利用磷肥厂副产氟硅酸防治小麦锈病的研究

作者于1966半报告了氟硅酸对小麦条锈病具有良好药效,氰硅酸是磷肥厂副产,资源丰富、成本低廉。1971年又用氟硅酸与尿素制成便于运输和贮存的晶态的氟硅脲,其分子式为(NH_2)_2CO]_4·H_2SiF_6。十多年来经过15个省市的田间试验,肯定了氟硅酸和氟硅脲对小麦三种锈病均有效。在山东烟台地区和四川内江地区的大面积推广试用均取得良好效果。防治有效浓度按H_2SiF_6计为0.05～0.10%,药液中须加入湿润剂。除扬花期不可喷药外,其它生育期均可喷药。对小麦的增产效果显著。小麦种子中未发现氟的反常残留。经卫生部门测定,十个样本中有6个氟残留量为0.71～1.98ppm,有1个样本中为3.47ppm,系过量喷药所致。其余3个样本中未检出氟。本文讨论了使用无机氟剂的环境保护问题。根据地球化学和环境化学的最近研究成果,在本文所建议采取的使用浓度下,用氟硅酸防治小麦锈病并无引起环境污染之虞。

CONTROL THE WHEAT RUST WITH FLUOROSILICIC ACID,A B-PRODUCT OF SUPERPHOSPHATE PLANT

Fluorosilicic acid,a by-product of the superphosphate plant,has been reported previously by the authors in 1966 as a cheap and efficacious fungi-cide in the control of the wheat rust.A Crystalline Complex compound (NH₂)₂CO]₄·H₂SiF₆,prepared later by the authors from fluorosilicic acid and urea,showed the same mode of action of H₂SiF₆.After some 10 years of research and field tests it is proved that they were highly efficacious incontrolling yellow,brown and stem rust of wheat under the concentrations of 0.05% to 0.10% a.i.of H₂SiF₆·A strong wetting agent is neccessary inpreparing the spray solution.The fluorine (F) residue in seeds were deter-mined.The level of detectable F in 6 samples were 0.71 to 1.98 ppm,and 3.47 ppm of F appeared in one sample was ascribed to over spraying.No detectable F were found in other 3 samples.The environmental problems are discussed under the highlight of recent development of geographical and enviornmental chemistry of fluorine.It is suggested that the utilization of fluorosilicic acid as a fungicide will not elicit any environmental pollution will the recommended concentrations.