Tomato (Lycopersicon esculentum Mill.) is one of the important vegetable crops grown throughout the year. Alkaline cultivable soil contains less available phosphorus. Due to higher concentration of calcium, whenever phosphatic fertilizers are applied in such soils, a large quantity gets immobilized and becomes unavailable to the crop. Phosphorus is one of the most important mineral nutrients for plant growth and development. It is second only to nitrogen, limiting the growth of crops. Plants acquire P from soil. However, most of the soil phosphorus, approximately 95–99%, is present in the form of insoluble phosphates (Abou El-Yazeid et al, 2007). As a result, the amount available to plants is usually a small proportion of the total P. To increase the availability of phosphorus to plants, farmers apply large quantities of phosphoric fertilizer. But, after application, a large proportion of available phosphorus quickly turned into the insoluble form (Rodriquez and Farag, 1999). Hence, a very small percentage of applied phosphorus is used by plants (Abd Alla, 1994). Several scientists (Asea et al, 1988; Surange et al, 1995; Nahas, 1996; Dutton and Evans,1996; Gull et al, 2004) have reported the ability of different bacterial species to solubilize insoluble inorganic phosphate compounds. Phosphate solubilizing bacteria play an important role in supplementing phosphorus to plants, allowing sustainable use of phosphate (Bhatacharya and Jain, 2000). Soil and seed inoculation with phosphate Effect of phosphorus solublizing bacteria (PSB) on growth and yield in tomato M.K. Poonia and B.L. Dhaka Krishi Vigyan Kendra Maharana Pratap University of Agriculture & Technology P.B. No. 4, Bundi-323001, India E-mail : kumarmp03@rediffmail.com ABSTRACT A field experiment was conducted to study the effect of phosphate solublizing bacteria (PSB) on growth and yield of tomato. PSB culture was applied through soil and seedling root dip before transplanting with two levels of phosphorus fertilizers, i.e., 75% and 100% of recommended P, and compared. Results revealed that application of 100% P with seedling dip in PSB 1:10 solution recorded significantly higher plant height (86.30cm), leaf area index (3.52), number of fruits/plant (16.32), fruit weight (77.75g), fruit yield/plant (1125g) and yield (392.26 q/ha) compared to other treatment combinations, except 100% P with 5kg/ha soil application of PSB. The same treatment also recorded the highest (3.41) cost:benefit ratio. However, no significant difference was noticed in 100% recommended P with seedling dip in PSB solution, or soil application. Key words: Tomato, phosphorus, phosphoros solublizing bacteria, PSB solubilizing bacteria (PSB) improves solubilization of fixed soil phosphorus and of applied phosphates, resulting in higher crop yields (Jones and Darrah, 1994; Toro et al, 1997; Bhatacharya and Jain, 2000). In this context, the present study is designed to evaluate the effect of PSB on growth and yield in tomato crop. A field experiment was carried out at farmers’ fields during Zaid 2010 (i.e., summer crop) to study the effect of phosphate solubilizing bacterial strain on growth and yield of tomato. Four week old seedlings of tomato were transplanted on ridges in the field toward the end of February with a spacing of 60cm x 45cm. Soil in the experimental field was clay loam in texture, slightly alkaline in reaction (pH 8.10), low in organic carbon content (0.38%), available N (205.4 kg ha-1) and available P (18.1 kg ha-1) but high in available K (350 kg ha-1). This experiment included a control and four treatments (which were a combination of two levels of P:75 and 100% of recommended P 2 O 5, i.e., 80 kg ha-1 and two modes of PSB inoculation (soil and root inoculation). Treatments applied were : T 1 – 100 % of recommended P (Control) T 2 - 75 % of recommended P with seedling dip in PSB 1:10 solution (1kg PSB:10 