Citrus

090 - Mandarin Pest Management

Principal Investigator: Beth Grafton-Cardwell, Department of Entomology, University of California, Riverside and Director of Lindcove Research and Extension Center

The California citrus industry is increasingly planting mandarin varieties due to the consumer demand for these ‘easy peelers’, especially the seedless varieties. Some of the insect pests appear to be attracted to and to develop better on mandarins, possibly due to their flushing patterns and dense growth. Problematic insects include citrus thrips, cottony cushion scales and aphids. Thresholds for economic damage by pests are not available for mandarins. An additional constraint for the mandarin industry is that theses fruit can not be high pressure washed to ameliorate problems of sooty mold caused by soft scales and California red scale infestations, thus tolerance for some pests will be lower than for navels and Valencias. A single variety block of mandarins being used at LREC for pesticide trials and economic threshold studies of citrus leafminer.

093 - Cold Hardy Mandarins and Clementines in Northern California

Principal Investigator: Deborah Giraud, University of California Cooperative Extension Farm Advisor, Del Norte County

Trees of cold hardy mandarin varieties will be planted at several small mixed farms in Humboldt County in the inland valleys where peaches, grapes and kiwi are currently successful. Olives are also being planted as a new crop. Growers are interested in exploring diversification and have started to plant mandarin varieties. The Farm Advisor is interested in cold hardy citrus varieties to be able to make science-based recommendations and in maintaining citrus germplasm in isolated areas far from disease sources.