Rear view with 8' boom on left and 12' on right		End of boom with fan spray tip turned sideways		Spray tank with 12-volt pump filled with dye; hydraulic powered front blade

Research shows that plants on the end of a yield plot receive more light and water than the plants within the plot. These end plants are usually larger and yield more, which leads to inaccurate yield results. To eliminate this, the rows must be shortened late in the growing season to include only plants that have had equal competition.

In the 1970's and 80's, end trimming was done by hand, weed trimmer, and self-propelled mower. Later a shield was mounted to a tractor with a three-point-hitch mower, which evolved into the machine we are using now. It consists of a John Deere 750 tractor with a Motte PTO driven flail mower and a hydraulically driven mower head at the front of the shield. The shield and front mower are in place to decrease tangling of lodged plants under the tractor tires and to give a cleaner edge to the plot. A twelve-volt powered sprayer, tank, and boom were added to spray a line of dye for the tractor driver to follow.

Our yield plots are 20' long when planted. After emergence, a 3' ally is cut between the plots, leaving the plot length at 17'. A wooden stake (harvest stake) is placed 8' from the center of each ally on each side of the field to give a measuring point to start end trimming. In the Fall, before harvest, the ends are trimmed using the equipment described above. The remaining plot length is then 12' and ready for harvest.

Procedure

1. Put sight pole 75" from harvest stake in first ally on each end of field.
2. Line up center of tractor with sight poles with shield toward the plot.
3. Turn on mower, mower head, and sprayer with 12' (right) boom valve.
4. Mow front end of range while spraying the back end of the range.
5. Turn off 12' (right) boom at the end of the range and turn around.
6. Line up shield with sprayed line on the back end of the range.
7. Turn on 8' (left) boom valve and mow the back end of the range while spraying a line on the front end of the next range.
8. Turn off 8' (left) boom and turn around.
9. Line up shield with sprayed line on the front of the second range.
10. Turn on 12' (right) boom and mow front end of second range while spraying a line on the back of the second range.
11. Continue until the back end of the last range has been mowed.