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

Commodities

Practices

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)