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Pratibha Sharma - One of the best experts on this subject based on the ideXlab platform.

Johanis Panggeso - One of the best experts on this subject based on the ideXlab platform.

  • efikasi ekstrak daun sirih terhadap Alternaria porri penyebab penyakit bercak ungu pada bawang merah secara in vitro
    AGROTEKBIS : E-JURNAL ILMU PERTANIAN, 2018
    Co-Authors: Muh Fahrun, Johanis Panggeso, Rosmini Rosmini
    Abstract:

    Bercak ungu disebabkan oleh jamur A . porri adalah penyakit penting yang menyerang pertanaman bawang merah dan menyebabkan kerugian dibeberapa sentra produksi di Indonesia. Pengendalian penyakit bercak ungu oleh petani masih menggunakan fungisida kimia sehingga diperlukan alternatif pengendalian dengan fungisida nabati. Salah satu fungisida nabati ialah daun sirih. Daun sirih memiliki sifat anti cendawan, dan anti oksidan dengan komponen minyak atsiri yaitu eugenol 63,39%, acetyleugenol 14,05%. Tujuan penelitian ini untuk menentukan efektivitas ekstrak daun sirih dalam menghambat pertumbuhan jamur A . porri penyebab penyakit bercak ungu pada bawang merah. Pelaksanaan penelitian di Laboratorium Jurusan Hama dan Penyakit Tumbuhan (HPT) Fakultas Pertanian Universitas Tadulako, Sulawesi Tengah. Palu. Penelitian dimulai pada bulan Januari sampai September 2016. Metode uji yaitu masing-masing konsentrasi ekstrak daun sirih di tuang sebanyak 2 ml ke dalam medium PDA. Setelah memadat, A . porri diambil menggunakan jarum ose dan diletakkan tepat di bagian tengah. Hasil penelitian menunjukkan, Ekstrak daun sirih efektif menghambat pertumbuhan A. porri, konsentrasi tertinggi dalam menghambat pertumbuhan A. porri adalah 8%. Hasil analisis regresi konsentrasi ekstrak daun sirih terhadap persentase penghambatan A. porri menunjukkan hubungan korelasi sangat    kuat (0,904). Kata kunci : Alternaria porri , Ekstrak, Sirih ( Piper betle L.).

  • uji antagonisme trichoderma sp terhadap jamur patogen Alternaria porri penyebab penyakit bercak ungu pada bawang merah secara in vitro
    AGROTEKBIS, 2013
    Co-Authors: Rusdam Muksin, I Rosmini, Johanis Panggeso
    Abstract:

    The objective of this study is to know the ability the fungus Trichoderma sp. as antagonistic to fungal pathogens Alternaria porri (EII. Cif.) on shallot. This study was conducted in the Laboratory of plant pests and Disease Department (HPT), Agriculture faculty  of Tadulako University, Palu in Plant Central Sulawesi. This study used the isolation and identification of fungal pathogen A.porri on onion and antagonism test of Trichoderma sp test against mold growth A.porri , with 2 treatments and 5 replications so that there were 10 experimental units. Local isolates of Trichoderma sp. Used in this experimen were derived from two institusion the Laboratory of plant pests and Diseases Faculty of Agriculture University of Tadulako and BPTP Biromaru. The result of this stady indikate that bolt of lokal isolate Trichoderma sp. quite effective in suppressing the growth fungi A.porri EII. Cif. disease-causing purple spots on the onion crop in-vitro, but percentage of inhibition bolth of isolate ware not significantly different at 5% level test results.

Ismail R. Abdel-rahim - One of the best experts on this subject based on the ideXlab platform.

  • Onion purple blotch symptoms, at Assiut Governorate (Egypt), caused by synergistic association between Alternaria porri and Stemphylium vesicarium
    Journal of Plant Diseases and Protection, 2017
    Co-Authors: Ismail R. Abdel-rahim, Sobhy I. I. Abdel-hafez, Kamal A. M. Abo-elyousr
    Abstract:

    The incidence of onion purple blotch disease was investigated at Assiut Governorate, Egypt during 2011. Lesions with typical symptoms of the disease were colonized by Alternaria porri , Stemphylium vesicarium or mixtures of the both pathogens comprising 2.6, 39.8 and 57.6 % of samples, respectively. Four isolates were selected for virulence evaluation according to the nature of isolation, whereas two isolates were individually associated with the diseased samples and two isolates were collectively recovered. Individually, A. porri AUMC9301 and AUMC10453 showed high virulence contributing 81.25 and 78.13 %, respectively. Also, S. vesicarium AUMC10512 and AUMC10519 exhibit severity comprising 37.50 and 25.00 %, respectively. On the other hand, mixture of A. porri AUMC10453 and S. vesicarium AUMC10519 exhibited highest virulence (91.50 %). In conclusion, this investigation proved that onion plants showing purple blotch symptoms mainly colonized by both A. porri and S. vesicarium . Consequently, increase in the disease may be attributed to the association between these pathogens.

