Calag Archive

Designed for applying insecticidal and fungicidal dusts to indoor ornamental crops—but practical elsewhere—a new power duster is efficient in glass, plastic, cloth, and lath houses where narrow walkways are customary.

The spotted alfalfa aphid—Therioaphis maculata (Buckton)—causes damage to alfalfa in a variety of ways.

Continual movement of the woolly apple aphid throughout the tree is one of the major difficulties in its control.

The predatory mites,Typhlodromus cucumeris and T. reticulatus, are effective in controlling cyclamen mites—Tarsonemus pallidus—on field strawberries when they gain a fairly early general distribution in new fields, and if chemicals detrimental to them are not applied.

The standard schedule for the control of walnut blight in California—one prebloom and one or two postbloom treatments with copper—depends on very accurate timing. If errors are made, control of the disease may not be achieved. Because of climatic conditions, sprays are sometimes applied when blooming is at an end. This is too late because the causal organism has had a chance to infect susceptible parts of the plant.

The 1955 infestations of the walnut aphid were exceedingly severe in certain areas, such as Linden. By early May, the average number of aphids found—on the next to the terminal leaflets—in some orchards exceeded 50.

Many cut-over forests in the California pine region are producing at much less than full capacity because of the practice of relying upon natural restocking by seed from the remaining trees. Some of these areas contain too few trees, some support trees of less desirable species, and some have been occupied by brush. If left as they are, many of these areas will require fifty to a hundred years before full production is achieved.

Irrigation waters applied to citrus orchards vary considerably—in their sodium and calcium content—in different locations, so studies were made with pure silica sand cultures with nutrient solutions of similar nitrate content and ratios of sodium and calcium.

Orange trees on trifoliate orange root-stock have certain desirable characteristics—smaller trees that yield well in proportion to their size; fruit of better than average quality and size; generally early fruit maturity; tolerance to quick decline; and more cold resistance than other combinations—and the trifoliate root itself is relatively resistant to gummosis and to nematodes. Because of these characteristics, the trifoliate orange is sometimes selected by growers as a root-stock for oranges.