Thankfully, several areas have recently received some badly needed rain, which has spurred growth in cotton. Several folks have applied top-dress fertilizer and/or are making those applications now. This will further spur growth if rains continue and we hope they will.

Now is typically the time when prebloom PGR applications are made. However, cotton in general is noticeably shorter than normal for this point in time, despite being planted within the normal window or noticeably earlier in some cases this year. The shorter cotton is likely the result of dry weather and spells of excessive heat in the absence of sufficient rains, however root systems appear to be very strong over most of the state, which will serve us greatly later in the season

The comments below regarding PGR considerations are only applicable to the current situation. Growth, and thus any PGR needs, may be drastically different in a couple of weeks, depending on weather.

The image below depicts 3 scenarios which are fairly common across the state but this illustrates why we don’t need to make “windshield” decisions regarding the need for PGRs, despite recent rains or fertilizer applicstions. We are generally hesitant to recommend aggressive prebloom applications in most years, and the scenarios shown below illustrate one reason why.

All three plants are roughly the same height, have been fertilized and received rain recently. The plant on the far left was planted in early to mid April. Due to heat and dry weather, the internodes of this plant are very compact. The uppermost internodes show signs of accelerated growth, but relatively speaking, the current growth rate is considered somewhat slow. Notice the size of squares on this plant. The earliest set squares are very near blooming (likely within a week). This plant is at a noticeably less than ideal height to be near first bloom, and therefore needs continued moisture and heat to accelerate growth so that premature cutout does not occur. The last thing it needs is a PGR application to slow it down, at least for now.

The middle plant is of similar height but planted later (early May) than the first plant on the left. The uppermost internodes are a little more elongated suggesting the current growth rate is slightly more aggressive. Likewise, squares are a little smaller and a little further from blooming (probably 10-12 days from first bloom). In this case, growth is not excessive but recent rains or fertilizer may spur growth to the point that a PGR may be needed. In this scenario, we would hold off any PGR applications for now until first bloom, and reassess PGR needs then.

The last plant on the far right was planted in mid to late May and has a similar plant height to the other two. The internodes are most elongated, and when coupled with much smaller squares, as well as the first fruiting branch appearing noticeably higher on the stalk than the previous two plants, the current growth rate of this plant is clearly most aggressive. A PGR application may be justified in this case.

Now, we are not saying that the last plant needs a PGR application, just that one could be justified based on other criteria such as variety growth potential and maturity, planting date, field history of rank growth, etc. 

In summary, all three scenarios currently show similar plant height but PGR needs are drastically different. Keep in mind that the best growth regulator is the developing fruit load. We interject with a PGR application when the plant, or other factors, suggests that the boll load is insufficient to restrain growth, based on all the other criteria previously mentioned. Therefore, we don’t want to make PGR decisions haphazardly or simply from “windshield” assessments of growth.