Calag Archive

The woolly whitefly, Aleurothrixus floccosus Mask., first discovered in residential San Diego during November 1966 surveys for the citrus whitefly, has been of deep concern to the citrus industry , the University of California, and various agricultural agencies. In 1968, a study by Harold Lewis for the California-Arizona Citrus League estimated potential losses to California citrus of $10 per acre for either whitefly or a 17 percent average increase in total pest control costs statewide.

The permanency of the water delivery systems such as drip irrigation systems and of some crops makes it desirable, if not essential, to have the capability of applying fertilizer through the irrigation system. Such a method of fertilizer application saves labor and energy and allows crop demand to determine the timing of nutrient application.

Walnut blight, caused by the bacterial organism Xanthomonas juglandis, is a disease of worldwide importance on walnuts. In northern California, blight may occur on a number of commercial varieties of English walnuts, although late-blooming varieties generally escape infection by leafing out after most of the spring rains are over.

Ruby Seedless is a red seedless variety used as a table grape and for the freezer. The clusters are well filled to compact. In some vineyards, looser clusters would be desirable to reduce bunch rot and to facilitate packing. Gibberellin sprays reduce set in Thompson Seedless and several wine varieties, so trials were established with Ruby Seedless to determine the possible benefits.

The five-year summary of results of a trellising tria1 with ‘Thompson Seedless’ vines grown in the San Joaquin Valley showed that a wide, four- wire double crossarm trellis increased vine growth by 38 percent, crop yields by 20 percent, and soluble solids by nearly 3 percent, when compared with a one-wire trellis. When a two- wire single cross-arm trellis was compared with a one- wire trellis the gain in vine growth was 14 percent, yield was enchanced by 13 percent, and soluble solids were the same.

Summary not abailable – first paragraph follows: Pear and apple scab fungi Veenturia pirina Ader. and Venturia inaequal-is (Cke.) Wint. caused major losses to growers in the pear and apple regions of the north coast counties of California in the 1974 and 1975 seasons. These diseases have become more important in recent years, especially on pears in Mendocino and Lake counties and on apples in the Sebastopol, Sonoma County region.

Demand for oat hay has been stimulated by an increasing number of pleasure horses in California. Production now involves more than 250,000 acres annually in the state, on irrigated as well as dry- farmed lands.