litre water), T 3 -100 % of recommended P with seedling dip in PSB 1:10 solution (1kg PSB:10 litre water), T 4 - 75 % of recommended P with soil application of PSB@ 5kg ha-1 Short communication J. Hortl. Sci. Vol. 7(1):104-107, 2012 105 Effect of PSB on growth and yield in tomato and T 5 - 100 % of recommended P with soil application of PSB @ 5kg ha-1. These treatments were arranged in a randomized block design and replicated four times. The N and K fertilizers in all treatments including control were applied as per recommended package of practices for the region and the PSB was supplied by IFFCO. Full amount of P as per treatments was applied just before transplanting through drilling in rows. Observations on growth parameters like plant height, leaf area index and yield attributing characteristics i.e. no. of fruits/plant, fruit weight (g), fruit yield/ plant, fruit yield (q/ ha) were recorded. The experimental data were subjected to statistical analysis of variance and test of significance through the procedure appropriate to the Randomized Block Design (Panse and Sukhatme,1989). The plant height and leaf area index are considered to be an important factor to judge the efficacy of phosphorus solublizing bacteria and were found to increase to a significant level with the application of phosphorus solublizing bacteria. The results in Table 1 revealed that the application of 100% recommended P with seedling dip in PSB 1:10 solution significantly increased plant height and leaf area index over control as well as other treatments. The treatment T 3 (100% P with seedling dip in PSB 1:10 solution) increased plant height (86.30cm) and leaf area index (3.52). The increase in growth characters might be due to stimulative effect of PSB on P solubilization leading to higher P availability and uptake by plants (Han et al, 2006; Kim et al,1997; Sharma et al,2007 and Turan et al,2007). Higher microbial activity in rhizosphere expressed as activity of hydrogenase, phosphates and nitrogenase enzymes was also reported (El- Tantawy and Mohamed, 2009). The results illustrated in Table 1 indicate that application of 100% of recommended P with seedling dip in PSB 1:10 solution was superior for enhancing number of fruit per plant and fruit size of tomato. This observation may be due to role of PSB inoculation in benefiting plant growth by improving root development, mineral uptake and plant water relationship. In addition to increased P availability, PSB also reported to produce growth promoting substances which might enhance the crop growth. These hormones from PSB might have increased the various endogenous hormonal levels in plant tissue, that may enhance pollen germination and tube growth, which ultimately increased the fruit set. The higher fruit set may also be due to higher percentage of productive flowers. It is clear from the data presented in Table-1 that application of 100 % of recommended P with seedling dip in PSB 1:10 solution (T 3 ) treatment was the superior for increasing the total yield (392.26q/ha) which is significantly higher over control and at par with T 5 . The highest yield might be due to the high yield contributing characters like number of fruits per plant and average fruit weight. Solubilization of ‘P’ from insoluble and fixed / adsorbed forms is an important aspect regarding P availability in soils. Microbial biomass assimilates soluble P, and prevents it from adsorption or fixation (Khan and Joergensen, 2009). Microbial community influences soil fertility through soil processes viz. decomposition, mineralization, and storage / release of nutrients. Microorganisms enhance the P availability to plants by mineralizing organic P in soil and by solubilizing precipitated phosphates (Chen et al, 2006; Kang et al, 2002 and Pradhan and Sukla, 2005). These bacteria in the presence of labile carbon serve as a sink for P by rapidly immobilizing