Saturday, April 13, 2024

Crop Inches Closer To Defoliation

Mike Milam

This has been such an unusual year for Missouri producers. We have set so many record highs, and we have worsening drought conditions. All of our cotton-growing area is classified as extreme drought. Although we have isolated and scattered showers forecast for the next 10 days, the drought monitor forecast through September calls for higher-than-normal temperatures and an equal chance for above-or-below average rainfall. With all of the 100 degree-plus temperatures, readings in the 80s and low 90s really feel good.

On June 29, we had 1,014 heat units at Portageville. This is from May 1 through June 29. This compares with 839 for the same period last year. According to the Crop Progress and Condition Report for the week ending July 8, cotton squaring and beyond was 79 percent – one week ahead of last year and four days ahead of normal. Cotton setting bolls and beyond was 12 percent – four days ahead of last year – but four days behind normal.

Cotton condition was 12 percent very poor, 30 percent poor, 41 percent fair, 15 percent good and two percent excellent. There really is a contrast between the irrigated and non-irrigated cotton this year. Most of the irrigated cotton looks good and has good yield potential. Some of the non-irrigated cotton is showing nutrient deficiency symptoms, is shorter and is not in the expected range for nodes above white bloom. It is not setting fruit very well either.

David Wright

The cotton crop was planted over an eight-week period in Florida due to droughts early and rains in some areas. Some early planted cotton has been blooming for a few weeks, while later planted cotton is just beginning to bloom. For the most part, there have been few insect pests, but producers need to keep a close check on fields that are near corn fields that are drying down.

Stinkbugs will be coming out of those fields and can cause boll damage and delay the crop even further. Anything producers can do to set an early crop and have it ready for harvest early this year is advisable since climate forecasters are predicting a wetter summer and fall. Wet weather can shorten the harvest period, which can reduce quality if the crop stays in the field longer. The new varieties of cotton look like they are fruiting well and have a high yield potential.

John Kruse

The Louisiana cotton crop has been struggling through a hot, dry spell, but recent rains in some parts of the state brought some much needed relief. The crop is generally between 12 and 18 nodes, with most varieties holding six- to eight- nodes above white flower. I have seen a few late planted fields that were dry and short in stature with blooms moving toward the top of the crop, but for the most part producers are pleased with this year’s overall progress and potential.

The hot and dry weather promoted spider mite infestations that are widespread and moderate to severe. I visited one farm where the mites left nothing but the plant stalk in different patches of the field. The dry weather has kept plant bug numbers pretty low compared to most years, but aphids are a bigger problem than last year. Many producers have put out their layby applications and are focusing their management efforts on arthropods and growth regulation.

So far, the crop looks good from a fertility perspective, but it is just starting to get early symptoms of potassium deficiency in leaves as bolls begin to fill. Weed control efforts have paid off as many producers saw the wisdom in including residual herbicides in their programs. Many farm fields (not just in cotton) have Palmer amaranth that producers know for certain were treated with glyphosate early enough and at rates high enough that it should have killed them but failed to do so.

LSU AgCenter weed scientist Dr. Daniel Stephenson described 2012 as “The Year of the Pigweed” for Louisiana. More producers need to be vigilant to stop glyphosate resistance at its current borders. Some fields are already under intensive irrigation management, but a good proportion has been able to get through on precipitation. We are still optimistic about this year’s crop.

Charles Burmester

Much of Alabama has experienced very dry weather and hot temperatures from the middle of June through the first week of July. Some of the cotton has been blooming for about two weeks, while late planted cotton is just beginning to bloom. Cotton has actually held up better than I expected during this period – mainly due to the low boll load on the plant. Cotton is much shorter than normal and, as more bolls are added, this will greatly increase the stress on the cotton plant and reduce vegetative growth even more.

Cotton recovery will largely depend on when significant rainfall (two inches or more) occurs and how much boll load remains on the plant. Cotton grown in the southern half of the state has a longer growing season and more time to set a second crop of bolls. Setting a second crop of bolls is more difficult in northern Alabama due to the shorter season and requires good growing conditions in August and September. Experience tells me it is much too early to give up on this Alabama cotton crop. Significant rainfall, however, will be needed in many areas during the first half of July to turn this cotton crop around.

Randy Norton

One of the most important decisions that a producer will make late in the season is when to terminate the crop or when to apply the final irrigation. This decision is best based upon late season crop conditions. Crop progression through the fruiting cycle and into cutout can be tracked by counting the number of nodes above the top first position fresh flower (nodes above white flower-NAWF). When NAWF reaches five or less, the crop is near cutout. At this point, the crop should be evaluated with respect to the potential for additional fruit set in a top crop.

The potential contribution from a top crop to the final yield is dependent upon various factors, including the type of variety (full or reduced season), current fruit load on the crop (research has indicated an inverse relationship between current fruit load and potential contribution from a top crop) and crop vigor. Keep in mind also that late season insect pressure may necessitate control measures that completely negate any additional yield achieved through a prolonged season.

Once a decision has been made to terminate the crop, there are a couple of things to keep in mind in determining when the final irrigation will take place. Research conducted in Arizona indicates that approximately 600 heat units (HU) are required to produce a mature harvestable boll from a fresh bloom. In most cotton-producing regions of Arizona, this equates to approximately 20 days in late August through September. Adequate soil moisture is required during the entire boll maturation period of 600 HU. Actual HU accumulations may be monitored for a specific location using the AZMET weather site at

Randy Boman

The June 2012 USDA-NASS report indicated that Oklahoma cotton acreage is around 330,000 acres, which is down about 20 percent from last year’s 415,000 acres. As of early July, the crop continues to make progress in areas where adequate moisture has been available. The 22 percent of capacity status of Lake Lugert is very concerning in southwestern Oklahoma as we head into the high water demand phase of the crop.

