Tuesday, July 23, 2013

Go For A Walk

If you are standing around getting frustrated waiting for the wheat to dry and need a diversion, take a walk in your soybean field.  Brian came in this morning and alerted me to increasing soybean aphid numbers. He is right, we need to watch this situation.
Look at the newest developing trifoliate. This is where they start because the youngest leaves are the juiciest.
Soybean aphids are born pregnant and can multiply rapidly.  Brian has already sprayed a couple of fields this year that got out of hand.  This is what the plants looked like before he sprayed.
The reason aphid numbers were so high was due to this grower not using any Cruiser seed treatment. Cruiser is extremely effective at controlling early infestations of aphids. The insecticide effect of Cruiser has now worn off.  Reports of aphids infecting treated soybeans are starting to come in.  Check different areas in the field.  Aphids will accumulate in "hot spots".  If you locate aphids come back to the same spot in 2-3 days.  If the numbers are increasing, pay close attention.  The threshold for spraying is 250 aphids per plant AND increasing numbers.  A terrific tool for helping determine whether you need to spray or not is a smartphone app that can be downloaded free from http://www.aphidapp.com/

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