Commonly used harvest-aid materials
CottonQuik- CottonQuik weighs 12.45 pounds per gallon and contains 2.28 pounds of ethephon per gallon and 7.30 pounds aminomethanamide dihydrogen tetraoxo -sulfate per gallon. Typically, satisfactory defoliation is achieved within 7 days. Adverse conditions such as low temperatures and/ or toughened plants may require up to 14 days. CottonQuik also provides limited control of cotton regrowth. Do not exceed a maximum of 3.5 quarts per acre per year. After application of CottonQuik, thorough rinsing of application equipment is strongly recommended. Refer to the label for additional instructions.
Def 6 and Folex- These phosphate-type materials have been the standard defoliants for a number of years. Their performances are equal. The lower label rates have performed well only under near-ideal plant and temperature conditions. Under cooler temperatures, or less favorable plant conditions, the higher the plant performs. These materials are labeled for combination with Dropp 50 WP or Prep/Super Boll. When combinations are used, the lower rate of Def 6 or Folex seems to perform well. These materials are not good regrowth inhibitors and are more rain fast than are other materials. Always follow the mixing instructions on the label.
Finish- When used at the rates labeled for expected field conditions, Finish may serve as a defoliant and boll opener. In some cases, such as rank growth, weed infestations, or insect infestations, the inclusion of other products is required. Finish may shorten the time internal between application and harvest as compared to Prep/Super Boll used alone. Activity against juvenile growth and regrowth suppression is good. Do not apply more than two quarts per acre per year.
Harvade 5F- Harvade is the only defoliant that states on the label that it is to be used with crop oil concentrate. Some recommended additives are listed on the Harvade label. It seems to be less sensitive to low temperatures than other defoliants and performs better than other materials when average temperatures are below 70 F. It is essentially odorless and provides limited desiccation of morning glories. Give special attention to the use precautions stated on the label.
Dropp 50 WP- Dropp significantly suppresses, or delays regrowth. The degree of regrowth control depends on the rate, plant conditions, and weather. Dropp performs best under warm, humid conditions. When nighttime temperatures (at treatment or for 2-3 days after treatment) drop into the low 60's, performance is reduced. Under cool conditions, tank mixing reduced rates of Dropp with methyl parathion, the phosphate defoliants, Prep/Super Boll, or a recommended crop oil concentrate will enhance defoliant activity while maintaining adequate regrowth inhibition. Under warm to hot conditions, Dropp is effective when used alone, at low label rates. When combinations are used, rate selection of materials in the mixture is important because higher rates may cause desiccation of leaves. Refer to the label for mixing and especially clean-up instructions.
Dropp Ultra- Dropp Ultra is formulated as a wettable powder containing 75 percent active ingredients (75 WP) and is packaged in water-soluble bags. It may take several days before the effect of Dropp Ultra becomes noticeable. Adverse conditions such as low temperatures may require higher dosages and/or longer times for more complete defoliation. Dropp Ultra inhibits regrowth after defoliation. Response of the cotton plant to an application of Dropp Ultra slows under temperatures below 60 F. Ideally, nighttime temperatures 2 to 3 days before and following application should be no less than 60 F or defoliation and/or regrowth inhibition can be reduced. Use of Dropp Ultra on heat and drought-stressed cotton (low leaf moisture, thick cuticle, etc.) can result in less that satisfactory defoliation and regrowth inhibition. Important: Read and follow all instructions on the label, especially Use Precautions, Mixing Instructions, Use of Adjuvants, and Directions for Use.
Prep/Super Boll- The active ingredient in Prep/Super Boll is ethephon and is formulated to contain 6 pounds per gallon of active ingredient. Prep/Super Boll is primarily a boll opener. It has exhibited positive benefits in increasing the degree of defoliation under adverse conditions and in speeding boll opening. Increasing the rate of boll opening has permitted harvesting operations to start several days earlier, increased the percentage of the crop harvested during the first picking, and made picking a once-over operation in many fields. The recommended rate for boll opening is 1 to 2 pounds of active ingredient per acre. The higher rate sometimes acts as a defoliant under optimum conditions. Use the lower rate in combination with other defoliants. Prep/Super Boll is compatible with Def, Folex, Dropp, and Harvade. Good agitation is a must. Do not mix Prep/Super Boll with sodium chlorate. Desiccants generally are not used as harvest aids for cotton to be picked by a spindle-type picker. If desiccation of weeds or regrowth vegetation is necessary, it generally is best to apply a defoliant, wait until leaf drop has occurred, and then apply the desiccant material.
