Partial Substitution of Chemical Fertilization of Dutch Fennel Plant (Foeniculum vulgare Mill.) by Bio Fertilization

The present work was carried out on Dutch fennel plant strain during the two successive seasons of 2017/2018 and 2018/2019 at Baloza Research Station, North Sinai Governorate, Egypt. The aim of the work was to evaluate the effect of bio-fertilizer applications as partial replacement for chemical fertilization on vegetative growth, fruits yield, essential oil productivity and its main components as well as chemical constituents of Dutch fennel plants under Sinai conditions. The experiment was planned in a randomized complete blocks design (RCBD) with three replications for each treatment. Treatments were the combination of five fertilization levels (full recommended dose of NPK only, 75, 50, 25% of the recommended NPK plus bio-fertilizers and bio-fertilizers only). The results showed that application of T2 (75% of the recommended NPK plus bio-fertilizers) increased vegetative growth measurements (plant height, number of branches/plant, herb fresh weight/plant and herb dry weight/plant), yield parameters (number of umbels/plant, weight of 1000 seed, seed yield/plant and seed yield/feddan), maximized the essential oil percentage and yield compared to other treatments. However, the lowest values of vegetative growth measurements, yield parameters and essential oil productivity were obtained with plants treated by T5 (bio-fertilizers only). As general, the major chemical constituents of Dutch fennel essential oil were trans-anethole and estragole.