From kandmhfarm@sprintmail.com Thu May 18 22:03:07 2000 Date: Thu, 18 May 00 20:49:22 -0500 From: kandmhfarm@sprintmail.com To: sanet-mg@cals.ncsu.edu Subject: Organic sweet corn We wish to comment on the discussion about growing organic sweet corn. Growing top quality, insect free organic sweet corn CAN be done. The product produced can actually be better than conventional. We grew 70 acres of OCIA certified organic processing sweet corn last year - all SH2 varieties, and grew 25 acres of sweet corn the year before. Growing organic sweet corn CAN NOT be done successfully using 'organic by neglect' or 'input substitution' approaches. We plow down large amounts of green manure cover crop - primarily red clover - and the straw from the previous year's wheat or spelt crop. Organic soil amendments as required according to soil test are applied to the cover crop the previous season. A balanced organic starter fertilizer is applied at planting. Weed control is accomplished by cultural control methods, supplemented with blind cultivation and then two passes with the cultivator. Weed control is excellent. Last year, in a severe Northeast drought, we saw no insect damage and averaged about 5.2 tons/acre. Much of the conventional sweet corn in the area was abandoned, due to poor kernel set, low quality and very low yield (are you paying attention, Mr. Avery? ). Healthy crops do not appear to attract bugs. Research at Ohio State University by Dr. Larry Phelan showed that European corn borers, given a choice between organic and conventional corn plants, would avoid the organic plants. His research is continuing to test two hypotheses for these observations. He feels that the organic soils, with a rich microbial population, may release plant nutrients more evenly over the season, resulting in slower, sturdier plant growth that is more resistant to insect attack. He also believes that the mineral balance of the soil and the plant plays a key role in insect resistance. In either case, the levels of complex molecules and water content in the plant tissue probably determines how tasty the plant is to an insect. Our observations suggest that excessive or unbalanced potassium levels in the soil attract insects in most crops. The first year we were talked into a Trichogramma wasp release to control worms, and the extension agent had to really search for one measly egg mass that had been parasitized. The wasps must have starved or gone next door to the conventional field corn that did show egg masses and worms, right across the fence. We did avoid the highest populations of ear worm flights by selecting an optimum planting time, based on historical records, but we're not sure that this was necessary. The processor of our sweet corn has told us that he has actually received letters, complimenting the quality of the sweet corn. From our own experience, there is no doubt there is a difference in flavor. The drought conventional corn last year lacked both sweetness and corn flavor, while the organic sweet corn tasted just as it should. This probably partly is because the higher soil organic matter held water until the end of the drought. The organic corn showed little damage from drought stress other than the yield was slightly down compared to a good year. In previous years, we had participated in Cornell replicated trials with the biological seed protectant, T22, on sweet corn. This Trichoderma fungal product colonizes the root zone of the growing seedling, and in a wet year, this may give valuable protection to untreated seed. In one very wet year, we did see a 30% yield increase where this product had been used as a seed treatment. There is also evidence that T22 can make nutrients more available to the plant. This product would be worth considering when planting sweet corn, especially SH2 varieties, early into wet cold soil. Hope this information helps someone out there. Klaas and Mary-Howell Martens To Unsubscribe: Email majordomo@cals.ncsu.edu with the command "unsubscribe sanet-mg". If you receive the digest format, use the command "unsubscribe sanet-mg-digest". To Subscribe to Digest: Email majordomo@cals.ncsu.edu with the command "subscribe sanet-mg-digest". All messages to sanet-mg are archived at: http://www.sare.org/san/htdocs/hypermail From jgruver@principia.edu Fri May 19 01:39:45 2000 Date: Thu, 18 May 2000 20:16:13 -0700 From: Joel B. Gruver To: "Lawrence F. London, Jr." , Hook Family Cc: sanet Subject: Re: organic corn Hello folks, It is certainly possible to grow excellent sweet corn organically... however one thing to keep in mind is the extremely low levels of ear worm damage tolerated by wholesale buyers of "conventional" sweet corn. I recall a conversation with Dr. Ruth Hazzard (Vegetable IPM specialist at U Mass) about acceptable levels of ear worm damage as we were harvesting and evaluating an organic sweet corn trial at Hampshire College in 1994. My recollection is that ~ 20% of our untreated organic sweet corn ears were damaged and that the plots where vegetable oil, oil + BT, Beauvaria sp... treatments had been applied to the young silks (not the tassels) all had significantly less damage... However as I recall, Ruth Hazzard commented that > 2 % damaged ears is considered unacceptable by conventional sweet corn growers. We were supplying 70 CSA memberships with sweet corn from the non-plot sweet corn in this field and had no problem finding sufficient good quality ears on our harvest days. The ~ 20 % damage was acceptable to us. See the following web site http://www.nysaes.cornell.edu/ipmnet/nerpt99/ma.html for a description of "Zea-later" the oil applicator device that was developed by Hazzard and Hampshire students. Joel Joel Gruver Visiting Faculty Principia College Elsah, Illinois 62028 (618) 374 - 5289 jgruver@principia.edu