Archives of Current Research International

Onion (Allium cepa L.) is a biennial bulb crop produced all over the world. It is attacked by many diseases, out of which purple blotch of onion caused by Alternaria porri is the major disease. It causes heavy yield loss in both bulb production and seed production. The experiment was conducted to evaluate the effect of Biofertilizer, Microalgae and Nigella sativa on Purple blotch (Alternaria porri) of Onion. The results revealed that minimum disease incidence was observed at 45 and 60 days after transplanting in T₇ Carbendazim (8.72%, 5.72%), followed by T₆ Rhizobium + Azotobacter + Nigella sativa + Microalgae (21.47%, 16.88%), T₄ Microalgae (23.54%, 17.21%) and maximum in T₃ Nigella sativa (31.45%, 21.75%). The maximum plant height (cm) at 45 and 60 days after transplanting was observed in T₆ Rhizobium + Azotobacter + Nigella sativa + Microalgae (45.21cm, 57.73cm), followed by T₄ Microalgae (45.03cm, 57.46cm) and least in T₃ Nigella sativa (36.23cm, 51.36cm). The maximum length of leaves (cm) at 45 and 60 days after transplanting was observed in T₆ Rhizobium + Azotobacter + Nigella sativa + Microalgae (45.21cm, 61.28cm), followed by T₄ Microalgae (45.03cm, 60.65cm) and least in T₃ Nigella sativa (36.23cm, 52.70cm). The maximum bulb weight (gm) and bulb size (cm) was observed in T₆ Rhizobium + Azotobacter + Nigella sativa + Microalgae (67.25gm, 6.76cm), followed by T₄ Microalgae (64.30gm, 6.30cm) and least in T₃ Nigella sativa (54.39gm, 4.45cm).