Title:Predicting the Effect of Potassin-p on the Straw Yield of Barley Grown under Water Stress Authors: M.S. Gaballah; M.A. El-kholy ; S.A. Ouda DOI: Aff: Author Email: Keywords: Barley cultivars; water stress; potassin-P; straw yield; predictive models URLs:ABSTRACT-HTML | FULLTEXT-PDF | Abstract:A field trial was conducted on six cultivars of barley (Hordeum vulgare L.), four hulled cultivars (Giza 123, 125, 126 and 2000) and two hull-less (129 and 130) were used to develop different models for prediction of straw yield under normal condition, skipping the last irrigation and/or application of foliar fertilizer (potassin-P). Results showed that straw yield was reduced as a result of skipping last irrigation in both hulled and hull-less cultivars. Whereas, the application of potassin-P improved straw yield. Results also proved that plant height was positively and highly correlated with straw yield for all cultivars, and with spike length for hulled cultivars, while for hull-less cultivars the tillers number/m2 and spike length showed high correlation coefficient with straw yield. Two models were developed to predict straw yield for both hulled and hull-less cultivars and spike length were used in Model (1). While in model (2), number of tillers/m2, mean temperature and relative humidity were used from planting to heading. Models were compared for its precision using R2 and SE%. Model (1) had the highest R2 and the lowest SE % for all tested cultivars under water stress condition and model (2) showed the highest R2 and the lowest SE% for all tested cultivars under normal condition, skipping the last irrigation and potassin-P application. The developed models proved to be useful as a decision making tool to attain early straw yield prediction in barley.