Out of Season Field Management for High-Risk and Designated Zone Fields

Purpose

Broomrape management does not end after tomato harvest. Soil movement and debris movement remain the key risks, and those risks continue during post-harvest work, tillage, bed preparation, rotation crop operations, and other field traffic. Any piece of equipment that carries soil or plant debris can move broomrape seed if it leaves a higher risk field and enters another site without adequate cleaning.

For that reason, the same sanitation logic used during tomato season should continue outside tomato season. Keep using the repeated cleaning area inside the field perimeter where practical. Avoid cleaning on roads, turn rows, and driveways where debris can be redistributed. Sequence operations from lower-risk fields to higher-risk fields when workable. Treat repeated cleaning locations, field exits, and other movement points as areas worth watching in future crops because they may become hotspots for later emergence.

Required Under the Current Compliance Agreement

For high-risk fields, the required field management program continues beyond tomato season and includes post-harvest management. Sanitation requirements continue during this period. Equipment leaving a high-risk field must be cleaned reasonably free of soil and plant debris, and the field management program must identify a designated area for equipment entering and exiting the field. Field personnel and contractors authorized to enter the field must be trained to recognize broomrape, and footwear must be cleaned of soil and plant debris before leaving the field.

UC Recommended Practices

Continue using the same designated cleaning area inside the field perimeter.
Avoid cleaning on roads, turn rows, or driveways where dropped debris can easily be redistributed.
Minimize unnecessary movement of tillage, cultivation, and other field equipment from higher-risk fields into lower risk fields.
Sequence operations from lower-risk fields to higher-risk fields where practical.
Monitor the repeated cleaning area in later seasons because it may become a hotspot for future emergence.
Maintain worker training and reporting expectations for any personnel entering known or suspected broomrape fields.

Suggested Practical Checklist

Has a repeated cleaning location been identified and marked?
Are post-harvest crews aware that sanitation still applies?
Are rotation crop operations being sequenced with risk in mind?

Thinking Through Rotation Crop Risk

When planning rotational crops after tomato, the main goal is to avoid creating conditions that could maintain or spread broomrape in known or suspected problem fields. Tomato is a well-established host. Broadly speaking, grass crops are generally considered the lowest-risk rotation category because monocots are not typical hosts of broomrape.

Beyond that, caution is warranted. Some broadleaf crops have been reported as hosts in parts of the literature, but host status and practical field significance are not equally well established across crops or production settings. For that reason, rotational planning in high-risk fields should be framed conservatively. Grass crops are generally the clearest lower-risk category. Tomato and other potentially susceptible broadleaf crops should be approached more cautiously, especially where broomrape has already been detected.