Evaluating the amount of trigonelline and growth factors on the medium reinforced with vermicompost and chemical fertilizer in Iranian fenugreek (Trigonella foenum-graecum L.)

This research was aimed to study the effects of different levels of fertilizer and vermicompost on performance indicators and the amount of hypoglycemic active ingredient (trigonelline) in fenugreek (Trigonella foenum-graecum L.) for domestic and pharmaceutical uses. The experiment was conducted in a completely randomized design with two treatments and five replicates in comparison with the control group. The treatments consisted of three levels of NPK fertilizer (5, 10 and 15 grams) and vermicompost (10, 20 and 30% by volume), and the control pots containing garden soil with no treatments. The plant height, leaf number, leaf length, dry weight, fresh weight, and the amount of trigonelline were measured and evaluated. Our results showed that high levels of vermicompost and fertilizer increased the growth characteristics and the amount of trigonelline. According to the results, the highest concentration of trigonelline, shoot dry weight, shoot fresh weight, and leaf length were recorded for the treatments of 30% vermicompost; 15 g fertilizer; 15g fertilizer and 30% vermicompost; and 15 g fertilizer and 30% vermicompost, respectively. In general, 15g chemical fertilizer and 30 % by volume of vermicompost were the best treatments to increase the concentration of trigonelline and growth factors. Thus, to avoid the hazards of chemical fertilizers, the use of vermicompost is recommended for the cultivation of Fenugreek.