The Effect of Simazine on Yield and Major Nutrient Uptake by Maize and Wheat¹

The results of the experiment revealed that the application of simazine, 2-chlorc 4, 6 bis (ethylamino)-s-triazine, at 1.0 kg/ha and above reduced the yield of maize (Z^ea nays L.) and residual wheat (Triticum aestivum) crops. Application of farmyard manure at the rate of 5,000 kg/ha was not found capable of reducing the toxic effect of the herbicide to maize. On the contrary, the residual farmyard manure effectively reduced the toxicity to wheat grains and straw (statistically significant differences in grains only) as concluded by the yield data. Farmyard application to wheat showed superiority to sludge and green manure (Ipomea carnosa) in increasing the yield. The nitrogen content indicated and increasing trend with increasing levels of simazine in both the crops. The phosphorus and potassium content were also found to rise with application of simazine over control. The total uptake of major nutrients was found to increase with the application of the chemical