In May 2012 in the Coachella valley, Riverside County, California, the decline of vines in table grape (Vitis vinifera) vineyards was observed. Foliar symptoms consisted of shoot blight with wilting and necrosis of leaves and drying and shriveling of berries. In some cases, the entire vine collapsed in the middle of the growing season (apoplexia). Wood cankers in the spurs, cordons, and trunks of affected vines were also present. The nine isolates recovered from the cankers were identified as Neoscytalidium dimidiatum (Penz.) Crous & Slippers based on morphological characteristics and DNA sequence comparisons. Two isolates were grown on potato dextrose agar (PDA) medium and a total of 50 conidia were measured per isolate. Conidia were ellipsoid to ovoid, with a truncate base and an acutely rounded apex, initially aseptate, becoming brown and two-celled at maturity, 7.2 ± 1.2 μm × 3.8 ± 0.4 μm. The rDNA internal transcribed spacer (ITS), and β-tubulin (BT) loci were amplified using primer pairs and methods previously described (4). A total of five isolates were sequenced. The DNA sequences of one N. dimidiatum grapevine isolate (UCR-Neo1) were deposited in the GenBank database (ITS, KC937066; BT, KC937067). Pathogenicity tests were performed by inoculating 12 grape cuttings cv. Thompson Seedless with isolate UCR-Neo1 and 12 control cuttings with sterile medium using a technique previously described (1). The experiment was repeated twice. After 20 weeks of incubation period in the greenhouse, the lesions length produced by N. dimidiatum averaged 13.5 mm and was significantly longer (P < 0.05) from the control (average 3 mm). N. dimidiatum was reisolated from all the inoculated plants and identified by colony morphology. The incidence of N. dimidiatum in table grape vineyards of the Coachella valley has been estimated at 15%, with nine vines infected out of 60 vines total. This pathogen has been identified in California in walnut nursery causing the death of trees due to the development of canker at the graft union (2). N. dimidiatum has also been identified as the causal agent of shoot blight, canker, and gummosis on citrus in Italy (3). The crop is also being grown in the Coachella valley and these findings warrant further investigation in order to determine the host range, distribution, and incidence of this pathogen in the area. References: (1) K. Baumgartner et al. Plant Dis. 97:912, 2013. (2) S. F. Chen et al. Plant Dis. 97:993, 2013. (3) G. Polizzi et al. Plant Dis 93:1215, 2009. (4) J. R. Urbez-Torres et al. Plant Dis. 92:519, 2008.

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‘Valencia’ orange trees subjected to a drenching shower twice a week or sprinkled daily with a fine water spray until their leaf surfaces were thoroughly wet were found to accumulate less fluoride than unsprayed trees when exposed to low concentrations of HF gas. In the early stages of leaf development the drenching shower and light sprinkling treatments were equally effective in reducing fluoride uptake. After the foliage was 3 or 4 months old, however, the daily sprinklings had little effect on fluoride uptake whereas the twice weekly 1 hr drenchings effectively prevented fluoride accumulation. Growth responses were inversely proportional to fluoride uptake with maximum growth suppression associated with maximum fluoride uptake. After 9 months of treatment, the drenchings had reduced fluoride uptake by 85% and growth suppression by approximately 87%. In the same period the daily sprinkling treatment had reduced fluoride uptake by 37% and growth suppression by 45%.