Field Trials of Organic Herbicides in Vegetable Production

Field Trials of Organic Herbicides in Vegetable Production

Summary

For the past five years Rhoads Farm in central Indiana has been experimenting with both formal and informal trials using organic herbicides and LP flaming for reducing weeding time/costs for organic vegetable production. The last two years, Green Earth Institute near Chicago, IL has joined in with formal trials both testing the effectiveness and the cost effectiveness of these weeding strategies. These trials have focused on using the weed control methods to set up a ‘sterile seedbed’ that is planted or transplanted into. The overall summary is that using this strategy for high value thickly planted quick growing short season crops like spinach or salad greens can dramatically reduce weeding time and over all cost. But using the herbicides on longer season crops, particularly where there are perennial weeds dramatically reduces the cost effectiveness and in some instances actually raises the cost of weed control.

It is important to note that any farmer planning on using these weed control methods has to be willing to take the time to learn what weeds they will kill, how to time planting and weed control and how to use the products. Rhoads Farm uses these products with great success with a number of different crops. In some instances with some crops the cost savings in weed control is dramatic.

Objectives/Performance Targets

The objectives of these trials were to determine the effectiveness of the herbicides, determine cost effectiveness and to provide information about possible uses and crops to use these products on. These objectives have been reached and will be reported on in more detail in the final report which will be filed by Jan 31, 2008.

Accomplishments/Milestones

We have determined that these strategies work best in the way we are using them in setting up a sterile seedbed with the kinds of crops on the kinds of weeds described in the summary above.

Impacts and Contributions/Outcomes

As more sophisticated weed control strategies become available for organic vegetable growers, it is important to provide information on the use of these products in order to boost cost effectiveness of weed control. We have made significant contributions to the knowledge needed for a farmer to begin exploring whether this can benefit their farm. With some crops, with some weed problems the cost savings can make a significant contribution to over all farm productivity. But the farmer has to be willing to take the time to learn how to use them correctly and with what crops and what weeds.