Inoculant Performance in Dry Weather Peanut Notes No. 119 2022

— Written By
en 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.

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 ▲

There are numerous areas in North Carolina where peanut are drought stressed. Most fields have adequate stands and some early season growth. But peanuts have stopped growing in these fields and will not progress further until we receive rain. One question is what is the status of the inoculant (with bacteria that fixes nitrogen in the air into a plant-usable source.) That is a challenging question to answer. My thoughts are that if the plant made a stand and progressed for a reasonable period of time, the infection of the root system has occurred and the bacteria is in place for nitrogen fixation. I suspect that if the root is in place the bacteria have survived after infection. We do know that dry weather can impact nodulation, nitrogen fixation, and survival of bacteria in soil, but I suspect the bacteria from in-furrow applications has the greatest chance at being viable. If one is relying on native bacteria in soil, limited growth of the peanut plant has also limited the infection because root mass may be low. Of course, sometimes when we are dry early in the season, there is a lot of investment in root growth by the plant so the opposite could be the case. Regardless, it is important to look at nodulation around 45 days after planting to determine if supplemental nitrogen is needed. If you have 15 or more nodules on the tap root that are healthy you should be okay. Less than 15 is marginal in terms of adequate nodulation. If you get rain and then begin to see peanuts with a deep yellow cast and limited nodulation, supplemental nitrogen may be in order. It also may be the case that when we get rains there will be an explosion in peanut growth and the amount of nodulation may not be adequate to supply the plants needs (even if inoculation was adequate.)  This too will show up as yellow plants but over time the nodules should catch up with nitrogen demand by the plant.

My recommendation on applying nitrogen is found on pages 24-28 in 2022 Peanut Information. Please feel free to call if you need to make this decision. Nitrogen prices are very high, and the numbers in the guide on ammonium sulfate reflect the economics before the fertilizer price spikes we are currently experiencing. I suspect we may be in a situation where the amount of nitrogen needed to correct a true nitrogen deficiency is not worth the investment. This is especially true when we have one planter unit not delivering inoculant. In fact, even at lower ammonium sulfate costs, half of the field has to be expressing a nitrogen deficiency for the rate of 500 pounds per acre to be cost effective.