Electronic Theses and Dissertation

Penelitian ini bertujuan untuk mengevaluasi pengaruh beberapa herbisida pratumbuh terhadap jumlah spesies, individu, dan bobot kering gulma pada tanaman kedelai. Penelitian dilaksanakan di Desa Blang Ketumba, Kecamatan Juli, Kabupaten Bireuen, serta di Laboratorium Pengelolaan Gulma Fakultas Pertanian Universitas Syiah Kuala pada Februari–Juni 2026, menggunakan Rancangan Acak Kelompok (RAK) dengan 7 perlakuan dan 4 ulangan. Perlakuan terdiri atas bergulma terus-menerus, bebas gulma, penyiangan pada 21 dan 42 HST, serta herbisida metribuzin, oksifluorfen, pendimethalin, dan pretilachlor yang masing-masing diaplikasikan dengan dosis 0,5 kg b.a ha⁻¹. Data dianalisis menggunakan sidik ragam (Anova) dan dilanjutkan dengan uji Duncan New Multiple Range Test (DNMRT) pada taraf 5%. Hasil penelitian menunjukkan bahwa seluruh perlakuan berpengaruh sangat nyata terhadap jumlah spesies, individu, bobot kering, dan persentase pengendalian gulma gulma pada pengamatan 4 dan 6 minggu setelah tanam (MST). Herbisida oksifluorfen 0,5 kg b.a ha⁻¹ paling efektif menekan jumlah spesies dan individu gulma pada 4 dan 6 MST serta persentase pengendalian gulma pada 6 MST, sedangkan bobot kering gulma paling efektif ditekan oleh oksifluorfen pada 4 MST dan pretilachlor pada 6 MST. Herbisida pratumbuh terbukti mampu menekan pertumbuhan gulma secara efektif pada fase awal pertumbuhan tanaman kedelai.

emergence herbicides on the number of weed species, weed individuals, dry weight, and weed control percentage in soybean. The research was conducted in Blang Ketumba Village, Juli Sub-district, Bireuen Regency, and at the Weed Science Laboratory, Faculty of Agriculture, Syiah Kuala University, from February to June 2026, using Randomized Block Design (RBD) with 7 treatments and 4 replications. The treatments consisted of no weeding, weed-free, hand weeding at 21 and 42 DAP, and the herbicides metribuzin, oxyfluorfen, pendimethalin, and pretilachlor, each applied at a dose of 0.5 kg a.i. ha⁻¹. Data were analyzed using analysis of variance (ANOVA) followed by Duncan's New Multiple Range Test (DNMRT) at the 5% significance level. The results showed that all treatments had a highly significant effect on the number of weed species, weed individuals, dry weight, and weed control percentage at 4 and 6 weeks after planting (WAP). The herbicide oxyfluorfen at 0.5 kg a.i. ha⁻¹ was the most effective in suppressing the number of weed species and individuals at 4 and 6 WAP as well as the percentage of weed control at 6 WAP, while dry weight of weed was most effectively suppressed by oxyfluorfen at 4 WAP and pretilachlor at 6 WAP. Pre-emergence herbicides were proven effective in suppressing weed growth during the early growth phase of soybean. Keywords: Metribuzin, Oxyfluorfen, Pre-emergence herbicide, Soybean, Weed