Calag Archive

Numerous cotton hybrids–offspring of a cross between two individuals of dissimilar genetic constitution–have been produced in limited quantities for a plant breeding program at the Shafter Cotton Experiment Station.

A fly stem borer–Melanagromyza virens (Loew)–of wide tastes, showed 100% infestation of late-planted experimentally grown safflower at Davis during 1958.

Lime-induced chlorosis is an important–and widespread–nutritional disorder of plants in California and other western states. Trees and shrubs are especially susceptible on soils containing calcium carbonate–lime. Although the chlorosis responds variously to iron compounds, it appears to be more complicated than a simple iron deficiency because yellow, chlorotic leaves sometimes contain more iron than healthy green leaves.

Two new strains of Pearson tomato– Pearson VF6 and VF11– developed and released to the seedsmen are resistant to Fusarium and Verticillium wilts.

Killing of a narrow strip of cambium and bark at the union of the Persian– Juglans regia–or English, walnut tree top and its rootstock is causing increasing losses of individual trees–even abandonment of entire mature orchards –in the walnut producing areas adjacent to San Francisco Bay.

OMPA was the most outstanding aphicide in studies at Linden, Walnut Creek and San Jose that included preliminary experiments with Phosdrin, Dicapton, Bayer 25141, Phosphamidon and Dibrom.

Cold storage of ponderosa pine seedlings–between nursery and field–is an integral part of the planting program in California. However, forestry agencies have been concerned for a number of years with the effect of storage on the subsequent survival of pine seedlings transplanted to the field.

The ammonium source of nitrogen is often considered less desirable than other nitrogen sources for some plants. Nitrate is believed–by many people– to be superior to ammonium nitrogen for citrus, especially under acid soil conditions.

Dog and cat fleas–like so many other insects–have become resistant to a number of insecticides and pet owners report that flea infestations on pets are no longer being controlled by previously effective dusts and sprays containing chlordane, lindane and DDT. Additionally, the more effective insecticides do not last for very long periods of time and–because of their high toxicity–have to be used with caution on infested pets.