could be used as a natural bactericide for E. coli and what, if any, effects that would have on plant growth and development of ‘Rex’ lettuce grown in a hydroponic NFT system. The fact of the matter is that increasing saponin levels not only failed to
Nathan J. Eylands, Michael R. Evans, and Angela M. Shaw
Gary E. Vallad, Kenneth L. Pernezny, Botond Balogh, Aimin Wen, Jose Francisco L. Figueiredo, Jeffrey B. Jones, Timur Momol, Rosa M. Muchovej, Nikol Havranek, Nadia Abdallah, Steve Olson, and Pamela D. Roberts
$3090 per acre based on 2007–2008 production costs and market values. Integrated management strategies for bacterial spot include using certified seed, disease-free transplants, field rotation, avoidance of cull piles, and the application of bactericides
Thomas A. Bewick, William M. Stall, Stephen R. Kostewicz, and Kenneth Smith
Cupric hydroxide, copper ammonium carbonate, basic copper sulfate, mancozeb, and a combination of cupric hydroxide and mancozeb were applied to American black nightshade (Solanum americanum Mill) before treatment with paraquat at 0.6 kg a.i./ha. Paraquat efficacy was reduced by all fungicides/bactericides, except a flowable formulation of basic copper sulfate, when compared to the herbicide only control. Compared to a surfactant only control, efficacy 1 week after paraquat application ranged from 86% with paraquat only to 42% with a combination of mancozeb and cupric hydroxide. Mancozeb and mancozeb in combination with cupric hydroxide resulted in greater shoot dry weight than the paraquat only control when measured 2 weeks after herbicide application. Chemical names used: 1,1'-dimethyl-4-4'-bipyridinium ion (paraquat); Mn, Zn ethylene bis diethyldithiocarbamate (mancozeb).
David J. Norman and Jianjun Chen
poinsettia is predominantly propagated through cuttings, overhead irrigation allows for easy spread of Xanthomonas during propagation. In addition to strict sanitation, bactericides are used for controlling Xanthomonas species in geranium and poinsettia. The
Manish K. Bansal, George E. Boyhan, and Daniel D. MacLean
Kocide, which acts both as a fungicide and bactericide, and is labeled for use on onions. It is used as a preharvest fungicide to prevent diseases in a number of fruits and vegetables. Copper hydroxide converts into ionic copper as the active ingredient
J.E. Flaherty, G.C. Somodi, J.B. Jones, B.K. Harbaugh, and L.E. Jackson
A mixture of host-range mutant (h-mutant) bacteriophages specific for tomato race 1 (T1) and race 3 (T3) of the bacterial spot pathogen, Xanthomonas campestris pv. vesicatoria (Doidge) Dye was evaluated for biological control of bacterial spot on `Sunbeam' tomato (Lycopersicon esculentum Mill.) transplants and field-grown plants for two seasons (Fall 1997 and Fall 1998). Foliar applications of bacteriophages were compared with similar applications of water (control) and of copper/mancozeb bactericides, the commonly used chemical control strategy for tomato seedling and field production. In 1997, the incidence of bacterial spot on greenhouse-grown seedlings was reduced from 40.5% (control) to 5.5% or 0.9% for bactericide- or bacteriophage-treated plants, respectively. In 1998, the incidence of bacterial spot was 17.4% on control plants vs. 5.5% and 2.7% for bactericide- and bacteriophage-treated plants, respectively, although these differences were not statistically significant at P ≤ 0.05. Applications of bacteriophages to field-grown tomatoes decreased disease severity as measured by the area under the disease progress curve (AUDPC) by 17.5% (1997) and 16.8% (1998) compared with untreated control plants. Preharvest plant vigor ratings, taken twice during each field season, were higher in the bacteriophage-treated plants than in either bactericide-treated plants or nontreated controls except for the early vigor rating in 1998. Use of bacteriophages increased total weight of extra-large fruit 14.9% (1997) and 24.2% (1998) relative to that of nontreated control plants, and 37.8% (1997) and 23.9% (1998) relative to that of plants treated with the chemical bactericides. Chemical names used: manganese, zinc, carboxyethylene bis dithiocarbamate (mancozeb).
