Optimizing fungicide application timing for spring dead spot based on soil temperature and season

IF 2 3区农林科学 Q2 AGRONOMY

Crop Science Pub Date : 2024-11-09 DOI:10.1002/csc2.21411

W. J. Hutchens, J. C. Booth, J. M. Goatley, T. L Roberson, D. S. McCall

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引用次数: 0

Abstract

Spring dead spot (SDS) (Ophiosphaerella spp.) is the most detrimental disease to warm‐season turfgrasses in areas with cold‐induced dormancy. Fungicide applications do not provide consistent SDS suppression. One reason for this inconsistency is the use of solely calendar‐based fungicide applications instead of considering both calendar date and soil temperature. A field study was conducted at three separate hybrid bermudagrass (Cynodon dactylon (L.) Pers. × transvaalensis Burtt Davy) locations in Virginia to determine the optimal soil temperature and timing for SDS suppression with tebuconazole and isofetamid. Tebuconazole (1.5 kg a.i. ha−1) and isofetamid (4.1 kg a.i. ha−1) were applied at 11 different timings throughout the year based on soil temperatures at a 0‐ to 10‐cm depth. Plots were assessed for SDS severity in the spring and early summer of 2021 and 2022. Two in vitro studies were also conducted with Ophiosphaerella herpotricha and Ophiosphaerella korrae isolates to (1) determine the optimal temperature for growth on potato dextrose agar (PDA) placed on a thermogradient table (13–33°C) and (2) compare the daily growth rate of O. herpotricha and O. korrae isolates at 11, 19, and 27.5°C on PDA. In the field study, isofetamid suppressed SDS more than tebuconazole. Fall applications when soil temperatures were 13°C consistently provided the best SDS suppression. For the in vitro studies, both species grew optimally between 24 and 25°C, yet O. korrae and O. herpotricha growth rates differed at 11°C.

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根据土壤温度和季节优化春季死斑病的杀菌剂施用时机

春季枯萎病（SDS）（Ophiosphaerella spp.）使用杀真菌剂无法持续抑制 SDS。造成这种不一致的原因之一是杀真菌剂的施用仅以日历为依据，而没有同时考虑日历日期和土壤温度。在三个不同的杂交百慕大草（Cynodon dactylon (L.) Pers.× transvaalensis Burtt Davy）进行了实地研究，以确定使用戊唑醇和异菌酰胺抑制 SDS 的最佳土壤温度和时间。戊唑醇（1.5 千克活性成分/公顷-1）和异氟氰菊酯（4.1 千克活性成分/公顷-1）根据 0 至 10 厘米深度的土壤温度在全年的 11 个不同时间施用。在 2021 年和 2022 年的春季和初夏，对地块的 SDS 严重程度进行了评估。还对 Ophiosphaerella herpotricha 和 Ophiosphaerella korrae 分离物进行了两项体外研究，以（1）确定在温度梯度表（13-33°C）上的马铃薯葡萄糖琼脂（PDA）上生长的最佳温度；（2）比较 O. herpotricha 和 O. korrae 分离物在 11、19 和 27.5°C 的 PDA 上的日生长率。在实地研究中，异噁唑胺对 SDS 的抑制作用比戊唑醇更强。在土壤温度为 13°C 的秋季施药，对 SDS 的抑制效果最佳。在体外研究中，两个物种的最佳生长温度都是 24 至 25°C，但 O. korrae 和 O. herpotricha 的生长速度在 11°C 时有所不同。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Crop Science 农林科学-农艺学

CiteScore

4.50

自引率

8.70%

发文量

197

审稿时长

3 months

期刊介绍： Articles in Crop Science are of interest to researchers, policy makers, educators, and practitioners. The scope of articles in Crop Science includes crop breeding and genetics; crop physiology and metabolism; crop ecology, production, and management; seed physiology, production, and technology; turfgrass science; forage and grazing land ecology and management; genomics, molecular genetics, and biotechnology; germplasm collections and their use; and biomedical, health beneficial, and nutritionally enhanced plants. Crop Science publishes thematic collections of articles across its scope and includes topical Review and Interpretation, and Perspectives articles.