Tracking nodes above white flower (NAWF) from first flower to cutout (NAWF=5) can offer great insight on the condition and potential of the crop. As we approach this time of the season, we are interested in using this tool to aid in crop termination. The first fields planted are not always the first to reach cutout. Monitoring NAWF throughout flowering is important because it insures we measure all plants, including dominant and less dominant ones. If only spot checks are made near the season’s end, we cannot be certain all plants are represented. It is not unusual for NAWF to increase after initial cutout, as weaker plants will have more growth while their dominant counterparts are cutting out. In Arkansas, the latest possible cutout dates using a 50 percent probability of collecting 850 heat units (HU) on a 30-plus year data set are: Aug. 9, Keiser; Aug. 14, Marianna; and Aug. 17, Rohwer. If we use the last five years’ weather data, these dates may be extended slightly (three to five days). Establishing the dates of cutout is important in identifying the last cohort or group of bolls that will contribute significantly to yield and profit. It is this group of bolls and their development on which we base our end-of-season decisions. General termination guidelines include plant bug, cutout + 250 HU; bollworm and tobacco budworm, cutout + 350 HU; irrigation, cutout + 350 to 450 HU; stinkbug, cutout + 450 HU; fall armyworm, cutout + 500 to 550 HU; defoliating insects, cutout + 650 HU; harvest-aid initiation, cutout + 850 HU. For more information, contact your local County Extension Agent.
The crop is well into peak in the majority of the state with the far southwestern region of Yuma approaching cutout. As we progress through peak bloom and toward the end of the primary fruiting, cycle decisions will soon need to be made regarding irrigation termination. Monitoring nodes above white flower (NAWF) is an excellent way of tracking crop maturity and will help in making appropriate decisions for irrigation termination and eventual crop termination. Crop monitoring data collected over many years has demonstrated a good relationship between the number of mainstem nodes above the uppermost first position, fresh bloom and progression through the fruiting cycle. At first bloom, NAWF should be around eight to nine. At peak bloom, values of six to seven NAWF are observed, while an observation of less than five NAWF indicates that the crop is rapidly progressing towards cutout. Identification of the last fresh bloom that will be taken to a harvestable boll is a good way for scheduling the final irrigation and is typically done well after the crop has reached less than five NAWF or physiological cutout. Approximately 600 heat units (HU 86/550F threshold) are required to complete the process of maturation from a fresh bloom to a mature harvestable boll. With late summer HU accumulations, 600 HU is approximately 21 days. Proper moisture is needed during that boll maturation period, helping to ensure proper fiber development. The number of irrigation events required to provide proper moisture through the boll maturation process will be dependent upon many factors, including soil water-holding capacity, crop fruit load and temperature and humidity levels. Monitor soil moisture conditions over this period to ensure that adequate moisture is available to the crop during this boll maturation time. For more information and specifics regarding these topics, go to cals.arizona.edu/crops.
The 2015 cotton crop is progressing toward maturity without too many problems to this point. Boll loads should have slowed vegetative growth by this time and protecting the crop that is set will be important for high yields. There is some spraying for stinkbugs on the later planted cotton where young bolls are vulnerable to damage. Most producers have managed the crop with minimal inputs where inputs could be cut to try to make a profit. Producers are still optimistic that prices will rise with news of the smallest crop since the early 1980s. Cotton will remain a viable part of the cropping systems in the Southeast Coastal Plains since it, along with peanuts, does better than other crops if grown without irrigation on sandy soils. Likewise, it is a good rotation with both corn and peanuts, and most producers prefer a three-crop rotation, so that there is more than one year between peanut crops. The current cotton crop has the potential to be above average with new varieties and good management and could see near record yields as we have had for the past couple of years.
