Penelitian ini bertujuan untuk mengetahui uji toleransi beberapa varietas padi (Oriza sativa L) terhadap variasi intensitas penyinaran. Penelitian ini dilaksanakan bulan November 2014 sampai dengan bulan Februari 2015. diKebun Percobaan Pasar Miring, Balai Pengkajian Teknologi Pertanian (BPTP) Sumatera Utara. Jl. Raya-Galang Km 8,2 Lubuk Pakam, Kec. Pagar Merbau, Kab. Deli Serdang, Sumatera Utara. Rancangan yang digunakan dalam penelitian adalah Rancangan Petak Terbagi (RPT) dengan 2 faktor, yaitu: yang pertama faktor Naungan (N) sebagai petak utama dengan 3 taraf yaitu: N0 = tanpa naungan (100% intensitas penyinaran), N1= dinaungi 25% (75% intensitas penyinaran), N2 = dinaungi 50% (50% intensitas penyinaran). Yang kedua faktor varietas padi (V) sebagai anak petak dengan 5 taraf yaitu : V1= varietas Sidenuk, V2= varietas Ciherang, V3= varietas Inpari 10, V4= varietas Inpari 30 dan V5= varietas Mugibat. Jumlah kombinasi perlakuan 15 kombinasi yang diulang sebayak 3 kali menghasilkan 45 satuan percobaan, jumlah tanaman per plot 40 tanaman dengan 10 tanaman sampel, jumlah tanaman keseluruhan adalah 1800 tanaman dengan jumlah sampel seluruhnya 450 tanaman. Hasil penelitian menunjukkan bahwa perlakuan intensitas penyinaran (naungan) berpengaruh nyata terhadap parameter tinggi tanaman 14 MST, jumlah anakan, jumlah anakan produktif, jumlah gabah berisi per malai, berat gabah kering per plot dan berat gabah kering per Ha. Sedangkan parameter tinggi tanaman 2, 4 dan 6 MST, panjang malai, jumlah gabah per malai, jumlah gabah hampa per malai, berat gabah 1000 biji, kandungan klorofil A, kandungan klorofil B, kandungan klorofil Total tidak berpengaruh yang nyata. Pada perlakuan varietas berpengaruh nyata terhadap parameter tinggi tanaman, jumlah anakan, jumlah anakan produktif, jumlah gabah per malai, jumlah gabah berisi per malai, sedangkan terhadap panjang malai, jumlah gabah hampa per malai, berat gabah 1000 biji, kandungan klorofil A, kandungan klorofil B, kandungan klorofil Total, berat gabah kering per plot, berat gabah kering per Ha, penggunaan varietas tidak memberikan perbedaan yang nyata. Interaksi varietas dan intensitas penyinaran memberi pengaruh yang nyata terhadap jumlah anakan dan jumlah anakan produktif. Sedangkan parameter tinggi tanaman, jumlah gabah per malai, jumlah gabah berisi per malai, panjang malai, jumlah gabah hampa per malai, kandungan klorofil A, kandungan klorofil B, kandungan klorofil Total, berat gabah 1000 butir, berat gabah kering per plot dan berat gabah kering per Ha tidak memberikan perbedaan yang nyata.

The latest technological developments in shallot cultivation can be done using True Shallot Seed (TSS). The obstacle is the character experiencing difficulty in senescence and long harvesting age. The presence of growth inhibitor is necessary to focus the energy on tuber formation. This research aimed to evaluate the effect of sulfur and paclobutrazol on the growth of shallots from TSS. The research was conducted using polybag in the community land in Medan, using a factorial randomized block design with 2 factors and 3 replications. The first factor was sulfur (0, 75, 150 kg ZA/ha) applications, and the second factor was paclobutrazol (0, 15, 30 ppm) applications. The results showed that 150 kg ZA/ha sulfur application increased the plant length 1-5 weeks after transplanting. The treatment of paclobutrazol and the interaction between paclobutrazol and sulfur applications had no significant effect on plant length and leaf number at 1-4 weeks after transplanting.

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Abstract. Elfiati D, Delvian, Hanum H, Susilowati A, Rachmat HH. 2021. Potential of phosphate solubilizing fungi isolated from peat soils as inoculant biofertilizer. Biodiversitas 22: 3042-3048. Phosphate-solubilizing fungi are the microbes that have the ability to dissolve insoluble phosphate and made it available for plants. Therefore, the purpose of this study was to obtain the phosphate-solubilizing fungi from peat soils. Peat soil samples were taken in a composite at a depth 0-20 cm from the peat ecosystem in Nagasaribu Village, Lintong Nihuta Sub-district, Humbang Hasundutan District, North Sumatra, Indonesia. Soil samples were isolated to obtain phosphate-solubilizing fungi using the Pikovskaya selective medium. The obtained isolates were tested for their ability to dissolve phosphate qualitatively by calculating the dissolution index values and quantitatively by calculating the available phosphorus on Pikovskaya medium by using four phosphate sources, namely Ca3(PO4)2, AlPO4, FePO4, and phosphate rock. Total of 12 isolates of phosphate-solubilizing fungi was obtained during the present study. Based on the results of qualitative and quantitative testing, all 12 isolates have the ability to release phosphate from the four tasted phosphate sources. The qualitative test obtains dissolution index values that vary from 2.55 to 4.25, while quantitatively, the isolates were able to dissolve phosphate in the value range from 17.77 ppm to 69.86 ppm. The top five fungal isolates with highest phosphate-solubilizing potential were FG5, FG8, FG9, FG11, and FG12. Based on molecular identification, these five isolates were identified as Aspergillus niger.

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