Correlation between different levels of NP; fertilization and population dynamics of cotton aphid (aphis gossypii)‎, whitefly (bemisia. tabaci)‎ and spiny bollworm (Earias insulana)‎ in cotton crop

الملخص EN

Three levels form each NPK fertilizer plus the recommended level were applied to study the efficiency of different levels on cotton aphid, Aphis gossypii, whitefly, Bemisia tabaci and spiny bollworm, Earias insulana population dynamics, and its reflect on the cotton yield in El-Noubaria district, Behaira Governorate, Egypt.

Consequently, the highest mean number of aphid, whitefly and spiny bollworm population in both seasons were obtained from plots applied with 250 kg nitrogen, and it gave the least cotton yield.

On the other hand, there was a decrease in the mean numbers of aphid, whitefly and spiny bollworm with decreasing level of nitrogen applied at 100 kg, but it increasing cotton yield.

While the increase in potassium fertilizer caused a decrease in the population density of aphid, whitefly and spiny bollworm.

For phosphorus fertilization, non significant correlation was observed among different levels of phosphorus fertilizer and the population densities of those tested pests.

Finally, it could be assumed that nitrogen was the most fertilizer that had an effect on infestation rates, all levels of it led to a high significant increase in the number of tested pests compared with other fertilization.