Investigations into the potential application of nanoparticles acting as nanofungicides in sustainable agriculture are rapidly expanding due to the high antimicrobial properties of these compounds, which do not risk inducing pathogen resistance to fungicides.  A detailed understanding of the impact of copper oxide nanoparticles (CuO NPs) on soil-borne phytopathogenic fungi is yet to be obtained.  This study aimed to explore the in vitro antifungal activity and control efficacy of CuO NPs applied via irrigation with respect to tobacco black shank (TBS) disease caused by Phytophthora nicotianae.  The results revealed that CuO NPs greatly interfered with the reproductive growth process of this fungus, repressing hyphal growth, spore germination and sporangium production.  Additionally, morphological damage, intracellular ROS accumulation and increased SOD enzyme activity in hyphae were the antifungicidal mechanisms of these NPs.  In pot experiments, treatment with CuO NPs at 100 mg L^–1 significantly suppressed TBS development, compared with the effect on control plants, and the control efficacy reached 33.69% without inducing phytotoxicity.  Exposure to CuO NPs significantly activated a series of defense enzymes, and resistance genes in tobacco can further explain the mechanisms by which CuO NPs suppressed fungal infection.  The Cu content in both the leaves and roots of P. nicotianae-infested plants increased by 50.03 and 27.25%, respectively, after treatment with 100 mg L^–1 CuO NPs, compared with that of healthy plants.  In particular, a higher Cu content was observed in infected roots than in leaves.  Therefore, this study showed the potential of CuO NPs applied as nanofungicides and as nanoinducers of fungus resistance genes for the management of TBS through inhibition of pathogen infection and stimulation of plant defenses.

Water shortage has threatened sustainable development of agriculture globally as well as in the North China Plain (NCP).  Irrigation, as the most effective way to increase food production in dry land, may not be readily available in the situation of drought.  One of the alternatives is to supply plants with enough nutrients so that they can be more sustainable to the water stress.  The objective of this study was to explore effects of irrigation and sulphur (S) application on water consumption, dry matter accumulation (DMA), and grain yield of winter wheat in NCP.  Three irrigation regimes including no irrigation (rainfed, I₀) during the whole growth period, once irrigation only at jointing stage (90 mm, I₁), and twice respective irrigation at jointing and anthesis stages (90 mm plus 90 mm, I₂), and two levels of S application including 0 (S₀) and 60 kg ha^–1 (S₆₀) were designed in the field experiment in NCP.  Results showed that increasing irrigation times significantly increased mean grain yield of wheat by 12.5–23.7% and nitrogen partial factor productivity (NPFP) by 21.2–45.0% in two wheat seasons, but markedly decreased crop water use efficiency (YWUE).  Furthermore, S supply 60 kg ha^–1 significantly increased mean grain yield, YWUE, IWUE and NPFP by 5.6, 6.1, 23.2, and 5.6% (across two wheat seasons), respectively.  However, we also found that role of soil moisture prior to S application was one of important greater factors on improving the absorption and utilization of storage water and nutrients of soil.  Thus, water supply is still the most important factor to restrict the growth of wheat in the present case of NCP, supplying 60 kg ha^–1 S with once irrigation 90 mm at the jointing stage is a relatively appropriate recommended combination to improve grain yield and WUE of wheat when saving water resources is be considered in irrigated wheat farmlands of NCP.

The current interest in the health benefits of whole wheat grain has prompted breeders to further increase the concentration of antioxidants in wheat. The objective of this study was to investigate the variation in antioxidant content among Chinese wheat grains and the relationship between antioxidants and grain color and morphological characteristics. A wide variation was observed in the total phenolic, carotenoid and flavonoid contents, as well as the antioxidant activity (AOA), of Chinese wheat varieties. Black wheat had the highest mean total phenolic, carotenoid and flavonoid contents and the highest AOA, followed by red and white wheats. The grain color parameters were significantly negatively correlated with total phenolic, carotenoid and flavonoid contents and AOA among all of the wheat varieties examined, and grain weight was also significantly negatively correlated with these traits. The same correlation between grain weight and antioxidant traits was also observed within individual groups of wheat, which indicates that grain weight may be used as an index for selecting wheat varieties with high AOA. Landraces had significantly higher flavonoid content than commercial wheat varieties. The results of this study may be useful for breeding nutrient-rich wheat varieties.