Calag Archive

Ewes and lambs fed cubed alfalfa wasted 10.5% less hay and gained 6.4 Ibs more per pair than those fed an equal amount and quality of baled hay, in this 44-day test—resulting in a $3.05-per-ton feed value advantage for the cubes.

Studies of potato storage have continued for several years at Tulelake Field Station. In the fall of 1966 this research program was directed at an investigation of the storage behavior of russet potatoes (netted gems) when held at differing levels of relative humidity. Past experience in the Tulelake region had suggested that humidity might be a critical factor.

Highest yields of safflower were obtained when a medium pre-irrigation of 18 inches and two supplemental 8-inch crop irrigations were applied, according to the trial reported here. When approximately the same total amount of water was applied in one pre-irrigation or in a pre-irrigation and one supplemental crop irrigation, the yields were significantly lower. This study strongly suggests that maximum safflower yields (on Panoche clay loam soil) depend on readily available soil moisture in the top 4 feet of soil during bud and flowering periods.

The fruit defect, sunken mottle, is a major problem facing Honey Dew growers in the Central Valley. It is an insect-borne malady, apparently caused by watermelon mosaic virus, type 2, according to this study. In recent years it has caused losses of about one-third of the Honey Dew acreage in Stanislaus County. It has been especially severe on late-planted fields. Control of the virus requires knowledge and control of the insect vector and any host plants. The best long-term solution to the problem maybe a breeding program for mosaic-resistant line of Honey Dew melons.

The navel orangeworm, Paramyelois transitella (Walker), is a sporadic pest of almonds in California. Crop damage caused by this pest tends to increase and persist at an economically significant level for a few years in a particular locality, and then to drop to a low, chronic level for an indefinite period. The factors causing these changes in infestation are not known. Since this moth does not attack an almond crop until the nuts begin to ripen, the grower usually does not appreciate the extent of its damage until harvesting begins. A system to detect and assess changes in the pest population would enable growers to adjust harvest operations, if necessary, to minimize damage; for example, to harvest and fumigate susceptible soft-shell varieties as early as possible. These studies were to determine the value of chemical attractants in a detection program.

Studies on Panoche clay loam soil showed the effectiveness of irrigation water and nitrogen fertilization for cotton to be highly interdependent. A lint yield equation was calculated to determine the combination of irrigation water and nitrogen that would minimize costs for specific yield levels and input cost conditions.

Studies of both the flower thrips and lygus bug indicate that they caused no serious sesame plant injury, reduction of pod set, or seed loss at the populations existing under the conditions of these experiments. It appeared that much larger population densities of these pests would be necessary to contribute to the poor pod set and low yields observed recently on untreated field plants. The green peach aphid caused up to 27% seed loss when present in moderate to large numbers, however. The aphid was effectively controlled by use of two applications of either oxydemetonmethyl or endosulfan.