Calag Archive

After a mild winter, Bartlett on Old Home rootstock bloomed earlier and more uniformly than Bartlett on other rootstocks or own-rooted Bartlett trees. Normal blossoming time of the rootstock appeared to be unrelated to its influence on the bloom period of the Bartlett scion. Also, differences in time of bloom apparently were not associated with tree vigor. This research indicates that Old Home rootstock may be valuable in areas where production of Bartlett is limited by insufficient chilling.

Early identification of pest species is essential to the successful planning and operation of integrated control and pest management programs. Growers can then minimize the damages caused by insects though timely manipulation of various control measures, including chemical treatments, cultural practices, and harvest schedules. Detection and survey methods used include the hand search for both mature and immature stages, direct collection by D-Vac (a suction insect collecting device), sweep nets, a study of the damage index, and use of various types of traps. Black light traps have usually been used for surveys; however in recent years, the pheromone trap has become more common.

Two possibilities exist as ways to eliminate hand thinning in lettuce production: (1) to combine precision planting with the use of a selective thinner; and (2) to plant to a stand, utilizing improved seed environment control with respect to plant protection, soil crust prevention, and moisture control. Regardless of which system the grower chooses, he must decide on a minimum spacing that can be tolerated, without sacrificing head size, quality or yield. If the thinner is used, the cutting mechanism should be set to leave plants as close as possible to that minimum spacing. If planting to a stand is practiced, then the minimum spacing will result in maximum plant population, thereby giving better yield insurance to cover any loss of stand. The purpose of this study was to determine the minimum plant spacing that could be tolerated without yield or quality loss under field conditions.

Single-cut or “once-over” harvesting of standard chrysanthemums may be possible commercially, according to results of trials conducted during the summer and fall of 1971 at floriculture greenhouses of the Deciduous Fruit Field Station, San Jose. Cultivars tested included ‘Albatross,’ ‘Detroit News’ and ‘Escapade.’ These are the major white, bronze and pink standards grown during the summer in California. Additional trials with other cultivars are in progress.

The development of selective herbicides has been basic to the profitable use of the mechanical tomato harvester. Weeds must be efficiently controlled if such machines are to operate effectively in California tomato fields. About 40% of California's tomatoes were treated with herbicides for annual preemergence weed control in 1965. Only five years later over twice this acreage was treated (87% in a 1970 survey). The most common weeds in tomato fields include barnyard grass, pigweed, nightshade, nutsedge, shepherd's purse, and many other broadleaf weeds and grasses.

Yields of safflower (following cotton) produced under minimum tillage (at substantially reduced costs) remained as high as when the crop was produced under maximum tillage practices, according to the three-year study reported here.

These trials indicate that several experimental materials would be very effective on peach twig borers. It is also apparent that dormant sprays provide an excellent means for reducing peach twig borer populations, and at a time of year when spraying results in probably the least ecological disruption. Dormant sprays in other trials have also proved effective for control of San Jose scale, and overwintering mite and aphid eggs.