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The root-lesion—or meadow—nematode has been found widely scattered in California by United States Department of Agriculture and Experiment Station workers. In 1941 it was found associated with die-back of bearing sweet cherry trees in Riverside County. About the same time it was found on walnut trees showing poor vigor in Ventury County. Since then it has been identified on walnuts in several southern California counties and also in the San Joaquin, Sacramento, and Santa Clara valleys and Sierra Nevada foothills. Fig and olive roots have been reported frequently infested with this nematode. Apple, almond, peach, pear, plum, and quince roots have been reported infested.

Spraying and dusting of agricultural crops with insecticides, fungicides, herbicides, hormones or fertilizers can be made more effective through accurate information as to the distribution pattern obtainable under various sets of conditions.

This is the fifth article in a series of brief progress reports on the application of the science of genetics to commercial agriculture.

Removal of old and overmature forest trees—and thinning to relieve competition in the young stands—can substantially increase the rate of timber growth.

Clingstone peaches can be dehydrated successfully—producing a dried fruit that has attractive appearance and pleasing flavor.

Further tests with 2,4-D sprays are necessary before any recommendations for their commercial use to increase fruit size are justified.

A new test for available phosphate in soils requires only standard laboratory equipment. It is rapid, economical and gives a better correlation with pot and field experiments than other extraction methods commonly used.

Downy mildew—Peronospora spinaciae—is the most important disease of spinach—Spinacia oleracea—in California, where it frequently causes major damage to the crop.

Placentia and Payne walnuts contain 20% to 30% more of the vitamins thiamine, riboflavin and niacin than do Fran-quette walnuts.