Calag Archive

Potato cracking results from poor handling procedures during harvest, while loading into storage cellars, and during removal from storage. The percentage of marketable tubers (and profits) decreases while the potential infection of tubers increases. Levels of tuber damage caused at various stops during handling of Russet Bur-bank potatoes were determined during 1971-72 at Tulelake. Pre-warming, by forced air heating before removal of potatoes from storage and lowering them through a vertical deceleration chute resulted in a marked reduction in the amount of tuber cracking.

The grape leaf folder, Desmia funeralis (Hbn.) Pyralidae: Lepidoptera, requires treatment every year in some Tulare County vineyards. The amount treated varies from a few acres to perhaps a third of the total acreage in the peak years. Although carbaryl (Sevin) gives excellent control, it causes disruptions of natural control factors under some conditions. In an effort to find more innocuous controls, many preparations of Bacillus thuringiensis Berliner have been tested against grape leaf folder over the last 13 years. The new high potency strain of Bt gives promise of highly effective control. This strain, known as HD-1, was isolated by the U.S.D.A.

Antitranspirants reduce plant water stress by decreasing water loss through the leaves of olive trees — thus increasing fruit growth. In areas, such as Northern California, where dry northerly winds occur, antitranspirants can markedly reduce the incidence of shrivelled fruit. The antitranspirants in this study were used on an experimental basis and have not yet received EPA approval, although efforts toward approval are being made. Therefore, the results presented indicate the potential of these materials for fruit sizing and are not intended as a recommendation at this stage.

In direct-seeded asparagus fields, areas where plants are missing (skips) can be filled in two times during the year following the seeding operation. Two methods discussed here have been used successfully to fill skips in direct-seeded experimental plantings at the University of California Agricultural Experiment Station at Davis: (1) transplanting one-year-old asparagus crowns or (2) planting asparagus seedlings that have produced secondary stems and roots.

Olea europaea ‘Swan Hill’ is difficult to root. However in each of five different lots, rooting of 80% was obtained. Rooting percentages of 60% to 80% were obtained in 10 other treatments. The mean rooting for all ten treatments in June 1970 was 64.5%. General trends indicate that auxin (IBA) concentrations of 1000 ppm may be adequate with softwood cuttings and 2000 ppm adequate with semi-hardwood cuttings, and that higher concentrations may be detrimental. Wounding may be beneficial with softwood cuttings under some conditions and it does not appear to be detrimental under any circumstance. The sensitivity of ‘Swan Hill’ in rooting response to season and auxin concentration might be used as a tool to develop methods of determining the time to take cuttings for best rooting response. ‘Swan Hill’ can be rooted satisfactorily from softwood or semi-hardwood cuttings. Because of the relatively long time required for rooting, care must be used to minimize algae growth on cuttings and flats, to select the most vigorous cuttings, and to exercise care in hardening-off and transplanting.

A new approach to irrigation, called drip irrigation, was developed in Israel in recent years. Under the leadership of Professor Dan Goldberg, Head, Department of Irrigation, Hebrew University, this system has now been tested for 10 years and developed to its present stage. About 10,000 acres of commercially grown vegetables, field crops, and fruit trees are being irrigated by drip irrigation in that country today.

Approximately 68,000 acres of cantaloupes are grown annually in California. The desert areas of Blythe and Imperial Valley grow about 12,000 of the total acreage in the early spring and fall. The largest acreage, 30,000 acres, is grown in Fresno County in the San Joaquin Valley. Generally the number of vines per acre will range from 5,000 to 8,000 with a trend by growers to increase the plant population per acre. This experiment was conducted at Davis to determine the effect of plant density on yield of marketable cantaloupes.