Final Report for FNE99-275
In this project, the farmer wanted to determine if shade cloth in the rows would prevent deer from eating lettuce while at the same time tempering summertime heat effects on a cool-weather crop. Lettuce was seeded in three-foot wide beds, fifty feet long. Shade cloth was cut into sections twenty-five feet long by three feet wide and suspended to hang perpendicular to the ground from four-foot fiberglass fence posts on the east side of each bed. It was attached using insulators and wiring at the top and bottom of each fencepost. The three-foot depth would provide shading for the summer lettuce crop, be manageable and moveable, and provide a barrier to deer browsing. By using a twentyfive-foot length, half of the row remained as an unprotected control treatment.
Wind proved to be the primary problem in this trial. The shade cloth, moving in the breeze in the direction of the planting, injured tender lettuce tops. To adjust for this, fence posts were moved to the west side of each bed when the wind direction seemed variable, but this was no help. The farmer also shortened the depth of the shade cloth to two feet to avoid injuring the tops of the lettuce, regardless of wind direction. Keeping the shade cloth attached in windy situations proved difficult.
At first, the shade cloth seemed to be effective at keeping the deer away and eating areas that were not protected. However, since it eventually blew down or off the posts in each trial, the deer took the opportunity to move right in and negate all the previous benefits by browsing the lettuce. The reduced shade cloth depth protected the lettuce from deer, but also reduced the amount of shade provided to a negligible amount and it would still blow apart, usually getting wrapped across the row and destroying lettuce plants just as effectively as browsing deer.
The farmer eventually switched from trying to produce mature lettuce heads to growing baby-sized lettuces that are sold in a mix.