Judul: Mempelajari Pengaruh Kandungan Air Tanah Dan Kecepatan Pembajakan Terhadap Kebutuhan Tenaga Tarik Bajak Di Pabrik Gula Jajtitujuh, Jati Barang- Cirebon
Abstrak: Tujuan dari penelitian ini adalah untuk mempelajari pengaruh kandungan air tanah dan kecepatan pembajakan ter- hadap kebutuhan tenaga tarik bajak, tenaga tahanan guling roda, slip roda traktor dan sifat fisik tanah yang melipu- ti porositas tanah sebelum dan sesudah pembajakan serta daya sanggah tanah ("cone index") sebelum dan sesudah pem- bajakan. Metoda penelitian menggunakan rancangan petak terbagi satu kali dengan analisa faktorial. Faktor pertama adalah Kandungan air tanah sebagai petak utama yang terdiri dari tiga taraf dan faktor kedua adalah kecepatan pembajakan sebagai subpetak sebanyak tiga taraf pula. Masing-masing unit percobaan mempunyai ulangan sebanyak tiga kali. Secara umum hasil penelitian ini menunjukkan bahwa : kandungan air tanah berpengaruh sangat nyata terhadap ke- butuhan tenaga tarik bajak, tenaga tahanan guling roda, slip roda traktor, porositas tanah sebelum dan sesudah pem- bajakan serta daya sanggah tanah sebelum dan sesudah pem- bajakan. Kecepatan pembajakan berpengaruh sangat nyata ...
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Judul: Mempelajari kapasitas, kebutuhan tenaga dan biaya pengolahan tanah kering untuk tanaman tebu di pabrik gula Subang
Abstrak: Tujuan penelitian ini adalah untuk mempelajari penga- ruh kecepatan putaran motor, kedudukan gigi transmisi dan pola operasi terhadap kapasitas lapang, efisiensi lapang, kebutuhan tenaga dan biaya pengolahan tanah untuk setiap kegiatan pengolahan tanah sampai siap tanam untuk tanaman tebu. Secara umum hasil penelitian menunjukkan bahwa : kecepatan putaran motor berpengaruh nyata pada kapasitas lapang dan kebutuhan tenaga; kedudukan gigi transmisi ber- pengaruh pada kapasitas lapang, efisiensi lapang, slip, waktu terbuang di headland dan biaya pengolahan tanah; pola operasi berpengaruh nyata pada kapasitas lapang, efisiensi lapang, waktu terbuang di headland dan biaya pengolahan tanah, interaksi antara kecepatan putaran mo- tor dengan kedudukan gigi transmisi berpengaruh nyata pa- da kebutuhan tenaga; interaksi antara kecepatan putaran motor dengan pola operasi berpengaruh nyata pada kapasi- tas lapang; interaksi antara kedudukan gigi transmisi de- ngan pola operasi berpengaruh nyata pada kapasitas lapang; ...
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Judul: Systematics of Desmos (Annonaceae) in Malesia
Abstrak: Desmos is a woody climbing genus of Annonaceae which has been widely used as traditional medicine in several countries such as China, Indo-China, Thailand, and Peninsular Malaysia to treat dysentery, vertigo, fever, and postpartum. Phylogenetic studies on Desmos showed a close relationship between Desmos and Dasymaschalon. They share similar moniliform monocarpic fruits, but their flowers are different. It has been debated among Annonaceae researchers whether both genera should be treated as the same or distinct genus. Therefore, investigation on the taxonomic delimitation of Desmos species and Dasymaschalon will be necessary. Plastid genome (plastome) identification, leaf epidermal section of Desmos species and Dasymaschalon species, a taxonomic revision of Desmos in Malesia using morphological data, the spatial distribution of Desmos species in Malesia, and morphological and genetic variation in Desmos chinensis population using ISSR marker were used to investigate taxonomic delimitation of Desmos. Plastome study of Desmos chinensis and Dasymaschalon dasymaschalum was carried out to determine the origin, evolution, phylogenomics, and identify marker candidates for Desmos and Dasymaschalon or with other genera in Annonaceae. We discovered that the plastome of Desmos chinensis was circular with the size of 167,677 bp (smaller than Dasymaschalon dasymaschalum), consist of 111 genes, including 78 protein-coding genes, 29 transfer RNAs, and 4 ribosomal RNAs. The plastome showed a typical quadripartite structure, i.e., large single copy (LSC), small single copy (SSC), and two inverted repeats (IRs). The plastome of Dasymaschalon dasymaschalum was 191,488 bp in length, which also exhibited a typical quadripartite structure (LSC, SSC, and two IRs). Desmos chinensis and Dasymaschalon dasymaschalum showed different copies of accD, ndhD, ndhF, rps18, and ycf2. Protein coding genes of rpoB, rpoC1, rbcL, matK, rpl32, infA, and rpl36 were identified based on nucleotide diversity, sequence variability, and parsimony-informative sites. The genes are defined as molecular marker candidates of plastome for phylogenetic, barcoding, and population genetic research. We predicted that Desmos chinensis and Dasymaschalon dasymaschalum separated at ca. 64 million years ago during the Paleocene. Leaf anatomical feature study was carried to support the taxonomic delimitation of interspecific Desmos and intergeneric of Desmos and Dasymaschalon. Leaf anatomy in the paradermal section of 20 taxa (12 species of Desmos, eight species of Dasymaschalon) have been carried out. According to the leaf epidermal section, Desmos and Dasymaschalon are two distinct genera mainly distinguished based on the anticlinal wall undulation of epidermal cells and supported by variation of the crystal type and size. The anticlinal wall undulation of Desmos was almost straight to slightly wavy and never sinuous; meanwhile, Dasymaschalon varies from almost straight to deeply sinusoid. The crystals of Desmos consist of rhombohedral, druse type A, and druse type B crystals, whereas Dasymaschalon has prism, druse type A, druse type B, and druse type C crystals. The recent taxonomic revision using the morphological data was mainly based on the examination of about 1374 specimens from BO, L, WAN, ANDA, SING, SAN, K, P, HUH herbaria. The Desmos species in Malesia consists of eight species: D. acutus, D. chinensis, D. chryseus, D. dunalii, D. pedunculosus, D. subbiglandulosus, two new records: D. lawii and D. macrocarpus, and one
Keyword: Dasymaschalon, Desmoid clade, Magnoliid, plastid genome, phylogenomics analysis