Calag Archive

Elimination of weight losses during cooling of nectarines lengthened the holding period of the fruit by 50% before shrivel appeared in these tests. Air velocity and relative humidity are the critical factors, but changing requirements from the cooling to storage phases make it inadvisable to use one room for both purposes at the same time.

Application of additional irrigation water increased hay yields, but water in excess of about 2 feet did not appear to be particularly beneficial, according to recent tests at Davis. Adding the depth of initial soil moisture storage, and assuming an irrigation efficiency of 70%, the total annual water requirement of alfalfa under these conditions is about 4 1/2 acre-feet. When water supplies are deficient, a good crop can be maintained with less than 8 inches of water applied, if the soil moisture reservoir is full in the spring. If about 2 feet of water is available for the hay crop, there appears to be little difference between applying water early or in equal amounts throughout the season.

Continued addition of sphagnum peat to a clay soil in greenhouse benches over a number of years has resulted in a decrease in wettability, according to observations recently confirmed by laboratory evaluation. Water did not penetrate easily, and many of the soil particles remained dry following irrigation. There is no practical method known at this time for preventing the development of non-wettability in these soils, but certain management practices reported here may be helpful in coping with this problem.

Combination spraying of peach trees with organophosphorus insecticides plus oil, and application in May rather than in the dormant season, are two important factors in obtaining more effective control of San Jose scale, according to recent tests in Fresno County.

Progress in the development of equipment for producing pitted dried prunes for the grocery retail trade has included the design of conveyor rollers to orient the fruit lengthwise and the use of a six-bladed pitting knife capable of removing pits efficiently with little or no loss of fruit flesh. The pitted fruit dried in two-thirds less time and had a superior, fresh flavor and good storage qualities.

Results of this three-year testing program in the San Joaquin Valley indicate that Verticillium wilt damage to cotton may vary from one area to another—but when wilt symptoms appear by mid-season, the wilt-tolerant Acala 4-42 variety will significantly outyield the two susceptible varieties, Cal 7 and Deltapine Smooth Leaf. When cotton is grown continuously on the same plots, more drastic declines in yield occur with with-susceptible varieties than for Acala 4–42.

Tarweed is well adapted for survival as a nuisance plant on California ranges. While expensive control measures may not be justified, effective methods are needed for minimizing the use of soil moisture by tarweed seedlings in the spring. Clipping or heavy grazing and nitrogen fertilization offer possibilities for reduction in density of tarweed seedlings in favor of the more desirable forage species.

Manganese and zinc deficiency symptoms on grapefruit leaves can be corrected by foliar spraying with these nutrients, but spring applications in desert areas will not prevent symptoms from reappearing on the new flush of leaves in the fall. Both spring and fall applications are recommended in desert areas, after the new flush of leaves has expanded to at least two-thirds normal size.