Penyakit penting pada tanaman jagung diantaranya adalah penyakit karat daun yang disebabkan oleh jamur Puccinia sorghi Schwein dan penyakit hawar daun yang disebabkan oleh jamur Helmithosporium turcicum Leonard et Suggs. Penelitian ini bertujuan untuk menguji keefektifan Pseudomonas fluorescens dan Paenibacillus polymyxa dalam menekan perkembangan penyakit karat dan hawar daun jagung serta memicu pertumbuhan tanaman jagung. Penelitian ini dilakukan pada bulan September sampai bulan Desember 2015 di Laboratorium Penyakit Tumbuhan Jurusan Agroteknologi dan di lahan petani di Kampung Baru Bandar Lampung. Perlakuan disusun dalam rancangan acak lengkap (RAL) terdiri atas lima perlakuan dan tiga ulangan. Perlakuan terdiri atas (1) P0 kontrol berupa tanaman jagung yang tidak diberi perlakuan fungisida, P. polymyxa dan P.fluorescens (2) P1 perendaman benih jagung dalam formulasi P. polymyxa selama 6 jam, (3) P2 perendaman benih jagungdalam formulasi P. fluorescensselama 6 jam, (4) P3 perendaman benih jagung dalam formulasi P. polymyxa danP.fluorescens selama 6 jam, (5) P4 perendaman benih jagung dalam fungisida propineb selama 6 jam. Data yang diperoleh kemudian dianalisis dengan menggunakan sidik ragam kemudian dilanjutkan dengan uji Beda Nyata Terkecil (BNT) pada tarif nyata 5%. Hasil penelitian menunjukkan bahwa (1) Aplikasi P. fluorescens dan P. polymyxa mampu menekan keparahan penyakit karat dan hawar daun jagung (2) Aplikasi P. polymyxa mampu meningkatkan tinggi tanaman dan jumlah daun jagung.

Heritability, potential ratio, and heterosis of soybean (Glycine max [L.] Merrill) resistance to soybean mosaic virus. The use of soybean cultivars with resistance to SMV is a way for controlling soybean mosaic disease. The objective of this research was to estimate the disease severity, the narrow sense heritability, potential ratio and heterosis of resistance character and number of pithy pods, number of healthy seeds, and healthy seeds weight per plant of ten F1 populations of soybean crossing result to SMV infection. The experiment was arranged in a randomized complete block design in two replications. Observed characters were disease severity, number of pithy pods, number of healthy seeds, and healthy seeds weight per plant. The result of this research showed that 1) the crossing combinations those which were resistant to SMV (lower disease severity) were Yellow Bean x Tanggamus, Tanggamus x Orba, and Tanggamus x Taichung, 2) the narrow sense heritability of disease severity was included in medium criteria, 3) number of pithy pods belonged to high criteria, and 4) number of healthy seeds and healthy seeds weight per plant were included in low criteria. The crossing combinations that had low estimation value of heterosis and heterobeltiosis of resistance to SMV infection were Yellow Bean x Taichung, Bean x Tanggamus and Tanggamus x B3570. Disease severity or resistance to SMV is influenced by genetic and environmental factors.

