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Boom type shakers—used for the mechanical removal of fruit from trees—may cause less strain on the roots and consequently less damage than the cable type shakers according to observations made in an extensive analysis of the basic engineering principles involved in tree shaking.

Taking hardwood cuttings in the fall—while the buds were in the rest period—treating them with indolebutyric acid, followed by immediate planting or holding at 60°F-65°F for several weeks before planting gave good rooting of several difficult-to-root tree fruit rootstocks.

Tremendous increases in quantity and quality of forage production on many acres of California's rangeland could be achieved by establishing and growing selected varieties of grasses and legumes.

Control of annual weeds—79% in 1957 and 81% in 1956—was achieved in winter crops of spinach and mustard greens by a new method of incorporating calcium cyanamid into the soil.

Precision cultivation and hand hoeing—the methods now used for weed control in lettuce production—become difficult where weed growth is thick and rapid. The lettuce may be overgrown to the point where cultivation is difficult and the lettuce suffers heavily from weed competition.

Results of experiments with three ammonium fertilizers—aqua ammonia, ammonium sulfate, and ammonium nitrate—have shown that not only the rate of nitrification but also the elapsed time required before the maximum rate is attained depends on the ammonia level in the soil.

Because the deficiency of micronutrients in avocado trees is often a problem in southern California orchards a fertilizer experiment was started to evaluate treble superphosphate—among other phosphatic fertilizers—as a source for the micronutrient content of the leaves.

The fungus—Septoria azaleae—attacks only the leaves of azaleas and causes a disease that appears as irregular, angular, brown lesions.

To avoid the lemon tree diseases of Dry Bark and Lemon Tree Collapse—so prevalent in the old line Eureka strains—new strains have come into use in Santa Barbara County within the past 10 years.

Although not officially released—and won't be for several years—four new asparagus varieties now occupy between eight and ten thousand acres for further testing.