Calag Archive

A new, resistant variety of alfalfa was quickly developed once the blue alfalfa aphid was recognized as a pest

Working with 63 mosquito control agencies throughout the state, University of California researchers have completed three major mosquito control projects:

Russet crack disease of sweet potatoes (Ipomoea batatas) was first reported in New Jersey in 1961 and it was suggested a virus might be the cause. Soon after, the disease was in California; probably it had been imported with propagative roots from the east coast. The present paper reports studies done at the University of California at Davis and in Merced County, California, to clarify the cause of russet crack and its method of transmission.

Wheat and barley are important crops to the Tulelake Basin and other intermountain valleys of northern California. Both bread wheats and durum wheats are grown. Barley is used for malting and as a feed grain. The yields of barley and wheat vary widely from field to field and from year to year, ranging from 2000 to 7000 pounds per acre. These fluctuations are attributed to climatic and soil factors, and to the cultural practices followed.

After more than a decade of devastating orchard losses to pear decline, the disease is now under effective control.

Grain yields of corn in the United States differ considerably between one area and another even when soil fertility and moisture supply are considered near-optimal. Reason for such variation are difficult to evaluate because direct comparisons are confused by difference in sunlight amount, temprature, photoperiod, and variety.

Firered, Redcal, Kearney, and Calred are four new freestone shipping peaches introduced by the University of California in 1977. All are highly colored clones, ripening in the above named sequence from about August 1 to August 25, as shown in the table. Their pedigrees are given in figure 1.

As pollution control becomes more and more important, many industrial plants must collect particulate matter from their stacks which would otherwise be distributed over the nearby landscape. Some of these materials, with or without further treatment, are being sold or potentially could be sold as micronutrient fertilizers, especially zinc fertilizer. The efficacy of these materials in comparison to zinc sulfate (ZnSO₄), which is the most common zinc (Zn) fertilizer at the present time, was investigated.

The growth regulator ethephon (Ethrel) has been shown to improve coloring of the table grape varieties, Red Malaga, Queen, Tokay, and Emperor if applied after some of the berries have begun to show color. Preliminary trials with Cardinals showed slight color benefits, of dubious commercial significance. Trials with Ribier have never shown benefit. More detailed trials were established at the Kearney Horticultural Field Station near Parlier in Fresno County during the 1976 season.

Grain sorghum has been grown as the second crop in double crop systems in California agriculture for years. Its use has been marginally profitable, especially in occasional years with early, wet falls. Growers interested in greater profits began investigating the possibility of substituting early maturing corn varieties for grain production in place of sorghum. When grown as a full season crop, corn usually shows a yield advantage over grain sorghum. These comparisons by growers indicated that corn did have a potential yield advantage over sorghum as a double crop and also showed the ability to overwinter when early autumn rains made fall harvests impossible.