Screening of Alternaria Blight of Linseed (Linum usitatissimum) Caused by (Alternaria lini L.) in In-vitro Condition

Linseed (Linum usitatissimum L.) is an important oilseed and fiber crop grown both for its seed as well as fiber.It is widely cultivated in Northern India during the Rabi season. It suffers from a variety of diseases among which Alternaria blight caused by Alternaria lini is one of the most yield limiting factors in India. The efficacy of botanicals (neem, ginger, garlic, bougainvilla and eucalyptus extract), bio-agents (T. harzianum and T. viride) and chemical fungicides (Mancozeb (0.2%), Carbendazim (0.2%), etc. were tested against Alternaria lini in in-vitro conditions. The result of in vitro studies revealed that Neem extract @ 150 ppm significantly reduced the mycelial growth of Alternarialini as 68.6 percent inhibition followed by Garlic bulb extract @ 150 ppm and Ginger rhizome extract@ 150 ppm as 65.45% and 58.65% inhibition respectively. Among fungicide Carbendazim at 500 ppm proved to be most effective in inhibiting mycelial radial growth of pathogen with 100% inhibition over control followed by Mancozeb that showed 93.94% inhibition over control under in-vitro conditions.