  • Fungicidal activity of extracellular products of cyanobacteria against Alternaria porri
    European Journal of Phycology, 2015
    Co-Authors: Sobhy I. I. Abdel-hafez, Kamal A. M. Abo-elyousr, Ismail R. Abdel-rahim
    Abstract:

    ABSTRACTAlthough cyanobacteria are recognized as renewable sources of biomass for bioactive compounds, they have received little attention as potential biocontrol agents of foliar plant diseases. The purpose of this study was to evaluate the fungicidal efficacy of cyanobacterial extracellular products against Alternaria porri, which causes onion purple blotch disease, in vitro and under greenhouse conditions. Among the tested cyanobacteria (Anabaena oryzae, Arthrospira sp., Nostoc minutum, N. muscorum and Oscillatoria sp.), extracellular metabolites of N. muscorum and Oscillatoria sp. reduced the linear growth of A. porri by 20.37 and 36.34%, respectively. Culture filtrates of both Oscillatoria sp. and N. muscorum contained high concentrations of phenolic compounds (104.33 and 145.0 mg l−1, respectively), and alkaloids (473.31 and 378.12 mg l−1, respectively). GC-Mass analysis revealed that the most prevalent component in culture filtrates of N. muscorum and Oscillatoria sp. was beta ionone (7.21 and 7.17...

  • Isolation of Trichoderma and Evaluation of their Antagonistic Potential against Alternaria porri
    Journal of Phytopathology, 2014
    Co-Authors: Kamal A. M. Abo-elyousr, Sobhy I. I. Abdel-hafez, Ismail R. Abdel-rahim
    Abstract:

    AbstractNine isolates of Trichoderma were collected from Assiut Governorate,Egypt, as leaf surface and endophytic fungi associated with onion florastalks. Four isolates were identified as Trichoderma harzianum, while fiveisolates were belonging to Trichoderma longibrachiatum. The antagonisticactivity of these isolates against onion purple blotch pathogen Alternariaporri was studied in vitro using dual culture assay. All tested Trichodermaisolates showed mycoparasitic activity and competitive capability againstthe mycelial growth of A. porri. Mycoparastic activity of Trichoderma wasmanifested morphologically by the overgrowth upon the mycelial growthof the pathogen and microscopically by production of coiling hyphaearound pathogen hyphae. Isolates of T. harzianum exhibited high abilityto compete on potato dextrose agar (PDA) medium causing the maximumrate of pathogen inhibition (73.12%), while isolates of T. longibrachiatumshowed inhibition rate equalling 70.3%. Chitinase activity of Trichodermawas assayed, and T. harzianum Th-3013 showed the maximum value con-tributing 2.69 U/min. Application of T. harzianum Th-3013 to control pur-ple blotch disease in vivo under greenhouse conditions caused diseasereduction up to 52.3 and 79.9% before and after 48 h of pathogen inocu-lation, respectively, while the fungicide Ridomil Gold Plus caused diseasereduction comprising 56.5 and 71.7%, respectively. This study proved thatT. harzianum Th-3013 as a biocontrol agent showed significant reductionin onion purple blotch disease compared with the tested fungicide.IntroductionPurple blotch disease, caused by Alternaria porri (Ellis)Cif., is one of the most serious diseases that wide-spread in many parts of the world, restricted to Alliumspp. and more prevalent in warm and humid environ-ments (Cramer 2000; Suheri and Price 2000). Purpleblotch disease caused significant reduction in bulband seed yield of the onion crop (Gupta and Pathak1988). The disease is more severe on seed crop ascompared to bulb crop causing sometimes 100% loos-ing of the seed production (Singh et al. 1992;Schwartz 2004). Although chemical control of onionblotch had been practised and its success depends lar-gely on high frequency of spraying, but today, thereare strict regulations on chemical fungicide use due tocarcinogenic effects, residual toxicity problems, envi-ronmental pollution and development of fungicide-resistant strains (Benitez et al. 2004; Rial-Otero et al.2005). Therefore, there are a large number of studiesthat have been devoted to apply a biological control asnature-friendly alternative method (Siameto et al.2010; Soria et al. 2012). The potential of Trichodermaspecies as biocontrol agents of plant diseases was firstrecognized in the early 1930s (Weindling 1932), andsince then, there have been extensive efforts in thecommercial production of them for disease control ina number of crops (Harman 1996; Gardener and Frav-el 2002). Recently, several investigation proved thatTrichoderma have been used to control many foliar

Rizki, Juliana Jambak - One of the best experts on this subject based on the ideXlab platform.

