Phytotoxic Effects of Calotropis procera (Aiton) W.T. Leaves Aqueous Extract on Seed Germination of some Cereal Crops Using Probit Analysis

Abstract

Certain plants suppress development of other plants by releasing many chemical substances into the environment. This study was carried out to investigate the phytotoxic effects of the leaves aqueous extract of apple of Sodom [Calotropis procera (Aiton) W.T.] on seed germination of Sorghum bicolor (L.) Moench (sorghum), Pennisetum glaucum (L.) R. Br. (millet), Zea mays L. (corn) and Triticum ae stivum vulgare L. (wheat) using probit analysis. The experiments were conducted at the University of Gezira in Sudan, in the 2014/15 agricultural season. Ten concentrations (2.11 to 21.05 g/l) were prepared from the stock solution (50 g / l). Sterilized-distilled water was used as control. The experiment for each crop, was laid out in a completely randomized design and the treatments were replicated four times. The crop seeds were checked for germination and its inhibition three days after the onset of germination. Data were subjected to probit analysis procedure (P ≤ 0.5). The results revealed that apple of Sodom’s leaves aqueous extract inhibited seed germination of the tested cereal crops and there was direct positive relationship between concentration (g/l) and inhibition (%). In addition, the result revealed that the LC50 was 17.6, 17.0, 19.2 and 16.7 g/l for sorghum, millet, corn and wheat, respectively. It was concluded that that the leaves aqueous extract of apple of Sodom had toxic effect to the seeds of the tested cereal crops.