Considerations for Expected Planting Conditions (Collins, Edmisten, & Cahoon)

— Written By
en Español / em Português
Español

El inglés es el idioma de control de esta página. En la medida en que haya algún conflicto entre la traducción al inglés y la traducción, el inglés prevalece.

Al hacer clic en el enlace de traducción se activa un servicio de traducción gratuito para convertir la página al español. Al igual que con cualquier traducción por Internet, la conversión no es sensible al contexto y puede que no traduzca el texto en su significado original. NC State Extension no garantiza la exactitud del texto traducido. Por favor, tenga en cuenta que algunas aplicaciones y/o servicios pueden no funcionar como se espera cuando se traducen.


Português

Inglês é o idioma de controle desta página. Na medida que haja algum conflito entre o texto original em Inglês e a tradução, o Inglês prevalece.

Ao clicar no link de tradução, um serviço gratuito de tradução será ativado para converter a página para o Português. Como em qualquer tradução pela internet, a conversão não é sensivel ao contexto e pode não ocorrer a tradução para o significado orginal. O serviço de Extensão da Carolina do Norte (NC State Extension) não garante a exatidão do texto traduzido. Por favor, observe que algumas funções ou serviços podem não funcionar como esperado após a tradução.


English

English is the controlling language of this page. To the extent there is any conflict between the English text and the translation, English controls.

Clicking on the translation link activates a free translation service to convert the page to Spanish. As with any Internet translation, the conversion is not context-sensitive and may not translate the text to its original meaning. NC State Extension does not guarantee the accuracy of the translated text. Please note that some applications and/or services may not function as expected when translated.

Collapse ▲
Based on the weather forecast right now for multiple areas across the state, it appears that we’ll have a greenlight for planting cotton beginning on Monday, April 29th (see our Planting Conditions Articles). Forecasted temperatures, at the moment, are expected to be essentially ideal for cotton, which is rare for us in late April or early May. Daily highs in the low 80’s with nighttime lows in the 60’s are ideal for cotton planting, as that gives us 50 DD-60s within the first 5 days of planting, and most areas are expected to have that. A few areas may dip to the low-mid 70s with a couple of nights approaching 50 degrees during the latter part of next week, but it is expected to be short lived. Remember that we must have highs above 70 with lows above 50 in order to have positive DD-60 accumulation. Highs that exceed 75 accompanied by lows exceeding 55 move planting conditions from “adequate” into the “good” category. As of right now, we should be good to go for planting on Monday the 29th. Weather forecasts during the spring are often fickle, so growers are advised to check the NCSU Cotton Planting Conditions Calculator (https://products.climate.ncsu.edu/ag/cotton-planting/) every morning in evening to account for potential changes in forecasts from the National Weather Service. Use this calculator to know when to initiate planting and/or when to temporarily cease planting. Pay attention to seed quality (warm AND cool germination) and adjust accordingly.
The only concern we may have early next week is soil moisture. When planting, we are only concerned with moisture in the upper inch or so of soil, since moisture below that point only serves as a buffer at best. Ideal temperatures for cotton planting also promotes rapid drying of soil in the planting zone for cotton which is 0.5 to 0.7 inches deep. Some areas currently have a little soil moisture while other areas do not. Unless rains occur between now and Monday, we could expect soil moisture to be even less by then, and it will likely deplete rapidly soon thereafter when warm temperatures set in. At the moment, the best chances of rain might be late next week but chances are rather weak in some areas.
Undoubtedly, growers instinctively will want to plant deep in order to chase moisture. This rarely is a good strategy. Planting deep only works when soil moisture is excellent below the top 0.5” of soil and in soft soils that do not crust when the next rain occurs. This is a rare scenario. In most cases, the more common scenario is planting deep (1” or so) into marginal moisture at best, which will further rapidly deplete following planting. In this case, there is a serious risk of having enough moisture to sprout seed, but not enough to sustain the seedling from germination to emergence. Planting deep prolongs the time for germinated seed to emerge and only adds stress to that seedling. In many cases over the years, planting deep into marginal moisture often results in partial stands. Multiple light rains that occur later may eventually allow for other seedlings to emerge but there is a risk that seedlings could die before emergence if later rains do not occur, or if a packing rain occurs and soils form a crust. Growers are generally better off planting shallow (0.5” as long as soil covers seed) into completely dry soil and waiting on a rain. We have been very surprised at how long cotton seed can remain in dry soil before a rain and still produce an excellent stand.
Another concern with minimal chances of rain during planting may be activation of pre emergence residual herbicides. Generally, residual herbicides need to be activated (worked into the soil profile) within 7 to 10 days to be effective. This is normally accomplished with rainfall but can also be achieved with irrigation. A couple of issues can arise if residual herbicides are not activated within 7 to 10 days: 1) some weeds can emerge from the soil without coming into contact with the herbicide and may survive and 2) we have likely lost some of the herbicide to degradation processes. Lastly, many growers ask how much rainfall or irrigation is needed to activate residual herbicides. Ease of activation is mostly driven by water solubility of the herbicide and its affinity to bind to soil. A general rule of thumb is that 0.5” or rain will suffice for activation of most herbicides. Keep in mind some residual herbicides can get by with less rainfall, and some need more for adequate activation. For example, a 0.25” of rainfall is sufficient to activate Reflex whereas 0.75 to 1” may be needed to activate Brake.