Periode Kritis Persaingan Tanaman Kacang Tanah (Arachis hypogaeaL.) dengan Gulma : Critical Period of Competition between Peanut (Arachis hypogaeaL.) and Weed

The research was carried out at Tanjung Sari, Medan, where the weeds were predominated by Eleusine indica. The research was begun from November 2015 until February 2016. The weeding treatments consisted of 14 treatments (weed free from 0-2 weeks after planting (WAP); weed free from 0-4 WAP; weed free from 0-6 WAP; weed free from 0-8 WAP; weed free from 0-10 WAP; weed free from 0-12 WAP; without weeding from 0-2 WAP; without weeding from 0-4 WAP; without weeding from 0-6 WAP; without weeding from 0-8 WAP; without weeding from 0-10 WAP; without weeding from 0-12 WAP; weed free until harvest and without weeding until harvest). The treatments were arranged in randomized block design with three replicates. Parameter observed were plant height, number of branch, number of flowering, number of peas per plant, number of peas per plot, peas weight per plant, peas weight per plot, seed weight per plant, seed weight per plot, weight of 100 seed, kind of weed, dominant weed height and weed’s weight. The result showed that the weeding time for peanuts has no effect on the plant height and number of flowering, but sifnificantly affected the number of peas per plant, number of peas per plot, peas weight per plant, peas weight per plot, seed weight per plant, seed weight per plot and weight of 100 seed. The critical periode of competition between peanut and weed occurred at 14 to 35 day after planting.   Penelitian ini dilaksanakan di Tanjung Sari, Medan. Lahan penelitian didominasi oleh gulma Eleusine indica. Penelitian dimulai dari bulan November 2015 sampai denganFebruari 2016. Perlakuan penyiangan gulma terdiri atas 14 taraf (bebas gulma dari 0–2 minggu setelah tanam (MST); bebas gulma dari 0–4 MST; bebas gulma dari 0–6 MST; bebas gulma dari 0–8 MST; bebas gulma dari 0–10 MST; bebas gulma dari 0–12 MST; bergulma dari 0–2 MST; bergulma dari 0–4 MST; bergulma dari 0–6 MST; bergulma dari 0–8 MST; bergulma dari 0–10 MST; bergulma dari 0–12 MST; bebas gulma sampai panen dan bergulma sampai panen). Penelitian menggunakan Rancangan Acak Kelompok yang diulang tiga kali. Peubah yang diamati yaitu tinggi tanaman, jumlah cabang, umur berbunga, jumlah polong per tanaman, jumlah polong per plot, bobot polong per tanaman, bobot polong per plot, bobot biji per tanaman, bobot biji per plot, bobot 100 biji, kerapatan gulma, tinggi gulma dan bobot kering gulma.Hasil penelitian menunjukkan bahwa waktu penyiangan pada tanaman kacang tanah berpengaruh tidak nyata pada tinggi tanaman dan umur berbunga, tetapi berpengaruh nyata terhadap jumlah polong per tanaman, jumlah polong per plot, bobot polong per tanaman, bobot polong per plot, bobot biji per tanaman, bobot biji per plot dan bobot 100 biji. Periode kritis kompetisi antara kacang tanah dan gulma terdapat 14 – 35 hari setelah tanam