Wednesday, August 8, 2018

Spraying for stinkbugs and weevils

   Today, I made an application of Warrior 2 insecticide to my pecan grove (photo at right).  This insecticide application was made primarily to keep stink bugs in check and to kill any early emerging pecan weevils that might have migrated into my grove from the neighbor's un-managed native pecan grove.
    At this point in the growing season, my Kanza nuts are approaching full water stage. It is too early for weevils to lay eggs but both stink bug and weevil feeding can cause serious nut drop. With our below average nut set this year, I definitely want to prevent any potential nut loss.

    My grove was established by grafting volunteer seedlings to cultivars such as Kanza, Hark, and Lakota. As a consequence, the orchard looks like a native grove with trees growing at random locations. Since the trees are not planted in rows one question often comes up: "How do you keep track of which trees have been sprayed?".  Since I use a Savage sprayer, I take into account that it is most efficient to spray in one direction at a time. I usually spray to the right side of the tractor (as pictured above). I start on the edge of the grove and spray inwards. When I get to the end of the field. I turn the tractor so that I'm 40-50 feet away from my initial path through the orchard.  Still spraying towards the right side of the tractor, I end up spraying the other side of the trees sprayed during my initial pass. When I weave through the orchard, I keep track of where I am by looking for the tire impressions I made in the tall, wet grass 40-50 feet to my right.  Once I get to the other end of the field, I turn around and retrace the tire marks I just made (the second pass through the orchard). Driving in the opposite direction on the same path and spraying to the right means I'll be spraying trees not yet receiving insecticide treatment. In the photo at left, look at the ground-cover  carefully, you can see bent over blades of grass that mark the trail I took through the grove.  I know its hard to see in the photo, but from my tractor seat I can see it clearly. By sticking to this travel pattern, I'm certain to cover every tree n the grove.
     A couple more notes on spraying. I like to spray early in the morning. The high humidity and calm winds at that time of day helps the sprayer deliver the pesticide to the entire canopy. Since I'm using a late model tractor to spray the grove, I have a digital reading of ground speed. With my 12 speed tractor, I drive in 3rd gear and average 1.9 miles per hour.  I operate the fan at full throttle.