Anyone else seeing deeper depletion than ET estimates suggest? As a hydrologist working with growers, I pulled 18% VWC at 20 cm on a loam this morning with a capacitance probe while the ETc sheet said about 24%, so I trimmed sets by 10 minutes and shifted to dawn runs. How are you tying Kc and rooting depth for late-season tomatoes, and I’m happy to share a simple log or quick soil test walkthrough if useful.
I’d bump effective rooting depth to 0.7–1.0 m and taper Kc from about 0.95 toward about 0.80 as the canopy senesces, or the ET sheet will over-trust shallow water while your ‘18% at 20 cm’ looks worse than it’s. Practical step: take a 30–60 cm pass (or one auger core), calibrate the capacitance probe to a site-specific curve, then trigger irrigation at about 45–55% TAW with dawn runs. Tomato roots are sneakier than the Kc table — are you seeing moisture at 40–60 cm?