Calag Archive

Total femaleness of flowers induced by applications of the plant growth regulator Ethrel resulted in smaller plant size, higher plant populations, and earlier maturity—all important factor in once-over mechanical harvesting of cucumbers for pickling.

High TEST WEIGHT and good grain yield can both be obtained by California's oat growers with Montezuma, a new oat variety released by the University of California Agricultural Experiment Station at Davis in cooperation with the U. S. Department of Agriculture.

EARLY SEASON treatments on cotton for control of lygus bugs often eliminate natural enemies of the bollworm, beet armyworm, cabbage looper, and spider mites. In the absence of biological control, these pests can often increase later in the season and may require multiple treatments to prevent plant damage in the cotton fields.

Four major cling peach varieties (Halford, Peak, Paloro, Carolyn) were effectively thinned with 3-CPA. Proper timing based on ovule length (8.5 to 9.5 mm is best) was essential for best thinning. The best sprays were of 300 ppm applied at 400 gallons per acre, or 1.6 gallons of formulated material per acre. Slight phytotoxicity usually occurred whenever thinning was obtained but was limited to a few yellow leaves which dropped two weeks later and some leaf tipburning and twisting. Fruit harvested after 3-CPA sprays appeared equal in size, maturity and quality to hand-thinned fruit. A small amount of pole or touch-up hand thinning was usually needed in addition to the thinning sprays to attain good commercial thinning.

“Choice box” for testing the repellency of insecticides to cockroaches. Back half of box is covered with fiberboard, creating preferred dark refuge for cockroaches. However, repellent insecticides will result in some of the insects learning to avoid the dark area before picking up a lethal dose.

Three lettuce experiments were conducted in which raw seeds, seeds with 5-to-1 and 10-to-1 clay-to-seed coating ratios, and fully coated seeds were compared when planted under soil, and when planted under soil sprayed on the surface with petroleum mulch, and when planted under stabilized vermiculite, or petroleum coke. Stabilized vermiculite and petroleum coke increased the percentage of emergence and lowered the time required, regardless of seed coating. Petroleum mulch also improved emergence, but not as much as the other materials. Counts showed that both 10-to-1 and 5-to-1 coated seeds improved, to a considerable extent, on the slower and poorer emergence that had been observed with fully coated seeds. Both minimum seed coatings and replacement of the soil seed covering by vermiculite or coke offer real advantages for the precision planting of lettuce.

ANGULAR LEAF SPOT of Cotton (Gossypium hirsutum), caused by the bacterium Xanthomonas malvacearum, became established in California in about 1951. By 1962, however, sanitation had eradicated it from cotton fields, and attempts in 1966-67 to demonstrate cotton-gin-contamination failed even though contamination had been readily demonstrated in 1958-60, when the disease was widespread.

BOTRYTIS or “fire”; in Easter lily foliage and flowers is a devastating disease in the lily growing areas of southwest Oregon and northwest California. Botrytis foliage blight is caused by the fungus, Botrytis elliptica. The disease causes a tear-drop shaped lesion on the leaves and may completely defoliate plants not protected by a suitable fungicide. Through a magnifying hand lens the mycelium of the fungus can be seen growing on the surface of the leaf. The fungus is especially prevalent during periods of cool, wet weather.