- Author: Ben Faber
The California Irrigation Management Information System (CIMIS) is a program unit in the Water Use and Efficiency Branch, Division of Regional Assistance, California Department of Water Resources (DWR) that manages a network of over 145 automated weather stations in California. CIMIS was developed in 1982 by DWR and the University of California, Davis (UC Davis). It was designed to assist irrigators in managing their water resources more efficiently. Efficient use of water resources benefits Californians by saving water, energy, and money. https://cimis.water.ca.gov/
CIMIS reflects the energy that has arrived to drive water use by crops. It is the past. Now the National Weather Service has devised a way of forecasting water use, so that growers can be better prepared for irrigation. The question is how well does this new system work. Well, here are the results or a study that should lend confidence in the predictive value of the system.
COMPARISON BETWEEN FORECASTS OF REFERENCE EVAPOTRANSPIRATION and ETo VALUES CALCULATED USING DATA FROM DIFFERENT CLIMATIC CONDITIONS.
G. Ben Hamouda, F. Ventura, D. Zaccaria, R.L. Snyder, K.M. Bali.
Evapotranspiration is the transfer of water from the earth's surface to the atmosphere. It comprises the sum of water losses to atmosphere due to the processes of evaporation of moisture from soil, water bodies and wet plant canopies, and the transpiration of water from plants. Forecasts of this crucial component of the hydrologic cycle can be very valuable for growers, farm managers, irrigation practitioners, water resource planners and managers, and reservoir operators for their planning, allocation, delivery and scheduling decisions, as well as to hydrologic scientists for research purposes. Verifying the reliability of models' forecasts is among the critical tasks for development and performance evaluation of physical models. In fact, the verification allows understanding the models' behavior under different climatic conditions, and evaluating their applicability and dependability.
The US National Weather Service (NWS) has released a product that provides forecasts of reference evapotranspiration (FRET) at 2.5-km grid resolution for the entire continental US. In this study, a comparison is made between ETo estimates from FRET and ETo values calculated by the California Irrigation Management Information System (CIMIS) for 68 days during summer 2019. Both the FRET forecasts and ETo values were obtained from NWS and CIMIS, respectively, on the basis of 15 CIMIS locations that are representative of different climatic conditions in California. In addition, air temperature, dew point temperature, relative humidity, wind speed, and vapor pressure deficit (VPD) data were also collected/calculated from the NWS and CIMIS websites to analyze the sensitivity of FRET forecasts to predictions of these parameters. All FRET forecasts were performed with timescales of 1, 3, 5 and 7 days. Statistical indices were calculated to assess the dependability of FRET values. They showed a good correlation of the FRET model outputs with CIMIS ETo data, with some differences depending on the climatic characteristics of selected weather stations' locations, suggesting that FRET data could be valuable for anticipating near-future water demand and improve irrigation management in California.
Look for a more detailed description of this study in a forthcoming edition of the Journal of Irrigation and Drainage Engineering – ‘Evaluation of Forecast Reference Evapotranspiration (FRET) for Different Microclimates Regions in California to Enable Prospective Irrigation Scheduling' - https://ascelibrary.org/journal/jidedh
FRET is available at:
https://www.weather.gov/abr/etforecasts
And more:
https://www.weather.gov/cae/fretinfo.html
https://www.weather.gov/abr/etforecasts
https://ui.adsabs.harvard.edu/abs/2016AGUFM.H21D1430O/abstract
- Author: Ben Faber
Seminar/Webinar August 17, 2021
CA Avocado Society/CA Avocado Commission/UC Cooperative Extension
Manipulating the Avocado and its Environment for Optimum Temperature and Light
- Author: Ben Faber
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- Author: Ben Faber
Slugs and snails, destructors of crops and gardens,
could be
controlled by bread dough
CORVALLIS, Ore. – New research from Oregon State University Extension Service found slugs and snails are strongly attracted to bread dough, a discovery that could lead to better ways of controlling these serious pests of agriculture, nurseries and home gardens.
Since the beginning of recorded history, slugs have ravaged crops and today are responsible for billions of dollars in damage – including between $60-$100 million to Oregon's valuable grass seed industry alone, according to Rory Mc Donnell, associate professor and Extension gastropod specialist.
“Damage to grass seed is a major issue,” said Mc Donnell, who collaborated with scientists from other states on a study that was published in a special issue of Insects that focuses on slugs and snails. “But that's just one crop. It's mind boggling when you think about it. A huge array of crops is affected. They even take out specialty crops like mint. Many times, I've seen farmers lose an entire crop.”
Currently, nurseries, farmers and home gardeners use commercial baits like metaldehyde, iron phosphate or sodium ferric EDTA to control slugs and snails. These molluscicides are relatively expensive, can be toxic to non-targets and work with varying degrees of success, Mc Donnell said. Given its simplicity, low cost and the ready availability of its ingredients, bread dough has potential not only for crop protection in the United States but also for developing countries where access to pesticides is limited by cost. A dry formulation would likely have an indefinite shelf life and be easy to ship. It can be used to attract the slugs to a trap, where they will die, or to attract them to a molluscicides.
“Bread dough is a nontoxic, generic and effective tool that could be used in the detection and management of gastropods worldwide,” Mc Donnell said. “It represents a tool to aid in managing pest gastropod infestations, either using baited traps or in attract-and-kill approaches. It could also be incorporated into existing baits to improve their attractiveness.”
