Studies on effect of PGPR on growth and yield of Tomato (solanum lycopersicum l.)

DOI: 10.22161/ijeab.114.17

Abstract:
The excessive dependence on chemical fertilizer has resulted in declining soil fertility, reduced microbial diversity, environmental pollution and increased production cost. The study aimed to evaluvate the efficiency uses of Azotobacter sp. and Pseudomonas sp. individually and in combination for promoting N-fixation, P-solubilization, siderophore production and phytohormone production like IAA and GA3. The PGPR microorganism namely Azotobacter sp. and Pseudomonas sp. were isolated from the rhizosphere soil of different tomato cultivating field in cuddalore district. Among the all isolates Az-5 and Az-2 recorded highest nitrogenase activity and cellular nitrogen content. Among the isolated Pseudomonas strain Ps-4 exihibited the greatest phosphate solubilization of followed by Ps-2 demonstrated significant phosphate solubilization of . Azotobacter isolates Az-5 and Az-2, Pseudomonas isolates Ps-4 and Ps-2 subjected to evaluvation of plant growth promoting traits like siderophore, IAA and GA3 production. Among the selected strain Az-5 and Ps-2 shows highest production of siderophore and phytohormone production. Azotobacter isolates Az-5 and Pseudomonas isolates Ps-2 were selected efficient strain used as the bioinoculant treatment in subsequent pot culture experiment. The result showed that dual inoculation of PGPR Az-5 and Ps-2 combined with 75% of the recommended NPK resulted maximum germination%, vigour index, No of fruits, fruit weight and fruit yield which is practically on par with 100% NPK. The study revealed that 25% of synthetic fertilizer have been reduced by using dual bioinoculant without reduction in yield.

Keywords:
Azotobacter, phytohormone production, Pseudomonas, siderophore production, synthetic fertilizer

Article Info:
Received: 18 Jun 2026; Received in revised form: 15 Jul 2026; Accepted: 19 Jul 2026; Available online: 26 Jul 2026

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