Investigation of the Effect of Different Levels of Humic Acid and Plant Density on Quantitative and Qualitative Characteristics of Fenugreek (Trigonella foenum- graecum L.)

The effects of applications of humic acid and planting density on characteristics of fenugreek were evaluated. Treatments were of three levels of humic acid (0, 5 and 10 kg ha-1) and tow density planting (25, 50 plants /m 2). This experiment was carried out as factorial based on randomized completely block design with three replications. The results showed that humic acid was significant on fresh and dry weight of the plant, so that the fresh and dry weight of the plant were recorded in 10 kg ha-1 humic acid and the lowest fresh and dry weight of the plant were obtained in control treatment, however, there was no statistically significant difference between treatments of 5 and 10 kg ha-1 in dry matter per plant. The results showed a significant effect of humic acid on the number of leaves and its pigments. The highest number of leaves (44.77) was observed from application of 10 kg ha-1 humic acid and the lowest number of leaves (32.55) was obtained in control treatment. Planting density was significant on the index of harvest index. The highest harvest index was obtained with 72.57% in the density of 50 plants/m 2 and the lowest was 57.79% in a density of 25 plants/m 2. Also, the interaction of humic acid and plant density on biological yield and 1000 seed weight were significant, so that the highest biological yield was observed in 10 kg.ha-1 humic acid and plant density 50 plants/m 2.