Allelopathic potential of sunflower (Helianthus annus L.) on soil metals and its leaves extracts on physiology of wheat (Triticum aestivum L.) seedlings.

The effect of a sunflower (Helianthus annuus L.) variety, namely Hysun 38, on metals and of aqueous extracts of its leaves on germination in two varieties of wheat, namely Margalla 99 and Chakwall 97, were studied under laboratory conditions. In particular, the effect of leaf extract on hormones produced by wheat seedlings and on electrical conductivity, pH, Mn, Ca, K, P, and soil moisture content was examined. The leaf extract significantly inhibited the rate of germination and growth of seedlings.