Calag Archive

A NEWLY RECOGNIZED leaf scorch disease has recently been found over a wide area in the state's almond-producing districts. First noted in 1958 on a few scattered trees in the Quartz Hill area of Los Angeles County, by (then) Farm Advisor J. A. Beutel, and soon after near Brentwood in Contra Costa County, the disorder has been referred to as "golden death" or "almond decline." Surveys made during the 1974 season have shown that the disease is sporadic but widespread in the central and northern portions of the Great Central Valley: from Merced County northward to Butte and Glenn counties, an important almond producing area.

Recent developments in plant physiology suggest possible new techniques for rapidly determining how well a crop is growing at various times in the season. Measurements of physiological activities of growing plants such as photosynthetic CO₂ uptake by leaves might be used to detect whether a crop was growing below its maximum potential rate, enabling the farmer to correct an agronomically controllable problem before crop losses were incurred. This report discusses the feasibility of such an approach and presents experimental data on the effects of deficiencies of phosphorus, potassium, magnesium, calcium, and manganese on various physiological attributes of sugar beets.

BEAUTY, TANTALIZING aroma, and delicious flavor are combined in ‘California,’ a new pear soon to be available to California growers. The new cultivar, the result of an extensive and continuous pear-breeding program in the Department of Pomology at U.C. Davis, is expected to be used primarily as a fresh fruit dessert. In form, flavor, soluble solids content, season, and storage life, the fruit resembles Cornice, but is distinguished by its more poignant aroma, freedom from russeting, and its color. The bright red on the side exposed to the sun harmonizes with the glistening yellows on the shaded areas, giving the fruit a strikingly attractive appearance. The originators feel that California will fill a need of the west coast pear industry for an excellent, productive, early- and annual-bearing fall and winter dessert Dear.

INTERNATIONAL MARKETING IS a complex subject, conditioned as it is by political and social factors as well as economic criteria. Present policymakers are attempting to balance international nonagricultural economic goals with domestic food needs, at the same time that cereal inventories are at low levels. This situation suggests the need for contingency planning, with a thorough evaluation of the risks in the management alternatives available in the U.S. and other countries. Each strategy has advantages and limitations in terms of administrative capability, flexibility, and cost.

A modified system of pruning President plum trees has reduced losses caused by a dieback disease, increased plum yields, and extended the life and productivity of the trees.

THE TWO-SPOTTED SPIDER MITE, Te-tranychus urticae Koch, is a persistent and destructive pest of pears in California. Bartlett pears are particularly susceptible to this mite, and severe defoliation can occur in relatively short periods of time. Contributing to the severity of mite infestations is the presence of weed hosts, such as morning glory (bindweed), around the base of tree trunks. These weeds can support large numbers of mites which will move up into the foliage when the weeds dry out or are treated with herbicides. Further complicating the mite control picture, is the necessity for chemical control of the codling moth, Laspeyresia pomonella (L.), which can result in the supression of naturally occurring or introduced mite predators.