Impact of Bio- and chemical fertilization on Growth, Yield, Essential oil and Chemical Composition of Fennel (Foeniculum vulgare Mill.) Plant.

Abstract

: Pot experiment was carried out in seventeen levels of fertilization to evaluate the effect of the bio-fertilizer mixture alone or in combination with chemical fertilizer (NPK) on Fennel ( Foeniculum vulgare Mill). Biofertilizer was a mixture of Azotobacter chroococcum , Bacillus circulans and Vesicular-arbuscular mycorrhiza. Results indicated that use of bio-fertilizer at 3.75 ml/pot four times with 25% of NPK gave the highest significant values of vegetative growth, yield parameters, and also NPK uptake; however, fertilizing with bio-fertilizers without NPK application showed the lowest significant values in the two experimental seasons. The same addition of biofertilizer gave the highest significant values of total microbial count of soil and increased cumulative CO 2 ; whereas addition of 100% NPK gave the lowest significant values in both seasons. The full dose of NPK significantly increased volatile oil percentage while the addition of bio-fertilizer only significantly decreased it in both seasons. GC analysis of essential oil showed that the highest percentage of anethol (12.77 %) was obtained by applying 3.75 ml/pot bio-fertilizer added one time + 25% NPK and decreased estragole (72.78%).