No release of irrigation water will occur this year in the District. Most producers have initiated irrigation where groundwater is available. Altus has already encountered 24 days of 100 degrees or more – one in April, nine in May, 11 in June and five days in July (through July 9). The good news is that winds have not been as bad as last year.

The Altus actual precipitation from Oct. 1 to June 30 was 18.2 inches, and the normal for that time period is 20.9 inches. Therefore, we are 87 percent of normal from Oct. 1. Many earlier planted fields have begun blooming, coming in at around seven to 10 nodes above white flower. This indicates a good to excellent yield potential IF rainfall is obtained or adequate irrigation can be maintained.

We have observed some four-bract cotton squares aborting, but thank goodness the difference from last year is that only the lowest squares are exhibiting this abnormality.

John Idowu

The cotton fields in New Mexico are looking good as we approach the mid-season. Many fields are now at square or bloom stage, depending on planting date and/or variety. There has been no particular pest or disease pressure. We have had some rainfall across the state, which has contributed to the water supply for cotton.

The rain was very much welcomed especially due to a prolonged drought that New Mexico has been facing. Water availability still remains a challenge in many parts of the state. Many producers’ water allotment has been cut back requiring more pumping of water from wells.

Operating the pumps has increased the cost of production for cotton. In the absence of any unforeseen problem, a good cotton crop is projected for the state in 2012.

Gaylon Morgan

As of Friday the 13th in July, the cotton season is winding down quickly in South Texas with heat unit accumulations about 20 percent above average. We have been fortunate to receive some rain throughout the state during the past couple of weeks. However, the rain has been extremely scattered. Cotton defoliation began in the Rio Grande Valley and Coastal Bend the first week of July, which was a couple of weeks earlier than usual. Dryland yields in the RGV are expected to be above average with more than a bale of cotton being quite common.

The irrigated cotton yields will probably be near the long-term average but below the 2011 yields. Cotton and other crops in the Coastal Bend region have struggled all season due to very limited subsoil moisture and little in-season rain. Many fields will not be harvested in this area due to very low yield potential. Cotton bolls are opening in the Upper Gulf Coast cotton, and this region has received more than eight inches of rain in the past month.

The overall yield potential in the Upper Gulf Coast is very good right now. The Blacklands is currently at or beyond cutout, and some bolls are opening. The overall yield potential is fair to good. We continue to observe potassium deficiencies in many cotton fields again this year in the Blacklands. In the Rolling Plains, it is a mixed bag from very poor to good cotton and from two- to four-leaf cotton to early bloom stage. Irrigated cotton generally looks good but is receiving a lot of irrigation water.

Darrin Dodds

The roller coaster ride of 2012 continues as we roll into August. An early planting season was followed by several weeks of hot, dry weather, which was followed by significant rainfall in many areas of the state during the first two weeks of July. Generally speaking, our crop is about two to three weeks ahead of normal, and defoliation applications in the earliest planted cotton will begin in August.

Although we do still have a good portion of this season in front of us, tarnished plant bug pressure to date has been light compared to the past couple of years. However, given recent rainfall and environmental conditions, an increase in insect activity would not be out of the question.

As mentioned above, some fields will likely be defoliated in August this year. It almost goes without saying but caution must be exercised with harvest-aid product selection and application rates, particularly if the dog days of August set in. Use past experience with harvest-aid application as a guide but be sure to take into account the weather when selecting products and rates. I tend to err on the side of caution as I can always make a follow-up application, but I have not yet found a way to unstick leaves.

Mark Kelley

In the Texas High Plains, scattered showers earlier in the week (July 9) brought relief to those dryland and irrigated cotton crops that were fortunate enough to be under one of the clouds that produced significant rainfall amounts. Amounts ranged from less than .25 inches to 2.5 inches or better in some locations. Condition of the cotton crops on the Texas High Plains is a mixed bag at this time.

Earlier planted cotton under irrigation is progressing well and most is in the second week of bloom. Later planted irrigated crops that were subjected to blowing sand and/or light hail events in early June are a bit behind and should be nearing the first bloom stage early next week. However, some of the fields that were subjected to the damaging weather events were either replanted and are around the four- to six-leaf stage or were replanted to an alternate crop.

In some areas of the High Plains, irrigated crops are struggling due to saline soils that resulted from the 2011 drought conditions. Difficulties range from stand establishment to cessation of growth and development. In these areas, more and greater rainfall events are needed to remediate the salinity issues. Finally, the dryland cotton crop is beginning to struggle in areas where precipitation has been elusive and will need moisture relief soon for continued growth and development.

Guy Collins

Rains continued for many parts of southwest Georgia through mid-July, resulting in decent boll set and development for the first two to three weeks of bloom for earlier planted cotton and continued vigorous growth for later planted cotton that was not yet blooming at the time. However, rains have been spotty, and temperatures remained relatively high as expected for July.

Signs of stress were evident for fields that happened to miss the rains that passed through, reminding us that we are never more than a few days away from a potential drought. However, as of mid-July, most of the stress was short-lived in these fields.

As I write this on July 13, most areas have experienced recent rainfall. However, some fields may have been neglected by recent storms. There have also been several reports of nematodes throughout the state, which can exacerbate drought stress as root systems in these fields may be poorly developed.

Heat and drought stress are more serious for blooming cotton but can have detrimental effects on pre-bloom cotton, depending on severity. Proper irrigation scheduling is critical to achieving optimal yields, and it always helps to have some rain.


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