Bruce MacKellar

Weather
Growing seasons are all unique and the 2009 growing season was no exception. What started out as an extremely wet and cool spring, ended up as a very dry and cool summer. Planting was delayed in many areas with large wet areas simply not being planted. This was especially true in southern Berrien County where the fields remained unworkable until June. We had an extended period of drought, roughly from June 20 until August 8 where widespread portions of eastern Van Buren and Kalamazoo counties received less than half an inch of precipitation during the most critical part of the growing season. And finally, we had some of the best growing conditions of the season in late August through early September.

While this late season improvement in conditions have been welcomed by growers, it is hard to make up for earlier challenges this season. We are at least a week to 10 days behind where we would normally be in terms of crop development, partially due to later planting dates, partially due to cooler than normal temperatures, and partially due to drought stress. The good news is that the crops are growing pretty well. But warm September daytime temperatures do not seem to be the same as warm July and August days. This year’s crops remain behind schedule. An early frost would still have a significant impact on many corn and soybean acres in southwest Michigan.

Crop report
The commercial crop was significantly impacted by drought, even beyond the devastated areas of Kalamazoo and eastern Van Buren counties. Many fields had firing of the lower leaf canopy. I would anticipate that this could lead to lower test weights for corn in many locations in the southwest corner of the state. Western bean cutworms are much more evident in many fields in the area this year. The counts in Van Buren County were in the 50 to 150 moths range (per season) with less in the southeastern corner of the county. In looking at fields for disaster declaration potential in Kalamazoo County, I would estimate that we would see a two to five percent western bean cutworm infestation rate on average, but it is impossible to know how many of those fields were protected by Herculex or sprayed for the pest. Western bean cutworm seems to be increasing in population in our area, and I would anticipate that it should be on producers’ radar screen for the next growing season and beyond. We also saw damage from spider mites on corn in a few fields. As we approach harvest, it will probably be important to evaluate your corn hybrids stalk strength, particularly if you want to reduce moisture content in the field as much as possible.

Late season soybean aphid populations were the big story in the southwest. We did not see significant numbers of the pest until fairly late in the season. The conventional logic is not to spray aphids beyond the R5 window, where the threshold is really around 1,000 aphids per plant. Usually, there are more aphids preparing to return to their overwinter host, the common buckthorn plant, and a higher percentage of the population in the fields are anticipated to be males. Also we get the benefit of high plant canopy wetness from morning dews that encourage the development of pathogenic fungi outbreaks, which can crash populations of aphids and spider mites in a hurry. And finally, the predator populations have reached the point where they can begin to have an impact on the populations of the pest. The challenge is that the crops were very late this year and aphid populations remained higher than anticipated longer this season. The overall drier conditions over late August and early September seemed to help suppress the effect of pathogenic fungi. What the impact will be on aphids returning to the overwintering host and next year’s populations remain to be seen.

Spider mites were a significant problem in sporadic areas across the region. Since the pest is very small, it needs to be detected by the stippling (yellowing to early bronzing) damage. The time to treat for the pest is fairly early where there are only a few pockets of damage showing in the field. We also have seen an increase in the incidence of Sudden Death Syndrome (SDS) in pockets of fields. Only a few fields had enough widespread damage from the disease to have significant yield impacts. But a few fields did. If you see signs of the disease (bright, yellow leaves, with green veins and dark areas between the veins), it can be a warning sign of a festering problem. Check your fields for soybean cyst nematode, which is almost always a co-factor in the development of Sudden Death Syndrome. We also saw issues with white mold in irrigated soybeans. Increasing air flow by limiting populations, planting in 30-inch rows, and avoiding excessive irrigation during early flowering can help. Watch for white mold development when planting in fields that have a dry or snap bean history.

Final thoughts
We will most likely be facing challenges during the harvest season this fall. We have both corn and soybeans that are significantly behind in maturity and will probably remain in the field longer than normal this year. Corn moisture levels will remain higher, which means more drying. There will probably be more green stems in soybeans during the harvest this year. Both of these situations can lead slowdowns in the harvest process and potentially plugged equipment. Take time to think about safety for yourself, your family and your employees when working around harvest equipment, particularly under these circumstances. Injuries can turn a challenge into a tragedy, so take the time to be safe on the farm and on the roadways.