稀土对棉花枯萎病的诱抗增产作用研究

本试验对稀土提高棉花抗枯萎病和增产作用进行了研究，结果表明，３００ｍｇ／ｋｇ稀土溶液处理种了，发病率可降低１８．９６％～１１．４５％，病情指数降低２５．６０～１７．４３，相对防效分别为２９．１９％～３９．３％，与多菌灵的防病作用相当，棉株生长和结铃数明量增加，皮棉增产率为１９．３５％～８．２５％。低浓度稀土溶液（５００ｍｇ／ｋｇ，１００ｍｇ／ｋｇ）有一定抗病增产作用，高浓度（５０ｍｇ／ｋｇ，１００

THE INFLUENCE OF RARE-EARTH APPLICATION ON RESISTANCE TO WILT (FUSARIUM OXYSPOEUM F. SP.VASINFECTUM)IN COTTON

Rare-earths containing different elements were applied to seeds of four upland cotton cultivars, two susceptible (Dai 16 and Jin 11) and to resistant (Zhong 12 and Chuan 73~27) to cotton wilt (Fussrium axysporum f. sp. vasinfectum), Rare-earth treatment at 300 mg/kg significantly enhanced wilt resistance of various cultivars:the rate of diseased plants was reduced by 18. 96% , 12. 08% , 15. 47% and 11. 45% ,the disease index was decreased by 22. 78,25. 60,19. 08 and 17. 43,the relative efficency of wilt prevention was 29. 19%, 29. 22%, 39. 23% and 29. 26%, and seed cotton yield was increased by 11. 4%, 19. 8%,8. 3 and 9. 6%,respectively,for the four cultivars mentioned above. The effect of rare earths of disease prevention and yield improvement appeared comparable with that of carbendozol. Rare earth solution at lower concentrations (50 or 100 mg/ kg)showed little, if any, effect of disease prevention and yield improvement, whereas at higher concentrations (500 or 1 000 mg/kg)the solution injured the plants.