Effects of co-inoculation of Bioformulates (PGPR's) on germination percentage and growth promotion in papaya (Carica papaya L.) seedlings

Abstract

Dormancy is a blockage to germination and represents an adaptive mechanism that allows papaya seed to delay its emergence. Rhizobacteria improve plant growth in several ways, phytohormone production, nitrogen fixation, phosphate solubilization and increase root morphology. The present investigation was conducted to determine the efficiency of rhizobacteria (PGPR's) Pseudomona protegens (CHA0) and Pseudomona putida (BMR 2-4) inoculated within three bioformulates to be evaluated within the percentage of germination, increase of absorbing hairs using rhizotrons and seedlings under consortia or in combination of phosphorus fertilizers. Under in-vitro conditions, BIOIMPULSE co-inoculation was very effective in increasing germination percentage with an average of 80%. In rhizotrons, a greater increase in absorbing hairs of 5.67 mm and root area of 0.86 mm2 per BIOIMPULSE was exhibited, comparable to the treatment with AIA (25 mg/mL). In seedlings, BIOIMPULSE is highly effective in improving root morphology and height by emendando 5 g/L phosphorus was observed Ø hypocotyl dimensions between (5.12 to 4.62 mm) and functional leaves (9.75 to 11.75). BIOIMPULSE modifies root functioning, improves plant nutrition, and influences vegetative physiology, being versatile over all other bioformulates by increasing the germination percentage, early appearance of root hairs and root growth in the presence of phosphorus fertilizers. This means that they can be useful to reduce the cost of chemical fertilizers.