Susceptibility of squas planted in newly reclaimed desert land to infestation by aphid species and their control by the use of safe comipounds

الملخص EN

Field studies were carried out on squash plants cultivated in sandy soil in newly reclaimed land at Regwa farm (62 km.

north Cairo) during the winter and the summer plantations (October, 2001 and April, 2002, respectively).

Results indicated that squash plants in winter plantation were more susceptible to aphids' infestation than those sown in summer.

Aphis gossypii was found to be the most dominant and abundant aphid species on squash plants, being 56.38 and 62.10 % for dominance degrees and 31.25 and 17.60 % for abundance degrees in winter and summer plantations, respectively.

The safe materials Kz oil, Pirimor, Biovar and Biofly were evaluated against aphids in squash fields using two techniques.

In the first technique, the populations of alate aphids were counted by green water pan during the period from plant emergence till fruit ripening.

However, in the second technique, direct counts of aphids on the squash leaves were made during the growing period of the plants.

The maximum reduction in aphid population and the highest squash yield were obtained after using transparent Biovar or transparent Biofly.

Therefore, it is advisable to use transparent Biovar or transparent Biofly for controlling aphids in squash fields.

Significant negative correlation was found between the accumulated mean number of aphids and the yield of squash fruits.