Managing teff as a living mulch for organic acorn squash in mesotunnel systems

View the project final report

Commodities

• Vegetables: cucurbits

Practices

• Pest Management: cultural control, disease vectors, mulches - living, mulching - plastic, row covers (for pests)
• Production Systems: organic agriculture

Cucumber beetles and squash bugs transmit the pathogens that cause bacterial wilt and cucurbit yellow vine disease (CYVD), respectively. This pest-disease complex devastates organic cucurbit crops in the NC Region. Organic growers have tried a range of strategies to combat this complex, but with inconsistent results. A new system called mesotunnels – 3.5-ft-high tunnels with nylon-mesh fabric over steel-conduit hoops that stay in place almost all season – keeps out pest insects and the bacterial diseases they carry. Mesotunnels have exciting potential to reduce – or even replace – reliance on organic insecticides while increasing marketable yield for cucurbit crops.

However, organic cucurbit growers have stated that weed control is a potential limiting factor to adopting mesotunnels. Suppressing weeds in the alleys between plastic-mulched crop rows is challenging because the tunnels remain in place for almost the entire season. A living mulch could suppress weeds, build soil quality, and minimize soil erosion. After an inconsistent performance by rye-clover mixtures in an earlier field trial in Iowa, we seeded a cereal grass called teff in 2020 Iowa field trials. Teff suppressed weeds effectively but also reduced crop yield due to competition.

I proposed to determine whether mid-season mowing of teff in the alleys between crop rows could make it suitable as a living mulch for acorn squash in organic mesotunnel systems. I hypothesized that mid-season mowing of teff would suppress weeds effectively while minimizing competition with the crop.

By demonstrating an effective weed control method in mesotunnels, my project provided a potentially attractive alternative management strategy for organic cucurbit growers in the North Central Region. My outreach program shared project results with farmers at a summer field day, at the Iowa State University field day, and through blog posts and videos.

• 200 NC Region growers became aware of mesotunnels’ potential for suppressing pests, reducing insecticide applications, and safeguarding yield.

Our results may have broader impacts by encouraging growers to expand mesotunnel use to other cucurbit and non-cucurbit crops.