Effect of Biofertilizers and Irrigation Intervals on Yield Component and Yield of Fenugreek (Trigonella foenum- graecum L.)

Introduction Drought is one of the most important factors whichdecrease crop production in arid and semi-arid regions of the world (1, 20). Appropriate nutritional management has an effective role in the resistance to environmental stresses on crops (7). An important issue about sustainability of food production is the maintenance of soil fertility through the use of organic matter and biofertilizers. One option to increase agricultural production is the use of beneficial soil microorganisms such as PGPR and fungi (45). This group of bacteria through biological fixation of nitrogen, increase phosphorus and potassium solubility, an increasethe availability of mineral elements in the soil, inhibits pathogen appearance and producehormones that regulate the growth of plants to affect crop yield (18, 47). Mycorrhiza enablesymbiosis with the roots of most crop plants, through the availability of phosphorus, nitrogen and other nutrients and thus increases water absorption and produces plant hormones, increases resistance to pathogens and environmental stresses, strengthens the soil microbial community and induces improving the growth and performance of plants in agricultural systems (5, 32, 37, 40).Fenugreek (Trigonella foenum- graecum L.)is an annual herbaceous plant that reaches a height of 50 cm (14). Since limited water is at very critical level now, the importance of further research in this area is felt. So, the study of medicinal plants considring water management and organic food is very important. Therefore, the aim of this research is to evaluate the effect of organic and biofertilizers and irrigation on yield and yield components of fenugreek in Birjand.
Materials and Methods In order to study the effects of irrigation intervals and biofertilizers on quantitative traits and yield of fenugreek, an experiment was carried out in a split plot based on a complete randomized block design with 3replications at the research station, Faculty of Agriculture, Azad University, Birjand, Iran, during 2010-2011. Experimental treatments were irrigation intervals in three levels (every 6, 9 and 12 days) and biofertilizer in five levels (nitroxin, biophosphorus, and micorhyza fungi G. mosseae, G. intraradices and control-no fertilizer). Fenugreek was planted through furrow in mid-April 2010. The distance between rows and between plants was 30 and 10 cm, respectively. Seeds were covered by Nitroxin (including: Azotobacterchroococcum, Azospirillum lipoferum and Azospirillum brasilense) and biophosphrous (including: Pseudomonas fluorescens) and then were cultured.They were used at a depth of 2cm below the seed from Glomusintraradiceand Glomus mosseae. Fenugreek was harvested in early July when the plants became yellow and at least 80% of the pods were reached. Statistical analysis of the data was performed using SAS 9.1 and MSTATC. Mean comparison were compared by the Duncan test at 1% and 5% level of probability.
Results of statistical analysis showed that irrigation treatments and biofertilizers had significant effect on most indices. Interaction effect of irrigation and biofertilizer were significant on seed and leaf yield (p