As I write this on July 8, the North Carolina cotton crop is generally in good shape but variable. Some of the 2015 crop is slightly ahead of schedule due to higher than normal heat unit accumulation in mid-to-late June. Plant bugs were an issue in some areas but seem to have subsided. Some areas in the northeastern part of the state have received ideal rainfall, while rains in other areas were excessive, and a few areas were noticeably dry. Hopefully, rains will prevail through the remainder of July and August to finish out this crop. By the time you read this in August, two issues may come to mind. First, it will be important to monitor the 2015 crop for various insects, including stinkbugs, caterpillars, plant bugs, spider mites and aphids, as always. Frequent scouting is a necessity during this time to preserve our yield potential. Second, hand-weeding some fields may be necessary to reduce the seedbank of pigweed. Our producers have done an excellent job of managing this weed pest, and many fields are very clean. However, it is still important to remove any survivors that happen to escape. Additionally, timely weed management following corn harvest could greatly help in reducing the seedbank for next year. With corn harvested in August and September, this leaves a wide window open for pigweed to grow and reach seed maturity before a frost. It is easy to neglect fields following corn harvest as we begin to focus on harvest of other crops. However, a well-timed herbicide application could pay big dividends for the following year.
The Louisiana cotton crop experienced an excessive amount of rainfall during the first 60 days of growth. Consequently, the crop appears to be average at this time. Older cotton fields started to bloom during the second week of June. Currently, mepiquat chloride applications are being applied to manage height control. During the first part of July, the cotton crop has experienced hot and dry weather for the first time this year. As of July 15, the earlier planted cotton fields have completed their fourth week of bloom and are between five to seven nodes above white flower. We should start seeing some open bolls during the last week of July. Bollworm and plant bug numbers were increasing during the past two weeks. Aphids and spider mites are becoming prevalent since the weather has become hot and dry. In conclusion, emphasis will be focused on controlling plant bugs by producers and consultants for the remainder of the season. Timely rains are needed during the latter part of July and the first two weeks of August to finish out the 2015 crop.
As we move into August, several things usually come to mind for those who grow cotton. Hopefully, we are nearing the end of applications needed to control plant bugs, and cracked bolls will likely begin to appear on this crop. Plant bug numbers in the northwest portion of Mississippi kicked into high gear in late June and early July. By mid-July, several producers were making their third to fourth application for this pest. However, in most cases our fruit retention was holding strong, indicating that we are battling migrating adults. As long as fruit retention numbers remain high, insecticide applications are likely having an effect even though plant bug infestation levels may remain high. The appearance of cracked bolls typically signifies that it is safe to terminate irrigation activities. Traditional recommendations are to terminate furrow irrigation at first cracked boll and terminate overhead irrigation a week to 10 days past first cracked boll. The discrepancy in termination dates for each irrigation method lies in the amount of water that is delivered by each method. Some folks choose to irrigate past these recommended cutoffs. However, keep in mind this is a risk/reward scenario. While you may increase yield by doing so, you may also increase the amount of hardlock and/or boll rot present. Irrigate until you are not comfortable doing so but don’t sacrifice the lower portion of the crop trying to make the upper portion.
According to the Missouri Crop Progress and Condition Report released on July 13, squaring is at 57 percent complete compared with 64 percent last year and 72 percent for the five-year average. Setting bolls is two percent compared with one percent last year and 16 percent for the five-year average. The condition is one percent very poor, 10 percent poor, 58 percent fair, 30 percent good and one percent excellent. At this time last year, the condition was three percent poor, 40 percent fair, 53 percent good and four percent excellent. This year, we were cool and wet, hot and dry, then wet. Now, we are in a hot phase. Most of our cotton was planted well past the optimum planting date. At this point in the season, one of my concerns is high night temperatures. After a rainfall event or irrigation, the hydrated plants can cope better with the temperatures. However, even moisture has limitations with the high night temperatures. For the next few weeks, night temperatures are predicted in the mid- to upper-70s for at least 10 days. The plants are unable to recover from the heat, and less carbohydrates are accumulated. This can result in loss of squares, bolls and other problems. We need to set all of the first position fruit that we can. Since our crop is late, we need a good fall and harvest season to gain the highest yield possible.
Cotton season is moving along very well in New Mexico. Rainfall has been encouraging in several parts of the state. Some few weeks ago, there were scattered hailstorms in southwestern New Mexico, which affected cotton and other crops. However, damage was not widespread, and the extent of the damage was variable in different fields. There has been no report of significant diseases or insect pests on cotton. Weed control has been very challenging in many fields – especially in those where early weed control was not put in place. Many cotton fields are in the late squaring stage, and some fields have already started to flower, especially the early planted cotton. As I said earlier, we have good expectations for the kind of cotton season we’ll have this fall.
