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Issue 1 - May 2, 2007 Sign up for the SWROC Crop Production list serve IPM Stuff Classics Corn
Planting Depth - 3/5/99 SWROC Pages: Home Page Other Cropping Newsletters: Minnesota Crop eNews - Regional Newsletters Minnesota Fruit and Vegetable IPM News The Bulletin - Other States IPM Newsletters
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Integrated Pest Management Newsletters and Information IPM Stuff Print this newsletter using Acrobat Reader |
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It is spring and it is a very good time of the year. As I sit at my computer pondering the beginning of another growing season, the realization that the first issue of IPM Stuff was produced 10 years ago is disconcerting to someone pushing half a century. There have been a lot of pest problems under the pest management bridge in those ten years. Intractable, chronic problems like weeds (herbicide resistant and otherwise) and soybean cyst nematodes (SCN) defy a permanent fix. The annual ebb and flow of old adversaries like European corn borer, Corn rootworm, Potato leafhopper and numerous diseases have shown the benefits of pest management on a field by field basis. Intense, short lived problems like white mold and spider mites have led to equally intense and short lived research programs. Then there are the new problems, most notably extended diapause Northern corn rootworm, Soybean aphids and Sudden death syndrome (SDS). Maybe someday Asian soybean rust will move northward out of Iowa grain bins. Crop pests certainly prevent boredom and keep Minnesota crop management strategies evolving. Agriculture has changed quite a bit in those ten years and will change more in the next ten. Bigger equipment and a host of new GPS based technologies are helping us farm faster and farther. The advent of GMOs has made a huge impact in how we view crop production, initially from a pest management standpoint. Weed management in soybean used to be a harrowing adventure. I know some of you remember discovering just how much corn borer, corn rootworm and soybean aphid can hurt yield. Unfortunately, some have leapt to the presumably erroneous conclusion that even imaginary pest problems are causing economic devastation. But it's spring. The longer days and warmer weather are welcome. It's a good hurt as my worn eyes adjust to the high in the sky sunlight and the bright colors of the new foliage, the first spring blooms and birds in courtship plumage. The intense green spring grasses stand in stark contrast to freshly worked and planted fields and offer a pleasant change of scenery after months of dim light, short days and a landscape dominated by somber, muted shades of tan and gray. The Twins are back on the radio and if there isn't a game on you can usually catch a pre-game prognostication or a post-game dissection of the young baseball season at news time. The playoffs are a real possibility. Over the next few months hopes and pessimism for sports championships will provide entertainment that rivals but cannot surpass the hopes and pessimism for the 2007 crop. Spring is the time for optimism. Every grower's hybrid and variety lineup is more than good enough to win the big one. The playing fields are groomed by the optimum drainage, tillage and fertilizer program. Every corn field has a shot at 300 bushels and every bean field could break a hundred. Many corn fields and a few soybean fields have just received the first pitch. There are no weather insect, weed or disease problems to slow down or bench any players. As typical, I plan to put an issue together as crop and
pest issues come up. In other words, the fewer of these you see during
the summer the better. Hang on and have a good 2007 growing season, Goldie has a near death experience Rain was building to the north on the warm, windy morning the last day of April. A chemical company tech rep, an intrepid plot technician and I were busy testing novel uses for corn fungicides. In between treatments a discussion on the number of thirteen-lined ground squirrel burrows and the potential for damage to research plots ensued. Sure enough, one of the culprits emerged from a nearby burrow. As typical, the ever vigilant chemical rep was the first to spot the problem. The gopher was more than likely developing a plan of attack for germinating corn seedlings. He obviously knew about the movie Caddy Shack. Even triple stack corn is not immune to these rodent pests.
These research plots are a lot of effort. Within reach was an appropriately sized dirt clod. The rest was instinct honed by years of really sub par baseball and softball playing. The uneven edges were quickly crumbled off. I always hated throwing to a left hander. The windup and the pitch...
