- Author: Chris M. Webb
Today, Ventura County UCCE’s Maren Mochizuki explains the routine maintenance required to keep CIMIS weather stations functioning accurately.
Data from CIMIS stations, please see previous post for details, provide accurate weather data to aid growers in irrigation planning and scheduling. To ensure that each individual station measures and records accurately, monthly maintenance is performed at all stations.
For the CIMIS station at the Hansen Agricultural Center in Santa Paula, Staff Research Associate Maren Mochizuki checks the functioning of all the sensors. She also checks the calibration of the relative humidity sensor using a psychrometer. A psychrometer has one thermometer exposed to ambient air and another thermometer attached to a wick that is saturated with distilled water; a battery-powered fan forces air past the wick to evaporate the water and cool the temperature measured by the thermometer.
Using a conversion table, we can estimate the relative humidity based on the difference between the ambient temperature and the wetted temperature. Drier air means more evaporation and a larger temperature difference between the two thermometers. If the difference between the relative humidity calculated by the psychrometer reading and the station sensor is greater than 5%, the station sensor requires re-calibration. The station is an inviting perch for birds so we also hose it down monthly to keep it clean.
inside of CIMIS station
psychrometer
- Author: Chris M. Webb
Ventura County UCCE staff research associate, Maren Mochizuki explains how weather data is collected and shared.
The California State Irrigation Management Information System (CIMIS) is a program of the California State Department of Water Resources Office of Water Use Efficiency.
CIMIS consists of a network of more than 120 weather stations throughout California that measure parameters such as air and soil temperature, precipitation or rainfall, wind speed, relative humidity, amount of solar radiation, and much more. This data is recorded every minute at most stations; data from some stations are available from as far back as 1982!
Growers use this data to aid in irrigation planning and scheduling for their crops but data from any of the stations is available free to the public the day after the data has been recorded.
To find stations nearest to you and to view a sample report with data from the last seven days, please visit: http://wwwcimis.water.ca.gov/cimis/frontSampDailyReport.do
Photos of CIMIS station
- Author: Chris M. Webb
Ventura County UCCE Staff Research Associate Maren Mochizuki shares with us how monitoring spore traps in avocado orchards can lead to better understanding and management of disease.
An important component of integrated pest management is frequent monitoring to understand which, if any, pests are present and at what time of year. In collaboration with Akif Eskalen a researcher at UC Riverside, Ben Faber, Ventura County UCCE Farm Advisor and Maren Mochizuki, Ventura County UCCE Staff Research Associate are sampling in three avocado orchards in Ventura and Santa Barbara counties using traps that catch spores, reproductive structures for many disease-causing organisms in avocado such as Dothiorella and Phytophthora
The spore traps consist of glass microscope slides suspended at two heights in the avocado tree canopy. Every two weeks, we remove the slide and replace it with a fresh one; researchers at UC Riverside examine and identify the spores under a microscope. We hope to improve our understanding of the life cycles of these spore-producing organisms for more effective disease management.
Young avocado tree killed by Dothiorella canker,
White, powdery exudates from a Dothiorella canker
Healthy green avocado foliage (right) next to the pale, yellow foliage of a tree with Phytophthora root rot
- Author: Chris M. Webb
An interesting study looking at the water requirements of common landscape plants, as told by Ventura County UCCE Staff Research Associate Maren Mochizuki.
Plants used commonly in the California landscape may have different water requirements for growth and aesthetics depending on the location in which they are grown. One indicator of the amount of water a plant needs is the local evapotranspiration (ET), which is the loss of water to the atmosphere from the surface of plants and soil (evaporation) and from plant tissues via their pores or stomata (transpiration). More information on evapotranspiration can be found at the California Irrigation Management Information System (CIMIS) website at, http://wwwcimis.water.ca.gov/cimis/infoEtoOverview.jsp.
Evapotranspiration varies considerably with the weather and location. In studies conducted by UCCE researchers across the state, (north coast, north inland, south coast, and south desert climates) nine common landscape species including agapanthus, day lily, and star jasmine are being watered based on 80%, 60%, 40% and 20% of daily local ET measurements. In the south coast region watering has ranged from weekly during the summer for the 80% ET to never for the 20% treatment.
Here in the south coast, the project is being conducted by Jim Downer, Ventura County UCCE Farm Advisor; Don Hodel, Los Angeles County Environmental Horticulture Advisor; and Maren Mochizuki, Staff Research Associate. When starting the project they allowed the plants to establish first, watering all of them equally and now have measured clippings and rated their appearance for the past two years. They are currently analyzing the data gathered so far and will continue the study one more year. Check back soon for some preliminary results!
agapanthus
day lily
star jasmine
- Author: Chris M. Webb
Ventura County UCCE Staff Research Associate Maren Mochizuki shares current research which hopes to provide an organic method to kill plant pathogens and weed seeds in production agriculture.
Synthetic chemicals to fumigate soil have been used in some production agricultural systems, to kill plant pathogens and weed seed before planting crops. Here in Ventura County, this is a common practice for strawberry production. Joji Muramoto, Associate Researcher at UC Santa Cruz and Oleg Daugovish, Ventura County UCCE Farm Advisor and Maren Mochizuki, Ventura County UCCE Staff Research Associate are investigating an organic method to treat soil before planting by creating anaerobic, or oxygen-free, conditions. Most organisms, including plant pathogens, cannot survive without oxygen.
We incorporated rice bran from the Central Valley into the soil as a carbon source to trigger microbial activity. To test the applicability within a strawberry production system, we created planting beds topped with plastic mulch. The beds needed to be well-sealed to ensure no air leaks that could add oxygen. Using drip irrigation, we added sufficient water to the beds to fill all soil pores, further pushing out any air/oxygen. Each day we monitor the soil environment with sensors measuring soil water content, temperature, and the level of anaerobic conditions and add more water as needed. At the end of three weeks, we will evaluate the survival of a significant plant pathogen, Verticillium dahliae.
ASD Sensors
ASD beds