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7 Tips for Successful Cotton Planting

From planting depth to thrips control, North Carolina cotton experts designed these reminders to help you achieve optimal stands and good early season growth.

By Guy Collins
North Carolina State University

The wet and cold 2016 planting season we encountered in North Carolina reminded us all about the fragility of cotton seed and the difficulty in establishing an adequate stand when Mother Nature is not cooperative. There are key points to keep in mind throughout the planting window every year and steps to take to avoid potential problems.

In years like 2015, when planting conditions were ideal across much of the state, it is easy to overlook some of these points when easily achieving optimal stands. And in years like 2016, when planting conditions were some of the worst on record, certain problems may be unavoidable.

However, in most years, challenges encountered during planting can be averted. Below are a few tips to consider for achieving optimal stands and early season growth.

Document each seed lot number, along with the seed treatment, whether it was treated upstream or downstream, warm and cool germination percentages, and seed size.

Tip #1:

Know what you purchased. Document each seed lot number, the seed treatment and all products included in the treatment, and whether the seed was treated upstream or downstream. Determine warm and cool germination percentages (contact your dealer or seed company rep for cool germ values) and seed size (seed per pound). Seed size is either explicitly printed on the bag or can be calculated by dividing the number of seeds in a bag by the bag weight.

Know what you purchased. Document each seed lot number, the seed treatment and all products included in the treatment, and whether the seed was treated upstream or downstream. Determine warm and cool germination percentages (contact your dealer or seed company rep for cool germ values) and seed size (seed per pound). Seed size is either explicitly printed on the bag or can be calculated by dividing the number of seeds in a bag by the bag weight.

The lot number and seed treatment code can be traced in case you have questions later or encounter emergence problems. Knowing the type of seed treatment tells you which products are included and rates of each for thrips management, and whether it includes additional fungicides or nematicides. Take extra effort to secure cool germ values.

Knowing seed size (seed/pound), along with warm and cool germ values, is a good indicator of likely seedling vigor relative to other varieties. Lastly, we encourage all producers to save a small seed sample (resealable plastic bagful) from each lot number in case problems occur during planting so the seed can be re-evaluated for various factors.

Tip #2:

Adjust your planting depth. One of the most common mistakes is planting cotton too deep. When young, the cotton plant is weak. It generally struggles to sprout, emerge and grow until it reaches the four- to five-leaf stage. In many cases, I see cotton planted at depths 1 inch or even greater. In 2015, warm temperatures and optimal moisture promoted rapid emergence so problems with planting too deep were infrequent. However, excellent planting conditions are not normal for us. Planting too deep will result in poor emergence and poor stands in most years, especially when less-than-ideal conditions prevail.

In most cases, producers set their planters at a certain depth, roll on and do not make adjustments for weather or seed size. In some cases, farmers plant deeper than they should to chase moisture. But the deeper cotton is planted, the more time and energy it has to expend to fully emerge. This lowers the chances of achieving an optimal stand, increases the likelihood of encountering injury, and results in a weaker seedling that has used up much of its energy reserves and seed treatment insecticides. If these seedlings emerge, they often are weaker and more vulnerable to thrips and seedling diseases.

Cotton should be planted no deeper than 0.5 to 0.7 inch deep, from the top of the seed to the top of the soil. For modern planters, the center of the furrow is often higher than the edges. Consider the distance from the seed to the soil surface directly above it (not the sides or walls of the furrow).

In fields with a history of crusting, seed should be placed at even shallower depths (if adequate soil coverage can be achieved) and/or planted in a hill-drop configuration. In no-till situations, cotton generally should be planted as shallow as possible with ideal soil-to-seed contact.

In all cases, plant into adequate soil moisture. When “chasing” moisture by planting deeper, it typically is marginal at best. Unless you are planting very late in the window and under excellent temperatures in soft soils without a threat of crusting, it’s best to plant shallower and wait on a rain. Chasing moisture presents a significant challenge in some cases.

Ideally, cotton should be planted into sufficient moisture for germination and emergence to avoid herbicide injury. Dusting in cotton and waiting on a rain may result in the first drink of water containing significant amounts of herbicide, which can cause injury. However, the same results can happen if you plant deeper to chase moisture and that moisture expires before adequate germination and emergence occurs.

If possible, delay planting and wait on a rain so you can plant into adequate moisture. Because there is no one-size-fits-all planting depth, make adjustments for various situations, such as temperature, moisture, potential for surface crust, etc.

Tip #3:

Manage varieties according to vigor. This is a combination of Tips 1 and 2. Knowing a variety’s warm and cool germ values along with seed size is a great predictor of relative vigor compared to another variety. Larger-seeded varieties with higher cool germ values can tolerate slightly deeper planting and slightly cooler weather than smaller-seeded varieties with lower cool germ values.

Manage varieties according to vigor. This is a combination of Tips 1 and 2. Knowing a variety’s warm and cool germ values along with seed size is a great predictor of relative vigor compared to another variety. Larger-seeded varieties with higher cool germ values can tolerate slightly deeper planting and slightly cooler weather than smaller-seeded varieties with lower cool germ values.

In very poor conditions, like we observed in 2016, all seed sizes will probably be challenged and have poor emergence. In great conditions, all seed sizes can achieve an optimal stand and good early season growth. In marginal conditions — less than ideal but not terribly poor — seed size and warm/cool germ values can mean the difference in whether an optimal stand is achieved or skips are present.

