BIO-CONTROL ACTIVITY OF BACTERIAL STRAINS ON POSTHARVEST PERFORMANCE OF Gladiolus L. HYBRIDS ‘MAMMOTH’

Abstract

A study was carried out to elucidate the efficacy of different bacterial strains on controlling detrimental bacteria and on vase life extension of Gladiolus L. hybrids 'Mammoth'. In a preliminary study, three bacterial strains (Bacillus pumilus, Delftia acidovorans, and Herbasperillum sp.) were isolated from the vase solutions of cut Gladiolus, identified and cultured to obtain the bacteria to be used in the study. These isolated strains were compared with two strains of Pseudomonas fluorescens (PF-279 and PF-417). All tested strains produced similar vase life of cut gladiolus stems, which was also similar to that of stems placed in tap water. However, stems placed in solutions with PF-279 Pseudomonas fluorecsens resulted in highest water uptake, while the stems placed in solutions with higher concentrations of Herbasperillum sp. (10 or 20 mL L-1) had lowest water uptake. Cut stems require low pH for sustaining water uptake and vase life extension, but use of nutrient broth to culture bacteria increased initial solution pH, which resulted in early senescence of cut stems due to rapid bacterial growth, vascular occlusion due to embolisms and reduced stem hydraulic conductance compared to the stems placed in tap water (control). In summary, tested bacterial strains had no effect on controlling detrimental bacteria present in the vase solutions or vase life extension of cut gladiolus and cannot be used in organic floral preservatives for holding cut stems after harvest.

Water Relationships, Vase Life and Quality of Solidago Cut Spikes as affected by some Natural Extracts in Holding Solutions

“…The sugar provides a respiratory substrate, whereas the germicide controls harmful bacteria and prevents plugging of the conducting tissues (Rahman et al 2012). A major form of deterioration in cut flowers is the blockage of xylem vessels by air and microorganisms that cause xylem occlusion (Ahmad et al, 2016). Numerous natural extracts and chemical preservatives are available to increment longevity.…”