92Y12 - May 11 55.8 bu/acre @ 13.5%
92Y12 - May 26 53.8 bu/acre @ 13.5%
91Y61 - May 11 56.0 bu/acre @ 13.0%
91Y61 - May 26 54.0 bu/acre @ 13.0%
Interesting how the yield difference was consistent with both varieties at 2 bushels apart. In a sense I am not surprised that the results were close. Looking back at my notes, the May 26 planting date was a full stage behind the May 11 date. (For a refresher, look at my "Down the Back Straight" post on August 10). Rainfall pattern favoured the later planting date. We went through late June and July on barely 1" of rain. August was kinder with 2.5 ". There were 12 days of over 30 degree highs in July and only 3 days in August which tended to favour yield development of the later planting date. The growing season was also long enough to allow full season varieties to reach maturity with time to spare.
Nonetheless, there was a definite response with the May 11 planting date which fits the longer term trend.
OMAFRA research into planting date response over 3 years shows a 4 bu/acre response for the same time period, May 10 to May 24.
Pioneer has initiated a number of planting date trials this year. I have been hearing of higher responses to earlier planting and will report the summary later.
On a different topic we also evaluated response to applications of Acapela fungicide on soybeans applied at the R1 stage. We had 5 locations of treated vs untreated and one location also had a strip of Headline as a comparison. The yield environments ranged from 50 to 64 bushels, so our selection of sites were generally higher yielding locations in the area.
Four of the five had positive response and one location had no response. The 4 positive responses accumulated a total of 8.4 bushels of extra beans for an average reponse over the 5 trials of 1.7 bu. The Acapela vs Headline resulted in the same 1.5 bushel response to both fungicides over untreated.
OMAFRA has studies which predict a 2 bu or 4% response to fungicide use which closely agrees with our results.
Not exactly the stuff to excite a fungicide sales person, but if you have your own sprayer there is a positive economic return. I tend to believe yield claims for fungicides, while usually overated, are still reflected in responses like ours.
Early planting dates and fungicides are tools in the toolbox useful for achieving maximum economic returns in soybeans.