Cotton planted in Thomas County is presently in several different growth stages, from just a few true leaves to bloom. Growth has improved now that we have gotten some rain and temperatures have decreased. Now that our cotton is growing again we need to control vegetative growth in order for the plant to allocate resources toward the fruiting structures on the plant. Mepiquat is one tool that is specifically used to manage “rank” vegetative growth. This shortens the plant’s internodes, reduces leaf area, reduces carbohydrate stress, and contributes to earlier maturity. Some things to consider when applying PGR’s in cotton are: growth stage, growth rate, pest control, and anticipated growth based on field history and management practices. Low rate applications can be made during the second week of squaring in irrigated fields and apply on a 14 day interval up to 4 times. A more aggressive approach is to apply 8-12 oz. per acre at first bloom and make a second application two to three weeks later. In dryland cotton, applying 8 oz. per acre at first bloom and potentially follow with subsequent applications.
In peanuts, growth regulators are seldom used, but can be beneficial. Prohexadione calcium, or Apogee or Kudos, are the only growth regulators registered for peanut applications. Some positive results from using Apogee included reduced vine length. This allowed for increased efficiency during digging, however, there was no consistent yield increase. If you think that this may be helpful to you, 7.25 oz. per acre should be applied once 50% of lateral vines are touching and then applied again 2-3 weeks later. Timing of these applications is very important and should only be used on irrigated peanuts. Our peanut scientists are still researching the use of these products so more information will be available soon. Please contact me at the extension office with any questions.
Image from: Biochemical, Physiological and Molecular Avenues for Combating Abiotic Stress Tolerance in Plants. 2018: 297-316
Thomas County has not seen a significant rainfall event in the past 30 days. Low humidity is also leading to high evapotranspiration. Recently we have been losing up to .30 in. from evaporation each day. All shallow soil moisture has basically been depleted at this point. Shallow soil temperatures are also very high – 88 degrees yesterday. Small tender plants are really suffering in this heat – the best solution for many growers is to irrigate at night (which is very difficult logistically because it takes up to 12 hours or more for a pivot to make a full rotation). Cotton and peanuts are in the early stages of production so all that has mainly been affected is emergence – many have had to replant. Those with irrigation systems can manage this issue, but those without need only pray for rain and manage weed and insect issues which have been made worse by the dry heat. Weeds are more competitive in this environment and insects have moved off of other drought stressed plants onto more tender, newly emerged crops. Good news – once cotton and peanut crops have emerged water demand is low (about a half in per week). In an average year – we have no average years – this would be taken care of by rainfall. By late June cotton and peanuts will be in peak water demand. Approaching or in tasseling stage corn so yields are also being severely affected due to water requirements being about 2.5 in per week. Pecans are also in need of irrigation with the onset of nut sizing coming up. With temperatures up around 100 degrees for several days growers will be tempted to increase the irrigation further, but this is not necessary. Pecan can still function normally at temps of 106 degrees as long as they have the water they need. Temperatures are much cooler at night though, which allows for some recovery for our crops. Rain is also in the forecast for this weekend so hopefully we can all get some relief soon. If not, good record-keeping and sound irrigation strategies can increase profitability in several different ways – reducing irrigation costs through reducing energy costs, and increasing yield.