Producers contemplate switching to soybeans

Fore­cast­ers are call­ing for a high pres­sure sys­tem to move into our area later this week-end and dry things out. I agree with all of you, it is much over­due. I really can’t remem­ber a spring like this. Hope­fully the improv­ing con­di­tion will stay with us well into next week or two and we can get most of the plant­ing done. The out­look for May 30-June 5 calls for near nor­mal rain­fall and tem­per­a­tures 3–5 degrees above nor­mal. It has been a really tough spring. After we all make it through, and when the next wet spring comes along, we can all look for­ward to say­ing, “Yes, its wet but it’s not even close to the spring of 2011.”

As we get later in May, a lot of pro­duc­ers are con­tem­plat­ing switch­ing to soy­beans because of the late date in plant­ing. When con­sid­er­ing what to do next, Anne Dor­rance, OSU Exten­sion Spe­cial­ist, Plant Pathol­ogy, sug­gests these fac­tors to consider:

- For fields that have been con­tin­u­ous corn — tar­get these first. The year of soy­beans will be great to help give a break to those pathogens that are residue borne. It will give that corn residue a chance to break down before adding to it. This is espe­cially impor­tant if there has been gray leaf spot, anthrac­nose or north­ern corn leaf spot in the field.

- For fields that were in soy­beans in 2009–2010: Con­tin­u­ous soy­beans leads up to a build-up of both soil borne and residue borne plant pathogens. The worst cul­prits are soy­bean cyst nema­tode and fro­g­eye leaf spot. In Ohio, both of these pathogens have con­tributed to sig­nif­i­cant yield losses when sus­cep­ti­ble vari­eties were planted in the same field year after year. Soy­bean cyst nema­tode is best man­aged with crop rota­tion — pri­mar­ily a non-host crop such as wheat or corn. Fro­g­eye leaf spot is man­aged with resis­tant vari­eties — and avoid­ing plant­ing soy­beans in fields that had fro­g­eye the year before. For those fields where you had been plant­ing soy­beans and were switch­ing to corn — avoid switch­ing fields where SCN has reached high num­bers. It is impor­tant to keep the rota­tion scheme in place.

- Check the resis­tance of the vari­ety. The pri­mary con­cern here is for Phy­toph­thora root and stem rot. Not all vari­eties sold have high lev­els of par­tial resis­tance (tol­er­ance) and unfor­tu­nately, these wet sat­u­rated soil con­di­tion have the pathogen “primed” for when soy­beans are in the ground. For Ohio, vari­eties with Rps1c, or Rps1k, or Rps3 or Rps6 PLUS high lev­els of par­tial resis­tance are required for opti­mum stand through­out the grow­ing season.

- Treat the seed. Soy­beans planted into soils that have been sat­u­rated need a seed treat­ment. There are a plethora of seedling pathogens in Ohio’s poorly drained fields and they need a seed treat­ment. Tar­get prod­ucts that will man­age both the true fungi and the water molds.

- From a soil fer­til­ity stand­point, switch­ing to soy­beans does not rep­re­sent much of a change in your fer­til­ity pro­gram. Any­thing you did last fall in prepa­ra­tion for this year’s corn will be to the ben­e­fit of your soy­beans. If you are break­ing a con­tin­u­ous corn sys­tem with soy­beans (while this may seem a bit early), plan on tak­ing a nitro­gen credit next year when you come back to corn. For those who did apply anhy­drous ammo­nia ear­lier this spring, soy­beans will be nitro­gen scav­engers in a nitro­gen rich envi­ron­ment, so those appli­ca­tions will not adversely impact your soy­beans this summer.

Rob Leeds is an OSU Exten­sion Edu­ca­tor for Agriculture/NR.

Posted by Rob Leeds on May 21 2011. You can follow any responses to this entry through the RSS Feed. Comments can be made below.