Judul: Disease Incidence and Severity of Blast (Pyricularia  oryzae) and Bacterial Leaf Blight (Xanthomonas oryzae pv. oryzae) on Rice  Plants in Gebang and Kuripan Villages, Pekalongan City, Central Java
Abstrak: Padi adalah sumber pangan penting bagi masyarakat di dunia terutama masyarakat Indonesia. Peningkatan produktivitas padi memiliki beberapa kendala seperti adanya penyakit tanaman. Terdapat dua penyakit penting padi di Indonesia yaitu blas (Pyricularia oryzae) dan hawar daun bakteri (Xanthomonas oryzae pv. oryzae). Penelitian ini bertujuan mengukur tingkat insidensi dan keparahan penyakit blas dan hawar daun bakteri pada tanaman padi di Kota Pekalongan, Jawa Tengah. Pengamatan di lapangan dilakukan pada 5 petak contoh di Desa Gebang dan 5 petak di Desa Kuripan. Pengamatan juga dilakukan terhadap bobot 1000 butir gabah kering panen dari tanaman contoh. Selain pengamatan di lapangan juga dilakukan wawancara dengan petani. Di Desa Gebang varietas yang ditanam adalah Varietas Inpari 43, sedangkan di Desa Kuripan ditanam varietas Inpari 42. Hasil penelitian menunjukkan bahwa serangan P. oryzae dan X. oryzae pv. oryzae ditemukan pada semua petak pengamatan. Keparahan penyakit blas pada lahan pengamatan di Desa Gebang relatif lebih tinggi (rata-rata 51.11%) dibandingkan dengan lahan pengamatan di Desa Kuripan (rata-rata 25.55%). Keparahan penyakit HDB pada lahan Desa Gebang juga relatif lebih tinggi (rata- rata 92%) dibandingkan dengan lahan pengamatan di Desa Kuripan (rata-rata 60.44%), Rice is an important crops as staple food in Indonesia. Increasing rice productivity has an important constraint such as plant diseases. Two important rice diseases in Indonesia are blast (Pyricularia oryzae) and bacterial leaf blight (Xanthomonas oryzae pv. oryzae). This study was aimed to measure the incidence and severity of blast and bacterial leaf blight diseases on rice plants in Pekalongan City, Central Java. As many as 5 sample plots of rice fields each in Gebang Village and Kuripan Village were observed. Observations were also carried out on the weight of 1000 dry-harvested grains from the sample plants. In Gebang plots were grown Inpari 43 variety, while in Kuripan plots were grown Inpari 42 variety. This study has shown that blast and bacterial leaf blight disease were observed in all observation plots. The severity of blast disease in the observation plots in Gebang Village was relatively higher (51.11%) than Kuripan Village (25.55%). Similarly BLB disease severity in Gebang Village was higher (92%) than in Kuripan Village (60.44%)
Keyword: Grain, Inpari 42, Inpari 43, Plots, Rice diseases

Judul: National Rice Production and its Important Disease Intensity in Sukabumi District
Abstrak: Produksi beras sebagai sumber pangan pokok ditingkatkan untuk memenuhi kebutuhan masyarakat Indonesia yang jumlah penduduknya selalu meningkat. Produksi padi di Indonesia berfluktuasi karena berbagai faktor abiotik dan biotik, termasuk hama dan penyakit. Produksi beras nasional Indonesia meningkat selama periode 2011-2017, kemudian menurun secara signifikan pada 2018-2020. Penurunan produksi beras juga terjadi di lima provinsi penghasil beras terbesar yaitu Jawa Tengah, Jawa Timur, Jawa Barat, Sulawesi Selatan, dan Sumatera Selatan pada periode 2018-2021. Petani padi di Kecamatan Jampangkulon dan Cibitung Kabupaten Sukabumi menerapkan cara budidaya dan pengelolaan OPT secara konvensional, yaitu mengandalkan pupuk kimia dan pestisida sintetik. Penyakit penting yang ditemukan pada padi varietas lokal, Trisakti dan IR64 dari pengamatan lapangan di Kabupaten Sukabumi adalah bercak daun lonjong atau blas jamur oleh Pyricularia oryzae dan hawar daun bakteri oleh Xanthomonas oryzae pv. oryzae. Insidensi penyakit P. oryzae mencapai 100% pada ketiga varietas dengan tingkat severitas berkisar 60,7-66,7% pada daun dan 52,3-60% pada malai, sedangkan hawar bakteri menyebabkan insidensi 76,7-93,3% dan severitas 33,0- 64,4%. Varietas padi lokal paling tahan terhadap P. oryzae