Using plant extracts to reduce asexual reproduction of apple scab (Venturia inaequalis)

Abstract

The aim our research was to develop effective methods for organic apple farming, based on the use of plant extracts to control the asexual reproduction of Venturia inaequalis. Plant extracts of artemisinin, chelidonine, thymol, and populin tested in vitro under laboratory conditions significantly slowed down the germination of V. inaequalis conidia. During a 2-year study under field conditions, the effect of 1% populin, an extract from black poplar buds, on apple scab was tested in parallel with synthetic fungicides and a nopesticide regime on Golden Delicious and Jonathan apples. Populin significantly reduced the number of scabbed leaves and fruits on Golden during the first year of the field evaluation compared to synthetic fungicides and had a similar effect as synthetic fungicides in the second year of application. The mean number of scabbed leaves on Jonathan was reduced significantly by both synthetic fungicide and populin applications in both years; however, while synthetic treatments did not reduce the number of scabbed fruits in the first year, populin significantly reduced the number of lesions on fruits. According to these results, we concluded that the severity of apple scab on commercial apple cultivars can be reduced using 1% populin plant extract as a cheap, alternative, and highly available method of reducing the conidial spores. The estimated costs of spraying populin per hector on apple plantations were much lower than costs for synthetic fungicides. Populin application may allow elimination or reduction of synthetic fungicide use and enable efficient organic apple farming.

In vitro and in vivo effect of poplar bud (Populi gemma) Extracts on late blight (Phytophthora infestans)

“…Populin extracts may have similar effects in reducing the growth rate of hyphae on leaves, although it may also reduce the germination rate of spores. Similar experiments in our previous study demonstrated Brought to you by | MIT Libraries Authenticated Download Date | 5/11/18 5:18 AM that this extract considerably reduced the germination of apple scab (Venturia inaequalis) conidia and furthermore that infestation levels were similar or lower than those of conventional treatments [13]. Much more information however will be needed to test the long-term effects of populin extract on the development of late blight including the durability of the plant extract's effectiveness.…”

“…Other plant extracts may have similar effects, one potential compound being populin, an extract from black poplar (Populus nigra). The positive effects of populin in dealing with apple scab have been reported under both lab and field conditions [13,14]. Because potatoes represent one of the most economically important vegetables and because late blight resistance against conventional fungicides has already been demonstrated, we hypothesise that populin may have a similar effect on late blight in potatoes.…”

In Vitro</span></i><span lang="EN-GB" style="font-size: 12.0pt; font-family: Times New Roman"> and <i>in Planta</i> Activity of Some Essential Oils&nbsp;against <i>Venturia inaequalis</i> (Cooke) G. Winter</span>

“…The highest inhibition level was achieved with thyme oil. Bálint et al (2014) and Theisz et al (2007) found thyme extracts effective as well. The high contents of phenolic monoterpens, especially thymol (40.6%) and its precursore p-cymene (24.6%), might be responsible for the antifungal effect of thyme oil (Gong et al, 2009), however, the synergistic effect of minor oil components might also contribute to the antifungal activity (Zambonelli et al, 2004).…”

“…Artemisinin, thymol and populin extracts effectively inhibited conidial germination as well. The 1% Populus extract gave similar control efficacy against apple scab on apple trees as synthetic fungicides in a 2 years field study (Bálint et al, 2014;Theisz et al, 2007). The preventive application of six plant oils (canola, corn, grapeseed, olive, soybean and sunflower) reduced scab infection on apple leaves significantly under controlled condition, however, orchard application of canola and soybean oil with emulsifier did not give better control level than that of the application of emulsifier alone (Northover and Schneider, 1993).…”

Elma Bahçelerinde Bazı Önemli Zararlılara Karşı Azadirachtin ve Kaolin Uygulamalarının Etkisi

“…Bitkisel ekstrakt veya uçucu yağların elma zararlılarına karşı kullanımına yönelik çok sayıda araştırma bulunmaktadır [10,11]. Son yıllarda tarımda partikül film teknolojisi çeşitli amaçlarla kullanılmaya başlanmış ve giderek yaygınlaşmaktadır.…”