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Specialists Speaking - September 2008

Get Ready For Harvest


MISSOURI
Mike Milam
milammr@missouri.edu

As farmers are applying their final inputs of insecticides and irrigation, we are rapidly approaching defoliation and harvest. There could be challenges with defoliation in some fields due to heat and moisture stress in non-irrigated fields.

I suspect that some of these fields will not be defoliated. When the first modules reach the gin, they could be ginned quickly to prevent leaf stain. Our heat units are mounting, and we have open bolls. As of Aug. 1, we have had more heat units, 1,522, than we had when we had our record yield (1,054 pounds/acre) in 2004.

That season we had accumulated 1,482 by this time. The difference, however, is lower than needed rainfall. As expected, some of our irrigated cotton really looks good.

Hopefully, a heavy boll load will keep the plants on track. As the season winds down, most of the nutrients and moisture will be gone to help the cotton open up and dry down. Our last effective bloom date is around the middle of August. Luckily, with boll weevil eradication, all of our producers have a “top crop” that they can depend on.

As I drive around our fields, I often see a lot of trash. Even in the rural areas, I see plastic bags and other potential contaminants. Most farmers are aware of the consequences of contaminated seed cotton and the impact at the mills. However, as a reminder, producers should check to make sure that they pick up this material prior to harvest.


FLORIDA
David Wright
wright@ufl.edu

The 2008 cropping season has been better to date than the past two to three years due to better weather conditions. Dry conditions early resulted in some spotty stands, but adequate moisture since late June has had an impact, resulting in better looking cotton fields.

Cotton yields and grades should be good this year if weather conditions during harvest are good. Producers should start looking for the optimum time to defoliate. Rainy conditions during this period have producers thinking about fungicides to prevent boll rot but applications made during boll opening do little good and should be made during bloom for optimum results.

Producers should consider defoliating soon after 60 percent of the bolls are open. The top few bolls seldom contribute much to final yield and waiting can often lead to loss of more high quality lint than is gained.

Likewise, days good for harvest in late September and early October are important since that is typically a dry period with fairly long daylight hours. Therefore, timely defoliation and picking can result in much faster harvests of high quality lint, and a week’s delay in starting in late September can multiply into a 21-day delay in finishing up at the end of the season with lower quality cotton.


GEORGIA
Glen Harris
gharris@uga.edu

Harvest time is my favorite time of year. Besides cooler weather, football games and dove shoots, it is a great feeling to literally gather in the fruits of your labor. The cotton crop in Georgia is shaping up well in most places.

Some areas of the state never seemed to receive significant rainfall and will yield below average. Most of the Georgia cotton belt however has received at least some rain, and where irrigation was also properly applied, the yields should help reach a respectable state average. Also, there is still a lot of late-planted cotton yet to be made as long as the scattered showers keep coming.

So besides cranking up the pickers and getting them fine-tuned and adjusted, one issue that is usually taken for granted – but can certainly help preserve lint quality – is proper module building, handling and placement. Starting with harvesting cotton at the proper moisture, where the moisture of the lint, seed and trash combined is 12 percent or less, will go a long way toward preserving lint quality and maximizing profitability.

Placing wet cotton in a module can lower the grade, and if the seeds are wet, may require excessive drying, which in turn also adds to ginning costs. Believe it or not, even in this high-tech age of sensors and monitors, using the old “if the seeds crack when you bite them” test to determine if the cotton is dry enough to pick is not a bad technique to use.

Module placement is also something not to be taken too lightly. Placing modules on high, well-drained areas and not where water will stand or run is the first rule. Choosing an area free of gravel, stalks and grass is also important.

Build the top of the module with a crown so it will shed rainwater. Properly fit module covers and check that they are free of any holes. Finally, do not “over pack” a module. Instead, aim for a final weight of about 14 bales’ worth. Besides seeing a Georgia football player find the end zone, one of the prettiest sights in the fall is a small field filled with many modules.


NORTH CAROLINA
Keith Edmisten
keith_edmisten@ncsu.edu

Talking about defoliation the day a field is to be defoliated is hard enough. Writing about it a month in advance is approaching on madness. There are some things we know about the crop already though. Spotty showers have left some fields with a top crop and some devoid of a top crop that are definitely harvestable.

Of course, we will need to start in the drought-stressed areas with no top crop. Hopefully, many of you won’t have much cotton like that. In North Carolina, if weevils are absent, and worm and plant bug damage is scarce, in most fields we tend to set a compact crop.

This means that the fruit are relatively close together in terms of age, compared to a crop grown in an area with a lot of insect pressure. This has meant that we can often defoliate some fields prior to 69 percent open, some as low as 20 to 30 percent open. What we have seen is that defoliating earlier may not result in a much earlier harvest if boll openers are not used fairly aggressively.

Remember the old rule of thumb that, if you do not harvest within 14 days, your cotton will open naturally without the use of a boll opener.

Keep in mind that this work was done on cotton at least 80 percent open and in fairly warm conditions.


LOUISIANA
Sandy Stewart
sstewart@agcenter.lsu.edu

One of the defining aspects of the 2008 Louisiana cotton crop has been high early fruit retention. Bolls set on the bottom third of the plant constitute a larger portion of harvestable yield than most years. High early retention has been followed by hot, dry conditions.

The end result is a compact crop that is maturing rapidly. In most years, almost the entire harvestable yield comes from a 12-node range on the plant in Louisiana. This is to say that 12 fruiting nodes usually contribute 95 percent of yield. Observations from 2008 indicate that for many fields a 10-node range on the plant is all that can be reasonably expected. This is due to such high early retention in the bottom third of those nodes followed by hot, dry conditions.

