Calag Archive

AN INQUIRY INTO the root and bulb diseases of Easter lilies, begun in the 1950's, has involved the whole lily-bulb industry in radical changes. Growers co-operating with University Extension and Experiment Station research workers field-tested methods developed in the laboratory and useful changes were quickly accepted by growers. Improved planting stocks were introduced, methods of propagation have been radically altered, and cultural practices have been changed. Improved methods of disease control have made many of these advances possible.

This study was made to determine the extent to which the species composition of timber stands and other types of vegetative cover could be interpreted from high-altitude, small-scale, vertical Ektachrome Infrared Aero photographs. Comparisons were also made between interpretations of conventional black-and-white panchromatic aerial photography—used extensively throughout the world by agriculturalists and foresters—and those derived from color infrared photography (a false-color tri-emulsion layer reversal film type originally developed for military purposes). Results indicate that while color offers only a slight increase in interpretation accuracy (at an added cost) over black and white, other factors involved may be even more significant. These include considerable savings possible in man hours and labor costs through the possibility of faster and less fatiguing analysis by the interpreters.

These experiments show that with the use of a particular application technique, DBCP (1,2-dibromo-3-chloropropane) effectively reduces the nematode population around the roots of greenhouse rose plants. The reduction in population of these nematodes in the soil also resulted in increased flower production. At the end of the 26th week after the first treatment there were approximately 13,000 more blooms per acre in the Pink Sensation variety plots, and 19,000 more blooms per acre in the Golden Wave plants, as compared with the untreated check plots.

Verticillium wilt caused by Verticillium albo-atrum and sclerotinia white rot caused by Sclerotinia sclerotiorum are two diseases of commercial chrysanthemums in San Diego County. Previously, the only control of verticillium wilt was soil treatment with chloropicrin or steam prior to planting. In young plants sclerotinia can be prevented by these same soil treatments but tests reported here also show control possibilities by pre-plant application of fungicides on the soil surface. Sclerotinia control may be variable in a maturing cut-flower crop under moist greenhouse conditions where the fungus attacks high on the stems.

An easy-to-train hedgerow planting of sweet cherries which begins bearing early and which can be maintained at a desirable height may have some advantages over current pruning and training systems.

Time of shearing does affect both wool and lamb production and also ewe mortality. Shearing during seasons of the year other than spring and summer can increase lamb production and also produce stronger wool fibers. Shelters and additional feed are required if bad storms strike after winter shearing.

PLASTIC CONTAINERS for avocado nursery trees are relatively new in California, but nurserymen are showing increasing interest in them. One of the most popular avocado nursery containers for many years has been the tarpaper cylinder made from heavy roofing paper. These tarpaper containers have two main shortcomings: the relatively high labor cost of cutting and stapling; and frequent disintegration.