The change in planting practices from seeds to transplants, a reliance on mechanical harvesting, minimum tillage practices and a greater adoption of drip irrigation have not only helped processing tomatoes expand yields to over 45 tons per acre, but have aided in the proliferation of field bindweed.

Sosnoskie is studying herbicide-resistance issues in bindweed, a particularly troublesome weed in processing tomatoes and melons. It not only competes with the vegetable crops for water and nutrients, but in processing tomatoes can cause problems with mechanical harvest techniques.

“I’m just doing the work that Tom Lanini started here before he retired,” Sosnoskie said.

Sosnoskie has multiple tomato research trials on two field sites on the UC Davis Campus. The California Tomato Research Institute is sponsoring a study to evaluate field bindweed control in early- and late-planted processing tomatoes.

Part of her work includes dose-response experiments. This includes spraying bindweed with various rates of commonly-used herbicides that are licensed for commercial use in California and then watching the weeds in a greenhouse setting for signs of resistance.

These experiments are looking at post-emergent herbicides for their damaging effect on bindweed at various stages of growth in a greenhouse setting. The aim is to discover how application timing impacts the plant. Sosnoskie is in her second year of these studies.

She plans to publish her findings in Weed Science Journal by early next year.