Unless fields frequently have significant challenges with stand establishment, make variety decisions based on performance, such as yield potential and stability, fiber quality, trait packages, etc. However, it’s important to consider vigor and seed size during planting and adjust management practices and planter depth depending on soils and prevailing conditions.

Comparing varieties for two years may indicate which ones will be more vigorous than others. Roughly 65 percent of seedling vigor ranking — how one variety compares to another — is related to seed size. It is important to document seed size for your lot number, and then compare it, along with warm and cool germ values, to other varieties. All can vary across lot numbers.

Because there is no one-size-fits-all planting depth, it should be adjusted for various situations, such as temperature, moisture, potential for surface crust, etc.

Tip #4:

Manage seeding rates for planting date, environmental conditions, soil types, etc. Generally speaking, North Carolina growers should plant 38,000 to 45,000 seeds per acre. Seeding rate adjustments are warranted for different planting dates, environmental

Manage seeding rates for planting date, environmental conditions, soil types, etc. Generally speaking, North Carolina growers should plant 38,000 to 45,000 seeds per acre. Seeding rate adjustments are warranted for different planting dates, environmental conditions and soil types. There is no one size fits all.

Use higher seeding rates in less-than-ideal conditions as is often observed in the early part of our planting window. Also plant at higher rates toward the end of the planting window to manage for earliness. If stands are poor, optimal yields cannot be achieved in any scenario. However, skippy stands may perform better than later-planted cotton where the crop has less time to compensate.

In addition, the lower range of recommended seeding rates only applies to excellent planting conditions (more likely to occur in the middle part of our planting window) in soft soils with ideal moisture. In challenging fields that often develop a surface crust, or in less-than-ideal planting conditions, higher seeding rates should be used. This applies to any other scenario that may result in poor stands.

Tip #5:

Watch the weather forecast and adjust practices accordingly. Throughout every planting window, Dr. Keith Edmisten does an excellent job of posting biweekly weather predictions and projections for DD60 accumulation. He also alerts growers when conditions are favorable to plant cotton. Find these notices at https://cotton.ces.ncsu.edu/ and use them to adjust seeding rates, planting depths and planting considerations for different varieties.

Paying attention to weather forecasts as well as planting depth and vigor characteristics can help avoid potential herbicide injury issues. For example, Warrant is a commonly used herbicide that can be applied both pre and post emergence. As seen in Dr. Alan York’s research over the past several years, it is very effective and is an integral part of many weed management programs. When planting conditions are good and seedling emergence occurs within a relatively timely manner — about four to six days after planting — there typically are few to no problems with using this herbicide.
When planting in poor conditions and when seedlings are very slow to emerge, about eight to 10 days after planting or longer, injury is likely. This is due to the herbicide’s encapsulation breaking down and seedlings emerging through a high concentration of herbicide. Considering forecasted planting conditions and adjusting planting practices accordingly helps you avoid this issue.

Farmers can expect less-than-ideal thrips control if in-furrow insecticide coverage is not adequate.
Photo: UNIVERSITY OF GEORGIA
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Tip #6:

Consider placement of starter fertilizers, which occasionally can benefit producers by somewhat improving seedling vigor. We generally support starter fertilizer use under certain conditions. These include: 1. Use the correct rate and don’t overapply starter fertilizers (10 to 13 gallons of 10-34-0, for example); 2. Apply adequate, actual pounds of nutrients versus exceptionally low rates of trace amounts of nutrients; 3. Apply starter sources that are economical in their contribution to the entire fertility program; and 4. Do not apply starter fertilizers in-furrow.

The last point is the most important. Now that many farmers are using in-furrow liquid insecticides, starter fertilizers are sometimes being applied in-furrow as well. Producers may get away with it several years in a row. However, when problems occur, they are usually severe with no recourse but to replant. Therefore, we do not recommend starters be applied in-furrow for cotton.

Tip #7:

Ensure that liquid in-furrow insecticides directly contact seed and good coverage is achieved. Farmers can expect less-than-ideal thrips control if coverage is not adequate. This is especially important now that thrips resistance to neonicotinoids has been observed in North Carolina.

Farmers also have expressed interest in reducing at-planting costs by eliminating the seed treatment and only using liquid in-furrow products. Some growers may not observe much thrips injury when doing this if thrips numbers are low and seedlings are growing vigorously.

However, neglecting to use a seed treatment is not advised. Dr. Dominic Reisig’s research indicates that a liquid in-furrow insecticide alone results in similar thrips control to a seed treatment alone, which we know is not adequate.
Without a seed treatment to provide some protection, there is no room for error in applying a liquid in-furrow insecticide and its direct contact with seed.

Lastly, compare the active ingredient concentration across many of the in-furrow imidacloprids. Some generics have a lower concentration of active ingredient per gallon of product compared to Admire Pro.

Therefore, some in-furrow insecticides should be used at higher rates to be equivalent to Admire Pro in terms of active ingredient per acre. Apply all products according to their labels.

In all cases, scout thoroughly and frequently for thrips — both adults and juveniles — and the presence of injury. If warranted, timely foliar sprays are important. If scouting suggests an application is needed, don’t put it off. Delaying foliar sprays can result in significant yield losses.

North Carolina State University contributing authors are Keith Edmisten, Alan York, Dominic Reisig and Carl Crozier.