Del Voight - Penn State Extension
Here we are in late February less than a month away from beginning to work on wheat pests and calibrating the sprayers and planters. I am looking at my most recent heat accumulation since Jan 1 and it appears that we are behind in heat compared to past years. Actually we have about half the accumulated heat than last season. This may have some implications for predicting the emergence of pests as well as the potential for early harvest of ryelage and alfalfa. As we move through this spring if we get some spikes in temperature we can certainly begin to move this season forward. For example a base of 41 for alfalfa as of today we have 67 heat units compared to 143 this same time last year. The historic accumulation of 94 indicates we are slightly behind. The Pa Pipe system is a great way to track. They typically get started sometime in Late March. This link will get you to where you need to view the interactive map and can be saved as a bookmark on your mobile phone or tablet PC. While some pests like it hot the Cereal Leaf Mite does not mind the cold. Here is a picture from Dr. Dively and his counts during the winter of the mite on Timothy leaves. Check it out the black are the eggs and the red are the adults. Too early spraying for these could miss alot of eggs later on.
Pa Heat Development Map