Electronic Theses and Dissertation

Abstrak. Gulma adalah tumbuhan yang tidak dikehendaki keberadaannya dan sangat merugikan bagi tanaman serta mengganggu kepentingan manusia dalam mengusahakan hasil pertanian. Alang-alang merupakan salah satu jenis gulma yang termasuk jenis rumput tahunan yang berkembangbiak melalui biji dan akar rimpang, alang-alang menyaingi tanaman lain dengan mengeluarkan senyawa beracun dari golongan fenol yang disebut alelopati melalui bagian akarnya. Penelitian ini bertujuan untuk mengukur aktivitas herbisida nabati berbagai konsentrasi ekstrak n-heksana alang-alang terhadap pertumbuhan gulma bayam. Penelitian ini dilakukan di Laboratorium Ilmu Gulma Jurusan Agroteknologi Fakultas Pertanian, Laboratorium Pendidikan Kimia dan Laboratorium Biologi Fakultas Matematika dan Ilmu Pengetahuan Alam dan Rumah Kasa Fakultas Pertanian , Universitas Syiah Kuala, Darussalam Banda Aceh. Pelaksanaan penelitian akan dimulai pada bulan Oktober hingga Desember 2021. Penelitian ini menggunakan metode Rancangan Acak Lengkap (RAL) pola non faktorial dengan enam perlakuan: D0= kontrol positif (2,4 D), D1= kontrol negatif (Aquades), D2= Ekstrak n-heksana konsentrasi 5%, D3= Ekstrak n-heksana konsentrasi 10%, D4= Ekstrak n-heksana konsentrasi 15% dan D5= Ekstrak n-heksana konsentrasi 20% yang diulang sebanyak tiga ulangan sehingga terdapat 18 satuan percobaan. Setiap unit percobaan terdiri dari dua unit gulma, sehingga terdapat 36 unit percobaan. Hasil penelitian menunjukkan Pemberian aplikasi ekstrak n-heksana alang-alang berpengaruh sangat nyata terhadap tinggi gulma dan diameter batang,. Pemberian aplikasi ekstrak n-heksana alang- alang dapat mengendalikan gulma bayam duri sebesar 54% dengan kategori sedang. Berdasarkan hasil uji fitokimia ekstrak n-heksana alang-alang mengandung senyawa steroid dan alkaloid.

Abstract. Weeds are plants whose existence is not desired and is very detrimental to plants and interferes with human interests in cultivating agricultural products. Imperata is a type of weed which is an annual grass that reproduces through seeds and rhizome roots. Imperata competes with other plants by releasing toxic compounds from the phenol group called allelopathy through its roots. The aim of this study was to measure the herbicide activity of various concentrations of n-hexane extract of alang-alang on the growth of spinach weeds. This research was conducted at the Weed Science Laboratory, Agrotechnology Department, Faculty of Agriculture, Chemistry Education Laboratory and Biology Laboratory, Faculty of Mathematics and Natural Sciences and the Screen House, Faculty of Agriculture, Syiah Kuala University, Darussalam Banda Aceh. The implementation of the research will start from October to December 2021. This study used a non-factorial completely randomized design (CRD) method with six treatments: D0 = positive control (2.4 D), D1 = negative control (Aquades), D2 = extract 5% concentration of n-hexane, D3= 10% concentration of n-hexane extract, D4= 15% concentration of n-hexane extract and D5= 20% concentration of n-hexane extract which was repeated three times so that there were 18 experimental units. Each experimental unit consisted of two weed units, so there were 36 experimental units. The results showed that the application of n-hexane extract of alang-alang had a very significant effect on weed height and stem diameter. The application of alang alang n-hexane extract was able to control spinach thorn weeds by 54% with a moderate category. Based on the results of phytochemical tests, the n-hexane extract of alang-alang contains steroid and alkaloid compounds.