Calag Archive

A SERIES OF statewide field tests were > conducted in 1973 to further study the performance of ethephon as an aid in fruit ripening of peppers under a wide variety of conditions. The tests were also intended to establish necessary residue and fruit quality information for registration. Greenhouse and field experiments conducted over the past five years in California indicated ethephon applications could result in improvement in ripening of chili, pimiento, and bell peppers for processing. Also observed were improvements in vine condition and fruit pod removal, which would greatly assist in a once-over, hand or machine harvest.

Benomyl or thiophanate-methyl applied as dips to strawberry nursery plants before planting provided significantly better control of Ramularia leafspot than all other materials tested. Benomyl in southern California and thiophanate-methyl or benomyl in northern California gave the best leafspot control when fungicides were applied as sprays after planting. Selecting leafspot-free plants or obtaining plants from nurseries following a benomyl spray program prevented leafspot developing in fields in southern California. Most fungicides tested were either phytotoxic or gave ineffective control of leafspot.

Cotton grown in smogfree carbon filtered air produced 20 to 30% more raw cotton compared with similar cotton growing in non-filtered air at Parlier, Hanford and Cotton Center. At Five Points, on the west side of the valley, the difference in favor of filtered air was about 10%. Vegetative growth was apparently not influenced by the presence or absence of the oxidants removed by carbon filters, but senescence was delayed several weeks in the fall by the removal of existing pollutants. All these experiments were conducted with Acala SJ-1 cotton. Future experiments will be conducted with newly released SJ-2 and T-1307 and soon-to-be-released T-4852, to determine their relative tolerance to air pollution as compared with SJ-1. Breeding for smog resistance seems to be the most practical means of living with this problem, which from all indications to date, is serious in rnanv parts of the San Joaquin Valley.

Mechanical harvesting of Bartlett pears appears practical, and economically feasible, with the collector-decelerator system showing the greatest potential, according to these tests. As with any harvest operation, yield, fruit losses, fruit quality and harvest rate are extremely important. Acceptable fruit quality has been achieved with this experimental equipment, and it is believed that commercial machines could be produced to equal or exceed this performance.

For several years, rapid tissue tests have been used in the field to evaluate plant nutritional status and to diagnose deficiencies. But they have been used only incidentally to make fertilizer recommendations, or to evaluate a fertilizer program, partly because they have lacked the accuracy of laboratory analysis. Research has revealed definite and consistent relationships between plant nutrient level and plant health. However, few crops are routinely tested to determine plant nutritional needs, because fertilizer has been plentiful and relatively low in cost, and because results from laboratory analyses are often delayed. Rapid tissue tests conducted in the field could overcome the problem of delay. By providing information about nutrients needed for a particular crop in any given field, the tests also enable growers to more fully utilize increasingly costly and limited fertilizer resources. In the field investigations reported here, a rapid tissue testing procedure (developed by R. H. Bray in 1945 at the University of Illinois) was found useful as a guide for evaluation of the nitrogen nutritional status of corn and sorghum. Resulting guidelines are given here for recommending application rates for nitrogen fertilization and for evaluation at the end of the growing season.

THE STUDIES TO CALIBRATE the rapid tissue test with the nitrogen nutritional status of sorghum were conducted in a nitrogen deficient field on the Rosolia Ranch near Orland. In 1970, initial soil samples were taken and plots laid out in a randomized complete block design with six treatments and three replications. The plots were 15 ft wide and 50 ft long. The treatments consisted of 0, 50, 100, 150, 200, and 250 lbs of nitrogen applied per acre. The nitrogen (as ammonium sulfate) was applied pre-plant and disked into the soil. Sorghum, variety NK 222, was planted on July 4, 1970 by drilling on 12-inch row spacing.

BECAUSE OF INADEQUATE air exchange in the storage environment, broccoli (Brassica oleracea var. Italica cv Gem) developed a strong, offensive odor after 8 to 10 days at 2.5°C (36.5°F). The restricted air circulation through containers of broccoli caused rapid oxygen depletion and carbon dioxide accumulation (graph 1) in storage tests conducted in the L. K. Mann Laboratory at the University of California, Davis.