Whitefly population and incidence of tomato yellow leaf curl virus in tomato fields grown in the northern regions of the west bank

الملخص EN

A survey was conducted in 2004/2005 to study the frequency of tomato yellow leaf curl virus’s infection of tomato during different growing seasons in the Tobas and Jenin districts.

The maximum viral incidence was recorded in Tobas, compared with Jenin district in all growing seasons.

The viral incidence was much higher on summer grown tomato in both districts compared with the other growing seasons.

The maximum viral incidence during the summer growing season was recorded in Al-Far'a (95%), followed by Kashda (70%).

Autumn was considered the second most serious growing season of tomato as the viral incidence ranged from 40- 70% and 20-30% in Tobas and Jenin districts, respectively.

In spring and early spring growing seasons the viral infection was much lower in both districts compared with the other growing seasons.

In this season the viral incidence was recorded to be 20-41% in Tobas and 21-29% in Jenin district.

In addition, studying the population trend of the whitefly vector in Tobas and Jenin districts showed that the population had a seasonal change throughout the year.

The maximum whitefly population was recorded between July and August to be in the Tobas district, and in August to be in the Jenin district.

Also, in Tobas the whiteflies started to appear during February, which is two month prior to its appearance in the Jenin district