Chemical Control of Pennesetum Purpureum Laboratory Trials

Abstract

Dichloral urea, diethyl chloracetamide, nitrourea, chloralhydrate, sodium trichloroacetate, sodium borate, ammonium thiocynate, sodium arsenite, arsenic oxide-sulphuric acid mixture, sodium chlorate, maleic hydrazide and the salts containing inorganic ions Cu/sup 2+/, Co/sup 2+/, MoO/sub 4//sup 2-/ and Zn/sup 2+/ were tested in experimental plots for their phytotoxic activity on a hybrid variety of Pennesetum purpureum. Sodium borate (2500 Kg/hectare), Sodium arsenite (250 Kg/hectare) and sodium chlorate (1000 Kg/hectare) through soil and ammonium thiocyanate (100 Kg/hectare) through direct spray function as growth retardants. Arsenic oxide-sulphuric acid (100 : 300 Kg/hectare) spray kills the existing leaves. Sodium chlorate (250 Kg/hectare) spray exerts phytocidal action on young plants (3 weeks). Maleic hydrazide (50 Kg/hectare) exerts permanent growth suppressant action on older plants (height >=1 m) and kills the existing leaves of younger plants (height=<0.5 m). Copper sulphate (100 Kg/hectare) induces partial drying of existing leaves and cobalt sulphate in the same dose induces yellowing of leaves extending the period of growth beyond the season of maximum growth of the control. Ammonium molybdate and Zinc acetate in the same dose do not exert any perceptible effect.