International Journal of Scientific Engineering and Research (IJSER) www.ijser.in ISSN (Online) : 2347-3878, Impact Factor (2014) : 3.05 Volume 3 Issue 11, November 2015 Licensed Under Creative Commons Attribution CC BY The Effects of Arbuscular Mycorrhizal Fungi (AMF) as Biofertilizer on the Growth, Yield and Nutrient Uptake of Tomato (Lycopersicon esculentum Mill.) Precelita L. Osillos 1 , Asuncion L. Nagpala 2 1 College of Arts and Sciences, Don Mariano Marcos Memorial State University, South La Union Campus, Agoo, La Union; School of Natural Sciences, Saint Louis University, Baguio City, Philippines 2 College of Agriculture, Benguet State University, La Trinidad, Benguet, Philippines Abstract: This study was conducted to determine the effect of arbuscular mycorrhizal fungi (AMF) to the growth, yield and nutrient uptake of tomato. AMF from the rhizosphere soil of wild legumes and cogon were trapped using corn roots as bait then isolated through wet sieving and sucrose centrifugation methods. Isolated spores of Gigaspora and Acaulospora dominated by Acaulospora laevis and colonized corn roots having a colonization rate of 86% were used as inoculants. The experiment utilized a completely randomized design with six treatments replicated three times. Data were evaluated using Levene’s test and ANOVA. Means with significant differences were compared using LSD and Games-Howell. Results showed that tomatoes inoculated with different preparations of AMF resulted to a faster increase in height, higher number of leaves and tallest plants from the 2 nd week to the 10 th week after inoculation. AMF application also resulted to earlier flower onset and fruit emergence. Inoculated plants had the highest yield of marketable fruits while those grown with the farmer’s practice gave the highest yield of non-marketable fruits. Leaves of inoculated plants had the highest amount Phosphorus (P), lower percentage of tissue Nitrogen (N), and higher Potassium (K) content as compared to the control. AMF inoculation did not affect soil pH but decreased the soil electrical conductivity (EC), K, P and gave the lowest increase of percent organic matter. Colonization was seen in all the plants treated with AMF, with T2 (100 AMF spores + 0.25 g colonized corn roots) registering the highest rate. Keywords: AMF, colonized roots, biofertilizer, tomato, Acaulospora 1. Background of the Study Improved and modern farming practices have been done to maximize crop production. These practices involve crop management through direct manipulation of soils, cultivars and pests (Johnson and Pfleger, 1992) which are not always advantageous to the ecosystem. The application of fertilizers contributes a lot in maintaining high crop productivity and soil quality. However, some studies have shown that continued use of inorganic fertilizers, herbicides and fungicides can diminish the quality and productivity of soils (Yang et al., 2004) by increasing soil acidity, change in soil nutrient availabilities and increased concentrations of NO – 3 -N and NH + 4 -N (Darusman, et al., 1991).In addition, human exposure to inorganic fertilizers and fungicides lead to a great health risk. Studies have shown that frequent exposure to these substances can cause liver and kidney damage, Blue Baby Syndrome, reduced immune response, birth defects and even cancer (Stout, 2010). The unfavorable effects of these chemicals to human health and to the environment promoted the use of beneficial microorganisms in the soil to increase crop yield and maintain soil ecological balance. Consequently, agricultural researches are now geared towards the discovery and use of microorganisms which are safer alternatives to inorganic fertilizers and chemical fungicides. Most farmers now use biofertilizers made up of living microorganisms. Application of biofertilizers to plant surfaces or soil allows the microorganisms to colonize the rhizosphere together with the plants and thus increase the supply or availability of nutrients to the host plants (Vessey, 2003). In this way, biofertilizers have been used as alternatives to chemical fertilizers to increase soil fertility and crop production in sustainable farming (Wu et al., 2004). The arbuscular mycorrhizal fungi (AMF) are well-known fungal symbionts that have an essential role in the establishment of plant communities, nutrient cycling and maintenance of soil structure (Miller and Jastrow, 1994 as cited by Rahman et al., 2006). They are capable of mobilizing Phosphorus, Nitrogen and serve as carbon sink in the soil (Bonfante and Genre, 2010). Their importance in sustainable agriculture is based on their role as link between plant and soil. They are agents of nutrient transfer and therefore contribute to soil conservation, soil nutrition and plant nutrition (Rai, 2006). The high metabolic rate and strategically diffuse distribution of these fungi in the upper soil layers allow them to efficiently translocate ions from the soil to the host plant. A number of studies had demonstrated that AMF influenced the growth and nutrient uptake of some crops like chickpea and custard-apple (Kumar et al., 2002). The symbiotic association of the mycorrhizal fungus also resulted to a greater uptake of P and increased chlorophyll content in AMF treated plants as compared to the non- mycorrhizal plants (Ojha et al., 2008). The abilities of AMF to colonize their host and facilitate the transport of nutrients from the soil to the plant make these fungi an interesting object of research to improve crop yield and soil quality. Paper ID: IJSER15576 49 of 65