Distribution and significance of causal agents of bacterial spot of pepper and tomato

Abstract

Bacterial spot of pepper and tomato regularly causes losses in production in Serbia. According to the new systematization, four Xanthomonas species have been reported as causal agents of leaf spots of pepper and tomato: X. euvesicatoria, X. vesicatoria, X. perforans and X. gardneri. Due to wide distribution and great damage at the global level, X. euvesicatoria is considered one of the most significant parasitic bacteria of pepper. Causal agent of the bacterial spot on tomato in Serbia is X. vesicatoria. Occurrence of of both species is observed every year under Serbian agroecological conditions, mainly due to the cultivation of susceptible assortment and conditions which are suitable for disease development. The disease is seed transmitted and it can cause defoliation and crop degradation if conditions suitable for its development occur. Bacterial spot of pepper and tomato cannot be combatted easily and application of several cultivation practices including conventional or microbial preparations - biopesticides is therefore required. The existence of natural antagonists (bacteriophage) isolated from soil has been confirmed, which could be used for biological control of pepper bacterial spot. In the absence of effective preventive measures, the solution should be sought within an integrated approach - the synthesis of knowledge about the biology and epidemiology of the pathogen, crop production technology, as well as bactericidal effect of some natural agents.

Prema najnovijoj sistematici kao prouzrokovači bakteriozne pegavosti paprike i paradajza navode se četiri vrste roda Xanthomonas: X. euvesicatoria, X. vesicatoria, X. perforans i X. gardneri. Prema rasprostranjenosti i štetama koje nanosi, prouzrokovač bakteriozne pegavosti lišća i krastavosti plodova X. euvesicatoria spada u najznačajnije bakterije parazite paprike u svetu, dok se u agroekološkim uslovima Srbije, usled gajenja osetljivog sortimenta i povoljnih uslova za razvoj bolesti, pojavljuje svake godine u većem ili manjem intenzitetu. Kao prouzrokovač ovog oboljenja na paradajzu navodi se X. vesicatoria. Bakterije se prenose semenom i u povoljnim uslovima za razvoj bolesti, mogu prouzrokovati plamenjaču, potpunu defolijaciju i izumiranje biljaka. U zaštiti od bakteriozne pegavosti paprike i paradajza potrebno je preduzeti niz mera koje podrazumevaju korišćenje konvencionalnih, ali i bioloških preparata. Utvrđeno je postojanje prirodnih antagonista (bakteriofaga) izolovanih iz zemljišta koji se mogu koristiti u biološkoj borbi. U nedostatku efikasnih mera, rešenje treba tražiti u integralnom pristupu, odnosno sintezi saznanja o biologiji i epidemiologiji patogena, tehnologiji biljne proizvodnje, kao i baktericidnom efektu pojedinih prirodnih agenasa.