A major problem in the pot production of Zantedeschia (Calla Lillies) is the bacterial soft rot Erwinia carotovora. Sometimes if the corn is infected there may be no symptoms until the plant falls over. This disease can destroy an entire crop very quickly. Z. albomoculata, Z. Elliottiana', Z. Solfatare; and Z rehmannii were soaked for 5 minutes and 10 minute in 50 ppm and 100 ppm respectively in Agrox Strep a combination bactericide and fungicide. The 50 ppm for 5 minutes gave sufficient control of soft rot provided the plants were not overwatered. However, if overwatered the incidense of soft rot did reoccur. This was controlled by watering the plants every 10 days with 50 ppm of Agrox Strep.
Fisun G. Çelikel and Michael S. Reid
The respiration of flowers of stock [Matthiola incana (L.) R. Br.] had a Q10 of 6.9 between 0 and 10 °C. Simulated transport for 5 days resulted in marked reduction in the vase life of flowers transported at 10 °C and above. Flower opening, water uptake, and vase life of the flowers increased somewhat in a vase solution containing 50 ppm NaOCl, and considerably in a commercial preservative containing glucose and a bactericide. Exposure to exogenous ethylene resulted in rapid desiccation and abscission of the petals, effects that were prevented by pretreatment with 1-methylcyclopropene (1-MCP). Even in the absence of exogenous ethylene, the life of the flowers was significantly increased by inhibiting ethylene action using pretreatment with silver thiosulfate (STS) or 1-MCP. STS was more effective than 1-MCP in maintaining flower quality.
Theo J. Blom and Wayne Brown
Four sterilants-bactericides (Physan-20, Fixed Copper, Phyton-27, and Virkon) were compared as preplanting dips of Zantedeschia elliottiana Engl. W. Wats `Yellow' (a susceptible cultivar) rhizomes to reduce plant losses due to latent field-infected Erwinia carotovora soft rot during greenhouse forcing as a flowering potted plant. All sterilant solutions were prepared in combination with Promalin, a commercially available product containing gibberellic acid (GA) used to enhance flowering. An additional group of rhizomes was inoculated with E. carotovora sp. as a preplanting dip in combination with the GA treatment but were not treated with a bactericide. Rhizomes were wounded by making two cuts on the distal part of the rhizome or left unwounded before application of the preplant dip treatments. After potting, plants were fertilized with either a high (3.0 mmol·L-1) or a low (1.0 mmol·L-1) calcium nutrient solution through subirrigation. More than 90% of the inoculated rhizomes collapsed within 5 weeks after potting due to bacterial soft rot. With the uninoculated rhizomes, the copper-based compounds (Fixed Copper or Phyton-27) provided better control of bacterial soft rot than either Physan-20 or Virkon only during the first 6 weeks of forcing. During the remainder of the forcing period, there were no differences in weekly losses of rhizomes with the four sterilants. Confirmation of Erwinia carotovora subsp. carotovora (Jones) Bergey et al. as the causal organism was made throughout the experiment. Incisions on the rhizome before planting or calcium nutrition during forcing did not have any significant effect on disease severity. Rhizomes treated with solutions of the copper-based compounds produced 0.5 flowers less per rhizome than either Physan-20 or Virkon. High calcium fertilization resulted in an increase of 0.5 flowers per plant compared to low calcium nutrition.
William H. Olson and Richard P. Buchner
English walnut (Juglans regia) producers in California compete with many insect and disease pests to produce an acceptable crop. Traditional control strategies work reasonably well for most pests. However, environmental concerns, loss of certain pesticides and new or impending regulations threaten the use of many traditional techniques for control of many of the pests. Codling moth (Cydia pomonella), walnut husk fly (Rhagoletis completa), and walnut aphid (Chromaphis juglandicola) are the major insects that affect California walnut production. Control strategies that use integrated pest management programs, beneficial insects, mating disruption, insect growth regulators, improved monitoring techniques and precise treatment timing based on the insect's life cycle are leading edge techniques currently available for insect control in walnuts. Major diseases include walnut blight (Xanthomonas campestris pv. juglandis), crown gall (Agrobacterium tumefaciens) and crown and root rot (Phytophthora spp). Both copper resistant and copper sensitive strains of the walnut blight bacterium are best controlled with combinations of copper bactericides and maneb instead of copper materials alone. A new computer model, Xanthocast, used to forecast the need for walnut blight treatment is under evaluation. Crown gall is managed using a preplant biological control agent and a heat treatment to eradicate existing galls. Phytophthora crown and root rot is dealt with primarily by site selection, irrigation management and rootstock selection.