it even in low P soils (Bünemann et al, 2004). Subsequently, PSB become a source of P to plants upon its release from their cells. Similar results were reported in tomato (El-Tantawy and Mohamed, 2009 and Shukla et al, 2009), Cauliflower (Kachari and Korla, 2009), turmeric (Padmapriya and Chezhiyan, 2009), pea (Chaykovskaya et al,2001) and guava (Dutta et al, 2009). Table 2 indicated that the highest net return (Rs. 242607.41) and benefit: cost ratio of 3.41 was recorded with 100% of recommended P with seedling dip in PSB 1:10 solution (T 3 ). This may be attributed to high yield recorded in this treatment. Similar observation were also reported in Table 1. Effect of phosphorous solublizing bacteria on the growth and yield attributes of tomato. Treatments Plant height Leaf area No. of fruits / Fruit Fruit yield/ Fruit yield (cm) index plant weight (g) plant (q/ ha) T 1 75.88 2.96 14.93 67.18 978.75 344.16 T 2 81.05 3.20 15.49 73.38 1040.00 364.61 T 3 86.30 3.53 16.32 77.75 1125.00 392.26 T 4 80.70 3.21 15.44 72.90 1038.75 362.47 T 5 85.58 3.51 16.24 76.98 1122.50 389.93 CD (P=0.05) 1.21 0.076 0.37 1.27 7.19 4.41 SEm+ 0.96 0.060 0.29 1.01 5.70 3.50 J. Hortl. Sci. Vol. 7(1):104-107, 2012 106 tomato (Premsekhar and Rajashree, 2009), clusterbean (Dadhich and Gupta 2001) and wheat (Singh et al, 2009). It could be concluded that root inoculation with PSB 1:10 solution (1kg PSB:10 litre water) in the presence of 100% P (full recommended P 2 O 5 dose) significantly increased plant height, leaf area index, number and yield of fruits per plant, fruit weight and yield per hectare. The highest net return and cost: benefit ratio were also recorded with the same treatment. REFERENCES Abd Alla, M.H. 1994. Phosphatases and the utilization of organic phosphorus by Rhizobium leguminosarum biovar viceae. Lett. Appl. Microbiol., 18: 294-296 Abou El-Yazeid, A Abou–Aly, H.E, Magdy, M.A. and Mousa, S.A.M. 2007. Enhancing growth, productivity and quality of squash plant using phosphate dissolving microorganisms (Bio phosphor) combined with boron foliar spray. Res. J. Agric. & Biol. Sci., 3: 274–286 Asea, P.E.A., Kucey, R.M.N. and Stewart, J.W.B. 1988. Inorganic phosphate solubilization by two Penicillium species in solution culture and soil. Soil Biol. Biochem., 20: 459-464 Bhatacharya, P. and Jain, R.K. 2000. Phosphorous Solublizing Biofertilizers in the whirl pool of rock phosphate-challenges and opportunities. Fert. News, 45:45-52 Bünemann, E. K., Bossio, D. A., Smithson, P. C., Frossard, E. and Oberson, A. 2004. Microbial community composition and substrate use in a highly weathered soil as affected by crop rotation and P fertilization. Soil Biol. Biochem. 36:889-901 Chaykovskaya, L.A., Patyka, V.P. and Melnychuk, T.M. 2001. Phosphorus mobilizing microorganisms and their influence on the productivity of plants. In (W.J. Horst, Eds.) Plant Nutrition-Food Security and Sustainability of Agroecosystems, pp: 668-669 Chen, Y. P., Rekha, P. D., Arunshen, A. B., Lai, W. A. and Young, C. C: 2006. Phosphate solubilizing bacteria from subtropical soil and their tricalcium phosphate solubilizing abilities. Appl. Soil Ecol., 34:33-41 Dadhich, L.K. and Gupta, A. 2001. Effect of phosphate solubilizing bacteria and phosphorus on the growth pattern of clusterbean. Annals of Biol, 17:107 110. Dutta, P. Maji, S.B. and Das, B.C. 2009. Studies on the response of bio-fertilizer on growth and productivity of guava. Indian J. Hort., 66:39-42 Dutton, V. M. and Evans, C. S. 1996. Oxalate production by fungi: its role in pathogenicity and ecology in the soil environment. Can. J. Microbiol., 42:881-895 El-Tantawy, M.E. and Mohamed, M.A.N. 2009. Effect of Inoculation with Phosphate Solubilizing Bacteria on the Tomato Rhizosphere Colonization Process, Plant Growth and Yield under Organic and Inorganic Fertilization. J. Appld Sci. Res., 5:1117-1131 Gull, M., Hafeez, F. Y., Saleem, M. and Malik, K. A. 