Calag Archive

Field studies reported here have shown that poor growth of safflower after years of rice tends to be associated with acute phosphorus deficiency. Applications of treble superphosphate, 11–48 and 10–50 ammonium phosphate dramatically increased seedling growth and yield of grain when placed with, or 1 inch below seed. Applications of 200 lbs of 11–48 or 10–50 one inch below the seed were found safe and economic under conditions of these Colusa County experiments. Applications of 100 lbs of 11–48 or 10–50 in the seed row were also found to be safe and effective, as shown in tests in both Colusa and Glenn counties. Generalizations are not yet possible on such questions as: (1) why some rice soils are phosphorus-deficient for safflower; (2) the critical soil phosphorus level for safflower the year following rice; (3) the amount of P required for maximum yields; and (4) other nutrients or soil conditions affecting safflower performance on old rice lands.

THE USE OF SPRINKLER IRRIGATION to provide frost protection for grapes, artichokes, and strawberries is an accepted practice on many farms in California. Some precautions should be taken, however, including careful consideration of the type of sprinkler used, particularly when low application rates are utilized.

Field bindweed (Convolvulus arvensis) is a widespread problem in coastal vineyards of central and northern California. Field trials by the Agricultural Extension Service since 1963 have compared several formulations, rates, and timing of 2,4-dichlorophenoxyacetic acid (2,4-D) sprays. Wax bars impregnated with 2,4-D have also been tried. None of the treatments in these trials have given commercial season-long control (table 1).

The results of research on nematicides, in addition to demonstrating remarkable yield increases of agricultural crops brought about by nematpde control, have also shown that EDB, DBCP and 1,3-D have no significant persistent adverse effects on the physical and biological composition of soil, or on the nutritional value of crops grown on treated soil. These successful nematicides are physically and/or biologically degradable.

With both yield and quality changes occurring rapidly from day to day, a simple objective method of field sampling broccoli is highly desirable for a once-over harvest operation by hand and is essential for machine harvesting. Studies reported here indicate the difficulty in devising such a sampling method and point out the need for good judgment by farmers and field men until a good method is developed.

Studies were conducted on the effect of side venting pattems on the cooling rate of nectarines in several commercial containers, and in a container with a new experimental design. The location of vents had some effect on cooling rate, but the differences did not appear to be commercially important. Dividing the vent area into a large number of small openings substantially slowed room cooling (the cooling of containers by placing them in a cold room) without improving uniformity. Room cooling was speeded considerably when the side vent area was increased to about 6 per cent. However, further increases in the vent area only slightly speeded room cooling. The value of vent areas greater than 6 per cent, especially when located along top or bottom score lines, must be weighed against their potential weakening effect on the container. When forced-air cooling was used (the forcing of cold air through the container and around the fruit) the cooling time was directly related to vent area regardless of size and location. The design of the experimental container facilitated air circulation, resulting in only small differences in cooling time between the 3.8 and 5.6 per cent side vent openings. The use of this container design and the choice of container venting may depend upon the results of static stacking tests which were not included in these studies.