Control effect of lanthanum against plant disease

Effect of La on emergence, growth and development of Isatis indigotica Fort. and Festuca arundinacea seedlings was researched by pot experiments of inoculating Rhizoctonia solani and with the mixture of Rhizoctonia solani and Fusarium solani in disinfected soil after the seeds were soaked in the solution with different concentrations of La3+. The results indicated that infection rate decreased and there were significant disease controlling effects on seed rot, bud rot and root rot caused by pathogenic fungi when the seeds were soaked by La3+. Thus, the rates of emergence of Isatis indigotica Fort. and turfgrass Festuca arundinacea were increased. When La3+ concentration was in a proper range, the growth and development of plant seedlings were promoted. Spraying La on rice plants showed a significant controling effect on Rhizoctonia solani. Furthermore, the EC50 of La3+ performed 128.7 and 128.1 mg/L at 1 and 7 d after spraying La in rice plants, respectively. The EC50 of La3+ performed in vivo (in rice plant) was lower than that in vitro (171.9 mg/L).