Agro-chemical and insecticidal studies on Iberis amara plant grown in Egypt

Abstract

The effect of different types of sulphur on growth and chemical constituents of Iberis amara grown in Egypt were studied in two successive seasons under Egyptian environmental conditions at the NRC Experimental Farm Station, Al-Giza. The insecticidal activity of different extracts of I. amara was investigated on cabbage aphids. Potassium sulphate increased plant height comparing to both ammonium sulphate and sulphur with a record of 74cm. Ammonium sulphate at a rate of 476kg/ha recorded the highest number of suckers (48 suckers/plant). Sulphur at rate of 357kg/ha recorded highest number of branches (35 branches/plant). The highest fresh weight of herbs and flowers reached 340g and 278g when plants fertilized with 476kg/ha ammonium sulphate and 357kg/ha potassium sulphate, respectively. Ammonium sulphate at rate of 476kg/ha leads to the highest contents of carbohydrate and fixed oils which reached 13.95%, 13.62% and 14.0%, 12.85% in first and second seasons, respectively. The highest content of glucosinolates and phenolic compounds was recorded when I. amara plants were treated with 476kg/ha ammonium sulphate while cucurbitacins content reached the maximum by the treatment of 357kg/ha ammonium sulphate. Insecticidal activity of different extracts showed that the higher concentration of ethanol extract induced the highest mortality for cabbage aphid as it induced 66.66% mortality after 96 hr followed by water extract after autolysis and chloroform extracts which induced 53.33% mortality at the high concentration. In contrast, hexane extract exerted the lowest effect on this insect.