Urrea K, Rupe J C, Rothrock C S
Department of Plant Pathology, University of Arkansas, Fayetteville 72701.
Plant Dis. 2013 Jun;97(6):807-812. doi: 10.1094/PDIS-08-12-0772-RE.
Seedling diseases are one of the major production problems for soybean. The primary control of soybean seedling diseases is by fungicide seed treatments but comparisons of seed treatments are difficult because stand responses are often erratic in the field. The objective of this study was to determine the efficacy of soybean fungicide seed treatments in naturally infested soils under controlled environments at three temperatures. Seed of three soybean cultivars were treated with six fungicide treatments or not treated and planted in two soil types collected from two fields in April, May, and June 2008 and 2009. Tests were conducted in growth chambers at 21°C (April planting), 25°C (May planting), or 28°C (June planting). Stands were determined when at least 25% of the seedlings reached the V4 growth stage. Seed treatments improved stands at all three temperatures, in both soils, and in both years. In general, the broad-spectrum fungicides trifloxystrobin + metalaxyl and mefenoxam + fludioxonil + azoxystrobin resulted in the highest stands. The selective fungicide treatments metalaxyl and pentachloronitrobenzene + carboxin were effective at all three temperatures, implying that Pythium spp. and Rhizoctonia solani, respectively, were involved in seedling disease and active over a range of temperatures. The efficacy of fungicides was not consistently associated with the cultivars used in this study.
幼苗病害是大豆生产中的主要问题之一。大豆幼苗病害的主要防治方法是进行杀菌剂种子处理，但由于田间的苗情反应往往不稳定，因此比较种子处理方法很困难。本研究的目的是在三种温度的可控环境下，确定大豆杀菌剂种子处理在自然感染土壤中的效果。对三个大豆品种的种子进行六种杀菌剂处理或不处理，于2008年和2009年的4月、5月和6月种植在从两块田地采集的两种土壤类型中。试验在生长室中于21℃（4月种植）、25℃（5月种植）或28℃（6月种植）条件下进行。当至少25%的幼苗达到V4生长阶段时测定苗情。种子处理在所有三种温度、两种土壤类型以及两年中均提高了苗情。总体而言，广谱杀菌剂肟菌酯+甲霜灵以及精甲霜灵+咯菌腈+嘧菌酯处理后的苗情最佳。选择性杀菌剂甲霜灵以及五氯硝基苯+多菌灵在所有三种温度下均有效，这意味着腐霉菌和立枯丝核菌分别导致了幼苗病害，并且在一定温度范围内具有活性。杀菌剂的效果与本研究中使用的品种并不始终相关。
