Purdue research: Varied yields from fungicide, insecticide
WEST LAFAYETTE, Ind. —As Indiana soybeans move from flowering to beginning pod, farmers may consider applying foliar fungicides and insecticides to their crops. But according to Purdue Agriculture research, yield increases from either treatment are inconsistent when disease and insect pressures aren't present.
Many growers are interested in possible fungicide and insecticide applications for other benefits, which may include retention of green leaf area that leads to extended seed fill and, ultimately, higher yields.
"The question remains whether such a management practice will result in consistent yield increases that will offset the added cost of the chemicals," said Purdue Extension plant pathologist Kiersten Wise.
Purdue researchers established field trials in 2009 and 2010 at three Indiana locations: Pinney-Purdue Agricultural Center in LaPorte County, the Agronomy Center for Research and Education in Tippecanoe County and the Southeast-Purdue Agricultural Center in Jennings County. The trials showed that yield increases from fungicides and insecticides are possible when pests are below thresholds, but Wise said those increases were not consistent.
Of the treatments included in the analysis, Wise said a single application of glyphosate at growth stage V3 gave the highest average net return of $435 per acre. While additional treatments, such as a tank mix of Headline at Warrior at growth stage R4, could result in higher net returns, the treatments weren't always profitable because of added pesticide and application costs, and lack of consistent yield increases.
"The additional cost of these pesticides and the variability of soybean market prices can influence the profitability of their use," she said. "According to our analysis, soybean growers will rarely benefit financially from their application if pests are not present. Therefore, we recommend that growers base their decisions to apply fungicides or insecticides on the presence or absence of significant fungal or insect pressures in their fields."
Additional study details and results are available at https://extension.entm.purdue.edu/pestcrop/2011/issue17/index.html#soybean
Writer: Jennifer Stewart, 765-494-6682, firstname.lastname@example.org
Source: Kiersten Wise, 765.496.2170, email@example.com