Re-Planting Decisions and Managing Late Planted Cotton (Collins, Edmisten, and Reisig)
Most areas of the state have experienced rainfall nearly daily for a week now. In my conversations with growers across the state, it appears that most growers are either done with planting cotton before this rainy spell arrived, have only a couple of days of planting left to do, or are only half to 2/3rds completed with planting cotton. For growers that still have some planting to do, there is naturally some concern with getting those final acres planted before the insurance cutoff date later this week, especially since the forecast doesn’t currently appear to offer much reprieve. Naturally there is an incentive to quickly resume planting as soon as it is dry enough to re-enter fields.
To ensure optimal stands for later planted cotton from here on out, it might be worthwhile to slightly increase seeding rates to 45-47,000 seed per acre and plant shallow to ensure both adequate stands if planting in muddy soils, and to manage for earliness as later planted cotton becomes more sensitive to skippy stands. For various reasons, we have had a noticeable amount of late-planted cotton for the past two years. We will/do not recommend planting beyond the insurance cutoff dates, however some growers often do plant beyond the recommended cutoff dates with some success. With later-planted cotton, we lose flexibility to account for fruit losses that occur throughout the summer months. Therefore, the success of later-planted cotton is dependent on several things going right throughout the season, such as timely summer rains and a sunny, warm fall without an early frost. Late planted cotton is only successful if growers, with the proper management and some help with the weather, can retain as much of the earliest-set fruit as possible. With that said, timeliness of management can improve the odds of success with later planted cotton. This applies to PGRs, plant bug management, bollworm management, proper fertility, irrigation, etc. It is absolutely critical to be very timely with any inputs on late planted cotton. Growers can not afford to be late on needed PGR sprays, however this point is not to be confused with “growers should be aggressive with PGRs”…..timeliness of PGR applications is much more important than using high rates, especially if high rates are not needed. Regardless of when cotton is planted, growers should be timely with sprays for thrips, plant bugs, stink bugs, and bollworms, however the negative impact of delayed applications can become greater with late planted cotton. Plant bug, stink bug, and bollworm pressure is higher in late-planted cotton and this year, thrips pressure will be highest for cotton planted at the end of May in most spots around the state. The only way to address this is with frequent and thorough scouting (twice per week, at least until applications are first made). Lastly, when possible, timely irrigation can be used to retain as many early set fruit as possible. Naturally, growers should also avoid any practice that may injure or further delay stand establishment or early season growth of late-planted cotton.
For cotton that has already been planted, we are now a week into this rainy spell so it’s time to be evaluating stands for fields planted just prior to the rainy spell. Most reports and my personal observations indicate that stands are surprisingly acceptable in many areas, although there are some areas that may need to be replanted. Heat has been on our side, and a little additional sunshine will certainly help. My initial concern was that heavy packing rains would likely form a surface crust severe enough to necessitate replanting. However, due to the frequency of rains, the soils surface remained wet throughout the past week allowing seedlings to emerge. My concern now is the frequency of heavy rains and the resulting saturated soils or standing water. In these cases where soils have been completely saturated (or where water has stood for more than 48 hours) to the point that germinating seed could not access oxygen, replanting may be necessary. It is important for growers to evaluate all fields to see if seed have germinated and are trying to emerge versus those fields where water saturation has killed these small seedlings. Again, in most areas, emergence and plant stands have been surprisingly good, perhaps only requiring spot-replants of problematic areas of fields.
In cases where crusting may still be a concern, light crust busting or rotary hoeing may be necessary if seedlings are still alive and trying to emerge. Usually, this practice is done when poor stands are noticed and is usually too late to help seedlings emerge or damages the few seedlings that have emerged. However, in our current situation, growers have a good opportunity to avoid stand problems by rotary hoeing or crust busting as soon as the soil surface begins to dry out and the crust begins to form. Delaying this practice for several days diminishes the likelihood of achieving optimal stands, therefore quick action could offset many problems and the need to replant. Evaluating planted fields now, and looking for the early signs of potential crusting such as swollen hypocotyls (necks) as the seedling approaches the soil surface, will help growers make the best decisions and take action in a timely manner.
Despite best efforts to achieve optimal stands, if replanting is necessary, growers should make replanting decisions on a case-by-case basis, and potential benefits must be weighed against additional costs (cost of additional seed, likelihood of achieving better stands by replanting, time lost, etc). Previous research in the Southeast suggests that replanting may generally be justified if approximately half (or more) of the planted area is occupied by 3-foot skips (2-foot skips in more conservative situations, such as late replanting or poor health/status of remaining seedlings that did emerge the first time). When determining how many 3-foot skips are present, remember to give appropriate credit to large skips (for example, a 12-foot skip should be considered as four 3-foot skips). In many cases, spot replanting in certain parts of a field may suffice.