Calag Archive

SCALE INSECTS are among the most serious pests known to agriculture, and San Jose scale, Quadraspidiotus perniciosas (Comstock), ranks as the primary scale pest on deciduous fruit and nut trees. It is distributed worldwide and has been collected from approximately 700 different hosts. Unlike many insect pests, San Jose scale has the ability to kill all or parts of infested trees, in addition to making infested fruit unmarketable.

Copper compounds were the only currently registered bactericides that controlled streptomycin-resistant strains of firelight bacteria in Bartlett pear trees, but they induced considerable amounts of fruit russet. An anti-transpirant material reduced the amount of russet caused by the copper materials when applied alternately, or in conjunction with copper sprays. A new organic bactericide, MBR 10995, provided excellent control of fireblight in a limited trial but is not currently registered. Biological control of fireblight with application of bacteria antagonistic to Erwinia amylovora was somewhat effective. The efficacy of bactericides can also be determined by their effect on epiphytic populations of E. amylovora in blossoms.

This report of the subfloor monitoring of the Shady Grove Dairy liquid manure holding pond near Chino offers further proof that such ponds are self-sealing and allow little or no seepage.

Results reported here, along with the results of similar studies conducted both in the field and in environmentally controlled glasshouses, emphasize the importance of climate in the production of marketable citrus fruits. The most important market criteria such as size, rind color, and maturity are determined to a large degree by the climate in which the trees are grown. These data can be useful in determining the most suitable varieties for trial in new areas.

Results from these initial studies into insect pathogen application demonstrated the promising potential for effective dispersal of insect pathogens with ground aerosol rigs.

SHOOTS SPROUTING from the basal area of the trunk are a problem in commercial fig orchards and considerable time and money is spent in removing these sprouts by hand pruning. A growth regulator spray which would prevent or retard this unwanted growth would be of economic value to fig growers.