Calag Archive

Our major food plants may be divided into two types-those which need nitrogen fertilizer (cereal grains, such as corn, wheat, and rice) and those which do not (alfalfa, soybeans, and other legumes). The latter group produces protain by manufacturing its own nitrogen in a process that uses energy from the sun-hence, the term “solar protain.”

Durum wheat, an important crop in northern California's Tulelake Basin since 1953, is planted in the spring in fertile, irrigated soil. The varieties used (developed by the U.S. Department of Agriculture and North Dakota State University) usually produce an average of 3,600 pounds per acre with good semolina quality. However, these varieties are susceptible to lodging, because they grow too tall in irrigated, highly fertile soil.

Environmental concerns have caused considerable change in methods of handling and usingdairy manure in California. This is chiefly because salts in manure, including those which are plant nutrients, may find their way into surface and ground waters. Research and experience, however, have shown that, with proper management, dairy manure can provide nutrients to grow crops with little if any significant impact on the environment. The key phrase is “proper management,” which includes appropriate handling, storage, and application.

Black scale, Saissetia oleae (Oliver), has, until recently, been a minor pest of olive in California, and the specific chemical controls established for black scale have seldom been used. Chemical control of another scale, Parlatoria, a more serious pest of olive, resulted in some inadvertent control of black scale.

Verticillium wilt, caused by Verticillium albo-atrum, is a major pathogen of cotton and several other California crops. The pathogen is a soilborne fungus, attacking its host through the root system. It survives long host-free periods in naturally infested soil as micro-sclerotia, which are formed in infested host tissue. Incorporation of this host tissue into the soil and its subsequent decomposition are responsible for the inoculum levels of this fungus in the soil.

Fertilizer uptake by irrigated plants is influenced considerably by fertilizer placement and timing and by water application methods. Because some fertilizer elements move with water in the soil, these plant nutrients must remain or arrive within the sphere of the plant roots after fertilizer and water are applied. The goal is to develop cultural practices by which crop nutrient needs are satisfied by maximum uptake from a minimum quantity of applied fertilizer.