Project Number: 5347-21410-005-03
Project Type: Specific Cooperative Agreement

Start Date: Jul 18, 2007
End Date: Sep 30, 2009

Objective:
The objective of this research was to determine the tolerance of lesquerella seedlings to alternative pre and postemergence herbicides. Broad spectrum weed control is essential for lesquerella [Lesquerella fendleri (Gray) Wats., Brassicaceae] production. Weed competition is particularly critical prior to closure of the lesquerella canopy, a point sometimes not reached until several months after planting. Weed seedlings can emerge in early fall and interfere with lesquerella growth and establishment.

Approach:
The study will be planted at the University of Arizona, Maricopa Agricultural Center and at Pecos, Texas. Efficacy and crop safety of lesquerella to preemergence herbicides will be evaluated during stand establishment under flood and sprinkler irrigation with a split-plot experimental design. Main plot factor is application time of preemergence herbicides and the sub-plot factor is the various herbicide treatments. Seven different herbicides will be tested and compared to untreated plots. The weed control efficacy and crop safety of postemergence herbicides during stand establishment in flood irrigated level fields will also be studied. Ten different herbicides will be tested at different rates along with 4 other treatments that combine two herbicides and compared to untreated plots. Seedling density will be determined prior to spraying in each plot by counting the seedlings in a 0.25 m2 quadrat. Formerly 5347-21410-004-07S (8/08).