Yesterday I headed southwest to the Kellogg Biological Station to conduct some our organic weed management research in corn and while I was there I also had the opportunity to attend the 2008 Vegetable Cover Crop Workshop put on by MSUE Vegetable AOE Team.
When using a propane flamer, the short burst of heat provided by the passing flame increases the temperature inside plant cells, causing the water to boil and the cell to rupture. The aim of our research at KBS is to find the best time of day for flaming. We flamed at 8am, Noon, 4pm, and 8pm. The corn was in the V1 stage, most of the broadleaf weeds (c. lambsquarters, c. ragweed, velvetleaf, clover spp., and pigweed spp.) were in the cotyledon to 2 true leaf stage, and the grasses were 1/8-1/2″ tall. After flaming the corn looked pretty crispy and the weeds were hard to find. The corn should outgrow the damage because the growing point is still protected below the soil surface. I will return next week to see what happens.
The cover crop workshop featured several speakers from MSU Extension and two invited speakers, Dr. Anne Verhallen from the Ontario Ministry of Agriculture and Dr. George Abawi from Cornell University. Cover crop related topics included biofumigants, nutrient management, soil and root health, and grass and legume mixes. After sitting in the air conditioning for a few hours we went out to tour a few field sites including the perennial wheat and rye crimping projects. The most interesting thing I learned from the day was how biofumigants “work”. When a Brassica plant (or other glucosinolate containing plant) is crushed the the glucosinolate compounds are broken down by enzymes (that are usually stored separately) and isothiocyanates are formed, which are the same chemicals found in synthetic fumigants.