See more from this Session: Cover Crops In Agricultural Systems: I
J. Grigar Jr., USDA NRCS E. Lansing, MI, D.K. Bromelmier & J. J. Sova, USDA NRCS Bellarie, MI, S. Moore & G W. Bird, Michigan State University Extension
Fumigation is a common practice to control nematode populations in new fruit orchards and potatoes in Michigan. However, large quantities of chemical fumigants are annually incorporated into soil as the reliable control of nematodes. During the summer of 2005 & 2006 Pacific Gold Mustard cover crop and high quality compost were evaluated for bio-fumigation control of herbivore nematodes prior to planting an apple orchard, two cherry orchards and a seed potato field. In the Home cherry orchard cover crops and compost was applied to the orchard site. Alternate tree rows were fumigated with VAPAM, sodium methyl dithiocarbamate, before planting cherry trees as a comparison treatment. Nematode counts before planting each site with cover crops and applying compost showed fumigation was needed.
Decomposition of the Pacific Gold mustard cover crop and high quality compost applied ahead of planting the cherry orchards and the seed potatoes had a positive effect on the soil biology by reducing the herbivore nematodes populations to a level where chemical fumigation was not necessary.
Cherry Tree diameter was measured on the Home Cherry Orchard at 25 cm above ground in 2009 to evaluate the impact of bio-fumigation verses fumigation on tree growth. Random measurement of 20 percent of the cherry trees in ten rows showed the 4 year old fumigated cherry trees, averaged ¼ inch larger diameter than cherry trees treated only with Pacific Gold Mustard cover crop and compost in 2006.
Pacific Gold mustard planted in June 2005, before planting potatoes in 2006, had an average height of five-foot under supplemental sprinkler irrigation before disking in July 2005. The results of the final nematode test showed that fumigation before planting seed potatoes was not needed.