Effect of Deficit Irrigation and Alion Herbicide Rates on Weed Populations in Citrus Grown in Central California.

Citrus crops are one of California’s most profitable and essential products to the state economy bringing in over $2 billion annually. A vast array of citrus crops in production in California include Navel and Valencia oranges, Minneola tangelos, grapefruit, lemons, and mandarins with a large portion based in the central San Joaquin Valley (SJV). The importance of the citrus industry for the sustainability of the local economy is fundamental, yet there are issues that can potentially decrease overall productivity of citrus in the SJV. In the current study, we are comparinge of the effects of deficit irrigation and Alion (PRE) herbicide rates and on weed populations. The experimental design is a split block design with main plots consisting of herbicide treatment and subplot as deficit irrigation levels, replicated three times. Five different irrigation treatments comprising of water application to satisfy the following percentages of the evapotranspiration (ET) requirements: 50, 75, 100 (farmers practice), 125, and 150 have been implemented. The four herbicide sub-treatments within each plot are 0, 0.5, 0.75, and 1.0 (growers practice) times the rate of Alion PRE herbicide traditionally applied by the grower. Data for the various parameters have now been collected and are currently being analyzed for presentation at the annual meeting in November 2014.