حصر ظاهرة عقم سنابل الشعير و علاقتها بنيماتودا ثآليل الشعير Anguina sp. في شمال سورية

الملخص EN

As early as 1986, the phenomenon of head sterility in barley fields has been observed in the major cultivation areas in northern Syria.

Infected plants are tall and usually associated with head sterility causing remarkable yield losses, especially in fields with continuous barley planting.

Studies on head sterility during the harvest of 1996 included 120 samples representing 30 barley fields in the Al-Bab, Qabbasin, Jerablus and Menbij areas of northern Syria.

Incidence of head sterility varied in the surveyed fields between 9.6 and 57% (average 23.4%).

Estimated grain losses ranged from 0.1 to 43.2% (average loss of 11.2%).

Preliminary results showed that head sterility prevails in short, normal and tall plants at rather similar levels i.e.

21.9, 23.3 and 31.1%, respectively.

Furthermore, the results showed a correlation between head sterility and presence of the seed gall nematodes.

The nematode was found in 93.1% of totally infected spikes.

Barley seed gall nematodes also infected Hordeum spontaneum in most fields.

A closer look at the spikes showed that nematodes invade the sterile lateral florets of two–rowed barley and the percentage of recovered galls from these varied between 28–68% (average 45%).

These galls were thin and light and easily mixed with the fine straw falling on the ground during harvest, and constitute an important source of infection without influencing barley yield in the same season