- Author: Sonia Rios
Control of weeds has always been a major economic cost in subtropical fruit production because of favorable climate that allows for weed germination and year-round growth. The use of chemical weed control has increased dramatically due to labor costs, equipment costs, product costs and availability, the shift to more narrowly spaced tree rows, and installation of low volume irrigation systems that prohibit the operation of mowing or tillage equipment under the tree canopy area (Futch 2001).
However finding herbicides that are labeled for certain subtropical crops can be a bigger challenge. UC Weed Science has updated the Subtropical Crops herbicides usage chart for California growers (Fig. 1 Attachment below). It also seems that preventive programs are most frequently overlooked as a method of weed control. Preventive programs entail the use of such practices as sanitation, spot spraying, or hand labor to prevent the source of weed infestation (seed and/or vegetative) from widespread dissemination throughout a given area. By removing the undesirable weed species prior to seed development, dissemination by wind or mechanical transport on equipment can be effectively delayed.
Weed control programs will vary from location to location within the state and can even vary within a given site based upon specific conditions such as soil type, variety, method of herbicide application, and the presence of specific weed species.
Before herbicide application, growers should survey the grove and determine the stage of growth and type of weeds for that given location. Many products do not provide control of emerged species, thus requiring the application of more than one product to provide both preemergence and postemergence protection (Futch 2001). Rotation of soil-applied herbicides should also be considered to prevent the buildup of resistant annual and perennial weeds. The resistant species may not be evident initially; however, if the same herbicide and cultural program is maintained, over time their populations may build up until they infest the entire grove and become the dominant weed species (Jordan et al 1992).
Herbicide damage to foliage and fruit has also been noted when herbicides were applied under windy conditions or use of improper equipment allowed the materials to contact areas other than the weeds or soil. Please make sure to follow the label's direction and use caution.
Attached below is a chart listing herbicides registered for avocado, citrus, date, kiwi, fig and pomegranate.
- Author: Sonia Rios
Rios completed an M.S. in Plant Science with an emphasis in Weed Science from California State University, Fresno, a B.S. in Plant Science from California State Polytechnic University, Pomona
Prior to accepting her advisor position, Rios served as a staff research associate in UCCE Tulare County where she assisted advisors in all phases of applied agricultural research (field and greenhouse research on cereal crops, cotton and weed management). She was involved in approximately 30 – 40 research projects that included research testing in herbicide resistance, variety evaluations, and pest management including evaluating new herbicides and insecticides. Rios has conducted and reported agronomy research experiments through data collection that is statistically analyzed, translated and disseminated to clientele; maintained research plots; prepared educational materials for research reports and University publications that would benefit California growers, industry clientele; assisted regulatory agencies with science-based information; conducted radio interviews; and she was a regular speaker at the Tulare County Pesticide Safety meetings. In addition to working with UC, she was also her main professors' student research assistant that would help with trials on campus, assist undergraduates with their research projects and spent time in the classroom teaching.
Rios had also worked with the United States Department of Food and Agriculture (CDFA) inspecting airplanes for Japanese beetle as an Agriculture Aide I. She also worked with the United States Department of Food and Agriculture (USDA) Forest Service as a Forestry Technician.
Rios will be working in education and applied research program in tree crops production and marketing in Riverside and San Diego Counties. Primary target crops are citrus, avocados and dates, but also include other subtropical and deciduous fruit and nut crops, such as pomegranates, figs, mangos and walnuts.
She will facilitate interactions and information exchange among campus based academic, Cooperative Extension advisors and community stakeholders. Focus is expected on increasing productivity and efficiency of commercial tree crops operations, thus maximizing the return on invested capital, and at the same time, providing consumers with a high quality, safe and reasonably-priced product. The advisor will address emerging production issues in subtropical fruit crops including: horticulture, entomology, plant pathology, integrated pest management, plant nutrition and variety testing. She will be working closely with the subtropical horticulture industries, local growers and members of the subtropical horticulture and nuts and fruits workgroup to identify research areas of highest priority. Her contact information is as follows:
Cooperative Extension Riverside County 21150 Box Springs Road, Suite 202 Moreno Valley, CA 92557-8718
Email Address: email@example.com