Since the first publication of this article on vole damage in citrus, a recent field observation regarding vole activity is worth noting. Voles prefer a situation where there is cover and shelter generally from weed or grass. In some orchards established in the last few years a plastic strip has been installed along the tree row for weed management (Fig 1). These strips appear to be offering a sheltered environment for vole activity in some cases (Fig 2). Recent observations in two such installations, one a block planted in 2013 and the other an eight year old planting exhibited significant vole activity. The young orchard at this point does not exhibit obvious tree damage although active tunneling is apparent (Fig 3). In the older orchard feeding damage to the trunks is very obvious (Fig 4).
Meadow Mice (Voles) can cause serious damage in a citrus orchard resulting in partial or complete girdling of a tree (Fig 5). Trees often exhibit damage to the bark of the tree from the soil line up 6-8 inches (Fig. 6 ). On close inspection, an open hole 1-1.5 inches in diameter may be found at the base of the tree (Fig 7).
Five species belonging to the genus Microtus are found in California, two of which “Microtus californicus” and “M.montanus” are reported to cause damage. Damage has been reported in permanent pasture, alfalfa, hay, artichokes, Brussels sprouts, carrots, cauliflower, potatoes, sugar beets, tomatoes, grains, nursery stock and the bark of apple, avocado, citrus, cherry and olive trees.
Microtus are often found where there is grass cover. They generally do not invade cultivated crops until the crop is tall enough to provide food and shelter. Meadow mice are active all year round. They forage at any time during the day or night but are chiefly nocturnal. They are usually found in colonies marked by numerous 2-- inch wide surface runways though matted grass. Small brownish fecal pellets and short pieces of grass stems along the runways are evidence of activity. The burrows consist of extensive underground tunnels, nest chambers and storage chambers. Home range is typically small, less than a 60 foot radius in the case of “M.californicus”. All meadow mice swim well. Therefore, irrigation ditches will not serve as effective barriers against meadow mice movement into fields. Meadow mice may forage beyond the sheltered runways. Food consists of tubers, roots, seeds, grain, and succulent stems and leaves.
Females breed at 4 to 6 weeks of age with litter size of “M.californicus” averaging around 4. Under natural conditions a female Microtus may produce from 5 to 10 litters a year. The major breeding season corresponds with the season of forage growth. Microtus populations build up to a peak every 3 to 4 years, followed by a rapid decline during the next breeding season. The exact causes of the cycle of buildup and decline are not known, though disease, food shortages, physiological stress from overcrowding, and other factors may be involved. It is assumed that in cultivated areas Microtus populations are permanently based in favorable habitat such as roadsides, canal banks or adjacent noncultivated land. Invasion of cultivated cropland occurs when the population builds up or when the wild habitat becomes unfavorable. Coyotes, badgers, weasels, snakes, hawks, owls, herons and gulls are among the principal predators. It is believed that predators are not able to prevent or control a population eruption because of the birth rate of the fast breeding Microtus population. Meadow mice are classified as nongame mammals by the California Fish and Game Code. Nongame mammals, which are found to be injuring growing crops may be taken at any time or in any manner by the owner/management. The most effective management options in an orchard situation are a reduction in ground cover and the use of toxic baits. Meadow mice are cover dependent. In situations where cover removal is not possible or is insufficient to solve the problem, the next best option is the use of toxic baits. Many bait carriers are used (e.g., oat groats, wheat bait). Baits: Crimped oat groats are the most satisfactory bait although crimped whole oats are used (e.g., oat groats, wheat grains, pelletized formulations, etc., but crimped oat groats have typically been most effective). The primary toxicants used for meadow mouse control include zinc phosphide, diphacinone, and chlorophacinone. Directions for management including baiting can be obtained by contacting the Agricultural Commissioner's Office. * Portions taken from J.P.Clark Vertebrate Pest Control
Two CASI farmer members, Darrell Cordova of Denair and Jesse Sanchez of Firebaugh, along with minimum till equipment entrepreneurs Alan Wilcox and Juan Trujillo of Walnut Grove, were recently called upon to provide some local San Joaquin Valley hospitality to international visitor groups from Mexico and Afghanistan.
The visit with Darrell was specifically held to showcase ways in which individual farmers like Darrell work with groups like NRCS and CASI to achieve both economically viable production with tangible conservation benefits. Darrel's work to improve his production system efficiencies has involved other CASI partners including CSU Fresno weed ecologist, Anil Shrestha and Valley Irrigation's Terry Ioerger, and evolved into a continuous no-till winter forage mix followed by corn, - both irrigated by a center pivot irrigation system now for about four years.
Following the farm visit with Cordova, the group made their way to the Walnut Grove manufacturing facility of Wilcox Agriproducts where they met with Alan Wilcox and Juan Trujillo, two founding CASI members and minimum tillage equipment designers and providers. In the meeting with Wilcox and Trujillo, the Mexican delegation learned about the success Wilcox Agriproducts has had in developing reduced pass tillage implements that save fuel and cut costs in a wide range of highly efficient crop production context, both here in California and also in Arizona. They also learned about the private-public partnership that Wilcox Agriproducts has had with CASI and how the two efforts have worked together over the years to develop and disseminate information on conservation agriculture systems here in California.
