An equivalent Sacramento Valley Field Day will be held in the Knights Landing area toward the end of May.

Broomrape 101 for Organic Vegetable Growers

May 19, 2026 | Noon - 1:00pm

Virtual Meeting (Zoom)

This webinar will cover:

• Identification
• Biology and field scouting
• Organic management tools
• Current BMPs, including conventional control tools

SANITATION: Timely Reminder from Farm Advisor, Patricia Lazicki

Spring is a good time to think about the spread of soilborne pests & pathogens

Many pests and pathogens of concern to vegetable crop production in the south Sacramento Valley are soilborne.Equipment used in spring fieldwork, when soils are moist, is more likely to transport soil between fields than the same equipment used in dry soil conditions, creating an important risk for moving these pests to new fields.

Even if a field has been rotated out of the susceptible crop, many soilborne pests (such as broomrape, fusarium species, southern blight, or resistance-breaking root knot nematode) can last for several years without a host. It’s a good idea to keep track of affected fields and to have a plan for reducing contamination to new fields.

Quaternary ammonium compounds (effective at killing broomrape seed) are deactivated by soil. So simply spraying a machine with sanitizer is unlikely to be effective if it has parts which are thickly encrusted with soil.

Matrix Chemigation: Why Use It?

Although more practices and materials are in the pipeline for new uses in 2027 and 2028, Matrix chemigation remains one of the few effective tools growers can readily implement today.

Recent UC research highlights that chemigating Matrix earlier than previously recommended - starting around 20 days after transplanting, followed by applications at 30 and 40 days - provides improved efficacy. Matrix chemigation targets broomrape seeds as they germinate, preventing attachment to tomato roots and reducing broomrape emergence by up to 85%, with no effect on tomato yield versus non-treated control plots.

This practical, grower-managed solution provides a cost-effective way to dramatically reduce broomrape incidence within fields and helps limit its spread from field to field and across broader regions. Adopting this updated chemigation timing offers growers greater control and protection of their 2026, and future, tomato investment.

Broomrape Scouting Resources

Nitrogen Management

Is Your Soil Keeping Up with Your Tomato Crop's K Needs?

Potassium (K) is critical to processing tomato health and fruit quality - but not all soils supply enough. In California’s southern Sacramento Valley, most soils aren’t naturally deficient. That said, long-term tomato rotations can slowly deplete available K.

Recent CTRI-funded research shows that soils coming into tomato after decades in other crops have higher available K than neighboring fields with continuous tomato history. While not all fields hit the threshold where K fertilization pays off, this drop over time suggests growers should keep an eye on levels.

Tomatoes are heavy K users: a 50-ton crop can remove up to 300 lbs of K per acre. If needed, a general fertigation recommendation is around 100 lbs K₂O per acre. Consider soil texture, root health, and competing ions when evaluating deficiency risks. More information in the links below.

Resistance-breaking Root-Knot Nematodes are Out There - Be Prepared

Field notes from recent work, led by Patricia Lazicki:

• Assume resistance is broken. Mi-gene varieties continue to support nematode reproduction. This reinforces prior CTRI-funded and UC work showing resistance-breaking strains are widespread.
• Nematodes make Fusarium worse. Combined infections increased disease severity and reduced plant growth, even in Fusarium-resistant varieties. Co-management matters.
• Variety choice won’t save you. Differences among Mi-gene cultivars were inconsistent and isolate-dependent. Field outcomes are driven more by the nematode population than the tomato.
• Non-fumigant tools can reduce losses, with context. Multiple non-fumigant nematicides have shown value in different situations. In a 2025 Dixon field trial, Salibro increased yields by ~11 tons per acre, likely by delaying symptom onset. Other materials in this class have shown benefits under different pressures and timings, reinforcing that product choice should be matched to field history and the overall pest complex, not viewed as interchangeable or universally effective.

Bottom line:

Expect resistance-breaking RKN in many fields. Manage nematodes and Fusarium together where they overlap, match nematicide tools to pressure and timing, and leverage sanitation programs for use across challenges (broomrape/fusarium/nematode).

Beet Curly Top Virus

Tomato Spotted Wilt Virus

So are your neighbors.

Automated transplanting is no longer something to dismiss as experimental. CTRI helped put this technology in front of the California processing tomato industry early, when adoption was near zero and the equipment still was not really built to the needs of our system. Today, many units are under commercial operation, more are on order for 2027, and growers are beginning to look at this as a real management tool with cost-savings, not just an interesting idea.

Weed control is next. Mechanical options are getting more cost competitive, and lower-cost spot spray technologies are starting to enter the market. Another area worth watching.

We build durable coalitions around the questions whose answers drive the long term success of the California processing tomato industry. Founded in 1968, the CTRI is a non-profit organization of processing tomato growers.