dibandingkan dua varietas lainnya, sedangkan Trisakti relatif lebih tahan penyakit hawar daun bakteri. Varietas IR64 paling rentan terhadap kedua penyakit tersebut dibandingkan dengan varietas lainnya. Berdasarkan analisis usahatani dan rasio keuntungan terhadap biaya (rasio B/C), varietas yang paling menguntungkan berturut-turut adalah lokal, IR64 dan Trisakti. Kata kunci: Rasio B/C, Xanthomonas oryzae pv. oryzae, Pyricularia oryzae, insidensi, severitas, fluktuasi produksi padi, Rice production as a staple food source is increased to meet the needs of the Indonesian people, whose population is always increasing. Rice production in Indonesia fluctuates due to various abiotic and biotic factors, including pests and diseases. Indonesia's national rice production increased during the 2011-2017 period, then decreased significantly in 2018-2020. The decline in rice production also occurred in the five largest rice producing provinces, namely Central Java, East Java, West Java, South Sulawesi and South Sumatra in the period 2018-2021. Rice farmers in Jampangkulon and Cibitung Subdistricts, Sukabumi Regency, apply conventional methods of cultivating and managing pests, which rely on chemical fertilizers and synthetic pesticides. The important diseases found in local rice varieties, Trisakti and IR64 from field observation in Sukabumi District were fungal oval leaf spot or blast by Pyricularia oryzae and bacterial leaf blight by Xanthomonas oryzae pv. oryzae. The incidence of disease by P. oryzae reached 100% in the three varieties with severity ranging from 60.7-66.7% on leaves and 52.3-60% on panicles, while bacterial blight caused incidence of 76.7-93.3% and severity 33.0-64.4%. The local rice variety was most resistant to P. oryzae than the other two varieties, while Trisakti was relatively most resistant to bacterial leaf blight. The IR64 variety was the most susceptible to both diseases compared to the other varieties. Based on the analysis of farming and benefit- cost ratio (B/C ratio), the most profitable varieties were local one, followed by IR64 and Trisakti, respectively. Keywords: B/C ratio, Xanthomonas oryzae pv. oryzae, Pyricularia oryzae, incidence, severity, rice production fluctuation
Keyword: B/C ratio, Xanthomonas oryzae pv. oryzae, Pyricularia oryzae, incidence, severity, rice production fluctuation

Judul: Analysis of NaTFSA Electrolytes on Sodium Ion  Batteries Using the DC-DFTB-MD Method
Abstrak: Pelarut air digunakan dalam sistem elektrolit NaTFSA pada baterai ion natrium karena sifatnya yang relatif aman. Namun, menghasilkan tegangan yang cukup rendah sehingga memiliki keterbatasan dalam pengaplikasiannya. Untuk mengatasi hal tersebut dikembangkan elektrolit berkonsentrasi tinggi. Pada penelitian ini, pengaruh konsentrasi elektrolit NaTFSA terhadap sifat struktur, dinamika, dan elektronik dianalisis menggunakan metode dinamika molekul pada level mekanika kuantum. Analisis mikroskopik struktur dan dinamika elektrolit NaTFSA menunjukkan bahwa seiring kenaikan konsentrasi, koefisien difusi air menurun sedangkan konduktivitas elektrolit cenderung meningkat sebanding dengan mobilitas ion-ion., The aqueous solvent is used in the NaTFSA electrolyte system in sodium ion batteries because it is relatively safer. However, the voltage window of the sodium ion battery is narrower than that of the lithium ion battery, thus it still limits its practical implementation. To overcome this problem, a high concentration of electrolyte was developed. In this present work, the salt concentration effect on structural, dynamic and electronic properties were analyzed using molecular dynamics methods at the quantum mechanical level. Microscopic analysis of the structural and dynamical properties of the NaTFSA electrolyte showed that as the concentration increased, the water diffusion coefficient decreased while the electrolyte conductivity tended to increase.
Keyword: Conductivity, DC-DFTB, Diffusion constants, NaTFSA electrolytes, Sodium ion batteries