Intensitas dan Luas Serangan Beberapa Isolat Fusarium Oxysporum F.sp. Zingiberi pada Jahe Gajah

Ginger is one of the spices and medicinal commodities which is cultivated in Indonesia. One of the obstacles encountered in the cultivation of ginger is the rhizome rot disease which is mainly caused by Fusarium oxysporum Schlecht f.sp. zingiberi Trujillo. This study is aimed to know the growth ability and virulence level of the isolates on ginger rhizome and plants. The research was conducted in the laboratory and in the screen house by using Complete Random Design consisted of 10 treatments and 4 replications. The parameters observed were growth ability of F. oxysporum f.sp. zingiberi, rhizome rot disease symptoms, incubation period, extensive decay and weight difference of the rhizomes. The results showed that F. oxysporum f.sp. zingiberi which was stored for 4 years in sterile soil medium was still capable to cause damage to the rhizome and plants. Incubation periods of rhizome decay and plant symptoms were from 3 to 11.5 and 55.5 to 68.5 days, respectively. The most virulent isolate was MSO1 with extensive decay of rhizome and the wilting intensity were 108.95 mm2 dan 33.88%, respectively. IntisariJahe merupakan salah satu komoditas rempah dan obat yang banyak dibudidayakan di Indonesia. Salah satu kendala yang dihadapi dalam budidaya jahe adalah adanya gangguan penyakit busuk rimpang yang disebabkan (terutama) oleh Fusarium oxysporum Schlecht f.sp. zingiberi Trujillo. Penelitian bertujuan untuk menguji daya tumbuh dan virulensi isolat F. oxysporum f.sp. zingiberi pada rimpang dan tanaman jahe gajah. Penelitian dilakukan di laboratorium dan di rumah kasa menggunakan Rancangan Acak Kelompok Lengkap (RAKL) yang masing-masing terdiri dari 10 perlakuan dan 4 ulangan. Parameter yang diamati meliputi daya tumbuh F. oxysporum f.sp. zingiberi, gejala penyakit busuk rimpang, masa inkubasi, luas pembusukan dan selisih bobot basah rimpang. Hasil penelitian menunjukkan bahwa F. oxysporum f.sp. zingiberi yang telah di simpan 4 tahun dalam medium tanah steril mampu menyebabkan kerusakan pada rimpang dan tanaman jahe. Masa inkubasi gejala busuk pada rimpang serta gejala pada tanaman masing- masing berkisar antara 3–11,5 serta 55,5–68,5 hari. Isolat yang paling virulen adalah MSO1 dengan nilai luas pembusukan pada rimpang dan intensitas penyakit masing-masing sebesar 108,95 mm2 dan 33,88%

Penentuan Patotipe Dan Keragaman Genetik Xanthomonas Oryzae Pv. Oryzae Pada Tanaman Padi Di Wilayah Karesidenan Banyumas

One of the major diseases of rice paddy fields in Indonesia and the Asian countries is bacterial leaf blight or kresek caused by X. oryzae pv. oryzae (Xoo). Losses caused by the disease in Indonesia reached 70–80%, in India reached 74–81%, and Japan reached 20–50%, thus causing great losses in the economy. The objectives of that research were: 1) Characterize Xoo from Karesidenan Banyumas; 2) To study of the amount of damage and AUDPC (the area under disease progress curve) of bacterial leaf blight disease at Karesidenan Banyumas; 3) To obtain of Xoo pathotype by using the test varieties; 4) To obtaining genetic diversity of Xoo that found in Banjarnegara, Purbalingga, Banyumas, Cilacap dan Kebumen region. Research was carried out in several stages: isolation and characterization of Xoo from Barlingmascakeb region, testing of Xoo with five varieties testing, assesment of disease intensity of bacterial leaf blight and AUDPC in the field, and testing the genetic diversity of Xoo. The results showed that pathogen of bacterial blight on rice is Xoo characterized yellow colour of colonies on SPA medium, negative gram reaction, catalase positive, oxidase negative, negative growth at 0.1% TZC, negative starch hydrolisis , and resistance to 0.001% Cu(NO3)2 positive. Xoo pathotype isolats found in Banjarnegara was pathotype X, Cilacap were pathotype I and II and Purbalingga was pathotype II. Eighteen of Xoo from Karesidenan Banyumas (Banjarnegara, Purbalingga, Banyumas, Cilacap and Kebumen) of RAPD differ one from the others

Applications of Potassium Fertilizer and Bacillus SP. Biopesticide for Increasing Tomato Resistance to Bacterial Wilt Disease

Bacterial wilt on tomato caused by Ralstonia solanacearum is a crucial disease, because it can reduce yield until 50%. The aims of this research were: 1) to find out biopesticide formula for Bacillus sp.growth, 2) to test Bacillus sp. against R. solanacearum in vitro, 3) to test potassium fertilizer combined with Bacillus sp. for enhancing tomato resistance to the bacterial wilt disease. The research was conducted in 2 steps i.e to test the persistence of Bacillus sp. In biopesticide formula, and to test the best combination of both potassium and the Bacillus sp. biopesticide. The results showed that Bacillus B298 was the best isolate in its persistence on the biopesticide formula of organic growth medium+CaCO3+CMC 1%+mannitol 1%, and in inhibiting R. solanacearum. The best biopesticide formula for the Bacillus sp. persistence was growth organic media+ CaCO3+CMC 1%+mannitol 1%. Bacillus sp. was able to increase tomato resistance to the bacterial wilt disease from the category of susceptible to be tolerant and becoming resistant

