Determining the Biggest Bang for our (Time) Buck: Dealing with Fall Brassica Diseases in High Humidity Environments

View the project final report

Commodities

• Vegetables: broccoli, cabbages, cauliflower, greens (leafy), other, radishes (culinary), rutabagas, turnips

Practices

• Farm Business Management: budgets/cost and returns
• Pest Management: biorational pesticides, cultural control, mulching - plastic, row covers (for pests)
• Production Systems: organic agriculture, organic certification

Fall brassicas are perceived as an easy and cheap crop for the Northeast. However, we’ve noticed a transition of our diverse fall brassicas from workhorse CSA standby into finicky drama queens sapping late season labor budgets.

For example, our CSA-ers’ favorite crop, broccoli, only reached target yields once (2019) in the past four years. 2021 yields fell 35% short, 2020 24% down, and 2018’s Alternaria disaster season short 92%! The fall brassicas we can distribute show lower quality and poorer storage due to heavy Alternaria and Black Rot (Xanthomonas campestris), with lower downy/powdery mildew and head rot pressure.

These crops comprise 20% of our farm mix and are a mainstay across our region’s direct market operators. We propose to reassess what cost effective disease control looks like for these crops in light of new variables of wetter weather and rising labor costs. Across four iterations of this trial, we will assess the interaction between three intensities of organic fungicide application on nine cultural control practices.

Intensively tracking labor, scouting, and yield data will inform a series of light enterprise budgets that assess the net profitability of different cultural/fungicide treatment combinations. We hope to gain and share a better financial understanding of how intensive, diversified veggie farmers can best manage brassicas when late season moisture levels rise, and to ascertain if the cost/benefit ratio of standard production strategies has changed under intensifying weather and disease pressure.

We will share these results with regional farmers through social media, presentations, and written articles.

The question we want to answer is what extra effort is worth putting into fall brassica disease management in damp years? Is it worth spraying after every storm, or are cultural changes or accepting some damage more cost effective? Our objectives include:

1. Do cultural strategies impact the cost effectiveness of each spray regimen? Does a particular mix of cultural practices provide equal or better control of disease/bring higher yield?
2. Is it cost effective to spray more frequently? Does the added time cost pay off through marketable product?
3. Where is the sweet spot in the combination of practices/spray frequency with the highest net return?

We anticipate this trial will yield time and cost data on how many spray applications are most cost effective; which cultural controls most reduce disease; and how the two interact through measuring:

• Cost of inputs for each treatment
• Time each treatment takes
• Plant health
• Yield per treatment—marketable yield per bed foot in units/dollar value

Our hope is that combining these results into basic enterprise budgets will give our farm and others a starting point to improve fall brassica net profitability even as labor costs rise and late season growing conditions become more extreme.