Therefore, producers should closely examine fields and determine if bolls are set in a more compact (10-node) range on the plant than expected. The end result of a compressed crop is that the difference in age from the oldest boll to the youngest harvestable boll is less than normal.

Defoliation timing is a balancing act between preserving quality and yield. The longer cotton is allowed to open prior to termination, the higher micronaire (mike) is likely to be. For a compact fruited crop spread over only 10 nodes, timing defoliation takes on greater importance.


MISSISSIPPI
Darrin Dodds
darrind@ext.msstate.edu

We are headed towards the finish line with the 2008 Mississippi cotton crop. Due to excessive rainfall during planting season, the majority of this year’s crop was planted during or after the third week of May.

Consequently, there is a portion of the crop that may be harvested two to four weeks later than normal.

However, there are areas of the state that did not receive any significant rainfall for six to eight weeks during the summer. The dryland crop in these areas will most likely be harvested in what would be considered a normal time frame. Defoliation is one of the final hurdles to cross before finishing another growing season. However, selection of a defoliation program that meets your expectations can be a frustrating task. Product selection can be further complicated as performance may change from year to year in response to environmental conditions, variety, etc.

It is important to remember that there is no silver bullet for cotton defoliation, and all products have strengths and weaknesses.


ALABAMA
Charles Burmester
burmech@auburn.edu

The 2007 cotton crop in Alabama had very low lint yields, and cotton quality was equally poor – mainly due to short staple lengths and very low micronaire levels. In this case, the farmers had very little control over cotton quality as the severe drought was the deciding factor.

In fact, each season’s cotton quality is largely determined by the environmental conditions during boll set and the cotton variety that is planted. So why worry about cotton quality? We are fast approaching boll opening, and yield and quality have already been determined on many of these bolls.

As we approach defoliation and harvest, this means we are now in the mode to try to protect the quality of the cotton that we have grown. Timing cotton defoliation correctly and getting a good leaf drop are two things we can do to maintain cotton quality.

TEXAS
Randy Boman
r-boman@tamu.edu

The 2008 crop year in the High Plains has been a tough one for our producers. Lack of early season rainfall has resulted in a somewhat later crop than normal in many places. The drought and high velocity, hot, dry winds in the first half of June damaged or reduced crop progress in many fields, and severe thunderstorms in the last half of June knocked out some areas.

It appears our abandonment this year will be about one million acres. Lack of rainfall in many areas in July and August has resulted in a difficult situation. All of this combined with higher energy prices and inputs such as irrigation and fertilizer has cut severely into crop budgets.

As we near the harvest-aid run, producers need to be aware of the numerous harvest-aid products that perform well under widely ranging crop and environmental conditions. Over the years we have seen vast improvements in color grades and reduced bark contamination by applying harvest-aid products in a timely manner.

Don’t forget that field weathering may result in significant reductions in lint value, and weather events may actually reduce yields of some of the looser varieties. As usual, we plan to initiate harvest- aid trials at several locations to see which products provide the best performance. How the fall will shape up for harvest-aid selection remains to be seen.


ARKANSAS
Tom Barber
tbarber@uaex.edu

The highly anticipated end to the 2008 season is near, and defoliation applications are going out readily on the early planted cotton. We have a unique situation in Arkansas this year due to the cool conditions early. Most of our crop is a little behind schedule.

Cooler temperatures, cloudy weather and rainfall in August have delayed maturity somewhat on the later-planted cotton. When making a decision to defoliate a particular field, variety characteristics and position of fruit set is very important for preservation of fiber quality.

Many cotton fields this year have a large boll set on the bottom of the plant. This should be taken into consideration when determining when to defoliate this crop. Because of the large fruit set lower in the plant, the field may be more mature than you think by a simple turnrow check.

Some high-yielding varieties also have the potential to produce higher micronaire values when they are defoliated late. It is important to know the history of the variety that you are producing. If there is a history of high micronaire with the variety in question, then management options to defoliate the fields containing these varieties should be weighed.

Defoliating at heat unit accumulations of 850 DD60s for most varieties in Arkansas will help maintain a lower micronaire and maximize profitability through yield and fiber quality. Depending on the fruit set in the field, this may occur at 40 to 50 percent open boll. A timely defoliation and harvest will maintain season long management efforts.


ARIZONA
Randy Norton
rnorton@ag.arizona.edu

As we begin harvesting the 2008 crop, a couple of things to keep in mind are safety and cleanliness. Millions of dollars each year are lost due to picker accidents and fires. Always make sure that the picker is adjusted properly and that you carry a fully charged and functioning fire extinguisher.

Start the season with a clean picker – particularly the engine and engine compartment. Approximately 75 percent of fires begin in that area. Make sure that employees are trained in what to do if a fire occurs. Keep a cell phone or radio with you in order to call for help in case of a fire. Keep trash removed and clear from around radiators and exhaust systems.

It is important to always clean up oil and fuel spills immediately and to use a pressure washer to keep oil and grease from building up on picker parts. The other item that can result in reduced fiber quality and may jeopardize our markets is cotton contamination. We compete in a global market place with manmade fibers, and it is critical that we keep our product free from contamination.

This process begins at the field level. The smallest piece of plastic or part of a degraded module cover can end up as a blemish in a finished fabric that then results in “seconds.” This can greatly reduce the value of our product. Some things to keep in mind are to properly maintain module covers.

When they begin to deteriorate, replace them with new covers. Use cotton (not plastic twine) to secure tarps on modules. Plastic that is used as liners in irrigation ditches should be removed from fields prior to harvest. Other garbage that can blow into fields, such as plastic grocery bags, are also a significant source of contamination.

 
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