Reducing Phytotoxic by Adjusted pH and Control effect of Loess-Sulfur Complex as Organic Farming Material against Powdery Mildew in Tomato

Abstract

The soluble loess-sulfur mixture allowed standing to remove insoluble component materials for five weeks after manufacturing. We decreased the pH level of soluble loess-sulfur mixture at pH 1.0 modified with decreasing 25% sodium hydroxide than original content. The pH ranges of soluble loess-sulfur mixture solutions were adjusted to pH 5.0-pH 11.0 (pH 1 unit) with brown rice vinegar (pH 2.8). The pH of original loess-sulfur mixture was about pH 13 and damaged the foliar parts and young leaves of tomato after twice application. These stock solutions can be diluted 500:1 with tap water to make a 0.05% working solution and were sprayed two times with 7 days interval to the leaf and stem of tomato, which were spontaneously infected with E. cichoracearum. Control efficacy of powdery mildew ranged from 85% to 90% at 7 days after first application. After second application, each loess-sulfur mixture solutions adjusted pH level significantly suppressed the powdery mildew disease in tomato. Consequently, loess-sulfur complex adjusted pH level with brown rice vinegar was suggested to be low in acute toxicity at all different pH values and suggested to use an agent for control of tomato powdery mildew in organic farming.

Bio-Sulfur Pre-Treatment Suppresses Anthracnose on Cucumber Leaves Inoculated withColletotrichum orbiculare

“…The occurrence of skin sooty dapple disease on Asian pear is decreased by treatment with lime-sulfur [18]. On tomato leaves sprayed with loess-sulfur, the occurrence of tomato powdery mildew is decreased [19]. Also, lime- or loess-sulfur has been used to prevent anthracnose by Colletotrichum gloeosporioides or circular leaf disease by Mycosphaerella nawae on sweet persimmon, respectively [20].…”

Suppression of Melanose Caused by Diaporthe citri on Citrus Leaves Pretreated with Bio-sulfur

“…It has been reported that disease severity of powdery mildew is decreased by about 90% in tomato plants treated with loess-sulfur mixture (Shim et al, 2014). Ginseng anthracnose caused by Colletotrichum gloeosporioides is also suppressed by treatment with lime sulfur diluted 400 times (Lim et al, 2015).…”

Accumulation of Heavy Metals in Soil Growing for Red Pepper (Capsicum annuum) with using Lime Bordeaux and Lime Sulphur Mixture

“…살균제로서 유황은 1800년대 프랑스에서 포도 흰가루병으로 인하여 포도주 생산량의 80%까지 감소하면서 포도 흰가루병을 방제하기 위하여 본격적으로 사용되기 시작하였고 (Shim et al, 2014;Tiecher et al, 2017), 1845년 미국 으로 전해져 포도과원에 흰가루병 뿐만 아니라 응애에도 방제효과가 있어 광범위하게 사용되게 되었다 (Buchanan and Amos, 1992;Emmett et al, 1992). 유황은 유기농업자재로서 미국, 유럽, 우리나라 등지에서 사용이 허용되어 있 다 (Ahn, 2010;EPA, 1991;OMRI 2012 Organic matter (g kg …”