Screening of Alleopathic Activity of the Leaves of Nicotiana plumbaginifolia Viv. on Some Selected Crops in Aligarh, Uttar Pradesh, India

Nicotiana plumbaginifolia Viv. is one of the fastest growing weed. It belongs to family Solanaceae. Sesquiterpenoid phytoalexins have been reported to be the chief components of secondary metabolites this family produces which are responsible for allelopathy. Every year due to its lush growth in the crop fields, N. plumbaginifolia as a weed leads to the destruction of thousand tons of crops around the globe. In the present study allelopathic effect of its leaf extract (2%, 6% and 10 %) on percent seed germination of 4 selected local crops of Aligarh (Pisum sativum L, Raphanus sativus L, Triticum aestivum L and Oryza sativa L), on its own seeds and its effects on the soil (control soil, rhizosphere soil of Nicotiana and leached soils) was studied. After eight days of incubation at room temperature, it was found that among the four plants Oryza sativa was most affected with zero percent seed germination with 2, 6 and 10 % of the leaf extract. Maximum percent of seed germination (80±10) was recorded with Pisum sativum at 2%. Nicotiana leaf extract was found autotoxic to its own seeds at 6 and 8% respectively. After 10 days of treatment, an increment of pH from control soil (pH: 7.10) to rhizosphere soil of the Nicotiana (pH: 7.28) was reported. Organic carbon, potassium and nitrogen also follow the same trend whereas the EC (0.44%) and P (13Kg/hectare) were found the maximum in leaf leached soil