The substitution of chemical fertilizers with organic and biofertilizers has gained increased
attention in recent years in order to sustain high yields and protect the environment. This study
was carried out to determine the vegetative growth, chemical compositions, and essential oil
content of Trachyspermum ammi in response to different levels of fertilizes and boron as well as
their combinations. Five levels of fertilizers, N1: control, N2: 100% mineral fertilizer, N3: 50 %
organic manure with biofertilizer, N4: 75 % organic manure with biofertilizer, and N5: 100 %
organic manure with biofertilizer, and three levels of boron 0, 100 and 200 mg/L were used. The
results obtained in a 2-years study (2018—19) with fifteen different fertilization treatments
showed that the combined treatments of N2 with 200 mg/L boron yielded the highest values for the
vegetative growth parameters and seed yield. Moreover, it enhanced mineral contents (N, P, and
K). On the other hand, the highest percentage of seed essential oil (4.01 and 4.02 %) was noted
after applying N5 with 200 mg/L boron in both seasons. Similarly, this dose produced the highest
yield of α-thujene (50.24 %). These results suggested that organic sources supplemented by NPK
may fully substitute for chemicals fertilizers without harming the growth and seed yield, chemical
constituents and oil productivity of ajwain |
