UC Nursery and Floriculture Alliance
University of California
UC Nursery and Floriculture Alliance

Spring 2010

Campus news

Compiled by Deborah Mathews

New genomics building opens on UC Riverside campus
In September 2009, faculty members began to move into the new Genomics building on the UC Riverside campus.  The 64,000 square foot building will house research laboratories of faculty from nine different departments that will address basic and applied research in the areas of plants, insects and fungi.  The facility will also be the home for the Institute for Integrative Genome Biology and contains a 100-seat state-of-the-art multimedia auditorium.

Grant obtained for water management education programs
Donald Merhaut  (UC Riverside) and Julie Newman, Ben Faber and Oleg Daugovish, (UC Cooperative Extension, Ventura County) received a $723,000 grant from the State Water Resources Control Board to host outreach programs to growers of nursery and floriculture crops, row crops and tree fruit crops over a three-year period.  These programs, both on-site and in the classroom, will help growers develop management practices to mitigate nutrient and pesticide runoff from production facilities while maintaining a profitable agricultural economy in the Ventura Country region and statewide. Donald Merhaut recently hired postdoctoral fellow Lea Corkidi, to assist with these programs.

IPM websites available
Cheryl Wilen, UC Cooperative Extension Area Integrated Pest Management Advisor for Los Angeles, Orange, and San Diego counties, has a website available dealing with general IPM issues where she posts information about research related to IPM in nursery and landscapes, as well as information from meetings that she has attended, along with a link to a table containing recommendations for herbicides to control weeds (http://cesandiego.ucdavis.edu/files/67580.doc).  Dr. Wilen created this table from her own experience and that of colleagues and is interested in your experiences with these and other weed control chemicals. She also maintains a blog with a variety of information from her Southern California IPM program (http://ucanr.org/blogs/South/). She can be contacted directly at: cawilen@ucdavis.edu.

Deborah Mathews is UC Cooperative Extension Specialist in Plant Pathology, Department of Plant Pathology and Microbiology, UC Riverside

Research Updates

Use of capillary mats as a low-cost greenhouse runoff retention system

by Richard Evans, Julie Newman, and Emma Torbert

Even under the best management practices, greenhouse and nursery growers must contend with runoff. In a project funded by the Hansen Trust, we tested the utility of capillary mats as an inexpensive system for capturing leachate to reduce runoff. These mats are normally used for irrigation, but we wanted to use them to catch runoff before it left the production area. In effect, we employed the mats as sponges. For the mats to be effective, they must absorb excess irrigation water, then dry out between irrigations so they can accept more water. We wanted to find out three things: Could mats hold enough runoff to be useful? Would crop quality be affected? Would salinity buildup be a problem if poor quality irrigation water were used?

We grew chrysanthemums and geraniums in 6-inch pots in a greenhouse, with capillary mats beneath the pots on half of the benches, and drip-irrigated using a nutrient solution made with either deionized water or moderately salty water (EC = 1 deciSiemens per meter [dS/m] ). The daily rate of evaporation from the mats between irrigations was about 60 gallons per 1000 square feet, and under typical growing conditions the mats held all of the runoff. They could accommodate a leaching fraction of 0.5, which is sufficient for salinity control even when water quality is poor. This use of capillary mats did not affect soil salinity or plant size and quality.

Basic capillary matting is available for about 20 cents per square foot, which makes this a relatively inexpensive measure for reducing runoff. Our experiments were conducted in greenhouses, but the mats should work for outdoor nursery crops as long as there is no direct capillary connection between the mat and the soil below. The lifespan of mats used in this way has not been studied, but we assume that it would be at least as long as the lifespan of capillary mats used for subirrigation of pots.

Richard Evans is UC Cooperative Extension Specialist for Environmental Horticulture at UC Davis, Julie Newman is UC Cooperative Extension Farm Advisor for Floriculture and Nursery Crops in Ventura County, and Emma Torbert is Post-Graduate Fellow at the Agricultural Sustainability Institute, UC Davis.

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