2. Learning Objectives The learner will be abble to : - identify the symptoms associated with bacterial spot on pepper and tomato - know the causal agents of bacterial spot on tomato and pepper - know the most widespread techniques used in the control of this disease
3. Introduction Bacterial spot on pepper and tomato - Major disease in FL and worldwide - Economic losses : up to 50% (Pohronezny and Volin, 1983) Tomato industry in FL : $ 550 millions in 2006 (USDA ERS, 2008) Pepper industry in FL - From November to May: National dependence for the supply of fresh peppers - 34 % of the national bell pepper acreage in 2004 (Mossler et al., 2006)
5. A : water-soaked young lesions B: enlarged lesions with water-soaked appearance C: necrotic tissues Sun, X., Nielsen, MC and Miller, JW. 2002. Bacterial spot of tomato and peper. Plant Pathology circular. No. 129. p. 4.
6. Fruits symptoms A : Fruits symptoms On Tomato B : Fruits symptoms On pepper Sun, X., Nielsen, MC and Miller, JW. 2002. Bacterial spot of tomato and peper. Plant Pathology circular. No. 129. p. 4.
7. Causal agent Causal agent : Xanthomonascampestrispv. vesicatoria(formerly) - X. perforans on tomato, and X. euvesicatoria on peper Cultivar of pepper and tomato have been used to characterize races of xanthomonadspathogenic to theses plants Jones, JB, and Stall, RE. 1998. Diversity among xanthomonads pathogenic on pepper and tomato. Annual Review of Phytopathology 36:41-58.
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10. Cultural practices Use disease – and pathogen –free transplants. Avoid clipping the seedlings to reduce bacterial secondary spread. Do not place cull piles near tomato or pepper fields. Avoid overhead irrigation watering in transplant production. Eliminate volunteer tomato and solanaceousweeds such cherry and nightshade in the vicinity of tomato or pepper fields. Decontaminate tools after working in the infested fields
11. Control of bacterial spot Copper based bactericides , routinely used - Frequent occurrence of resistant copper strains Copper + an EBDC fungicide (mancozeb, maneb…) Copper resistance genes in Xanthomonasperforansin strains from Florida , Oklahoma ,from California
12. Control Actigard : Application every 14 days - Activation of plant defense response Phages (bacteriophages) - Phages are viruses that infect bacteria. - A registered product is Agriphage (AgriPhi, Inc, UT). - formulated phages could be applied twice a week at sunset for the management of bacterial spot
13. Integrated Management Purpose - reduction of bacterial sources and minimization of plant susceptibility. Factible combinations : Actigard and copper-mancozeb combination. or Actigard and AgriPhage combination : Application of Actigard : every 14 days. Use of phage twice a week : Application before sunset