Whenever CAFA receives a request for information we do our best to provide an answer or find a source knowledgeable on the subject. The two topics that have recently prompted phone calls are the horse market and gopher control.
Both topics were on the agenda in December at the combined, National and California Alfalfa Symposium in San Diego. Dr. Anne Rodiek of Cal State Fresno addressed the dynamics of the horse market, while UC Cooperative Extension Specialist, Terrell Salmon of San Diego discussed rodent control in alfalfa.
Based on recent calls to CAFA, there appears to be more interest in the horse market. It's a large market, but getting a handle on the exact size is challenging. As Rodiek pointed out, there's no government agency that tracks the number of horses in California and estimates range from 270,000 to a high of one million. Her statistical analysis puts California's horse population at around 625,000. “An estimated 625,000 horses in California could eat as much as 2.5 million tons of hay per year,” she stated.
Rodiek doesn't shy away from discussing health problems blamed on alfalfa and discusses other types of hay. She noted that, “research has not addressed most of the claims against alfalfa hay for horses. The relative merits or shortcomings of alfalfa hay differ depending on the nutrient requirements and management of horses. However, as research findings from several studies accumulate, some of the allegations against alfalfa hay have been refuted.”
Rodiek also discusses grass hay versus alfalfa and ends with a discussion on “Selling to Horse People.” Her presentation and all other Alfalfa Symposium presentations are available on the Web at, http://ucanr.org/alf_symp/. The 387-page, 2004 Symposium Proceedings book can be ordered from UC Davis. The cost is $12 and checks should be made payable to UC Regents. Send your request and check to: Jee Liu, Department of Plant Sciences, Mail Stop 1, University of California One Shields Ave., Davis, CA 95616-8780.
Another topic in the Symposium Proceedings that's of interest to CAFA's members is gopher control. It was part of a presentation by UC's Terrell Salmon, who also discussed meadow voles and ground squirrels.
According to Salmon, fumigation isn't usually considered to be effective for controlling pocket gophers. But, he maintained that aluminum phosphide (a Restricted Use Material) works well if properly used. However, smoke or gas cartridges usually aren't a good option. Gophers normally seal off their burrows when they detect smoke or gas, he explained.
Salmon's complete text in the Symposium Proceedings discusses the full complement of control strategies, including cultural practices and predators. “There is considerable interest in providing artificial nest boxes to encourage barn owls to live near alfalfa fields,” he reported. Owls bring prey back to the nest, but evidence of gopher feeding can be misleading because “there's no information on where these gophers were taken. We do know that owls forage some distance from their nests, often in open grasslands and other non-agricultural areas,” he pointed out.
Salmon noted that, “successful control programs depend on early detection and prompt measures to prevent damage.” It's a statement that echoes what several growers have recently told us when discussing gopher problems.