Microorganismos asociados a frutos embolsados de guayaba taiwanesa variedad Tai Kuo

Abstract

This study was conducted to identify a putative guava microorganisms observed on bagged fruits in a commercial plantation established in Carrillo de Poás, Alajuela, Costa Rica, during the dry and rainy seasons of year 2007. Laboratory isolations were conducted to determine the presence and nature of the microorganisms associated with the symptoms. Four different materials were used to bag the fruits: wax paper, tergal (nylon bag), telephone directory paper and Taiwanese bag. Damaged tissues were placed in PDA and PDA + lactic acid as culture media, and the isolates were transferred to YDC, King agar and potato fleshy tissue to identify possible bacteria. Microorganisms identified in both seasons were: Colletotrichum sp., Pseudomonas, Pestalotia and two unidentified microorganisms. Highly significant differences were found (X2= 7,52 × 10 -4) in the incidence of the diseases in the following ranking: control > telephone directory paper bags > tergal bags> Taiwanese bag > wax paper bags, during the dry season. Highly significant differences were also found (X2= 0,04773) for microorganisms incidence during the rainy season, when control > tergal bag > Taiwanese bag. The results suggest that the microorganism isolated from diseased fruits could be responsible for losses of commercial fruits in tropical guava field plantations. (English) [ABSTRACT FROM AUTHOR]