Mekanisme Antibiosis Bacillus Subtilis B315 Untuk Pengendalian Penyakit Layu Bakteri Kentang

Antibiosis mechanism of Bacillus subtilis B315 for controlling potato bacterial wilt disease. Bacillus subtilis B315 isolated from rhizospheric potato has antibiosis mechanism against Ralstonia solanacearum in vitro and become potentially used as controlling method of bacterial wilt in the field. The objectives of this research were to study the mechanism of B.subtilis B315 in controlling bacterial wilt disease, to study of B. subtilis B315 potency as both biocontrol and plant growth promoter, and to evaluate the mechanism as biocontrol agent. This green house experiment used CRD (Completely Randomized Design) with 5 treatments and 6 replicates. The treatments were control (without B. subtilis B315), B. subtilis B315 wild type, antibiosis mutant M16, antibiosis mutant M4, and antibiosis mutant M14. Variables observed were incubation period, disease index, infection rate, effectiveness of control, and growth components (i.e number of bud, plant height, leaf area, plant fresh and dry weight). The result of this research showed that B. subtilis B315 could delay incubation period, suppressed the disease index up to 64,9% and could promote the plant growth (leaf area). B. subtilis B315 had the antibiosis and other mechanisms that induced sistemic resistance. The implication of this research was that B. subtilis B315 could be used for biocontrol the bacterial wilt and promoted the potato growth

AKTIVITAS SIDEROFOR BACILLUS SUBTILIS SEBAGAI PEMACU PERTUMBUHAN DAN PENGENDALI PATOGEN TANAMAN TERUNG

Siderophore activity of Bacillus subtilis as plant growth promoters and biological control agent of eggplants pathogens. The aims of this research were to identify the siderophores of B. subtilis, to assess its activities as plant growth promoters and biological control agent of eggplants pathogens. Five isolates of B. subtilis i.e.B46, B209, B211, B298 and B 315 grown on SDCASA medium. The isolate which showed the best siderophores production was then further studied on its ability as a growth promoter on eggplants in two soil types with different Fe content. The inhibitory test was conducted against two kinds of pathogens, namely Colletotrichum sp. and Ralstonia solanacearum. The greenhouse experiment was arranged using a factorial completely randomized block design. The first factor was the B. subtilis (B. subtilis B298 and without B. subtilis B298), second factor was the type of soil (Ultisol and Andisol). The variables measured were Fe uptake by plants, plant growth parameters on eggplant i.e. height, leaf number, root length, root volume, weight of fresh and dried shoot as well as fresh and dry root, percentage of inhibition to fungal and bacterial eggplant pathogens. The results showed that the five isolates of B. subtilis were able to produce siderophores as catecholate and hydroxamate types. The best siderophore production was showed by B. subtilis B298. The ability of B. subtilis B298 in accelerating the growth of plants was indicated by the increased of uptake Fe, plant height, leaf number, root volume, weight of dried plants by 45.62%, 25.48%, 19.45%, 41.10% and 34.89% respectively. The inhibition to the fungal and bacterial eggplant pathogens best shown by the isolates of B. subtilis B298 with 55.4% and 22 mm respectively

Bacillus Subtilis From Potato Rhizosphere as Biological Control Agent and Chili Growth Promoter

Bacillus subtilis is an antagonist bacteria that inhibits the growth of fungal and bacterial plant pathogens. The B. subtilis has roles as biocontrol agents and plant growth promoting rhizobacteria (PGPR). This research aimed to evaluate the potency of B. subtilis isolates (B209, B211, and B298) as a biocontrol agent to anthracnose (caused by Colletotrichum spp.) and as PGPR to increase the growth of Chili plants. The experiments were divided into two batches. The first batch was conducted in the laboratory to evaluate the characteristics of B. subtilis (as biocontrol) and PGPR (phosphate solubility, producing IAA and nitrogen). The second batch was conducted in the field in Rempoah Village, Baturraden Regency, Banyumas District, with 5 treatments and 6 replications. Parameters observed were inhibition percentage to Colletotrichum spp., disease intensity, the component of PGPR, plant growth of Chili, and phatosystem. The results showed that B209, B211, and B298 isolates inhibited the growth of Colletotrichum spp, with the highest inhibition percentage on B298. B209, B211, and B298 have characteristics as PGPR, i.e. the ability to soluble phosphate, to produce IAA and nitrogen. The ability of B298 to promote plant growth was shown by the increase of plant height, leaf number, plant dry mass, and dry root mass (38.0%, 54.7%, 61.7%, 61.8%, respectively). B298 and B211 could increase the fresh crop mass (41.2% and 37.1%) and fresh root mass (36.4% and 34.4%). B298 and B209 were similar in increasing the root length (25.2%). Root volume could be increased by 33.3% by applying B211 isolate. B209 was the best isolate to reduce anthracnose up to 80.36%