EFFECT OF ORGANIC AND INORGANIC FERTILIZERS ON THE COWPEA APHID (APHIS CRACCIVORA KOCH.) INFESTING BROAD BEAN PLANTS AND THE ASSOCIATED PREDATORS AT ISMAILIA, EGYPT.

Different fertilizers were used over two successive seasons 2001/2002 and 2002/2003 in a newly reclaimed sandy area at Ismailia, Egypt. The effects of these fertilizers on the infestation of broad bean plants with the cowpca aphid Aphis craccivora Koch., the associated predators and seed yield were assessed. The fertility treatments included: recommended rate of farmyard manure (F), sewag sludge (S), F. + S. mixture, an equivalent rate of tafla, NPK and untreated control. Results showed that aphid population was significantly higher in plots treated with NPK (inorganic) followed descendingly by untreated control, farmyard manure, sewage sludge, F+S mixture and tafla. The assodated predator numbers were positively correlated with aphid numbers. Treatments arranged due to their seed yield improvement percentages comparing with untreated control were F+S mixture (12.11 and 13.80), farmyard manure (11.33 and 13.06), sewage sludge (9.61 and 12.55), NPK (4.17 and 5.46) and tafla (1.92 and 2.77) for the two seasons, respectively. Aphid reproductivity significantly affected by fertilizer treatments and could be arranged descendingly, NPK, untreated control, farmyard manure, sewage sludge, F+S mixture and telfa.