Pesticdal action of three natural additives as organic farming procedures on infestation with the two-spotted spider mites and onion thrips on strawberry and tomato plantations under field conditions

In this study, the effect of three natural additives (biofertilizers) used in organic agriculture on two vegetables, strawberry and tomato on the population of two main sucking pests (the two spotted- spider mite, Tetranychus urticae Koch; and onion thrips, Thrips tabaci Lind. was studied under field conditions at Tahrir Province during two successive years; 2008 and 2009 growing seasons. The obtained data proved that, in general, the infestation with the two spotted spider mites was higher in strawberry plants than on tomato plants in both two successive years; while the vice versa was true with onion thrips where the infestation was higher on tomato plants than on strawberry plants. There was significant difference between the treatments with Compost Tea, Humic acid treatments and Super biofert control (without treatment) in the infestation with the two-spotted spider mites on strawberry plants in both seasons. While, there was significant difference between the treatments with Compost Tea, Super biofert treatments, and Humic acid and control in case of onion thrips in the same plants. The same trend was true with the infestation on tomato plants with the two pests. Compost Tea came the first as regards to its action on some sucking pests.