- Specialists Speaking -
Crop Status Varies Greatly
The Louisiana cotton crop is in good-to-excellent condition as of mid-June. Most of the acreage has reached the nine- to 13-leaf stage, which means that fruiting branches are developing, and the cotton is squaring. It is critical that the crop be protected from stress and insects during early fruiting to maintain at least 80 percent fruit retention. Otherwise, vegetative growth could become a problem, and plant growth regulators will be needed.
We have entered a dry spell, and fields with irrigation systems should be irrigated whenever needed. Regular scouting to determine if insecticide treatments are needed for fleahoppers and plant bugs or other insects that could affect square development should be done. According to our AgCenter nematologist, Dr. Charles Overstreet, some fields are showing symptoms of nematode damage, either reniform, root-knot or, in some cases, both.
Although little can be done to control nematode problems at this time, reducing the stress on plants through irrigation will offset some of the damage to the root systems. This is, however, a good time to evaluate fields to determine future strategies to control nematodes. Since the control is different for reniform and root-knot, it is important to determine which nematode species are present.
Rotation with corn will control reniform but not root-knot. Root-knot nematodes can be controlled by rotation with resistant varieties of soybeans. Control can also be done in following years by site-specific applications of nematicides.
Usually, treating entire fields with nematicides is too expensive and unnecessary. Suspicious areas in the fields should be sampled and the samples sent to the nematology lab for diagnosis and control recommendations.
Samples should be kept cool and moist for accurate results. Send the samples to Dr. Overstreet at the Nematode Advisory Service, Department of Plant Pathology and Crop Physiology, 302 Life Science Building, Baton Rouge, La., 70803. There is a $10 charge per sample.
Cotton planting in Missouri has gone from bad to worse. While Missouri was forecast to have 300,000 acres, I know that some of these acres will be planted to soybeans, and some of the cotton planted will be destroyed and planted to beans. We have fields near the St. Francis River in Dunklin County that have seep water and may not be planted to anything due to the wet conditions.
Heavy rainfall has resulted in many fields having been replanted several times, and there is still not a decent stand. I know of spot planting after June 1. Most of the cotton that has a good stand was planted after our recommended planting dates. With shallow roots, the non-irrigated cotton will start suffering when the really hot days get here in late June or July.
Looking at the DD-60s from May 1, we only had 365 through June 8. For comparison purposes, on July 15 last year, we had only accumulated 726, which was the lowest for the past four years. We were fortunate last year in that we received timely rains, and we were able to get the crop planted and out of the field. In spite of concerns for the crop last year, Missouri producers had a record yield of 1,106 pounds per acre. Reports of thrips and plant bugs have resulted in the need for spraying. There also are reports of aborted terminals. Regardless, we’ll have an expensive crop as we go forward.
Much of Alabama’s cotton crop is behind normal due to an extremely wet May across the state. Cotton maturity could become a concern – especially with cotton planted in the northern part of the state. Farmers should scout cotton closely to avoid factors that may delay the crop further. Plant bugs are a major cotton pest in northern Alabama, and some of the highest damage levels have occurred when June conditions are wet and cool.
This scenario allows the wild host plants to stay alive longer and the plant bugs to migrate to cotton over a longer period of time. Since cotton is delayed this year, the early squaring cotton could be very susceptible to plant bug damage. Cotton’s pinhead square retention should be monitored closely to maintain 80-plus percent square retention. Northern Alabama cotton can be seriously delayed by plant bug damage, and that is one thing we do not need this year.
A large portion of the Georgia cotton crop is somewhat behind schedule at the time of this writing. However, temperatures have picked up signi-ficantly, rainfall patterns are becoming more “typical” and the crop should progress quickly. Although boll development may be a few weeks away, stink bug scouting and management should be a priority once flowering begins.
Not only can stink bug infestations negatively affect cotton yield, they can also reduce cotton quality characteristics associated with fiber length, maturity and color. To ensure that we manage these pests properly, it’s important to make sure that we monitor the crop closely and be observant for stink bug pressure in two ways, through infestation level and species composition.
The two main species of stink bugs that are observed in Georgia are the southern green and brown stink bugs. When making management decisions, remember that organophosphate insecticides provide good control of both brown and southern green stink bugs, whereas pyrethroids will provide good control of southern green stink bugs but only fair control of brown stink bugs.
The Arkansas cotton crop remains extremely variable. Cotton growth ranges from 10 to 11 nodes to just emerged, with the majority of the crop averaging four to six leaves. The USDA Agricultural Statistical Service recently estimated that only four percent of the crop was squaring compared to 23 percent last year. The five-year average is 41 percent. There is no doubt that the majority of the crop is behind and later than we have seen in many years.
Much of the cotton has finally turned the corner and is growing and fruiting rapidly thanks to the higher temperatures and sunny weather. The high heat unit accumulation across the middle and southern part of the state has been perfect for growth and development of seedling cotton and new nodes can be found every two to three days.
While the northeastern portion of Arkansas continued to receive heavy rains, high winds and hail fell in some localized fields. In many of these counties, it will take a few days for the cotton to recover, especially fields in low areas or fields affected by seep water. Cotton health continues to be an issue, and some acreage may still be destroyed and eventually planted to soybeans.
How Important Is July?
It is a critical month for setting a good boll load, which affects the final yield. The cotton-planting season was spread over a long time period due to wet conditions in some areas and dry conditions in other areas. This makes scouting and management more critical to ensure that early planted cotton is managed and protected as cotton starts to bloom.
Blooming is expected to be somewhat later than normal due to the late planting, which will reduce the weeks of effective bloom period. It is very critical to set an early crop to keep cotton height down. Cotton will continue to grow with a light boll load and needs growth regulators until growth is slowed by a good boll set.