Judul: The use of bioagentsTrichodermaspp. and bacteria cellulotic.as decomposer of Ageratum conyzoides var hirtum (Lam), Tithonia diversifolia (Hamsley) A. Gray and Sago Waste to produce organic fertilizer for Chili (Capsicum annuum L.).
Abstrak: Ageratum conzoides var hirtum (Lam), Tithonia diversifolia (Hamsley) A. Gray and waster sago can be used as organic fertilizer or compost. Some isolates of Trichodermaspp. and bacteria cellulotic had been tested as the antagonize agent for controllingPhytophthora capsici(wilt disease on chili). These microorganism were used as decomposer of weeds, A.conyzoideshirtum var (Lam), T.diversifolia(Hamsley) A. Gray, and sago waste. The aims of the study were to select microbes that has capability to degradation cellulose and able to accelerate the composting process of A.conyzoideshirtum var (Lam), T.diversifolia(Hamsley) A. Gray, and sago waste; and determine the effect of formula compost on plant growth of chili, resistance to infection of P. capsici L and yield of chili. This study was conducted in three phases: 1). Selection of Trichoderma spp and bacteria isolates on Carboxy methyl cellulose (CMC) media, 2). Composting A.conyzoides var hirtum (Lam), T.diversifolia(Hamsley) A. Gray and sago waste by isolates ofTrichoderma spp and bacteria cellulotic which had been selected; 3). Application of compost formulas on chiliplants. The visualization of cellulase activities on CMC mediawere shown as the clear zone around the colony. Six isolates of Trichoderma spp (PO3, S1, N34, IU, PB 13, SKM) have the clear zone ratio range between 3.0 -5.3 and six isolates of bacteria (St109, Sk7, Cm58, Sk14, Sk 10 and St18) havethe clear zone ratio range between 2.6 to 5.4; were selected to decompose weeds and sago waste.The result showed that Trichoderma spp and bacteria cellulotic inoculantsor themixed of them were able to reduce the duration of composting process from 17–18 days to 13-15 days. The products of compost formula are appropriate with the SNI19-7030-2004 and standards minimumof technical organicfertilizer.Application of compost formulas and goat manure on chili plants affected the growth, the disease attacked and the yield of chili. The application of formula D{goat manure+A. conyzoides var hirtum (Lam)+ sago waste} caused the diseaseattacked about 33.3%but the yield was 524,56 g. While the diseaseattackedatgoat manuretreatment was 16.67% and the yield was 132.3 g. Formula D increased the yield of chili 3.96 times compare than goat manure only.
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Judul: The Use of Trichoderma hamatum and Fluorescent Pseudomonad BJ10-86 in Controlling Phytophthora capsici on Chili (Capsicum
Abstrak: Phytophthora capsici is an important plant infecting oomycete with a worldwide/cosmopolitan distribution. The pathogen has a wide host range, especially capsicums and cucurbits, and attacks nearly all plant parts and at all growth stages. Chemical control is proofing no longer effective due to reported pathogen resistance development, not to mention the related environmental concerns and the consumer demands for low, if not zero, use of fungicides. Biological control is a sustainable option. Several biocontol agents have been reported effective against this pathogen. In this research, the biocontrol activities of Trichoderma hamatum and fluorescent pseudomonad BJ10-86 against P. capsici were studied in order to propose an optimization of their application. The objectives of the biological control application were to improve chili pepper seed germination, reduce damping off disease incidence, and improve the growth of the seedlings. The studies were done in vitro as well as seed treatment assays and polybag application experiments. Fluorescent pseudomonad isolate BJ10-86 was subjected to molecular identification by amplifying the 16S rRNA region and sequencing the nucleotides before searching for similar sequences in the BLAST search engine. The isolate was identified as Pseudomonas aeruginosa and deposited in the GenBank under the accession number KM102771 as P. aeruginosa BJ10-86. The in vitro experiments involved plating the micro-organisms in dual and triple culture assays on agar media. The results showed that both biocontrol agents were compatible and increased the inhibition of P. capsici. Chili pepper seeds treated with the biocontrol agents, individually or in combination, were sown in commercial nursery media that had been pre-inoculated with P. capsici zoospores. Results of data collected over a period of 35 days indicated that seed treatment significantly (P=0.008) reduced damping off disease incidence. Combined application of T. hamatum and fluorescent pseudomonad BJ10-86 was the best biocontrol treatment with an area under disease progress curve (AUDPC) of only 36.61 units compared to 92.87 units in the control treatment. This combination was seen to increase biocontrol efficacy to 60.58%. Both organisms evidently had a synergistic interaction. Seed treatment had no effect on seed germination and seedling growth. In further experiments, the objective was to utilize synergism between T. hamatum and fluorescent pseudomonad BJ10-86 in order to reduce root and collar rot caused by P. capsici and promote chili pepper plant growth under field conditions. The treatments involved individual and combined polybag application of the biocontrol agents as conidial and bacterial cell suspension as soil drench. These were either administered 14 days before transplanting or during the transplanting day. The results indicated that fluorescent pseudomonad BJ10-86 increased the chili pepper plant height and number of leaves. Combined T. hamatum and fluorescent pseudomonad BJ10-86 had synergistic effects against root and collar rot disease incidence through delaying the disease onset. For better effects, these combined application of biocontrol agents should be at least 14 days before transplanting. Based on these findings, it is proposed that chili pepper seeds should be treated with a combination of both organisms. These organisms are effective at concentrations of 2×108 CFU ml-1 and 9.4×105 spores ml-1 for P. aeruginosa BJ10-86 and T. hamatum respectively.
Keyword: biological control, damping off, collar rot, synergism, growth promotion

Judul: Fenomena Arus Rabak (Rip Current) Di Kawasan Pantai Panjang, Kota Bengkulu
Abstrak: Tingginya kunjungan wisatawan namun minim pengetahuan tentang kondisi pantai, dapat menyebabkan adanya risiko kecelakaan pantai yang tinggi. Arus rabak adalah salah satu penyebab terjadinya kecelakaan pantai. Tercatat sebanyak 35 kasus terseretnya wisatawan pernah terjadi di Pantai Panjang dari tahun 2009 hingga tahun 2021. Penelitian ini bertujuan menggambarkan kondisi oseanografi pada lokasi yang berpotensi munculnya arus rabak berdasarkan musim, jenis arus rabak, serta menjelaskan karakteristik arus rabak melalui ciri dan proses pembentuk arus rabak. Lokasi penelitian dilakukan di Pantai Panjang, Kota Bengkulu. Analisis arus rabak menggunakan model SWAN, kedalalaman perairan, angin dan citra satelit. Topografi dasar laut pesisir Bengkulu relatif landai. Gelombang signifikan tertinggi terjadi pada bulan Januari 2017 yaitu 0.25 m dengan periode gelombang terlama terjadi pada bulan April 2021 yaitu 1.63 s. Karakteristik tipe gelombang pecah Pantai Panjang yaitu plunging. Fenomena arus rabak kerap terjadi di Pantai Panjang dengan jenis bar-gap rips. Pembentukan arus rabak dipengaruhi oleh kondisi topografi. Arus rabak yang terjadi di Pantai Panjang dapat ditemui s
Keyword: Arus rabak, Gelombang, Pantai Panjang, SWAN, Topografi, Panjang Beach, Rip Current, Topography, Wave