Effect of Plant Oils and Extracts on Uredospores of Hemileia vastatrix Germination and Attack Intensity

Abstract

<em>Rust disease caused by fungus </em>Hemileia vastatrix<em> is a major disease of Arabica coffee</em><em>, which reduces yield by 20%–70%.</em> <em>Botanical fungicide </em><em>is a potential alternative because environmentally friendly and safe to humans health. The research aimed to analyze the effect of oils and extracts of fungicidal plants on uredospore germination and attack intensity of </em>H. vastatrix<em>. The research was conducted </em><em>in laboratory and greenhouse of Indonesian Industrial and Beverages Crops Research Institute (IIBCRI), Sukabumi, from January to December 2016. The plant oils were of cloves, citronella, </em>Reutealis trisperma<em>, and neem, while the plant extracts use</em><em>d were mahogany, </em>Ageratum conyzoides<em>,</em><em> and wood vinegar. Those oils and extracts were assessed on uredospores germination of </em>H. vastatrix<em>, both in vitro and on coffee seedling</em><em>s in the greenhouse. A complete randomized block design was used with 9 treatments and 5 replications. The oils and extracts at 5% concentration were applied on coffee leaves of 6 months old plants then inoculated with </em>H. vastratrix<em> uredospora simultaneously. </em><em>Attack symptoms, incubation period, attack percentage and intensity were observed. The results showed that plant oils and extracts used in present study effectively reduced the uredospora germination of </em>H. vastatrix<em>. </em><em>However, oils of neem and </em>R. trisperma<em> </em><em>as well as </em>A. conizoides<em> extract are more potential to suppress </em>H. vastatrix<em> infection in coffee le</em><em>aves in greenhouse and reduced attack intensity from 22.2% to 3.6%; 5.2%; and 7.6% with inhibitory level at 83.8%; 76.6%; and 65.8%, respectively. Therefore, they are considered as potential biocontrols for rust disease.</em>

Tingkat Keparahan Penyakit Karat Daun Tanaman Kopi Liberika Pada Lahan Gambut Kebun Raya Sriwijaya Provinsi Sumatera Selatan

“…Pengendalian penyakit jamur H. Vastrix pada tanaman kopi liberika di halaman gambut dengan karakteristik lahan yang asam dapat dilakukan dengan pengguna varietas kopi yang penggunaan mikroba yang bersifat berlawanan dengan karakteristik penyakit yaitu menggunakan bakteri Bacillus thuringienesis dan jamur Verticilium hemileia, serta penyemprotan fungisida (Yuza Defitri 2016), terutama fungisida nabati yang akan lebih ramah lingkungan, karena menurut (Harni et al, 2018) penggunaan fungisida sintetik secara terus menerus pada lahan akan menyebabkan timbulnya ras fisiologi baru H. vastatrix yang telah berevolusi selama penggunaan fungisida dalam jangka waktu yang lama.…”