{"id":1776,"date":"2019-08-02T15:29:53","date_gmt":"2019-08-02T15:29:53","guid":{"rendered":"https:\/\/agrilife.org\/texasrowcrops\/?p=1776"},"modified":"2019-08-02T15:29:53","modified_gmt":"2019-08-02T15:29:53","slug":"east-and-south-texas-cotton-harvest-aids-the-art-and-science","status":"publish","type":"post","link":"https:\/\/agrilife.org\/texasrowcrops\/2019\/08\/02\/east-and-south-texas-cotton-harvest-aids-the-art-and-science\/","title":{"rendered":"East and South Texas Cotton Harvest Aids: The Art and Science"},"content":{"rendered":"

By James Griffin<\/p>\n

Cotton Extension PhD. Student<\/p>\n

 <\/p>\n

Applying cotton harvest aids has been referred to as an art.\u00a0 In this article, we will examine methods to change the narrative to more of a science.\u00a0 The first decision to make is when to \u201cpull the trigger,\u201d secondly rather to make one or two applications, and finally which products to use.\u00a0 From my experience, the 60% open boll method has been the standard for some time although other methods are most likely more accurate than eye balling percentage open while driving down the turn row.\u00a0 Furthermore, the percentage open boll method does not always accurately represent maturity of cotton plants as boll positioning or fruiting gaps sites can potentially be misleading.\u00a0 Finally, research has shown applying harvest aids prior to 60% open bolls can reduce yield.<\/p>\n

Two other popular methods are maturity of uppermost harvestable boll which consists of cutting bolls in half and looking at seed coat coloring (Figure 1).\u00a0 Seed coats with tan to brown coloration are mature and are primed for boll openers.\u00a0 The last method is nodes above cracked boll (NACB).\u00a0 When using the NACB methods, first locate the uppermost first position cracked boll, and then count the main stem nodes above up to the uppermost harvestable boll. Sufficient research has shown that harvest aids applied at four NACB will not result in any lint weight loss. If harvest aids are applied at NACB greater than four, yield loss can be expected.<\/p>\n

The second decision is the number of harvest aid applications.\u00a0 This decision is based on the stature of the plant meaning larger, ranker plants generally need an additional shot to removed lower vegetation sometimes referred to as the \u201cskirt.\u201d\u00a0 A two pass program is more desirable than an aggressive rate one pass program that requires a second pass.\u00a0 In a two pass system, as much vegetation should be removed as possible to reduce lint staining and trash, while minimizing desiccation or \u201csticking\u201d leaves, which is due to defoliants \u201ckilling\u201d the leaves before a proper abscission layer can be from at the base of the petiole.\u00a0 \u00a0A general rule of thumb is to use lower harvest aid rates to injure the leaf, but not desiccate it.\u00a0 \u00a0\u00a0The final decision is which harvest aid program to apply.\u00a0 Successful harvest application is affected the most by the condition of the cotton plants, namely the fruit load, available nutrient supply, water stress\/excess, among many others.\u00a0 Drought stressed cotton may require higher rates due to thickened leaf cuticle.\u00a0 Harvest aid selection is also determined by how quickly a producer wants to begin harvesting.\u00a0 Along those lines producers should not apply harvest aids without intentions of harvesting within 14 days or lint values can significantly be reduced beyond this timeframe.\u00a0 In other words, do not get ahead of yourself with the sprayer.\u00a0 Potential weather delays and general timeliness between harvest aid application and harvest may factor into the decision to add a regrowth limiting product such as thidiazuron. Table 1 below shows each labeled product.\u00a0 One final note is to ensure adequate spray coverage, as most harvest aids do not translocate throughout the plant. Harvest aids should be applied with a minimum water volume of 15 GPA.\u00a0 Recent research has shown, water volume has a greater significance than nozzle type, with that said, the recommendation is to still use flat fans or hollow cone nozzle tips.<\/p>\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n
Harvest Aid1<\/sup><\/td>\nActive Ingredients<\/td>\nLabeled Broadcast rate oz\/ac<\/td>\nMax use\/ Season (oz)<\/td>\nRainfree Period (hours)<\/td>\nEstimated min. temp (F)2<\/sup><\/td>\nMature leaves<\/td>\nJuvenile growth<\/td>\nRe-growth prevention<\/td>\nBoll opening<\/td>\n<\/tr>\n
Folex 64<\/sup><\/td>\nTribufos<\/td>\n16-24<\/td>\n24<\/td>\n1<\/td>\n60<\/td>\nExcellent<\/td>\nFair<\/td>\nPoor<\/td>\nNone<\/td>\n<\/tr>\n
Harvade 5F<\/td>\nDimethipin<\/td>\n6-10<\/td>\n14<\/td>\n6<\/td>\n55<\/td>\nExcellent<\/td>\nFair<\/td>\nPoor<\/td>\nNone<\/td>\n<\/tr>\n
Ginstar4<\/sup><\/td>\nThidiazuron +<\/p>\n

