Calag Archive

Results of this trial with high-moisture milo and barley were similar to previous studies with carn—all can satisfactorily replace a major portion of a concentrate mix in a dairy ration on an equal dry matter basis. However, it takes from 20 to 30 per cent more high-moisture grain than dry grain to obtain equal dry matter intake and, subsequently, equal milk production.

Alfalfa hay usually provides at least b half of the roughage used for California milk production by dairy cows during some portion, if not all, of the 365 days of the year. It may be the only source of nutrients for dairy cows on grade B dairies during the winter season. Selection of alfalfa hay is a major management consideration for California dairymen because the nutritive value and feeding quality are highly variable. An accurate gauge of the nutritive value of a given lot of hay is the level of crude fiber it possesses. A method for evaluating nutritive value from the crude fiber content has been developed by the California Experiment Station. Commercial laboratories, using this method, have been available to test samples of hay submitted by progressive dairymen.

Corn silage production in San Joaquin County has doubled in the last five years because of higher yields, as well as increased acreage. Because much of this silage is used for dairy cattle feed, and little information has been available as to its relative value under current California conditions, feeding trials were needed.

Twenty-three navel orange trees were grown in outdoor solution cultures for a period of 11 years to measure the effect of iron deficiency on fruit production and quality. When the concentration of iron in spring-cycle leaves was below 30 ppm (based on weight of dry leaves) in September, the production of fruit was less than when iron concentration exceeded 30 ppm. As the iron content decreased below this value, fruit production declined progressively and reached essentially zero at 15 ppm of iron. Fruit quality at harvest was not seriously affected except for some loss in color and the fact that iron content of the juice was about proportional to that in the leaves. The decrease in yield was due to fewer fruits being matured. Actual fruit sizes were the same or slightly larger in iron-deficient trees. Twig dieback was observed as a symptom of the degree of iron deficit that caused loss of fruit yield.

Weed costs for the state's 110,000 acres of almond orchards totaled $1,160,000 in 1964, according to estimates by the California State Chamber of Commerce Weed Control Committee. In the same year, a survey by the Agricultural Extension Service indicated that 88% of almond orchard weeds were annuals and 12% perennials. Most of the cost of control has been for machinery and hand labor necessary to control the weeds in the tree row. Continued disking has also frequently been injurious to both roots and trunks of young trees.

Cottons derived from the species Gossypium hirsutum such as the Acala varieties, and from G. barbadense such as Sea Island and Tanguis varieties—or hybrids between the two species—have been found easy to propagate vegetatively by cuttings. There are obvious advantages in certain disease studies to conducting experiments with genetically uniform or clonal lines of cotton. There may also be advantages to the seed industry. For example, a plant selected as a basic seed parent for superior yield and quality could be increased many fold by cuttings and an abundant seed crop realized—sufficient to reduce the time between initial selection, and release of the seed to growers by perhaps one seed generation.

Dairy Herd Improvement Association (DHIA) milk production records are estimates of total production based on the production recorded only once each month for each animal. The milk from each milking is weighed on a spring scale and the individual milk weights are summed to obtain a daily-total. The daily production is multiplied by the number of days in the month, and the pounds of milk credited for the individual months are then summed to obtain animal lactation totals. These practices have brought up the questions of whether (1) sampling a cow's production once monthly provides an accurate estimate of the total lactation and (2) if DHIA-accepted measuring devices contribute much error to these estimates. The relative impact of a random error on the precision of DHIA records is determined by the magnitude of the existing error variance due to day-to-day variation in yield. This study with Holstein cows was to determine the magnitude of daily variance in dry-lot milk production.

The Sacramento and San Joaquin Valleys contain 70% of the State's 1.16 million acres of alfalfa. Alfalfa grows on one of every six acres devoted to field crops, and it provided California farmers with a gross revenue of $173,000,000 in 1966. Development and evaluation of new and improved alfalfa varieties constitute an important part of the University of California's alfalfa research and extension program.