NEWS for North Dakotans
Agriculture Communication, North Dakota State University
7 Morrill Hall, Fargo, ND 58105-5665
September 2, 1999
The USDA 1998 summary of pesticide management practices, released in late August, contains results of a producer survey. The yes-no responses to the survey questions reveal some considerable differences in how producers of various crops in various regions of the country manage pests, says an agronomist at North Dakota State University.
"Corn and soybean producers in the north central region, which includes North Dakota and Minnesota, seem to do really well with respect to some of the good things," says Denise McWilliams, extension crop production specialist with NDSU and the University of Minnesota. "But I'm surprised that more adaptation of some of the practices hasn't occurred."
The survey questions defined pests as being weeds, insects and diseases. The USDA summary groups pest management practices into four categories: prevention, avoidance, monitoring and suppression.
"What we need to do is utilize all these practices to keep pests at a level we can contain," McWilliams says.
Prevention methods include using pest-free seeds and transplants, preventing weeds from reproducing, choosing cultivars with genetic resistance to insects or disease, irrigation scheduling to avoid situations conducive to disease development, cleaning tillage and harvesting equipment between fields or operations, and eliminating alternate hosts or sites for insects and disease organisms.
Avoidance tactics include crop rotation, using trap crops, choosing cultivars with maturity dates that reduce threats from developing pest populations, employing fertilization programs that promote rapid crop development, and not planting certain areas of fields where pest populations are likely to cause crop failure.
"The most well-adapted pest-management practice for corn and soybeans, all grains actually, was crop rotation, a comparatively passive strategy," McWilliams says. "Producers of higher-value crops, such as fruits, nuts and vegetables, said scouting was their most common pest-management practice."
The USDA's category for monitoring includes such activities as identifying pests through surveys or scouting, via trapping and soil testing, where appropriate. Suppression involves a wide array of cultural, biological and chemical strategies.
"The north central states did extremely well in comparison to other states in terms of scouting for pests," McWilliams says. "More than 50 percent of corn and soybean producers in this region said they scouted crops for pests, but only about 15 to 20 percent of the producers said they used scouting to make decisions."
McWilliams says one reason for the disparity between those percentages may be because the scouting showed that pests were not at economic threshold levels.
The USDA summary contains two sets of data related to farm size that McWilliams finds revealing. One set involves the percentage of acres receiving pest management practices and the other the percentage of farms utilizing pest management practices. The percentage of acres receiving the practices is greater than the percentage of farms utilizing the practices--for both corn and soybeans.
"What this tells me is that the larger corn and soybean farms are probably making use of more of the pest managements practices," McWilliams says.
The pest management practices showing the most change from 1997 to 1998 involve the use of genetically modified crops, McWilliams says. Corn producers increased their acreage of insect-resistant corn (primarily Bacillus thuringiensis or Bt) from 5 percent to 20 percent of their total acres. During the same period, soybean producers increased their acreage of herbicide-resistant varieties (mostly Roundup Ready) from 10 percent to 48 percent.
"That is a quantum leap in changing soybean varieties," McWilliams says. "We're seeing some unusual trends in the adaptation of genetically modified, herbicide-resistant crops. Will these trends hold? It will be interesting to see what next year's survey reveals."
USDA's 1999 summary of pesticide management practices will be released in April 2000, in time for producers to alter some of their practices based on information about what other farmers are planting and the practices they're using, McWilliams says. The entire 1998 summary is available via the Internet (http://usda.mannlib.cornell.edu/reports/nassr/other/pest/).
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Source: Denise McWilliams (701) 231-8160
Editor: Dean Hulse (701) 231-6136