Enhancing grain yield and quality of winter barley through agronomic strategies to prolong canopy greenness

An agronomic improvement in grain yield and quality in winter wheat could be obtained through the application of strategies, such as application of foliar fungicides or fertilizers, that protect health of the last leaves and delay the senescence process during ripening. Only a few studies have reported the effect of these practices on barley, although these treatments could represent a new opportunity to specialize in feed and food barley markets and raise farmer profitability. The aim of this study was to compare the effect of different late-season strategies, N and S foliar fertilizers and fungicides applied at barley anthesis, on crop canopy greenness during the ripening stages and to establish the relationship between these strategies and barley yield and quality. Four field experiments have been conducted in NW Italy during 3 growing seasons, according to a full factorial design with 4 treatments, 3 barley cultivars and 4 replications. The following parameters were recorded: canopy greenness, grain yield, test weight (TW), thousand kernel weight (TKW), grain protein content (GPC), foliar disease incidence and severity and deoxynivalenol (DON) contamination. The collected data clearly underline the importance of prolonging canopy greenness of barley in order to increase grain yield and to improve quality. Of all the compared treatments, the application of a fungicide with an azole mixture at anthesis has shown to play the most important role in delaying the senescence process, and has resulted in a higher gran yield (+ 25%), TW (+ 1.3 kg hl-1) and TKW (+ 2.8 g). The effect of the fungicide treatment on barley grain yield was significant for all the compared cultivars and in almost all the environmental conditions, but led to a greater advantage in the cooler environments with prolonged ripening. The fungicide also led to a clear, significant control of foliar disease and a reduction in DON contamination. The use of N and S foliar fertilizers was able to prolong canopy greenness and enhance barley yield and quality but only in environments characterized by a prolonged grain filling period.