AGRONOMIC MANAGEMENT OF WINTER CEREAL HYBRIDS FOR THE ENHANCEMENT OF YIELD, QUALITY AND SUSTAINABILITY OF CEREAL CROPPING SYSTEMS

The thesis evaluates the agronomic performance and resource use efficiency of barley and wheat hybrids under different agronomic managements. Biomass and Methane Produc)on in Double Cereal Cropping Systems with Different Winter Cereal and Maize Plant Densi)es Field trials were carried out according to a factorial combina<on of 4 cropping systems (maize as a sole-crop or aAer hybrid barley, tri<cale and wheat) and 2 maize plant densi<es. The biomass and methane yield of wheat was higher than tri<cale or barley. A delay in maize sowing reduced the yield poten<al of the crop. The high plant density increased the biomass yield in the sole-crop maize and in the maize grown aAer barley. The highest biomass and methane yield within the cropping systems were obtained for hybrid barley followed by maize at a high plant density. A Comparison of the Agronomic Management of a Winter Barley Hybrid and a Conven)onal Genotype: Effect of the Seeding Rate, Soil Tillage and Nitrogen Fer)liza)on A hybrid genotype was compared with a conven<onal genotype, according to a factorial combina<on of 4 genotype per seed density, 2 soil <llages (conven<onal CT vs minimum <llage MT) and 2 N fer<liza<on strategies. The hybrid showed a higher grain yield (+8%) than the conven<onal one. The lower ear density of the hybrid (-20%) was compensated by a higher number of kernels per ear (+16%) and a higher grain weight (+14%). A higher seeding rate did not increase the ear density and the grain yield. Furthermore, CT and a higher N fer<liza<on at the <llering stage led to a more rapid crop establishment. The hybrid showed a higher suscep<bility to deoxynivalenol contamina<on (+51%). The higher grain yield of the hybrid led to lower greenhouse gases emissions (-9%), compared to the conven<onal genotype. The MT resulted in a further reduc<on of the environmental impact (-21%). The introduc<on of hybrids combined with a correct adapta<on of the crop prac<ces could improve the efficiency of the cereal cropping system. Field Programs for the Cul)va)on of Barley and Wheat Hybrids This study has evaluated the agronomic performances of barley and wheat hybrids, compared to conven<onal genotypes, considering different N fer<liza<on rates and fungicide treatments. The hybrids consistently outperformed the conven<onal genotypes, achieving 8% and 10% higher grain yields for barley and wheat, respec<vely. This yield advantage was due to an improved <llering ability, larger ear size (+23% and +22%), and kernel weight (+3% and +4%). In addi<on, the wheat hybrid showed an improved N use efficiency (NUE), while the barley hybrid showed an improved tolerance to foliar diseases. Overall, hybrid genotypes, together with tailored agronomic prac<ces, could promote a sustainable intensifica<on of cereal cropping systems. Op)mizing Nitrogen Rates and Timing of Applica)on for Improving Yield and Nutrient Use Efficiency of Cytoplasma)c Male-sterility Winter Wheat Hybrids This study aimed to compare a cytoplasma<c male-sterility (CMS) wheat hybrid with a conven<onal genotype to assess its agronomic and produc<ve performance. The compared treatments were a factorial combina<on of 2 genotypes (a hybrid and a conven<onal wheat) and 20 top dressed N fer<liza<on strategies. The hybrid outperformed the conven<onal cv in grain yield (+11%), mainly due to a higher number of kernels per ear (+11%) and grain weight (+36%). Moreover, the hybrid resulted in a beZer NUE, that could be enhanced by tailored fer<liza<on managements. Overall, CMS hybrids represent a promising innova<on to respond to present and future challenges of agriculture. Conclusions The research ac<vity demonstrated that hybrid genotypes could represent an innova<on that would be able to enhance the efficiency of cereal cropping systems by suppor<ng their sustainable intensifica<on.