Development of formulations of biological agents for management of root rot of lettuce and cucumber

Abstract

The effect of various carrier formulations of Bacillus subtilis and Pseudomonas putida were tested on germination, growth, and yield of lettuce and cucumber crops in the presence of Pythium aphanidermatum and Fusarium oxysporum f.sp. cucurbitacearum, respectively. Survival of B. subtilis and P. putida in various carriers under refrigeration (about 0 degree C) and at room temperature (about 22 degrees C) was also studied. In all carrier formulations, B. subtilis strain BACT-0 survived up to 45 days. After 45 days of storage at room temperature (about 22 degrees C), populations B. subtilis strain BACT-0 were significantly higher in vermiculite, kaolin, and bacterial broth carriers compared with other carriers. Populations of P. putida were significantly higher in vermiculite, peat moss, wheat bran, and bacterial broth than in other carriers when stored either under refrigeration (about 0 degree C) or at room temperature (about 22 degrees C) for 15 or 45 days. Germination of lettuce seed was not affected in vermiculite, talc, kaolin, and peat moss carriers, but germination was significantly reduced in alginate and bacterial broth carriers of B. subtilis compared to the non-treated control. Germination of cucumber seed was not affected by any of the carriers. Significantly higher fresh lettuce and root weights were observed in vermiculite and kaolin carriers of B. subtilis compared with P. aphanidermatum-inoculated control plants. Lettuce treated with vermiculite, and kaolin carriers of B. subtilis, or non-inoculated control lettuce plants had significantly lower root rot ratings than talc, peat moss, bacterial broth, and P. aphanidermatum-inoculated control plants. Growth and yield of cucumber plants were significantly higher in vermiculite-based carrier of P. putida than the other carriers and Fusarium oxysporum f.sp. cucurbitacearum-inoculated plants.

Advances in plant growth-promoting bacterial inoculant technology: formulations and practical perspectives (1998–2013)

“…Short-term storage is highly affected by temperature. Using various organic, inorganic, and polymeric formulations, Bacillis subtilis survive at room temperature (~22°C) for 45 days, but Pseudomonas putida requires refrigeration (~0°C) and depends on the type of carrier that is used (Amer and Utkhede 2000). When γ-irradiated cork compost or perlite inoculants, with zero contamination, were stored at 25°C, rhizobia in these inoculants remained unchanged for 90-120 days of incubation; inoculants composed of two clays maintained a high bacterial population for more than 5 months (Albareda et al 2008).…”

The biological activity of bacterial vaccine of Pseudomonas putida2 and Pseudomonas fluorescens3 isolates to protect sesame crop (Sesamum indicum) from Fusarium fungi under field conditions

“…Mean of fungi growth in control treatment (Amer & Utkhed, 2000). Under sterilized conditions inside Lab, Biocide was prepared for each isolate in concentration of 9 log 10 15 cfu/1 ml in sterilized Petri dishes size 9 cm, each contains 10 ml of bacterial vaccine with 10 gm from wheat bran powder.…”

Evaluation of Different Carrier Materials for Development of Bacterial Bio-Control Agents Formulations with Enhanced Shelf-Life

“…This is in accordance to the observation that once the dormancy was broken, perlite II with larger pores (8 μm) was more effective in stimulating the proliferation of the vegetative cells than perlite I with smaller pore size (3.7 μm). Amer and Utkhede (2000) were formulated the Bacillus subtilis and Pseudomonas putida using various carrier material such as vermiculite, talc, kaolin, and peat moss. In all carrier formulations, B. subtilis strain BACT-0 survived up to 45 days, the populations B. subtilis strain BACT-0 were significantly higher in vermiculite, kaolin, and bacterial broth carriers compared with other carriers.…”