Alabama Cotton Picksack

• Dry Season in the South..........................................D. Monks, W. Birdsong, D. Delaney
• Reniform Nematode Control on Tenn. Valley Soils .................................C. Burmester
• Plant Bug Control .................................................................................................... R. Smith
• Cotton Market Update.....................................................................................W. Goodman
• Physiology Update: Early Root Growth.........................................D. Monks, D. Delaney
• Cotton Calendar.................................................................................D. Monks, D. Delaney

South Alabama producers have had to contend with extremely dry conditions throughout this spring. In addition to the dry soils, cooler temperatures slowed seedling growth causing the plants to be susceptible to diseases. Rotary hoes have been put to good use this spring as producers hurried to save stands where heavy rainfall occurred. Thrips have been heavy in many fields this year and, according to Ron Smith, plant bugs appear to be out in force on wild vegetation around the fields and in ditch banks.

The majority of the cotton was planted in the central and Wiregrass counties by the third week of May. Most producers are getting a stand although some replanting has taken place. Southwest producers in Monroe, Escambia, and Baldwin counties finally received significant rainfall the third week of the month; however, Mobile county producers did not.

Some things to keep in mind as the season progresses follow. The crop is running a little behind because of the delays in planting caused by soil moisture. Keep a close watch on the plant bug pressure and fruiting to make sure the crop is up to full potential. With temperatures destined to increase during June, the crop should grow rapidly towards bloom. With many fields planted to Roundup Ready varieties this year, keep a close watch on growth stage as the cotton will likely be to the fourth leaf very quickly.

If you would like to monitor DD60's as they accumulate throughout the season or if you would like to keep up with cotton across the state (this includes soybeans as well), logon to the website at: http://www.aces.edu/department/cotton/index.html. To get the most up to date insect control information via telephone, use Dr. Ron Smith's insect hotline at: 1-800-458-3738.
 
 

Nematodes have not been a great concern for most cotton farmers on the red silty clay soils of northern Alabama. However, that is changing rapidly as apparently reniform nematodes can live very well on these soils. In the early '90's reniform nematodes were first found in the western Valley counties south of the Tennessee River. An on-going nematode survey is finding that the reniform nematodes are now spreading eastward and across the Tennessee River. The reniform nematode is very persistent and once they are in a field, present technology and rotations can only suppress the populations, not eliminate them from the fields.

The good news is that after three years of research in the Tennessee Valley it appears that we can suppress the reniform nematode fairly effectively with only a minimal increase in cotton production costs. Tests were conducted from 1995 through 1998 in Colbert county in fields with known 'high' levels of reniform nematodes. We found we could suppress these nematodes with 5 to 7 pounds per acre of Temik 15G applied in-furrow at planting. Additional nematode suppression was needed at about pinhead square as populations began building again. In these studies Vydate C-LV was applied in two 8.5 ounce foliar applications 10-14 days apart beginning at pinhead square. In both studies the Vydate C-LV extended the reniform nematode suppression. Yield increases with the treatments were dramatic (Table 1 and 2).

Side-dress Temik applications were also evaluated in 1995 and 1996 and produced similar results as the Temik plus Vydate treatment (Table 1). Later studies are also indicating that the two foliar Vydate treatments may be combined into one application with equal effectiveness on nematodes. This reduces trips across the fields and also increases Vydate's effectiveness on plant bugs.

This research indicates that reniform nematodes can cause serious cotton damage, but it appears they can be economically controlled. There are also other chemical products and strategies such as crop rotation that can help manage reniform nematodes. Research is continuing to see how to fit them into the cotton production system in north Alabama.
 
 
 

Just a reminder that the mid May through June weather will have a lot to do with our plant bug problem this season. Continued dry weather will result in a short but limited migration of adults to cotton during the early squaring period. Cloudy weather with adequate to abundant rainfall will produce an extended migration into cotton that will begin in early June and continue into July. Remember that we want to base our decisions on the percent square retention and not adult plant bug numbers. Bollgard cotton should be sprayed to control plant bugs if square retention drops to 80-85% or below. Conventional cotton should not be treated for plant bugs during a tobacco budworm moth flight or when the chance of an egg lay is great. Otherwise we will have excessive budworm damage behind the plant bug spray or either a very expensive insecticide bill.
 
 

The first official USDA forecast for the 1999 season projects U.S. cotton production at 18 million bales, up 29 percent from 1998. With U.S. cotton stocks estimated at 3.6 million bales at the start of the 1999 season and production projected to exceed total demand, stocks are expected to increase significantly next season. In 1999/2000, domestic mill use is forecast to rise only slightly, to 10.6 million bales, as the continued rise in textile imports is expected to nearly offset the anticipated growth in retail cotton consumption. On the other hand, U.S. raw cotton exports are projected to jump by one-third to 5.5 million bales next season due to the large U.S. crop.

This report projects U.S. cotton planted area in 1999 at 13.9 million acres, with projected harvested area of 13 million acres based on average abandonment. The projected yield is 665 pounds per harvested acre. The 1999 U.S. cotton crop would rise 4 million bales (29 percent) from 1998's weather-reduced crop.

With current stocks at 3.6 million bales at the start of the 1999 season and production projected to exceed total demand, stocks are expected to increase significantly next season. Based on these estimates, U.S. stocks would rise nearly 2 million bales to 5.5 million, giving us a very high stocks-to-use ratio of 34 percent, which would depress prices significantly.

Marketing advice for 1999 continues to be 'price cotton early'. As of May 9, U.S. cotton planting progress was running behind both last year and the 5-year average. Thirty-five percent of the crop was planted as of May 9, compared with 37 percent in 1998 and an average of 42 percent. Delays were most noticeable in Arizona, Georgia, and South Carolina, where the percent planted is lagging behind the 5-year average by 15-20 percentage points. In contrast, progress in California and Missouri show plantings above the average and well ahead of last season. Don't be distracted by supply problems, the market is demand-driven. A few weather problems may cause blips in the market's continued decline, but it will continue to decline barring a major catastrophe in several growing regions.
 
 

The effects of early-season seedling diseases can last throughout the summer. Early diseases like Pythium, Fusarium, and Rhizoctonia can weaken the root system and stems. After temperatures warm up and the soil dries, plants will generally grow out of the early season damage. However, if Pythium and other opportunistic organisms cause enough damage, the taproot system can resemble a fibrous system later in the year. The impact of the limited root system will show up especially during periods of drought during the bloom and boll development stages. Fields may exhibit potassium deficiency symptoms where soil levels would actually be adequate during a normal year.

Root health is essential to carry the crop through the entire growing season. In conventional cotton where cultivation is used to control weeds, producers may notice square shed following close cultivation. This is a direct response of root pruning and ethylene production in the damaged roots. Fruit shed will likely be greater when cultivation is used during periods of drought and heat stress.
 
 

You can access cotton and other row crop information through our website at:
http://www.aces.edu/department/cotton/index.html

As always, if we can be of service at the Alabama Cooperative Extension System, please do not hesitate to call or visit your local county Extension office.
 

Alabama Cotton Picksack Newsletter Reference: PSK-5-99; D. Monks and C. Burmester, Editors

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