UC Delivers

UC studies improve the efficiency of weed control in broccoli production

The Issue

In broccoli production, a wide variety of techniques are used to control weeds: cultural practices, mechanical cultivation and hand weeding. Weeding costs generally represent a significant proportion of the broccoli production budget, and profit margins can be narrow. In addition, the current debate over immigration reform has increased concern about the availability of labor to conduct hand weeding operations in broccoli and other vegetable crops. Given the labor uncertainties, it is imperative that research be conducted to evaluate techniques that make weeding operations more efficient and effective.

What Has ANR Done?

UC researchers have been evaluating a wide range of weed control techniques in vegetable production systems for a number of years. With its thick outer layer (the cuticle), broccoli can tolerate foliar application of fertilizers. This natural tolerance allows the development of a system to selectively remove weeds from the broccoli field with little or no injury to the broccoli itself. In 2003, UC researchers began investigating the application of a new formulation of oxyfluorfen for use over the top of young broccoli plants with 2 to 3 true leaves. This new oxyfluorfen formulation was relatively safe to broccoli but killed a wide range of broadleaf weeds, including the summer annual purslane, which was not well controlled by other methods. The UC researchers determined the rates of oxyfluorfen required and evaluated the environmental conditions under which the application was least-injurious to broccoli. This research led to the 2007 registration of oxyfluorfen for post-emergence use on broccoli.

The Payoff

Improved weed control efficiency for broccoli

Weed control in broccoli continues to be a challenge as the types of weeds and conditions vary from field to field. However, feedback from growers indicates that the post-emergence use of oxyfluorfen has helped to reduce weed pressure in broccoli production fields and has greatly increased the efficiency of subsequent hand weeding operations.

Contact

Supporting Unit:

Richard Smith,(831) 759-7350, rifsmith@ucdavis.edu
Steve Fennimore,(831) 755-2896, safennimore@ucdavis.edu