حساسية أصناف من الرقي للإصابة بالحلم ذي البقعتين

الملخص EN

A field study was conducted to evaluate the response of three different cultivars of water melon Citrullus lanatus (Charlestong Gray, Crimson Sweet, Charle) to infestation by two spotted spider mite Tetranychus urticae Koch in abu Ghraib area.

The seeds of the three cultivars were bought from local market and planted on 25th April 2008.

Results indicated no significant differences in mobile stages of Mites during the first and second week.Moreover,the eggs were found on Charlston gray and crimson sweeet on the second week of the sample collection (7th may 2008).

However, there were no eggs found in Charle cultivar until the 14th May 2008.Results also showed significant differences in the response level according to the age of the cultivar.The charleston gray was more sensitive, the general mean number for eggs and mobile stages during the season 37.92, 54.23 mobile stages,egg/leaf respectively.

The lowest mean of mobile stages and eggs were 2.4,2.3 respectively on Charle cultivar in which the infestation of this cultivar were noticed on the seventh week of the experiment (11-6-2008).

However, in crimson sweet cultivar the number of mobile stages and eggs were in the middle of the two others, they were 14.36 , 13.56 individual,eggs/leaf respectively.

The mobile stages and eggs were increased in charleston gray followed by crimson sweet , then charle was less in their infections .

Therefore, choosing suitable cuitivar for water melon should take in consideration its reponses to infestation of various pests in addition to the quatitative and qualitative characters.