former professor and Extension agronomist –cotton, Dr. Gaylon Morgan, associate professor and Extension agronomist –cotton and Dr. Mark McFarland, professor and Extension soil fertility specialist wrote an excellent overview of this phenomenon, which can be found at http://cotton.tamu.edu/news.htm 2.

“The rain has been a true blessing this week,” says Kerry Siders, IPM agent for Hockley and Cochran Counties. “But with rain comes clouds and with clouds reduced solar accumulation. This in turn should cause cotton to shed small squares. These three days of cloudy weather should start to impact fruit retention within the next few days. I expect to see at least a 5 percent to 20 percent loss of squares.”

It might not be a big deal. “Fortunately most all cotton fields have retained better than 80 percent of the squares up to this point. There is usually a lag time of five to seven days or more sometimes from when a stress, such as cloudy weather, occurs until its effects are actually seen on the cotton plant.”

Cloudy weather results in a shortage of carbohydrates produced by the plant during photosynthesis. The carb shortfall means the plant has to give up something. So it sheds squares so that the rest of the plant can survive.

Siders says lack of damaging insect pests so far may be a plus. But growers can’t afford to neglect scouting.  “Because we will be seeing natural square shed one must scout to make sure that additional fruit loss does not occur from insect pests in each individual field. This is the when, why, and how a professional consultant earns his/her keep.”

Other reports indicate decent rainfall totals in the San Angelo area and into East Texas, as well. No one is declaring an end to the multi-year drought but farmers and ranchers feel a bit better about their options as they head toward mid-summer.

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