As of this writing in mid-July, the cotton crop has progressed very well in most areas. June rainfall was somewhat below normal in many places, but this was buffered by the record amounts that occurred in May. Most cotton was planted during the first three weeks of June, with a few acres planted a bit later. Early growth was generally vigorous with large leaf development due to fairly calm conditions. Minimal thrips pressure was noted, but cotton fleahopper populations were worth watching during the squaring phase. The earlier planted fields should be blooming soon. Winds have been noted for the past three weeks or so, which challenged producers to find calm days to apply herbicides and insecticides for early season management. Glyphosate-resistant Palmer amaranth is a major concern of many producers, and most have made valiant attempts to target timely control practices. Most farms where residual herbicides were used have observed good weed control. As the calendar moved into July, some additional rainfall was obtained in some areas, but others missed the mark. June ended up being somewhat below normal in precipitation, and July has resulted in a dry run for a substantial amount of cotton acreage in Jackson and Tillman Counties. Irrigation will be initiated soon in the drier areas. Directed applications of residual herbicides to provide overlapping control of pigweeds are required. Other areas received several inches during the second week of July. Forecasts indicate that summer will arrive with a vengeance, and multiple days of triple-digit forecasts for southwestern Oklahoma are noted.
Warm temperatures and sufficient rain in early July led to aggressive growth and an increased need for plant growth regulators as Tennessee moved into flowering. Many responded with a heavy shot immediately before bloom and found the chance of rain in the forecast to be low. Although several of the varieties Tennessee has typically grown in the past have required a heavy hand, many of our currently grown varieties are quite responsive to plant growth regulators. Furthermore, we are just beginning to get a good grasp on how responsive several of these new varieties are to PGR applications. With a new trait likely coming on board next year, a low-rate, multiple application approaching plant growth management should be considered – especially on new varieties. Given the often biweekly triggered plant bug applications around flowering, there are many opportunities to apply these low-rate PGR shots without wasting the expense of an extra application. The appeal to this type of an approach is that it lets us manipulate rate and thereby plant growth in response to internode elongation. As always, you can find additional information on utcrops.com and catch updates on news.utcrops.com.
The cotton crop has kicked into high gear across the state with hot and dry weather from the Rio Grande Valley (RGV) through the Blacklands. However, it is common for defoliation to begin in the RGV the last week of July, but it will be two to three weeks later for the majority of the acres this season due to the late planting. The Coastal Bend cotton is progressing quickly, but many fields are highly variable in growth stages due to a record wet spring. Fruit set and growth stages are highly variable by location and variety in the Upper Gulf Coast and Blacklands. PGR and insect management decisions were challenging for most farmers in South Texas because of the high degree of variability within and between fields. Tough decisions on timing and product selection will also be necessary for defoliating this cotton crop. The Southern and Northern Rolling Plains look good with uniform crop growth and some of the earliest fields in the second week of bloom; however, the majority is early to mid-square. A good rain across much of the Rolling Plains during the second week of July tremendously increased the yield potential of this dryland and limited irrigation crop. With good moisture has come significant flushes of weeds and more glyphosate-resistant weeds being discovered. With the increased yield potential, additional nutrients may become necessary. Nitrogen needs to be applied prior to first bloom to optimize yield potential.
Excessive rains during late June and early July raised concerns over the need for foliar fertilization or additional soil-applied nutrients during the early bloom period due to leaching losses of nitrogen, potassium and sulfur. Many producers made the decision to apply extra nutrients with foliar sprays for insect control and plant growth regulators. This year may show promise with the applications of foliar fertilizers, given the potential for significant leaching losses with acute rainfall totals in some areas. Looking forward into August and the early to mid-bloom period, producers should be focusing on final plant growth regulator management applications and most importantly the timely application of insecticides to control stink bug and bollworm infestations. When making decisions on insect control, use scouting tools developed using scientific datasets to maximize the efficacy/stewardship of insecticides. There were reports of individuals from the general public approaching Virginia producers over the application of insecticides during bloom in cotton. The concern over pollinator health has intensified across the country, and I am afraid that these confrontations may become more commonplace. Using scouting/- decision aids based on scientific datasets will go far in minimizing the concern over in-season insecticide applications. I am looking forward to another above-average year for Virginia producers and hoping that the weather is favorable during the boll fill period.View More in our Archives