Barocco Rebecca Leigh, Sanjel Santosh, Dufault Nicholas Steven, Barrett Charles, Broughton Benjamin, Wright David L, Small Ian Malcolm
North Florida Research & Education Center, University of Florida, Plant Pathology, Quincy, Florida, United States;
Department of Plant Pathology, University of Florida, Gainesville, Florida, United States;
Plant Dis. 2021 Mar 23. doi: 10.1094/PDIS-11-20-2390-RE.
Diverse field characteristics, weather patterns, and management practices can result in variable microclimates. The objective was to relate in-field microclimate conditions with peanut diseases and yield and determine the effect of irrigation and fungicides within these environments. Irrigation did not have a major impact on disease and yield. Stem rot () and early () and late () leaf spot were most affected by changes in environmental patterns across seasons. Average non-treated stem rot was 12.9% in 2017 which dropped considerably in 2018 to 0.2% but emerged again in 2019 to 3.2%. Stem rot incidence varied across the field, and the response to fungicides depended on management zone. Leaf spot defoliation in non-treated plots was severe in 2019 reaching an average of 73% at 126 days after planting but only reached 15% in 2017 and 35% in 2019 at the same stage. A low-input fungicide schedule was able to reduce foliar disease in all zones and seasons, but the microclimatic conditions in the low-lying area favored leaf spot in 2017 and 2018 although not in the dryer 2019 season. Seasonal differences in disease and plant growth affected the level of protection against average yield loss using a standard low-input program which in 2017 (527 kg/ha) was not as great as 2018 (2,235 kg/ha) or 2019 (1,763 kg/ha). Disease prediction models built on dynamic environmental factors in the context of multiple pathogens and natural field conditions could be developed to improve within-season management decisions for more efficient fungicide inputs.
多样的田间特征、天气模式和管理措施会导致微气候的变化。目的是将田间微气候条件与花生病害及产量联系起来，并确定灌溉和杀菌剂在这些环境中的作用。灌溉对病害和产量没有重大影响。茎腐病（）以及早（）、晚（）叶斑病受季节间环境模式变化的影响最大。2017年未处理地块的平均茎腐病发病率为12.9%，2018年大幅降至0.2%，但在2019年又回升至3.2%。茎腐病发病率在田间各处有所不同，对杀菌剂的反应取决于管理区域。2019年未处理地块的叶斑病落叶情况严重，在种植后126天平均达到73%，但在2017年同一阶段仅达到15%，2019年为35%。低投入的杀菌剂施用方案能够在所有区域和季节减少叶部病害，但低洼地区的微气候条件在2017年和2018年有利于叶斑病的发生，不过在较为干燥的2019年季节则不然。病害和植株生长的季节差异影响了使用标准低投入方案对平均产量损失的保护水平，2017年（527公斤/公顷）不如2018年（2235公斤/公顷）或2019年（1763公斤/公顷）高。可以建立基于多种病原体和自然田间条件下动态环境因素的病害预测模型，以改进季内管理决策，实现更高效的杀菌剂投入。