Diuron<\/td>\n

6.4-16<\/td>\n16<\/td>\n12<\/td>\n60<\/td>\nExcellent<\/td>\nExcellent<\/td>\nExcellent<\/td>\nNone<\/td>\n<\/tr>\n
Aim<\/td>\nCarfentrazone<\/td>\n0.5-1.6<\/td>\n3.2<\/td>\n8<\/td>\n55<\/td>\nExcellent<\/td>\nExcellent<\/td>\nPoor<\/td>\nNone<\/td>\n<\/tr>\n
ET<\/td>\nPyraflufen<\/td>\n1.5-2.0<\/td>\n5.5<\/td>\n1<\/td>\n55<\/td>\nExcellent<\/td>\nExcellent<\/td>\nPoor<\/td>\nNone<\/td>\n<\/tr>\n
Sharpen5<\/sup><\/td>\nSaflufenacil<\/td>\n0.5-1.5<\/td>\n2<\/td>\n1<\/td>\n55<\/td>\nExcellent<\/td>\nExcellent<\/td>\nPoor<\/td>\nNone<\/td>\n<\/tr>\n
Dropp SC4<\/sup><\/td>\nThidiazuron<\/td>\n1.6-3.2<\/td>\n9.6<\/td>\n24<\/td>\n65<\/td>\nExcellent<\/td>\nExcellent<\/td>\nExcellent<\/td>\nNone<\/td>\n<\/tr>\n
Finish 6 Pro<\/td>\nEthephon +<\/p>\n

Cyclanilide<\/td>\n

21-42<\/td>\n42<\/td>\n6<\/td>\n60<\/td>\nExcellent<\/td>\nPoor<\/td>\nFair<\/td>\nExcellent<\/td>\n<\/tr>\n
FirstPick<\/td>\nUrea sulfate +<\/p>\n

Ethephon<\/td>\n

96-112<\/td>\n112<\/td>\nN\/A<\/td>\n60<\/td>\nExcellent<\/td>\nPoor<\/td>\nPoor-Fair<\/td>\nExcellent<\/td>\n<\/tr>\n
Roundup PM4<\/sup><\/td>\nGlyphosate3<\/sup><\/td>\n22-32<\/td>\n<\/td>\n4<\/td>\n55<\/td>\nFair<\/td>\nFair<\/td>\nExcellent<\/td>\nNone<\/td>\n<\/tr>\n
Prep 64<\/sup><\/td>\nEthephon<\/td>\n21-42<\/td>\n42<\/td>\n6<\/td>\n60<\/td>\nFair<\/td>\nPoor<\/td>\nPoor<\/td>\nExcellent<\/td>\n<\/tr>\n
Gramoxone4<\/sup><\/td>\nParaquat6<\/sup><\/td>\n3.1-8.0<\/td>\n192<\/td>\n30 mins.<\/td>\n55<\/td>\nFair<\/td>\nExcellent<\/td>\nPoor<\/td>\nFair<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

 <\/p>\n

Table 1: Harvest Aid options and Anticipated Performance<\/p>\n

1<\/sup>Adjuvants may increase harvest aid performance during low night temperatures or when cotton is drought stress, although when temperatures are warmer, adjuvants increase chances of vegetative desiccation or \u201csticking.\u201d<\/p>\n

2<\/sup>Estimated temperatures are estimates only and are not exact.\u00a0 Conditions such as rain free period, crop stress (drought), temperatures, and remaining nutrient levels also affect product performance.<\/p>\n

3<\/sup>Glyphosate performance rating only for non-glyphosate traited varieties<\/p>\n

4<\/sup>This is a brand name and many products containing the same active ingredient are available<\/p>\n

5<\/sup>Sharpen requires 1% v\/v MSO plus ammonium-based adjuvant according to label<\/p>\n

6<\/sup>Usage of paraquat inhibits development of immature bolls; rates depend on open boll percentage<\/p>\n

Source: University of Tennessee Extension, \u201cCotton Harvest Aids\u201d Drs. Chris Main and Robert M. Hayes<\/p>\n

 <\/p>\n

This table listing does not indicate an exclusive endorsement of these products alone.\u00a0 Table 1 is not a complete list of products in the market place, as other products are available and may be comparable.\u00a0 Always read and follow labeled rates for your area.<\/p>\n

Other Resources:<\/p>\n

Cotton Harvest Aid Recommendations, Texas A&M-San Angelo:<\/p>\n

https:\/\/sanangelo.tamu.edu\/extension\/agronomy\/agronomy-publications\/cotton-harvest-aid-recommendations\/<\/a><\/p>\n

Preparing for the 2015 South Texas Cotton Harvest:<\/p>\n

Preparing for the 2015 South Texas Cotton Harvest<\/a><\/p><\/blockquote>\n