Farm Enterprise Profitability:
Clearly, farm enterprise profitability is the issue of centermost importance. Even though growers are asking production questions about herbicides, varieties, and fertilizers, the underling concern is the economics of production practices. With many of the agronomic crops, the margin of profitability is low and many times non-existent. These crops are important as rotational crops for other more profitable crops, but, for the farm business to survive; all crops must be able to show a profit. American agriculture is competing on a world market against cheap land, labor, water and government subsidies. What we have in our favor is our technology, information and the ability to adapt.
Alfalfa Production:
Alfalfa Remote Sensing (Precision Agriculture): New technology is becoming affordable and readily available to growers and consultants. These new tools can aid in the diagnosis of field problems and more precise, economical management of farm fields. The project objective is to evaluate satellite images to estimate alfalfa yield, and diagnose field production problems.
Weed Mapping (Precision Agriculture): Utilizing GPS and GIS to map location, weed type and density is just a new twist on the field weed ID cards that Fresno County Farm Advisor Bill Fisher used 30 years ago. The idea is still valid, but the technology is making it easier, more efficient and much more accurate. Once weed infestations are mapped, weed control practitioners can use the information for site specific control practices, evaluate past practices and monitor the development or retreat of a weed infestation.
Alfalfa weevil management/control: Alfalfa weevils continue to be an annual problem that alfalfa growers must treat. The old UC economic threshold levels are not being used by PCA's and are believed to be incorrect. New insecticides are being developed and need field efficacy data for California registration. This state wide threshold study is being conducted to re-evaluate treatment threshold levels for weevil populations in alfalfa.
Alfalfa nutritional studies: Molybdenum, phosphorus, sulfur and potassium are all essential for good alfalfa growth and quality. They are commonly deficient elements in alfalfa grown in the Sacramento Valley. Soil tests are not useful in determining sulfur and molybdenum levels and are only good at predicting growth responses from applied P and K when test levels are very low. Plant tissue tests have been very reliable for Mo and S, but have not been as reliable in predicting P and K responses. The major problem with the P and K tissue analysis is the nutrient dilution that occurs as alfalfa grows and gains dry matter. The old standard critical level for tissue testing was to take the sample when the alfalfa reaches the maturity stage of 1/10th bloom. However, with the market incentive for higher quality, growers rarely let their hay mature beyond the bud stage. The literature suggests that the tissue values be increased by 10% if taken before the 1/10th bloom stage. No data could be found to substantiate this adjustment. Due to the unpredictable results obtained from tissue testing at early stages of maturity, the critical levels for testing alfalfa at early stages of development need to be established. As we suspected, the rate of dilution was between 3 to 10 times more (depending of the actual stage of maturity) than the 10% level suggested in the literature.
Malva control in established alfalfa: Common Mallow or malva (Malva neglectra Wallr.) is a winter annual or biennial weed that is troublesome to the production of alfalfa. It is not controlled by the common weed control practices and will lower quality and price of alfalfa hay infested with this weed. The objectives of this project are: a) Develop a cost effective control strategy for controlling common mallow in established alfalfa. b) Evaluate the several registered herbicides with some effect on malva for possible malva control when applied in tank mix combinations. Two herbicide screening trials were conducted in 2003-04 that tested timing, rates, and tank mixes of the various herbicides that have at least shown some effect on malva. Treatment timing, sequential treatments and herbicides are part of a control strategy that was derived from this study.
Small Grain Production:
Wheat variety evaluation: Evaluating new wheat varieties that are resistant to the new strains of stripe rust and other wheat diseases are of critical importance to California wheat growers. New stripe rust strains have been developing within a couple years that render standard varieties ineffective in warding off the disease symptoms. UC has a wheat germplasm and variety development program that looks at yield, quality and pest resistance. Private companies also have new lines with various levels of resistance. These new lines need to be field tested through out the wheat growing areas of California. The wheat variety evaluation program is an ongoing program that has demonstrated it's importance again this last year with an outbreak of a new strain of stripe rust that devastated the 2003 crop. Growers and processors utilized our variety trial information from the various parts of the state and changed wheat varieties on a grand scale based on our results. They are continuing to look to this program for up to date information on the changing resistance by variety situation.
Wheat Stripe Rust Fungicide Study: Wheat Stripe Rust continues to be an economic problem for wheat growers as new strains of stripe rust develop and wheat varieties that were once resistant are no longer resistant to this disease. The objectives of this project are: a) Evaluate registered and soon to be registered fungicides to control Stripe Rust of wheat in the northern Sacramento Valley. b) Quantify through yield and quality measurements, the possible benefit of fungicide application on several varieties of wheat that are known to differ in Stripe Rust resistance. c) Evaluate economic return on investment for different fungicide applications on the different wheat varieties. Our trials have shown that varieties of differing levels of resistance, weather conditions and new strains affect the economic outcome of a fungicide treatment program. We have developed economic threshold data to aid growers in making treatment decisions.