Comparative Study of Some Synthetic and Herbal Pyrethroids on Leuttuce Contents in Saudi Arabia

Three synthetic and one botanical pyrethroids were evaluated during growing of lettuce using the recommended concentrations as suggested by the Saudi Ministry of Agriculture. We conducted experiments to examine the impact of multiple insecticides and fertilizer applications on lettuce photosynthesis and yield. Those pesticides named deltametherin, azadirechtin (herbal), fury ( EW-10 % zeta-cyprmethrin) and biotrin (botanical). The objectives of the study were comparable ( chlorophyll, carbohydrates, proline contents) under applications of organic fertilizer, chemical and herbal pesticides and also to assess the variations of these parameters at two different doses for 3 months. Tested pyrethroids were compared, the data revealed that the high dose of biotrin alone or combined with fertilizer was the most effective treatment resulted in a more increment in chlorophyll and total sugar and proline contents, while high dose only induced significant decrease in carotien and soluble sugar. Zeta- cypermethrin came in the second order with the average of 56 % increased in sugar ( 39 %), and chlorophyll (36 %). High dose of deltametherin and azadirechtin were the least effective treatment. In the present study, biotrin alone or with fertilizer is recommended to be used for controlling the pest in lettuce because of its excellent performance with minimum side effects on the plant contents. However, consideration the long term effects of chemical pesticides on the soil, we recommend that biotrin with organic fertilizer should be considered for incorporation in soils to improve the levels of chlorophyll in lettuce plants and preferably harvesting should be done for animal consumption. Conclusion These studies suggest that lettuce photosynthesis may be susceptible to some insecticides at the seedling stage. Consequently, we found that biorational insecticides introduced to manage insect pests in lettuce, have no influence on lettuce physiology at the seedling stage.