Leonardo Rocha
Soy Envoy
leonardo.rocha@siu.edu
Leonardo Rocha
Soy Envoy
leonardo.rocha@siu.edu
LEONARDO ROCHA UPDATES
The recent precipitation events left the soil with high moisture levels, helping double cropping soybean fields to emerge. This particular field was planted about two weeks ago, under drought and without access irrigation, but plants are emerging with high vigor and uniform stand. With more rain on the radar, this particular field has good yield potential at this point.
Despite the drier conditions, the soybean crop is progressing and reaching reproductive stages in this area of the state. In my last report, I visited a field with known root-knot nematode pressure, so this week, I decided to check a location with a history of elevated SCN populations. That field had numerous fully developed SCN females (cysts) and foliar symptoms. We may see more SCN foliar this season compared to other years due to the widespread drought.
I will leave some SCN scouting recommendations below. Please visit The SCN Coalition (TheSCNCoalition.com) for detailed SCN sampling recommendations and management insights.
– Visit areas with a history of SCN pressure.
– Look for potential field symptoms (patches with yellow plants and reduced growth – Figure 1).
– Dig (don’t pull) some plants using a shovel (see video 3). Pulling plants may leave some of the females in the soil, especially with the drier-than-normal conditions.
– Inspect the roots and look for adult females. They are small but can be observed with the naked eye (Figure 2).
– Females will look from white/light yellow to brown, depending on their developmental stage and age.
The lower-than-average precipitation not only slows plant growth but also intensifies symptoms caused by soil-borne pathogens (SCN, root-knot nematode, etc.). In this field, just outside Carmi, we can observe severe symptoms caused by the root-knot nematode (Meloidogyne incognita). The symptoms were limited to only a patch in the field over a sandy hill. This nematode does not cause nearly as much damage as SCN in Illinois, but we must keep an eye open for it.
This nematode prefers sandier soils and is most likely found in areas closer to the rivers. If you see patches with stunted plants, dig up some plants and look for galls (see image 2). There is nothing we can do to manage this nematode in this season, but a seed-applied nematicide can help in the future. Corn is also a host of this nematode, so crop rotation is less effective in this case.
Excellent soybean field under irrigation near Valmeyer (Monroe County). High yield potential and probably one of the best weed management programs I have seen this season.
Plants are reaching R1 stage this week and beginning to display drought stress symptoms. Some farmers are already running irrigation systems in the region. High temperatures, elevated sand content, and lack of precipitation may limit plant growth in the following weeks in fields without access to irrigation
This is the same field in White County from my 05/17 report. Plants have reached V3 stage (V1-V2 last week). Great overall weed control, along with some post-herbicide application injuries (see photos). The recent precipitation has left the fields with high moisture levels, but the dry and warm forecast along with elevated sand content in this region may cause water stress soon.
This soybean field is located in White County, just south of Carmi. Field is currently at V1 stage, with some plants reaching V2
This soybean field has uniform germination and good plant stand.