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Tests with gibberellins indicate several uses in grape production. They were found to produce an excellent set in Black Corinth. They also greatly increased berry size of Thompson Seedless when the sprays were applied at the proper time for girdling. Gibberellin can be applied in conjunction with girdling or separately. In some cases gibberellin applied separately produced larger berries than those obtained from girdling only. The largest berries resulted from a combination of girdling and treatment with gibberellin.

A three-year experiment at the Hop-land Field Station compared lambs sired by rams of a large breed with those sired by rams of a smaller, earlier-maturing breed. The lambs compared were sired by Suffolk and Southdown rams, and were out of range ewes.

Weeding with geese has proved to be an effective and cheap means of controlling grassy annual and perennial weeds when combined with other good farming practices. From 175,000 to 200,000 geese are being used in crops in California each year; the practice has been widely accepted and has spread rapidly since geese were first used for weeding commercial fields about seven years ago.

Applications of 2,4-D to annual clovers growing on the range in El Dorado County generally affected dry matter production of subclover much less than that of rose clover. Rose clover yield was higher when the treatment date was later, but was never higher than the untreated plots. The dry matter yields were significantly reduced by spraying at the high rate at either of the first two dates.

Collapse in lumber—an extreme form of shrinkage which causes large volume loses and is accompanied by warping and splitting—is being studied in order to find ways to rehabilitate wood that has collapsed during drying and to develop a practicable technique to prevent collapse.

Limb cankers that expand rapidly and often girdle and kill major limbs within three or four years are reported to be of increasing incidence in California almond orchards. One or several limbs may be attacked in a single season. Where the condition continues, the trees must be severely pruned or removed. The cankers are typified by a depression of the infected tissues and the production of an orange, frothy gum. The disease is frequently found in the Winters, Chico, and Rumsey areas and occasionally as far south as Stanislaus County. The Texas (Mission) variety is most susceptible to the cankers, as measured by the girdling and killing of branches, but Nonpareil, Peerless, and Ne Plus Ultra are often severely damaged. The Drake variety is less susceptible, and cankers on these trees apparently expand more slowly than the cankers on trees of the other varieties.

The following article is the twelfth annual report of progress in studies on orchard frost protection published in California Agriculture.

All new potato varieties and a large number of advanced generation experimental lines from many sources have been tested for disease resistance and adaptability to California growing conditions. A true breeding program with the production and evaluation of large numbers of F₁—first generation hybrid—seedlings was initiated in the spring of 1958.