2004. Phosphorus uptake and growth promotion of chickpea by co-inoculation of mineral phosphate solubilizing bacteria and a mixed rhizobial culture. Aust. J. Exp. Agric., 44:623-628 Han, H.S.; Supanjani and Lee, K.D. 2006. Effect of co- inoculation with phosphate and potassium solubilizing bacteria on mineral uptake and growth of pepper and cucumber. Plant Soil Environ., 52:130-136 Jones, D.L. and Darrah, P.R. 1994. Role of root derived organic acids in the mobilization of nutrients from the rhizosphere, Plant Soil, 166: 247-257 Kang, S. C., Hat, C. G., Lee, T. G. and Maheshwari, D. K. 2002. Solubilization of insoluble inorganic phosphates by a soil-inhabiting fungus Fomitopsis sp. PS 102. Curr. Sci. 82:439-442 Kim, K.Y., Jordon, D. and McDonald, G.A. 1997. Effect of Phosphate- solubilizing bacteria and vesicular – arbuscular mycorrhizae on tomato growth and soil microbial activity. Biology and Fertility of Soils, 265:79-87 Khan, K. S. and Joergensen, R. G.; 2009. Changes in microbial biomass and P fractions in biogenic household waste compost amended with inorganic P fertilizers. Bioresour. Technol.,100:303-309 Kachari Manisha and Korla, B.N., 2009. Effect of biofertilizers on growth and yield of cauliflower cv. PSB K-1. Indian J. Hort., 66:496-501 Nahas, E. 1996. Factors determining rock phosphate solubilization by microorganism isolated from soil. World J. Microb. Biotechnol., 12:18-23 Table 2. Effect of phosphorous solublizing bacteria on the economics of tomato crop. Treatments Gross return Net return B:C (Rs) (Rs) ratio T 1 275325.19 204825.19 2.91 T 2 291688.89 221288.89 3.14 T 3 313807.41 242607.41 3.41 T 4 289974.07 219674.07 3.12 T 5 311940.00 241040.00 3.40 CD (P=0.05) 3529.73 3529.73 0.05 SEm+ 2801.23 2801.23 0.04 Poonia and Dhaka J. Hortl. Sci. Vol. 7(1):104-107, 2012 107 Padmapriya, S. and Chezhiyan, N. 2009. Effect of shade, organic, inorganic and biofertilizers on morphology, yield and quality of turmeric. Indian J. Hort., 66:333-339 Panse, V.G. and Sukhatme, P.V. 1989. Statistical methods for agricultural workers, ICAR, New Delhi Pradhan, N. and Sukla, L. B. 2005. Solubilization of inorganic phosphate by fungi isolated from agriculture soil. African J. Biotechnol., 5:850-854 Premsekhar, M. and. Rajashree, V. 2009: Influence of bio- fertilizers on the growth characters, yield attributes, yield and quality of tomato: Am.-Eurasian J. Sustain. Agric., 3:68-70 Rodriquez, H. and Farag, R. 1999. Phosphate solubilizing bacteria and their role in plant growth promotion. Biotechnol. Adv., 17:319- 339 Sharma, K., Dak, G., Agrawal, A., Bhatnagar, M. and Sharma, R. 2007. Effect of phosphate solubilizing bacteria on the germination of Cicer arietinum seeds and seedling growth. J. Herb. Med. Toxicol., 1:61-63 Shukla, Y.R., Thakur , A.K. and Joshi, A. 2009. Effect of inorganic and bio-fertilizers on yield and horticultural traits in tomato. Indian J. Hort., 66:131-133 Singh, R., Singh, B. and Patidar, M. 2009. Effect of preceding crops and nutrient management on productivity of wheat (Triticum aestivum) based cropping system in arid region. Indian J. of Agron., 52:267 272 Surange, S., Wollum, A. G., Kumar, N. and Nautiyal, C. S. 1995. Characterization of Rhizobium from root nodules of leguminous trees growing in alkaline soils. Can. J. Microbiol., 43:891-894 Toro, M., Azcon, R. and Barea, J.M. 1997. Improvement of Arbuscular Mycorrhiza Development by Inoculation of Soil with Phosphate-Solubilizing Rhizobacteria To Improve Rock Phosphate Bioavailability ((sup32) P) and Nutrient Cycling, Appl. Environ. Microbiol, 63: 4408-4412 Turan, M. Ataoglu, N. and Sahin, F. 2007. Effect of Bacillus FS-3 on growth of tomato (Lycopersicon esculentum L.) plant and availability of phosphorus in soil. Plant Soil Environ., 53:58-64 (MS Received 13 January 2012, Revised 4 May 2012) Effect of PSB on growth and yield in tomato J. Hortl. Sci. Vol. 7(1):104-107, 2012