Sodium Chlorate- Sodium chlorate acts as a desiccant at higher rates of application, tending to stick leaves to the cotton plants. At the normal use rates for defoliation, the chlorates are not as effective as the phosphates. Chlorates are not good inhibitors of regrowth. Do not mix the chlorates with phosphate defoliants, phosphate insecticides, or Prep. Sodium chlorate is usually a good follow-up treatment and generally performs well under cool conditions.
Starfire- Starfire is labeled for desiccation and as a harvest aid. For harvest-aid applications, the label recommends 11 ounces of Starfire plus 1 pint of a phosphate defoliant, or 3 to 6 pounds active ingredient of chlorate per acre in a minimum of 10 gallons total volume by ground, or 3 gallons total volume by air, applied when 80 percent or more of the bolls are open and the remaining bolls to be harvested are mature. Starfire is also labeled at 4 to 6 ounces per acre tank- mixed with Def, Folex, Dropp, Harvade, or Prep/Super Boll for defoliation and boll opening. Apply in a minimum total volume of 10 gallons per acre by ground or 3 gallons per acre by air. Apply when a minimum of 60 percent of the bolls are open and the remaining bolls to be harvested are mature. Starfire applied at the 4- to 6-ounce rate in combination with defoliants may improve defoliation under adverse conditions. Starfire is also labeled as a desiccant to be applied after defoliation applications. For this purpose, apply 11 to 21 ounces per acre in a minimum total volume of 10 gallons per acre by ground or 3 gallons per acre by air. Apply when at least 75 percent of the bolls are open. Development of immature bolls will be inhibited. Follow the use precautions as stated on the label.
Roundup D-PAK or Roundup Ultra- Roundup can be used in a tank-mix with various defoliants to achieve late-season control of weeds and to reduce populations of perennial grasses and vines. Apply after 60 percent open bolls at 15 to 20 ounces D-PAK or 16 to 64 ounces of Ultra per acre in a tank-mix, with a suitable defoliant at recommended rates. Apply in 3 to 1 0 gallons by air or 10 to 20 gallons by ground. Do not apply to crops grown for seed. Do not apply more than 1 quart per acre of Ultra by air.
STARKVILLE, Miss. -- Rain, cool weather, more rain and some wind have slowed cotton maturation, but since the crop was a little behind schedule, the damage may be less than if harvest were already underway.
Darrin Dodds, cotton specialist with the Mississippi State University Extension Service, said recent weather is causing some yield loss, but it is hard to estimate how much.
“Being late to a degree helped the crop because rain did not string out open cotton, but given that we are running out of heat, we may have been better off with an earlier crop that had been defoliated and was standing up when the rain came,” Dodds said.
STARKVILLE, Miss. -- Cotton will always have challenges, but few of them will ever compare to the boll weevils that thrived in Mississippi from 1904 until 2009.
“It is nearly impossible for this younger generation of consultants, scouts and growers to understand how hard boll weevils were to control and how much boll weevil control hurt beneficial insects and complicated cotton management,” said Will McCarty, who served as the Mississippi State University Extension Service cotton specialist during “the boll weevil wars.”
MACON, Miss. -- Farmers' independent natures make them strong, but when agricultural producers join forces, they can take success to the next level.
Darrin Dodds, cotton specialist with the Mississippi State University Extension Service, commended Mississippi farmers for their efforts to unite in the battle to eradicate boll weevils from the state.
“Historically, boll weevils were the prime pest in cotton fields. To control them, it took numerous pesticide applications,” he said. “Those treatments were costly and ate into the growers’ profit margins.”
STARKVILLE, Miss. -- Mississippi’s row crops have had enough rain, and most fields just need sunshine.
Erick Larson, grain crops specialist with the Mississippi State University Extension Service, said corn is mature and will gain no benefit from additional moisture. In the first couple of weeks of August, skies were overcast or rain was falling across most of the state.
STARKVILLE, Miss. -- Tropical Storm Cindy did not help the state's cotton crop that struggled with cool and wet weather all spring.
Darrin Dodds, cotton specialist with the Mississippi State University Extension Service, said in mid-June, cotton received about a week of the heat and sun it needs to thrive. Weather before that was not ideal, and rain remains in the forecast.