Pengaruh jarak tanam dan dosis urea terhadap pertumbuhan hasil dan kualitas umbi bibit bawang merah (Allium cepa L. Aggregatum group)

MASNANTO, Agus, Dr.Ir. Endang Sulistyaningsih, M.Sc

2006 | Tesis | S2 Agronomi

Suatu penelitian dengan tujuan untuk mengetahui pengaruh jarak tanam dan dosis urea serta kombinasinya terhadap pertumbuhan, hasil dan kualitas umbi bibit bawang merah, telah dilakukan di desa Srigading kecamatan Sanden pada bulan April sampai Juni 2005 (musim kemarau) dengan jenis tanah Regosol. Rancangan percobaan yang dipakai percobaan 2 faktorial, disusun dalam rancangan petak terbagi (split plot). Faktor pertama adalah dosis urea, terdiri dari lima aras yaitu 0 kg/ha, 50 kg/ha, 100 kg/ha, 150 kg/ha dan 200 kg/ha. Faktor kedua adalah jarak tanam yaitu 20 cm x 15 cm, 15 cm x 15 cm dan 15 cm x 10 cm. Pengamatan dilakukan terhadap total berat kering gulma, pertumbuhan tanaman yang meliputi jumlah daun, luas daun, indeks luas daun, berat kering tanaman, laju asimilasi bersih, laju pertumbuhan tanaman, tinggi tanaman, indeks panen, hasil dan kualitas hasil. Variabel hasil dan kualitas hasil yang diamati meliputi jumlah umbi, berat segar umbi, berat kering simpan umbi per rumpun, berat kering simpan umbi per hektar, berat kering oven umbi, susut berat umbi, diameter umbi, tinggi umbi, rasio diameter dengan tinggi umbi, warna umbi, kekerasan umbi, N tanaman dan berat jenis umbi. Data yang diperoleh dianalisis sidik ragam 5 %, apabila ada beda nyata antar perlakuan dilanjutkan dengan DMRT 5 %. Hasil penelitian menunjukkan bahwa tidak terdapat interaksi yang nyata antara perlakuan dosis urea dan jarak tanam terhadap semua variabel pengamatan. Pemberian urea pada dosis yang berbeda tidak berpengaruh terhadap total berat kering gulma, pertumbuhan tanaman, hasil dan kualitas umbi bibit bawang merah. Sedangkan jarak tanam berpengaruh terhadap total berat kering gulma, pertumbuhan tanaman, hasil dan kualitas umbi bibit bawang merah. Semakin rapat jarak tanam menyebabkan bertambahnya tekanan terhadap pertumbuhan gulma dan tanaman, tetapi tidak menurunkan hasil keseluruhan. Pada jarak tanam 15 x 10 cm2 diperoleh hasil dan kualitas bibit bawang merah yang tertinggi dan terbaik dengan produksi sebesar 34,04 ton/ha dan rata-rata diameter umbi sebesar 1,95 cm. Pada jarak tanam 20 x 15 cm2 diperoleh hasil bawang merah yang lebih baik untuk keperluan konsumsi dengan produksi sebesar 21,71 ton/ha dan ratarata diameter umbi sebesar 2,53 cm.

The aim of this research was to study the effects of crop spaces and urea dosages and its combination on the growth, yield and quality of shallot seed. The research was conducted at Srigading village of Sanden sub district from April to June 2005 (dry season) at Regosol. The research was designed in split-plot design with 2 factorial treatments. The first factor was urea dosages consisted of five levels i.e. 0 kg/ha, 50 kg/ha, 100 kg/ha, 150 kg/ha and 200 kg/ha. The second factor was crop spaces consisted of three levels i.e. 20 cm x 15 cm, 15 cm x 15 cm and 15 cm x 10 cm. The data were observed in the total of weeds dry weight, crop growth included of the leaves number, the leaves area, the index of leaves area, the dry weight of crop, the oven dried weight of crop, net assimilation rate, crop growth rate, the crop height, harvest index, and the yield and its quality. The yield and quality of yield variables included of the number of bulbs, the fresh weight of bulbs, the dry weight of bulbs per crop, the dry weight of bulbs per hectare, the oven dried weight of bulb, the shrinked of bulb weight, the diameter of bulb, the height of bulb, the ratio of diameter height bulb, the color of bulb, the bulb solidity, the nitrogen content of crop and the bulb bulk. The data obtained were analyzed with Analysis of Variance with 5 % level of significance, and if between the treatments are significantly different the analysis will continue to the DMRT (Duncan Multiple Range Test) with 5 % level of significance. The results showed that there was no significant interaction between urea dosages and crop spaces in all of data observed. The application of urea dosages did not affect on the total of weeds dry weight, crop growth, yield and quality of shallot seed bulbs. The crop spaces affected on the total of weeds dry weight, crop growth, yield and quality of shallot seed bulbs. Moreover, the widest crop space gave the higher reduction of weed and crop growth, excepted for the total yield. The highest yield and the best quality of shallot seed bulbs were obtained in the crop space at 15 x 10 square cm i.e. 34,04 t/ha with 1,95 cm in diameter of the bulbs. In addition, the crop space at 20 x 15 square cm could be used for production of bulb consumption which reached 21,71 t/ha with 2,53 cm in diameter of the bulbs.

Kata Kunci : Bibit Bawang Merah,Kualitas Umbi,Jarak Tanam dan Dosis Urea,nitrogen, crop space, shallot