Reaction of some hollow stem bread and durum wheat cultivars to wheat stem sawfly (Cephus pygmaeus L., Hymenoptera: Cephidae) infestation in Southeastern Anatolia

Wheat stem saw fly (WSS) (Cephus pygmaeus L.) is a notorious pest causing significant yield reductions in wheat crop. The use of tolerant cultivars is the most important management tactic against WSS. However, the reactions of frequently cultivated hollow-stemmed bread (Triticum aestivum L.) and durum (Triticum durum Desf.) wheat cultivars to WSS in southeastern Anatolia region of Türkiye are unknown. This study investigated the reactions of hollow-stemmed bread and durum wheat cultivars (twelve each) to WSS in Diyarbakir and Adiyaman provinces in southeastern Anatolia region during 2021-22. The cultivars were tested under field conditions and data relating to number of infested stalks (NIS), infestation ratio (IR), stalk wall thickness (SWT), spike length (SL), number of grains spike-1 (NGS), grain weight spike-1 (GWS), grain yield (GY) and grain yield loss were recorded. The tested wheat cultivars significantly differed for the NIS and GY at both locations. Similarly, SWT, NGS, SL, and GWS significantly differed among cultivars and higher values of these traits were recorded for healthy stalks than infested stalks. Overall, bread wheat cultivars i.e., ‘Kale’ (7127 and 5642 kg ha-1), ‘Dinç’ (6788 and 5628 kg ha-1 and ‘Hazar’ (6249 and 5821 kg ha-1) and durum wheat cultivars i.e., ‘Zühre’ (6261 and 5272 kg ha-1) and ‘Hasanbey’ (6038 and 5141 kg ha-1) with higher SWT recorded the highest grain yield at Diyarbakir and Adiyaman locations. Yield losses varied from 2.5% to 5.3% for bread wheat and 1.57% to 8.39% for durum wheat cultivars at Adiyaman and Diyarbakir, respectively. It is recommended that wheat cultivars with high GY and SWT should be planted to lower WSS infestation and yield losses in the region and breeding solid stem cultivars.