| Abstrakt: |
[Objectives] The effects of copper-based nutrient foliar fertilizer on photosynthetic characteristics, yield, accumulation and distribution of trace elements in various organs, disease prevention effect and soil enzyme activity were studied, so as to provide a theoretical basis for the application of foliar fertilizer in cotton production. [Methods] Through two years of field experiments, six treatments were set in total, namely spraying water (CK), traditional Bordeaux mixture (BDM), Kocide 2000 (KCD), copper-based nutrient foliar fertilizer (CF), iron-copper-based nutrient foliar fertilizer (CFFe), and zinc-boron-copper-based nutrient foliar fertilizer (CFZnB). Randomized block arrangement was adopted. Chlorophyll content in leaves was measured at each growth stage of the cotton. Photosynthetic characteristics of leaves were measured at the peak boiling stage. Plants were sampled at initial boll opening stage. The whole plant was divided into root, stem, leaf and cotton boll parts, in which the total copper, total zinc, total iron contents and accumulations were determined. Soil samples were collected from each plot, followed by the determination of soil enzyme activity. Disease index was investigated at bud, flowering and boll-forming and boll opening stage. [Results] (1) Spraying CFFe, CFZnB, CF and KCD could significantly improve chlorophyll content of cotton leaves, and the CFFe treatment had the highest increase up to 13.30%, followed by the CFZnB treatment, which was 11.40% higher than the CK; and photosynthetic rate, stomata conductance and transpiration rate could be improved significantly, and the CFFe treatment showed the highest photosynthetic rate, which increased by 26.35% compared with the CK, followed by the CFZnB treatment, which increased by 17.96% compared with CK; and intercellular CO2 concentration was significantly reduced. (2) Spraying BDM, KCD, CF, CFFe and CFZnB can significantly increase total copper content and accumulation in various cotton organs (except the total copper content in the stem part of the CFZnB treatment; the CFZnB and CFFe treatments can significantly increase total zinc content and accumulation in various cotton organs; and spraying CFFe, CFZnB and CF can significantly increase total iron content and accumulation in various cotton organs (except the total iron content in the stem part of the CF treatment). (3) Spraying CFFe, CFZnB, CF, KCD and BDM greatly reduced the disease index at flowering and boll-forming and boll opening stages. (4) The CFZnB and CFFe treatments had the highest soil urease activity, which was 7.14% higher than that of the CK, but the difference from the CK was not significant; the catalase activity of each treatment was significantly higher than that of the BDM treatment; and the sucrase activity of each treatment was significantly higher than that of the CK. (5) Spraying CFFe, CFZnB, CF and KCD significantly improved lint yield of cotton, and the CFZnB treatment showed the highest yield increase up to 12.34%, followed by the CFFe treatment, with an increase in the range of 8.77% - 10.20%. [Conclusions] Copper-based nutrient foliar fertilizer have dual functions of disease control and prevention and plant nutrition and health care, and not only can significantly increase cotton yield, but also has certain disease prevention effect. It is recommended to use copper-based nutrient foliar fertilizers. [ABSTRACT FROM AUTHOR] |