Of the 28 exotic or non-native slug and snail species in Oregon two are particularly troublesome – European brown garden snails (Cornu aspersum) and gray field slugs (Deroceras reticulatum), which plague nurseries and feed on hundreds of important crops with significant financial cost. If European brown garden snails are found in shipments of Oregon nursery plants at ports of entry in other states, the items are either shipped back or treated in place, Mc Donnell said. Either way it's expensive.
“With worldwide trade and travel, we are getting a homogenization of slugs and snails on planet Earth because of the widespread introduction of species,” Mc Donnell said. “This is not just a modern phenomenon. Slugs and snails have been traveling with humans for thousands of years. But it's getting more severe because of purposeful introductions, global trade, intensification of agriculture and development of new crops.”
Mc Donnell and his collaborators haven't determined yet why bread dough – a simple mixture of flour, water and yeast – attracts slugs and snails, but theorize that it is the fermentation process that draws them. They used a range of food in addition to bread dough to determine which would be the most attractive bait, including beer, cucumber, lettuce, strawberries, citrus, tomatoes, hostas and Marmite (a yeast-based food product popular in Great Britain).
“We gave them a choice of food and they consistently went for the bread dough,” Mc Donnell said. “They really, really like it. They went bonkers for it. Bread dough outperformed everything.”
In one instance, over 18,000 snails were trapped in 48 hours, according to Mc Donnell. The research revealed the bread dough can be effective in the field in Oregon for at least eight days.
“It has something we call ‘good field life,'” Mc Donnell said. “That's really, really important. If it worked for 12 hours, that would be good, but eight days gives a much bigger window for use.”
The project was a collaboration between Mc Donnell and his team; Robin Veasey and Jocelyn Millar, University of California at Riverside; Arnold Hara, University of Hawaii at Hilo; Amy Roda, U.S. Department of Agriculture, Miami; Gary Adams, U.S. Department of Agriculture, Billings, Mont.; and Ian Foley, Montana Department of Agriculture. This work was supported by funding from the U.S. Department of Agriculture under the Plant Protection Act Section 7721.
- Author: Ben Faber
PEST ALERT – Black Fig Fly
(Diptera: Lonchaeidae: Silba adipata)
Invasive Fig Pest Recently Discovered in Southern California
Overview: Fig growers need to be aware of the black fig fly (BFF), an invasive insect that was recently discovered infesting figs in multiple counties in southern California. The BFF has been reported in the following counties: Los Angeles, Orange, Riverside, Santa Barbara, San Bernardino, San Diego and Ventura. Movement of figs from these counties is strongly discouraged to prevent any artificial spread of BFF to other areas of the state. University of California Cooperative Extension personnel are currently working with the California Department of Food and Agriculture to further delineate populations, as well as develop improved monitoring and management strategies.
Life Cycle: The BFF only attacks figs and prefers unripe and unfertilized fruits. The adult female deposits eggs into the fruit through the ostiole (Figure 1)
and larvae subsequently feed internally on the fruit (Figure 2).
This feeding damages the fruit and causes it to prematurely drop from the tree. Upon completion of development, the BFF larvae make their way out of the fruit (Figure 3),
drop to the soil and pupate. In some cases, BFF pupae have been recovered inside of fruits as well (Figure 4).
Black fig flies overwinter as pupae in the soil. In the spring they emerge, mate and begin to attack figs. The BFF can have between 4 to 6 generations per year (more in warmer areas, fewer in cooler areas).
Monitoring: Fig fruits can be inspected for signs of BFF activity, such as larval feeding or exit holes. Focus on unripe fruits that have recently fallen from the tree. Populations of BFF adults can also be monitored using McPhail-type traps (Figure 5) baited with torula yeast lures, although the efficacy of this trap/lure combination is still under evaluation.
Management: Biological control appears to be limited and there are currently no chemical controls registered specifically for this pest on California figs. As such, orchard sanitation is critical, and growers should make sure to remove and destroy any BFF-infested fruits. Larvae in infested fruit are protected from pesticide sprays and there are no effective soil drenches for pupal control. Insecticidal baits (e.g. GF-120 NF Naturalyte®) may be useful for control of adult BFF but note that label rates have not been directly tested for efficacy against this pest. Consult with a licensed pest control adviser and your County Agricultural Commissioner before applying any chemical controls.
Do Not Move Figs: California figs are primarily grown in the Central Valley between Merced and Fresno, with many smaller orchards spread along the coast and in southern California. Movement of figs from the infested counties is strongly discouraged to prevent any artificial spread of BFF to other areas of California.
Reporting the Pest: If you find infested fruit or suspect that BFF may be attacking fruits in your orchard, please contact your local UCCE Farm Advisor and/or County Agricultural Commissioner.
Contact Information: If you have any additional questions, please contact Houston Wilson (Houston.wilson@ucr.edu).
Authors: Houston Wilson (Dept. Entomology, UC Riverside), Kadie Britt (Dept. Entomology, UC Riverside), Phoebe Gordon (UC Cooperative Extension), Ben Faber (UC Cooperative Extension), and Sonia Rios (UC Cooperative Extension).