USDA's September crop report projects Mississippi to harvest a record soybean crop this year. Projected yield is 34 bushels per acre, which ties the highest yield ever produced (in 1992). It is my opinion this estimate is too low, and recent rains insured that — the late portion of the crop benefited greatly from the rains in late September.
If you compare 1992 to this year, rainfall was more frequent, but we also experienced Midwest temperatures virtually season-long — something we did not observe in 1992.
Although Mississippi's soybean crop is going to be above average, it has not been void of problems. I realize this is probably not the time of year to discuss plans for next year, but I wanted to highlight several items for consideration this fall. I am only going to mention these briefly; I will attempt to discuss these in detail over the next few weeks.
- Seed treatments
This option may not contribute to an increase in yield versus non-treated seed, but the year it does you will know it. Getting a stand the first time is the key to increased yields. There is no substitution for planting date, and if it takes using a seed treatment to achieve a stand in April versus May, this is your yield increase.
The impact of early planting is real, and we must continue to do everything in our power to capitalize on it.
In addition, the use of the proper seed treatment must be addressed. Many are using Apron + Thiram. This is not as broad spectrum as was needed this year. A broad spectrum seed treatment utilizing a higher rate of Apron on clay soils should be considered if you are having problems.
Many observed that anything less than an Apron Max/Apron Vitavax combination was not adequate after the type of conditions in which we harvested seed beans last fall. Harvest conditions last fall contributed to lower germination and lower vigor in some varieties, which was obvious following planting.
- Variety selection
It all begins here. There are many things we cannot control, but the easiest approach to minimizing some major yield-robbers is variety selection. This is particularly true with stem canker. I have continued to try new varieties in an attempt to achieve top yields, but I feel my approach has not been justified on some fields.
In the future, new varieties will occupy very small acreages where I am involved, and we will use race horse varieties in high yield environments, not all environments. This coming year, I doubt I will need 10 fingers to count the varieties we will plant in our verification program.
Updated variety information is not yet available, so I may be premature with this comment, but I seriously doubt it.
- No-till plantings
Continuous no-till fields continue to cause us concerns every year. Many soils in our state will respond to tillage and we need to attempt to identify those soils. A stale seedbed system is probably all that is needed to avoid some of the problems we have observed over the last five years.
This is an age old problem, but if we did nothing but open up our tail ditches we would solve a lot of problems. Many fields are too flat so they need some help from time to time. Water on/water off, both are very important.
We observed far too much charcoal rot in irrigated soybeans this year. Charcoal rot lets us know that some stress occurred — either too wet or too dry.
- Timing of fungicide and insecticide applications
To continually produce high yields will require some degree of late season management. Whether that requires the use of a fungicide, insecticide, or a combination of the two, timing is the key to achieving benefits.
We used Dimilin on all our dryland fields and a Dimilin/Quadris combination on our irrigated fields. I realize that all do not feel these treatments are justified, but if you recognize what these products can do, and properly time your application, they can provide benefits.
I have two gentlemen that work with me, that have observed the benefits of Dimilin under numerous scenarios since the early 1980s. This is over a 20-year period under various environments. Are this or other treatments justified to make a blanket application on every field every year? No, but you need to know what they can and cannot do for you, so you can make a better informed decision on when to use them.
I spoke to a friend from Arkansas the other day and he told me that he has tried Dimilin in test plots several times and has not gotten a yield increase. That may be true possibly due to the maturity group, time of year applied, cropping system, planting date, etc.
However, in the same breath he asked me what we were doing for salt marsh caterpillars in Mississippi. We have not sprayed any salt marsh caterpillars in our verification fields, and you know why, because we used Dimilin. Dimilin will smoke salt marsh caterpillars, providing a three to three and a half week residual.
It is so effective on several worm species (velvetbean caterpillars, green cloverworms, and cabbage loopers) that populations fail to develop following an application. Realize that nothing is absolute. It is often difficult to observe benefits from small plot research when it comes to diseases and insects. My research counterparts will cringe at this comment, but growers have a greater potential for problems due to increased variability/inoculum. Working in the precision ag arena has made me rethink my approach on large fields.
- Late applications of Roundup
For the second year in a row we have observed fields that stay green from applications of Roundup made to blooming/early podding soybeans. The stems stay green and the plant retains its leaves and petioles. The pods will dry down, but not the plant itself.
Yields have still been pretty decent, but if you scout beans by looking from the turn row you will fail to see that pods are dried and ready to harvest. The best way to avoid this is do not push the label. If a field gets a little wooly we can make a preharvest shot after plants approach maturity. Until we learn more about this problem, do not push an application too late.
Alan Blaine is the Mississippi Extension soybean specialist. e-mail: firstname.lastname@example.org.