Electronic Theses and Dissertation

Gulma merupakan tumbuhan yang bersaing dengan tanaman budidaya dalam memperoleh air, unsur hara, cahaya, dan ruang tumbuh sehingga menghambat pertumbuhan serta menurunkan hasil tanaman. Salah satu alternatif pengendalian gulma yang ramah lingkungan adalah pemanfaatan senyawa alelopati dari beberapa jenis gulma sebagai bioherbisida alami. Pelarut memegang peranan penting dalam proses ekstraksi, dan n-heksana digunakan karena efektif mengekstraksi senyawa non-polar. Penelitian ini bertujuan untuk mengetahui pengaruh aplikasi ekstrak n-heksana beberapa jenis gulma terhadap pertumbuhan gulma bayam duri (Amaranthus spinosus L.). Penelitian ini dilaksanakan di Laboratorium Ilmu Gulma Departemen Agroteknologi, Laboratorium Farmakologi Fakultas Kedokteran Hewan, Laboratorium kimia Organik Departemen Kimia Fakultas Matematika dan Ilmu Pengetahuan Alam dan Kebun Percobaan Fakultas Pertanian, Universitas Syiah Kuala, Banda Aceh. Penelitian ini berlangsung dari bulan Desember 2025 hingga Februari 2026. Penelitian ini menggunakan Rancangan Acak Lengkap nonfaktorial yang terdiri atas 18 perlakuan dan 3 ulangan. Perlakuan terdiri atas kontrol negatif (aquades), kontrol positif (2, 4-D 0,686 kg b.a ha⁻¹), ekstrak n-heksana kirinyuh (Cromolaena odorata), alang-alang (Imperata cylindrica), teki (Cyperus rotundus), dan paitan (Axonopus compressus) pada konsentrasi 5%, 10%, 15%, dan 20%. Hasil penelitian menunjukkan bahwa ekstrak n-heksana beberapa jenis gulma pada berbagai konsentrasi berpengaruh sangat nyata terhadap seluruh parameter pengamatan pada 7, 14, 21 dan 28 HSA. Hasil penelitian menunjukkan bahwa perlakuan terbaik diperoleh pada ekstrak n-heksana teki konsentrasi 5% dengan persentase pengendalian gulma bayam duri sebesar 100% pada 7 HSA. Hasil uji fitokimia menunjukkan ekstrak n-heksana kirinyuh mengandung terpenoid, n-heksana alang-alang dan n heksana teki mengandung alkaloid dan steroid, dan n-heksana paitan mengandung steroid.

Weeds are plants that compete with cultivated crops for water, nutrients, light, and growing space, thereby inhibiting growth and reducing crop yields. One environmentally friendly alternative for weed control is the utilization of allelopathic compounds from certain weed species as natural bioherbicides. Solvents play a crucial role in the extraction process; n-hexane is used due to its effectiveness in extracting non-polar compounds. This study aimed to determine the effect of applying n-hexane extracts from several weed species on the growth of spiny amaranth (Amaranthus spinosus L.). The research was conducted at the Weed Science Laboratory (Department of Agrotechnology), Pharmacology Laboratory (Faculty of Veterinary Medicine), Organic Chemistry Laboratory (Department of Chemistry, Faculty of Mathematics and Natural Sciences), and the Experimental Garden (Faculty of Agriculture) at Syiah Kuala University, Banda Aceh. The study took place from December 2025 to February 2026. A non-factorial Completely Randomized Design was employed, consisting of 18 treatments and 3 replications. The treatments included a negative control (distilled water), a positive control (2,4-D at 0.686 kg a.i. ha⁻¹), and n-hexane extracts from Chromolaena odorata, Imperata cylindrica, Cyperus rotundus and Axonopus compressus at concentrations of 5%, 10%, 15%, and 20%. The results indicated that n-hexane extracts from the tested weed species, at various concentrations, had a highly significant effect on all observed parameters at 7, 14, 21, and 28 days after application (DAA). The best treatment result was obtained with the Cyperus rotundus n-hexane extract at a 5% concentration, which achieved 100% control of Amaranthus spinosus at 7 DAA. Phytochemical test results indicate that the n-hexane extract of Chromolaena odorata contains terpenoids; the n-hexane extracts of Imperata cylindrica and Cyperus rotundus contain alkaloids and steroids; and the n-hexane extract ofTithonia diversifolia contains steroids.