苯醚甲环唑等杀菌剂包衣种子防治花生冠腐病和根腐病

为筛选能兼治花生冠腐病和根腐病、安全而高效的种子处理药剂,采用室内生测法比较了4种杀菌剂对花生冠腐病菌和根腐病菌的毒力,评价了其包衣种子对花生的安全性,并进行了温室接菌盆栽和田间防治试验。结果显示,苯醚甲环唑、氟啶胺、咯菌腈和氟菌唑对花生冠腐病菌的毒力差异较大,EC_(50)分别为0.05、6.56、0.52和1.43 mg/L;对花生根腐病菌的毒力均较高,EC_(50)分别为0.49、0.31、0.44和0.37 mg/L。氟菌唑2 g(a.i.)/kg种子包衣后,花生出苗率和幼苗的根长、株高和茎叶鲜重均降低,出苗时间延迟1~2 d;而氟菌唑0.5、1 g(a.i.)/kg种子包衣及苯醚甲环唑、氟啶胺、咯菌腈3种杀菌剂的所有剂量处理对花生出苗和幼苗生长均无影响。苯醚甲环唑0.5、1、2 g(a.i.)/kg种子,氟啶胺0.4、0.8、1.6 g(a.i.)/kg种子,咯菌腈0.1、0.2、0.4 g(a.i.)/kg种子和氟菌唑0.5、1 g(a.i.)/kg种子包衣对花生冠腐病、根腐病的温室接菌盆栽防效均在80.19%以上。苯醚甲环唑1、2 g(a.i.)/kg种子和咯菌腈0.4 g(a.i.)/kg种子包衣对花生冠腐病、根腐病的田间防效较高,均在75.30%以上,且对荚果的增产率为5.60%~11.10%。表明苯醚甲环唑和咯菌腈包衣种子对花生安全,且可有效防治花生冠腐病和根腐病,具有开发为兼治药剂的潜力。

Seed-coating treatment of four fungicides against peanut crown rot and root rot diseases

To screen safe and highly efficient seed-coating fungicides for controlling peanut crown rot and root rot diseases, the toxicity of difenoconazole, fluazinam, fludioxonil and triflumizole to Aspergillus niger and Fusarium solani were determined,and the safety of seed-coating with the four fungicides on peanut was evaluated. The seedling inoculation experiments in the greenhouse and field trial were conducted. The toxicity of difenoconazole, fluazinam, fludioxonil and triflumizole in inhibiting the spore germination of A. niger were different and their EC₅₀ values were 0.05, 6.56, 0.52 and 1.43 mg/L, respectively. The toxicities of the four fungicides in inhibiting the mycelial growth rate of F. solani were all relatively high, with EC₅₀ values of 0.49, 0.31, 0.44 and 0.37 mg/L, respectively. When triflumizole was used as seed-coating at the rate 2 g (a.i.)/kg seed, the emergence rate, root length, plant height and shoot and leaf fresh weight were lower, and the emergence were delayed by 1-2 days. When difenoconazole, fluazinam and fludioxonil were used as seed-coating at all dosages, and triflumizole at the rates 0.5, 1 g (a.i.)/kg seed, the peanut seedling emergence and growth were not significantly affected. When difenoconazole was used as seed-coating at the rates 0.5, 1 and 2 g (a.i.)/kg seed, fluazinam at the rates 0.4, 0.8 and 1.6 g (a.i.)/kg seed, fludioxonil at the rates 0.1, 0.2 and 0.4 g (a.i.)/kg seed and triflumizole at the rates 0.5, 1 g (a.i.)/kg seed against peanut crown rot and root rot, their control efficacies were all higher than 80.19%. In field trials, the control efficacies of difenoconazole at the rates 1, 2 g (a.i.)/kg seed and fludioxonil at the rate 0.4 g (a.i.)/kg seed against the two diseases were all higher than 75.30%, and the yield growth rate ranged from 5.60% to 11.10%. Difenoconazole and fludioxonil were both safe and highly efficient fungicides in controlling peanut crown rot and root rot by seed-coating treatment, and had the potential for development.