The gopher was sure it would be high and outside. At the last moment, the side arm slider broke down and inside. The gopher thrashed and went down. Cautiously, I walked toward the plate to check on his injuries. Was he hurt bad or just pouting over misjudging a pitch? I was fearful that the victim and a dugout full of irate rodents could rush the mound at any moment. The tech rep paced off the distance to make sure everything was on the up and up.
There are three reasons for relating the story, none of which is a delusion that I should be a Major League relief pitcher. First, don't be over confident and assume that you can't have pest problems. Secondly, over the next few weeks agriculturalist should be evaluating stands. This involves some gopher-like digging behavior. Finally, a reminder that working high clay content soils on the wet side can create some rather substantial clods. You may find some of the results of tillage of wet soils as you are evaluating stands.
Oh yeah, Goldie, a little more
humble, eventually recovered. With the warm soils we currently have I am hopeful that we have minimum problems from stand reducing insects. Damping off fungi are going to be primarily dependant on heavy rainfall. The remainders of stand problems have a high probability of being caused by operator error.
The following excerpt originally appeared in SW Minnesota IPM STUFF 2002-2 (5/03/02). Some of the more gung-ho types have scouted some pre-emerge corn just to make sure that things are going ok underground. Hopefully, this was also done as part of the planting process to verify seeding depth. I am pleased to report that in the cases I've examined, the radicals (roots) on the 2002 2007 corn crop are pointed down and the coleoptiles (shoots) are pointed up.
Corn scouting should begin in earnest as soon as fields can be rowed. Initial efforts should focus on evaluating stand. Determining the cause in areas with poor emergence might require some detective work because there are many potential causes of poor stand. My suggestion is to start with the obvious. Was seed planted? Most of us can make a mistake once in a while and any mechanical devise is predestined for failure.
Look for corn seed. How about the planting depth? Shallow planted corn might emerge later and less evenly than corn planted a bit deeper. Shallow planted corn (< 1 ˝ inches) is exposed to greater temperature fluctuations and less consistent moisture. Shallow seeded corn is also at risk for poor root development and root feeding insect damage when it does emerge.
Did the seed germinate? Lack of moisture or cold conditions are the primary cause of poor germination. Has the seed rotted? Fungicide seed treatments protect seed and seedlings from fungal pathogens but can be overwhelmed under prolonged wet conditions.
Is there evidence of insect feeding? Seedcorn maggot and wireworms are the two insects most often associated with corn emergence failures in SW Minnesota. Seedcorn beetles can also occasionally reduce stand. Slow emerging corn is at greater risk from these below ground pests. Unfortunately, there is no effective treatment, other than replanting, for these insects after corn is planted.
I would appreciate hearing about any wireworm infestations you encounter this spring. Pesticide Labels- To obtain current labels and MSDS for agricultural chemicals see the CDMS website http://www.cdms.net.
Weather - To keep up to date on all the crop weather details during the growing season see: http://swroc.cfans.umn.edu/Weather/weather.htm.
Next time it rains, you can be well armed with climate and weather trivia when you stop in at your local café for coffee. The MN climatology working group website provides an abundance of facts at: http://climate.umn.edu/climatology.htm.
From a pest management perspective, one of the pieces of information on the above site that I find useful several times a growing season is degree day accumulations: http://climate.umn.edu/ddgen/ddgen.asp. The temperatures are updated once a week on Monday.
Alfalfa - Most fields in SW MN avoided winter kill. After a freeze-delayed late start, moisture and heat are now pushing things along.
Small grains - The Southwest Research and Outreach Center spring wheat and oats have emerged. Winter wheat wintered well.
Corn - Rain delay. Wet soils delayed planting, especially west of highway 71. SWROC corn planting began on April 29. Planting progress is much farther along to the east and some early planted corn is beginning to emerge.
Soybeans - Yes, it is time
to plant soybeans provided seed bed conditions are good. Many seed beds
are in good condition now. Crop production events in SW MN SWROC Summer field Day - Thursdau. July 12
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