Antraknosa adalah penyakit terpenting dalam budidaya cabai besar karena menyebabkan kehilangan hasil di lapangan mencapai sekitar 75%. Penelitian ini bertujuan untuk mengetahui pengaruh ekstrak babadotan, tumbuhan siam, alang-alang, dan teki sebagai alternatif pengendalian penyakit antraknosa pada tanaman cabai yang ramah lingkungan. Penelitian ini dilaksanakan di Laboratorium Penyakit Tanaman dan Laboratorium Lapangan Terpadu Fakultas Pertanian Universitas Lampung pada bulan November 2012 sampai dengan Maret 2013. Rancangan yang digunakan dalam penelitian ini adalah Rancangan Acak Lengkap (RAL) terdiri dari 5 perlakuan dengan 5 ulangan. Setiap unit percobaan terdiri atas 2 tanaman cabai (dalam satu polibag). Perlakuan terdiri atas air steril sebagai kontrol (M0), ekstrak Ageratum conyzoides (babadotan) 100 g/100 ml air (M1), ekstrak Chromolaena odorata (tumbuhan siam) 100 g/100 ml air (M2), ekstrak Imperata cylindrica (alang-alang) 100 g/100 ml air (M3), dan ekstrak Cyperus rotundus (teki) 100 g/100 ml air (M4). Pengamatan dilakukan dengan selang waktu tujuh hari sekali. Adapun peubah yang diamati adalah keparahan penyakit pada daun, pada buah, bobot buah cabai sehat, dan bobot buah cabai sakit. Data dianalisis ragam dan dilanjutkan dengan uji Beda Nyata Terkecil (BNT) pada taraf nyata 5 %. Hasil penelitian menunjukkan bahwa (1) ekstrak A. conyzoides (babadotan), C. odorata (tumbuhan siam), I. cylindrica (alangalang), dan C. rotundus (teki) berpengaruh dalam menekan keparahan penyakit antraknosa (2) pengaruh ekstrak A. conyzoides (babadotan), C. odorata (tumbuhan siam), I. cylindrica (alang-alang), dan C. rotundus (teki) berbeda-beda namun ekstrak C. odorata (tumbuhan siam) dan C. rotundus (teki) lebih efektif dari pada A. conyzoides (babadotan), I. cylindrica (alang-alang) dalam menekan keparahan penyakit antraknosa pada daun dan buah cabai.

Abstract. Prasetyo J, Ginting C, Akin HM, Suharjo R, Niswati A, Afandi A, Adiwijaya R, Sudiono, Nurdin M. 2021. The effect of biological agent and botanical fungicides on maize downy mildew. Biodiversitas 22: 1652-1657. This study was conducted to evaluate the effect of the combination of Trichoderma asperellum and mycorrhizae with botanical fungicides made from betel leaf extract or turmeric extract against maize downy mildew. The study used a randomized complete block (RCB) design with three replications. The treatments applied were: single applications of T. asperellum (Ta); arbuscular mycorrhizal fungi (AMF); turmeric extract (T); betel extract (B); the combination of T. asperellum and AMF (TaM); turmeric extract and T. asperellum (TTa); turmeric extract and AMF (TM); turmeric extract + T. asperellum + AMF (TTaM); betel extract + T. asperellum (BTa); betel extract + AMF (BM); betel + T. asperellum + AMF (BTaM); and Control (C). The observed variables were disease incidence, incubation period, and shoot dry weight. The data were analyzed using ANOVA. Differences between treatments were tested by the LSD test at 5% significance level. The results showed that the combination of botanical fungicides with biological agents could reduce the incidence of downy mildew, extend the incubation period, and increase the dry weight of corn shoots. The best combination treatment was achieved from the combination of T. asperellum with betel extract. There was a synergistic effect between botanical fungicides and biological agents in reducing the disease incidence.

Influence of  tobacco mosaic virus infection to vegetative and generative growth of various hot pepper varieties  (Capsicum annuum L.). This experiment was conducted to investigate the effect of TMV infection on vegetative and generative growth of various hot pepper varieties. Treatments were arranged in completely randomized design in split plot experiment with four replications. Mainplots were virus-inoculated and uninoculated plants; subplots were three hot pepper varieties: Cimerti, HP-Typhoon, and HP-Tornado. The results of the experiment showed that TMV infection caused decrease vegetative and generative growth.  The decrease of vegetative and generative growth  indicated by the reduction of leaf width, plant height, and yield.  HP-Tornado and Cimerti varieties showed susceptible reaction proved by significant reduction of the growth and yield;  HP-Typhoon was tolerance reaction to TMV infection indicated by significant reduction of the growth and lowest reduction of the yield.