Incidence of strobilurin- and benzimidazole-resistant strains of <i>Pestalotiopsis longiseta</i>, causal agent of gray blight, and practical control in tea field of Kagoshima Prefecture.

DOI JASI Web Site 5 References
  • OMATSU N.
    Tea Division, Kagoshima Prefectural Institute for Agricultural Development
  • TOMIHAMA T.
    Soo Irrigated Agriculture Promotion Center
  • NONAKA Y.
    Kagoshima Prefectural Economic Federation of Agricultural Co-operatives

Bibliographic Information

Other Title
  • 鹿児島県内の茶園におけるストロビルリン系薬剤とベンゾイミダゾール系薬剤に耐性を示すチャ輪斑病菌の発生実態と薬剤の防除効果
  • カゴシマ ケンナイ ノ サエン ニ オケル ストロビルリンケイ ヤクザイ ト ベンゾイミダゾールケイ ヤクザイ ニ タイセイ オ シメス チャ リン ハン ビョウキン ノ ハッセイ ジッタイ ト ヤクザイ ノ ボウジョ コウカ
  • Incidence of strobilurin- and benzimidazole-resistant strains of Pestalotiopsis longiseta, causal agent of gray blight, and practical control in tea field of Kagoshima Prefecture.

Search this article

Abstract

Gray blight caused by Pestalotiopsis longiseta is one of the most important diseases of tea plant. Thiophanate-methyl (benzimidazole) and azoxystrobin (strobilurin, QoI) fungicides have been used to control gray blight in Kagoshima Prefecture. However, benzimidazole-resistant strains of P. longiseta have been found in tea fields in Kagoshima Prefecture since 1983 and strobilurin-resistant strains since 2008. Therefore, we examined samples of P. longiseta from several green-tea-cultivation regions in Kagoshima Prefecture in 2008 and 2009 for their sensitivities to strobilurin and benzimidazole. As a result, 31.7% of the strains in 2008 and 33.6% in 2009 were strobilurin-resistant. The rate was especially high in the Nansatsu region and low in the Aira and Hokusatsu regions. On the other hand, 80.9% of the strains were benzimidazole-resistant in 2009, found widely in separated fields. Strains that were highly resistant to benzimadazole were frequently found in the same fields as moderately resistant strains. Highly resistant strains to both fungicides occurred in as much as 20.0% of the tea fields. Azoxystrobin was not effective against QoI-resistant strains. In addition, the control effect of azoxystrobin on P. longiseta was decreased with the increase in the rate of QoI-resistant strains in the tea fields. Just a one-time application of QoI-fungicide remarkably increased the percentage of QoI-resistant strains in the tea field. This was the case for thiophanate-methyl.<br>

Journal

References(5)*help

See more

Keywords

Details 詳細情報について

Report a problem

Back to top