The post-tour evaluation summaries we have received from each of these tour groups reveals that they very much appreciated and greatly benefited from the very kind, generous and helpful information that they received from each of these CASI hosts. Their willingness to give of their time and to step up in such gracious ways accomplished very tangible measures of SJV hospitality and broader reach that CASI is now beginning to have.
Mitchell, the chair of the UC Conservation Agriculture Systems Innovation Center, made the comment at the 6th World Congress on Conservation Agriculture in Winnipeg, Manitoba, last month.
After attending the congress, Mitchell said he is more strongly convinced that greater efficiencies and brighter economics in California agriculture could be achieved by employing conservation principles.
“Focusing on soil care will improve soil water intake and storage,” he said. “Reducing soil water evaporation can be achieved by preserving surface residues. Together these steps reduce energy use and greenhouse gas emissions – very important goals.”
The Manitoba congress drew more than 350 participants representing 47 countries. It was co-sponsored by the Conservation Agriculture Systems Alliance, the Conservation Technology Information Center, and the Canadian Soil and Water Conservation Society. California's CASI was represented by Mitchell and Monte Bottens, president of California Ag Solutions of Madera, a consulting and custom fertilizer support company.
Speakers at the conference suggested conservation agriculture principles are “transformative and not merely incremental means for achieving the kinds of change must be made to meet the global challenges of food production and natural resource conservation in the 21st Century,” Mitchell said. Modestly tweaking today's conventional agricultural systems, he said, “is not an option.”
Today conservation agriculture is used on about 11 percent of the world's total arable land. Implementation is increasing at an annual rate of about 7 to 8 million hectares, according to the U.N.'s Food and Agricultural Organization. Nearly half of the world's conservation agriculture acreage is found in the developing world. The South American countries of Brazil, Argentina and Paraguay, where the movement had its beginnings as a farmer-led process dating back to the mid-1970s, has about 80 percent implementation.
During his keynote address at the conference, David Montgomery, University of Washington professor of geology and author of Dirt: The Erosion of Civilizations, issued a “call to action.”
“Global soil degradation,” he said, “is an under-appreciated environmental crisis that occurs because of how we farm. We need to be more creative in terms of how we're intensifying agriculture to feed the post-oil world without cheap, fertilizer-intensive agriculture.”
Congress speaker Dwayne Beck, agronomy professor at South Dakota State University, also sounded an alarm.
“Never in history has mankind knowingly faced this type of impending catastrophe,” Beck said. “It is time to stop doing incremental things and start doing transformative things. You do not cross a chasm in two steps. We need to focus on where we want to be and emphasize systems, not details; actions, not reactions; and commitment, not merely involvement.”
CASI members are working with foundations and granting agencies to better position the organization to support implementation of conservation agriculture in California. For more information, contact Mitchell at (559) 303-9689.
About 50 ranchers gathered this week in Willows to learn how they can convert straw left over from the rice harvest into a palatable and nutritious feed for cattle, reported Tim Hearden in Capital Press.
By baling rice straw before it dries and tarping it to keep the straw moist until it is fed to cattle, the feed, called "strawlage," is comparable to low-quality alfalfa, UC Cooperative Extension scientists say.
“We haven't figured everything out, but with the drought conditions as serious as they are, we feel the time is right to share our research with growers,” said Glenn Nader, the UCCE advisor who organized the field day.
Because of the drought, "There's going to be a significant problem with feed coming into this winter and rice strawlage may be an answer," said Peter Robinson, a UCCE specialist in the Department of Animal Science at Davis.
The feed can turn black and become a little slimy, but the cows don't seem to mind.
“The cattle do eat this really well,” rancher Herb Holzaphel said during the workshop. “It didn't feed as good as silage, but it fed better than normal straw.”
For more information, see the UC Rice Project website.
Cows attacking rice strawlage as tractor drops into feeder.
Product Development Representative
LOCATION: California – Fresno, North
The Product Development Representative will be responsible for managing field research in an assigned territory (California – Fresno North). The major crops of interest are tree nuts, grapes, rice, stone fruit, cotton, corn and miscellaneous vegetables. Major emphasis will be place on two categories: (1) development of new proprietary active ingredients; and (2) work supporting activities of Nichino Marketing and Sales personnel. The successful candidate will have an advanced degree in an agricultural science and field experience in plot design and data analysis. In addition, the Product Development Representative must be an effective communicator (written and verbal), well-organized and able to manage time effectively in a large, crop-diverse geography.
- Management of field and laboratory trial work conducted in the assigned geography.
- Development of local programs to support sales of existing products as prioritized by Nichino Product Management.
- As needed, provide Nichino Product Management with technical recommendations for use of existing branded products (labels, brochures, technical bulletins) and for labeled uses of new active ingredients.
- On a monthly basis provide a written summary of activities and key results in the assigned area.
- Serve as Nichino America's technical expert within the university research and extension community as well as with agricultural consultants and local commodity groups.
Advanced degree (M.S. OR Ph.D.) in an agricultural science.
Nichino members enjoy an excellent health benefits package, competitive pay, paid vacation and leave.
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