Calag Archive

Monthly mastitis testing in Fresno County has been mandatory for Dairy Herd Improvement Association members since the beginning of 1971. Voluntary participation before 1971 was such that approximately 90% of the DHIA-tested cows were also mastitis tested with the California Mastitis Test (CMT). In 1961 an average of 11,206 cows were CMT-tested per month. Ten years later in 1971, an average of 22,687 cows were tested per month including approximately 10 per cent which previously had not been on the CMT but had been DHIA testing. This two-fold increase follows a similar increase in total DHIA cows (table 1).

The increased awareness of environmental qualities has made it desirable to obtain quantitative data on the contributions of agricultural and urban sources to water pollution. For this reason an investigation was initiated in the Coachella Valley on (1) the chemical composition of drainage water from cropped fields under various agricultural managements and (2) the effluents from the Indio sewage treatment plant.

The conventional trailer system of handling seed cotton directly from the picker to the gin doesn't always provide an uninterrupted flow of cotton from the field through the gin. Growers sometimes have to stop picking because all their trailers are full, waiting to be ginned. Gins may have to work short shifts or shut down temporarily for lack of cotton, during the first or last part of the season or if adverse weather makes picking impossible. Storing part of the crop between picking and ginning alleviates both problems. Growers can complete their harvesting at an earlier date and ginning costs are reduced.

Small-scale rectangular plots at Davis are being used to determine how long chemicals applied in rice fields persist in flood and seepage waters, where the chemical residues go, and how fast they get there. This article presents data from some dye tracer experiments using two chemical application techniques (uniform application on the water surface and slug injection at the point of water inflow) and three water management practices (static, flow-through, and recycled systems). The distribution, persistence, and movement of a rhodamine dye tracer in flood waters was found to be greatly affected by these different water management systems.

Design, dispenser size and type, and trap placement are important factors influencing pink bollworm trap efficiency. Omnidirectional traps are essential for maximum efficiency, and the new cone trap meets this requirement. It does not require any sticky or poisonous substance and is easy to operate. Catches on fallow land may be increased by placing the trap on a silhouette, or close to the ground surface.