Optimizing fungicide timing for the control of Rhizoctonia crown and root rot of sugar beet using soil temperature and plant growth stages

被引：36

作者：

Kirk, W. W. ^{[1
]}

Wharton, P. S. ^{[1
]}

Schafer, R. L. ^{[1
]}

Tumbalam, P. ^{[1
]}

Poindexter, S. ^{[2
]}

Guza, C. ^{[3
]}

Fogg, R. ^{[3
]}

Schlatter, T. ^{[3
]}

Stewart, J. ^{[3
]}

Hubbell, L. ^{[3
]}

Ruppal, D.

机构：

[1] Michigan State Univ, Dept Plant Pathol, E Lansing, MI 48824 USA

[2] Saginaw Cty Extens MSU, Saginaw, MI 48607 USA

[3] Michigan Sugar Co, Bay City, MI 48706 USA

来源：

PLANT DISEASE | 2008年 / 92卷 / 07期

关键词：

Beta vulgaris;

D O I：

10.1094/PDIS-92-7-1091

中图分类号：

Q94 [植物学];

学科分类号：

071001 ;

摘要：

Azoxystrobin is applied early in the sugar beet growing season in north-central United States for control of \Rhizoctonia damping-off and Rhizoctonia crown and root rot caused by Rhizoctonia solani anastomoses groups (AGs) 4 and 2-2, respectively. Fungicide application timings based on crop growth stage and soil temperature thresholds were evaluated in inoculated small-scale trials and in commercial fields with a history of Rhizoctonia crown and root rot. Soil temperature thresholds of 10, 15, and 20 degrees C were selected for fungicide application timings and used to test whether soil temperature could be used to better time applications of azoxystrobin. In both small- and large-plot trials, timing applications after attainment of specific soil temperature thresholds did not improve efficacy of azoxystrobin in controlling damping-off or Rhizoctonia crown and root rot compared with application timings based on either planting date, seedling development, or leaf stage in a susceptible (E-17) and a resistant (RH-5) cultivar. Application rate and split application timings of azoxystrobin had no significant effect on severity of crown and root rot. Other environmental factors such as soil moisture may interact with soil temperature to influence disease development. Cv. RH-5 had higher sugar yield attributes than the susceptible cultivar (E-17) in seasons conducive and nonconducive to crown and root rot development. All isolates recovered from both small- and large-plot trials in all years were AG 2-2. R. solani AG 4 was not identified in any samples from any year.

引用

页码：1091 / 1098

页数：8