Allelopathic cover crops, roller crimping, and soil steaming as an integrated non-chemical weed management strategy in tomato

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Commodities

• Vegetables: tomatoes

Practices

• Crop Production: conservation tillage, cover crops, cropping systems, no-till
• Education and Training: on-farm/ranch research
• Pest Management: allelopathy, competition, cultural control, integrated pest management, physical control, smother crops
• Production Systems: organic agriculture
• Soil Management: soil analysis, soil quality/health

Weeds are a major problem in organic tomato farming, with Palmer amaranth and yellow nutsedge causing season-long interference and significant yield reductions. Current weed control methods are limited, with handweeding being the most common but also costly and ineffective against perennial weeds. A promising solution is to use thermal weed control (steaming) along with allelopathic cover crops. Roller-crimping cover crops can also be used to terminate them before planting without chemicals, reducing residual weed biomass and minimizing tillage.

Our research project aims to discover an integrated non-chemical weed management strategy that can effectively suppress the most troublesome weeds while still producing high-quality tomatoes and increasing yields. We will be conducting field experiments in Mississippi, Arkansas, and Georgia, where we will be experimenting with allelopathic cover crops, as well as combining them with roller crimping and soil steaming to control problematic weeds in tomato production without the use of herbicides. In addition to our primary objectives, we recognize the importance of evaluating the long-term economic viability of our non-chemical approach for organic tomato growers. We will conduct a comprehensive economic analysis, including labor, materials, and overall production costs, to provide growers with a holistic understanding of the economic benefits our approach offers.

In addition to sharing information on effective cover crop varieties, we will also be sharing our findings on the effectiveness of roller crimping and soil steaming in suppressing weeds with tomato growers across various states through extension agents. We plan to share the project's findings with more than 1,000 stakeholders at the Annual Tomato Field Day (MS, AR, GA), U.S. Tomato Council Convention, and SWSS Annual Meeting, with a particular focus on how these findings can benefit tomato growers outside of the three states where we conducted our field experiments.

1. Greenhouse trial

   1.1. Screening and identification of allelopathic cover crops (CC) against problematic weeds in tomato (MSU-Tseng & UA-Burgos)

   1.2. Identify the most effective soil steaming depth x steaming duration combination for killing yellow nutsedge tubers (MSU-Tseng & UA-Burgos)

2. Field trial

   2.1. To test the integration of allelopathic cover crops (identified from Objective #1), roller crimping, and soil steaming (depth and duration identified from Objective #1) to suppress weeds and improve tomato yield/quality (MSU-Tseng/Broderick, UA-Burgos, Rodale-Stallworth/Acharya)

   2.2. To determine the effect of cover crop x roller crimping x soil steaming on soil health and diversity (MSU-Tseng/Shanmugam, UA-Burgos, Rodale-Stallworth/Acharya)

3. Testing the most effective cover crop x roller crimping x soil steaming combinations at grower’s field (Certified Naturally Grown and conventional) (MSU-Tseng/Broderick, Growers)

4. Economic Analysis (MSU-Tseng, UA-Burgos, Rodale-Stallworth)