Pratiwi, Annisa Hasta - One of the best experts on this subject based on the ideXlab platform.

  • Uji Efektivitas Fungisida Propineb 70% Terhadap Penyakit Bercak Ungu Yang Disebabkan Oleh Jamur Alternaria porri Pada Tanaman Bawang Merah Dan Pengaruhnya Terhadap Jamur Filosfer Secara In Vitro
    2018
    Co-Authors: Pratiwi, Annisa Hasta
    Abstract:

    Penyakit bercak ungu (purple blotch) merupakan salah satu penyakit penting yang menyerang tanaman bawang merah. Penyakit bercak ungu disebabkan oleh jamur Alternaria porri. Kehilangan hasil dan kerugian akibat penyakit ini diperkirakan mencapai 30-50%. Pengendalian penyakit bercak ungu menggunakan fungisida berbahan aktif propineb masih banyak digunakan. Propineb merupakan bahan aktif fungisida golongan ditiokarbamat yang secara luas digunakan sebagai fungisida dan mengandung komponen belerang organik yang merupakan kelompok utama dari fungisida untuk mengendalikan kurang lebih 400 patogen pada lebih dari 70 tanaman. Namun, penggunaan fungisida memiliki risiko menimbulkan ketahanan jamur patogen terhadap fungisida dan juga menyebabkan kematian sasaran lain seperti parasit, antagonis dan patogen serangga, termasuk jamur filosfer. Filosfer merupakan salah satu bagian tanaman yang dapat terkena secara langsung oleh penggunaan fungisida. Penggunaan fungisida propineb dapat menyebabkan terganggunya pertumbuhan jamur-jamur filosfer pada tanaman dan dapat mengurangi jumlah populasinya pada daun. Tujuan penelitian ini adalah mengkaji efektivitas fungisida berbahan aktif propineb terhadap pertumbuhan jamur A. porri dan mengkaji pengaruhnya terhadap beberapa jamur filosfer pada tanaman bawang merah. Penelitian dilaksanakan di Laboratorium Penyakit Tumbuhan, Jurusan Hama dan Penyakit Tumbuhan, Fakultas Pertanian, Universitas Brawijaya, Malang pada bulan Juni 2017 hingga Januari 2018. Penelitian ini terdiri dari dua tahapan yaitu pengujian efektivitas fungisida terhadap jamur A. porri dan pengujian pengaruh fungisida terhadap jamur-jamur filosfer secara in vitro. Penelitian ini menggunakan Rancangan Acak Lengkap (RAL) yang terdiri dari lima perlakuan dan diulang sebanyak lima kali. Hasil penelitian menunjukkan fungisida propineb mampu menghambat pertumbuhan jamur A. porri dengan pengaruh yang berbeda nyata pada masingmasing konsentrasi. Fungisida konsentrasi 0,25 g/l efektif menghambat pertumbuhan jamur A. porri dengan presentase penghambatan sebesar 70.56%. Hasil isolasi dan identifikasi terhadap daun tanaman bawang merah ditemukan dua genus jamur yang tidak teridentifikasi, yaitu Filosfer 1 dan Filosfer 2 serta tiga genus jamur teridentifikasi yaitu Penicillium sp., Fusarium sp. dan Nigrospora sp. Pengaruh fungisida propineb terhadap jamur filosfer menunjukkan hasil analisis ragam yang berbeda nyata secara statistik. Hasil peneltian menunjukkan bahwa fungisida propineb selain efektif menghambat jamur patogen A. porri juga menyebabkan terhambatnya pertumbuhan jamur-jamur filosfer tanaman bawang merah. Konsentrasi 0,25 g/l mampu menghambat jamur Penicillium sp. sebesar 73,78%, Fusarium sp. sebesar 29,67%, Nigrospora sp. sebesar 48,33%, jamur filosfer 1 sebesar 10,89% dan jamur filosfer 2 sebesar 17,85