Project Overview

Reports

Commodities

• Vegetables: tomatoes

Target Pests

• Target Pests: weeds

Practices

• Pest Management: allelopathy, biological control, chemical control, competition, cultural control, mechanical control, pesticide application timing, pesticide resistance management, precision pesticide use, smother crops, soil solarization, temperature treatment

• Crop Production: cover crops, high tunnels or hoop houses

• Production Systems: organic agriculture

• Soil Management: organic matter, soil microbiology, soil quality/health

• Sustainable Communities: sustainability measures

1. Problem: Weed control is a major limiting factor in tomato production, arguably more so than disease control. Reduced tillage may reduce weed emergence but delays soil warming. Even though the crop is primarily grown in a plasticulture system, difficult weeds are still a major problem. Major weeds in tomato include yellow nutsedge, purple nutsedge, large crabgrass (or other annual grasses), and Palmer amaranth. Of these, yellow and purple nutsedge are the most problematic, causing significant yield losses and reduced fruit quality. At a high density of purple nutsedge (160 shoots/0.1 m²), tomato yield can be reduced by up to 53%. Without weed control, tomato plant growth is inhibited, and individual fruit size, number, and weight are reduced. To overcome limited weed control options and preserve or improve tomato quality and yield for growers, there is a great need to find an integrated weed control strategy that can effectively reduce the weed pressure around the crop and, at the same time, protect the yield and quality of the fruits. A promising integrated weed control option is to use thermal weed control (steaming) in combination with allelopathic cover crops and biochar herbicide protection pods (HPPs).
2. Approach: The specific objectives of this project are (1) to conduct a greenhouse trial to evaluate the effectiveness of biochar herbicide protection pods (HPPs) in improving the tolerance of tomato to S-metolachlor, halosulfuron, and metribuzin herbicides; (2) to conduct field trials to test the integration of soil steaming, allelopathic cover crop, and biochar HPPs to suppress weeds and improve tomato yield and quality; and (3) to determine the effect of cover crop x soil steaming x biochar on soil health and diversity.
3. Impact: The potential economic impact of this project on the tomato industry is immense. The US is second only to China globally in tomato production. Fresh and processed tomatoes account for more than $2.5 billion annually in the US. Considering that yield and fruit quality of tomato is reduced by up to 53% by weed interference, the estimated economic loss can be up to $1.3 billion annually in the US. Tomato production in the US has increased significantly over the last 15 years. With this, the need to manage weeds is becoming a bigger issue to protect the yield and quality of tomatoes. The primary beneficiaries of the project will be all tomato growers in the southern US, representing over 272,900 acres. Providing tomato grower’s techniques to control weeds using soil steaming combined with cover crops and biochar can protect these crops from losses caused by weeds, thus increasing the marketable yield and quality of tomato. The availability of eco-friendly and effective weed management strategies in tomato will also allow growers to reduce the usage of herbicides and increase crop productivity with minimal dependency on herbicides for weed control. Integrating soil steaming and cover crops will be an effective option for managing weeds, especially in organic production where herbicides are not permitted to be used, and weed control options are limited. Adopting soil steaming with cover crops and biochar can also encourage reduced or no-till practices, which are more sustainable.

1. On-farm interviews with stakeholders
2. Host two field days with stakeholders
3. Develop and deliver one webinar for stakeholders
4. Create a scientific bulletin
5. Write one article for CSA magazine
6. Introduce soil steaming as an effective means of weed control