The mechanical properties of bioplastic prepared from avocado seed starch and mycrocrystalline cellulose from sugar palm fibers as filler using Schweizer's reagent as solvent was studied. Bioplastics were prepared from avocado seed starch and reinforced with microcrystalline cellulose (MCC) from sugar palm fibers with composition ratio were 7:3, 8:2 and 9:1 (w/w) and using glycerol as plasticizer with variation of 0.1; 0.2; 0.3 and 0.4 (v/w of starch). Microcrystalline cellulose dissolved in the copper solution (Schweizer reagent) with ratio of MCC:copper solution is 1:10. Degree of crystallinity of microcrystalline cellulose was 97.5 %. Morphologycal analysis showed that the isolated microcrystalline cellulose from sugar palm fibers are rod-like shape with diameter of 5.55-9.44 µm and crystallite size of 25.08 nm. Mechanical properties of bioplastic showed that the best condition of bioplastics obtained at comparison of mass starchmicrocrystalline cellulose 7:3 and the addition of glycerol 0.1 (v/w) for tensile strength 20.874 MPa and elongation at break of 6.22 %.

Maize (Zea mays) is one of the major crops and widely grown in Indonesia. On average, current maize yields are still below its potential. Thus, it needs to increase by good agricultural practices such as applying biofertilizer, which consists of beneficial bacteria. This research was aimed to find out the impact of the bacterial consortium of nitrogen-fixing bacteria (BPN) and phosphate solubilizing bacteria (BPF) on the maize growth. The study was conducted in the greenhouse and arranged in a completely randomized design (CRD) with treatments, i.e.: (1) negative control (no inorganic fertilizer and BPN-BPF); (2) positive control (100% inorganic fertilizer); (3) only BPN-BPF applied (no inorganic fertilizer); (4) 75% inorganic fertilizer + BPN-BPF; and (5) 50% inorganic fertilizer + BPN-BPF. The results revealed that the consortium of nitrogen-fixing bacteria and phosphate solubilizing bacteria significantly improved certain soil chemical properties, such as C-organic, cation exchange capacity (CEC), and the availability of nitrogen and phosphorus in the soil. Besides, the consortium of BPN and BPF also increased the maize growth and total biomass up to 19%. Further, a consortium of BPN and BPF increased the fertilizer efficiency by reducing the dosage of inorganic fertilizer up to 50%.

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This research was aimed at obtaining varieties of soybean adaptive to acid soils and to obtain Plant Growth-Promoting Rhizobacteria (PGPR) isolates that can improve the agronomic characteristics of soybean and increase the ultisols fertility. This research was conducted in two-stages research on Sampali Village, Percut Sei Tuan sub-District, Deli Serdang District, North Sumatra Province, Indonesia from August 2019 until March 2020. The first stage (adaptive varieties screening) using the non-factorial Randomized Block Design (RBD) with the varieties of Argomulyo, Wilis, Kaba, Dena-1, Devon-1, Dega-1, Demas-1, Burangrang, Detam-1, and Kipas Merah. The second stage (application of PGPR isolates singly and in combinations) using the factorial RBD, the first factor of applicative single and the combination of PGPR isolates, the second factor of adaptive varieties including Detam-1 and Wilis. Data were analyzed with ANOVA and followed by DMRT at P<0.05. The results showed that the Detam-1 and Wilis varieties had significantly higher yield per plant of 14.73 g and 14.54 g, respectively, than other varieties. The applications of a single and combination of PGPR isolates significantly increased the number of branches, stem diameter, plant height, yield per plant, soil pH, organic-C, available-P, and total-N and decreased the soil C/N. The Detam-1 variety had the higher in yield per plant compared to Wilis variety. The isolates combination of Rhizobium leguminosarum+Rhizobium sp2+Bacillus sp+Burkholderia sp for Detam-1 and Wilis varieties can be recommended to support the growth and yield of soybean on ultisols.

Tujuan dari penelitian adalah untuk mendapatkan komposisi, dan teknik aplikasi Corynebacterium terbaik dalam mengendalikan penyakit layu fusarium serta dapat meningkatkan hasil tanaman cabai merah. Penelitian ini dilaksanakan di Desa Pematang Pelintahan Kecamatan Sei Rampah Kabupaten Serdang Bedagai, dengan ketinggian tempat ± 7-13 meter di atas permukaan laut. Penelitian dilaksanakan pada bulan Mei 2020 sampai Agustus 2020. Rancangan penelitian adalah Rancangan Acak Kelompok (RAK) Non Faktorial yaitu Faktor Pemberian Corynebacterium terdiri dari 4 taraf : C0 = 0 ml/l air, C1 = 5 ml/l air, C2 = 7,5 ml/l air, C3 = 10 ml/l air. Peubah yang diamati dalam penelitian ini adalah persentase daya hambat, persentase penyakit layu fusarium dan persentase penyakit antraknosa. Hasil penelitian menunjukkan bahwa perlakuan pemberian Corynebacterium berpengaruh nyata terhadap persentase daya hambat layu fusarium, persentase penyakit layu fusarium, persentase penyakit antraknosa. Perlakuan pemberian Corynebacterium terbaik diperoleh pada perlakuan 10 ml/l air.