Calag Archive

Reductions in Valencia orange juice quality or yield are less likely to occur from applications of pest control oil spray in the late summer than at any other time of the year, according to a three-year investigation conducted in Orange County. Potential reduction of juice quality following the use of oil spray on citrus has assumed increased economic importance recently because larger volumes of the crop are going to the juice concentrates market.

Only five minutes are required by the melon aphid—Aphis gossypii Glover— after feeding on a diseased citrus tree, to transmit the tristeza—quick decline— virus to a healthy tree. However, the aphid does not remain infective long— probably most individuals lose their ability to transmit the virus shortly after leaving the diseased tree—and apparently only an occasional individual aphid is able to transmit the virus at all.

Stratified Tilton apricot seeds, from trees sprayed in the spring of 1954 with 2,4,5-T — 2,4,5-trichlorophenoxyacetic acid—to increase fruit size and reduce preharvest drop, germinated very poorly after being planted in the nursery row in March, 1955. The few seedlings that did grow from these seeds were very abnormal when compared to seedlings from parent trees of die same variety mat had not been sprayed with 2,4,5-T.

Most soil borne plant parasites grow more vigorously in soil freed of competing organisms by previous sterilization than in natural soils where they have to compete with other organisms. Some of the competing organisms are antagonistic to the parasites and tend to suppress the activity of the detrimental forms.

Three wasp species—Praon palitans, Trioxys utilis, and Aphelinus semiflavus —parasites of the spotted alfalfa aphid, are being propagated in the insectaries at Riverside and Albany.

Where sizable acreage is involved, aerial control of range rodents has several advantages over hand application of cereal baits.

Physical incorporation of tenderizers into meat is an important factor influencing their effectiveness.

Many sheepmen who raise replacement ewes have stopped using rams of the finewool breeds and have substituted rams of medium-wool, dual-purpose breeds.

Hair Sprout—a disorder of potatoes that has been increasing in California during the past few years—is characterized by long thin sprouts produced by the tuber. The sprouts often produce small aerial tubers.