PERTUMBUHAN DAN HASIL BAWANG MERAH PADA KERAGAMAN KETINGGIAN TEMPAT

MUHAMMAD ANSAR, Ir. Tohari, M.Sc.

2012 | Disertasi | S3 Agronomi

Bawang merah ‘Palasa’ yang dibudidayakan pada areal dataran tinggi (> 700 m dpl.) dan ‘Palu’ di Lembah Palu pada dataran rendah (< 300 m dpl.) tidak mampu memenuhi kebutuhan bahan baku bawang goreng, karena produksi rendah yang disebabkan oleh masalah ketersediaan air rendah di areal tersebut. Penelitian ini dilaksanakan dengan tujuan untuk mempelajari pertumbuhan, hasil dan kualitas umbi ‘Palasa’, ‘Palu’ dan ‘Sumenep’ pada berbagai ketinggian tempat dan lengas tanah serta pemberian sungkup dan mulsa untuk modifikasi faktor lingkungan. Percobaan pot di rumah kaca dilakukan di Yogyakarta pada tiga ketinggian tempat (100, 400 dan 800 m dpl.), varietas (‘Palasa’, ‘Palu’ dan ‘Sumenep’) dan lengas tanah (50, 100 dan 150 % KL). Percobaan pot pada enam lokasi berbeda (tiga lokasi berbeda di Yogyakarta dan tiga lokasi di Sulawesi Tengah) terhadap tiga varietas (‘Palasa’, ‘Palu’ dan ‘Sumenep’) untuk percobaan kedua. Percobaan lapangan dilakukan di Sulawesi Tengah pada tiga lokasi dengan ketinggian tempat berbeda (100, 450 dan 750 m dpl.) terhadap tiga varietas (‘Palasa’, ‘Palu’ dan ‘Sumenep’) yang diberikan sungkup plastik (tanpa disungkup dan disungkup) dan mulsa (tanpa mulsa, jerami padi dan plastik hitam) untuk percobaan tahap ketiga. Rangkaian penelitian tersebut dilaksanakan pada Februari 2009 - Juni 2010. Hasil penelitian menunjukkan ‘Palasa’ tidak dipengaruhi ketinggian tempat dan lengas tanah. Bawang merah ‘Palu’ dan ‘Sumenep’ pada dataran tinggi 800 m dpl. dengan suhu rendah membutuhkan lengas tanah rendah-optimum (50-100 % kapasitas lapangan), namun pada dataran rendah-menengah (100-400 m dpl.) membutuhkan lengas tanah optimum-tinggi (100-150 % kapasitas lapangan). Bawang merah ‘Palasa’ menghasilkan bobot segar umbi 13,68 t.ha -1 , ‘Palu’ 7,67 t.ha -1 dan ‘Sumenep’ 12,67 t.ha -1 secara rata-rata dari semua ketinggian tempat. Pemberian mulsa jerami padi dan mulsa plastik hitam dapat meningkatkan bobot segar umbi per hektar masing-masing 29,3 % dan 24,7 % dibanding tanpa mulsa. Dari peenelitian ini dapat disimpulkan ‘Palasa’, ‘Palu’ and ‘Sumenep’ dapat dibudidayakan pada semua ketinggian tempat (100 - 800 m dpl.) dengan air irigasi yang cukup (100 % Kapasitas Lapangan). Aplikasi sungkup plastik bening setebal 0,13 mm bersama mulsa jerami padi setebal 5 cm meningkatkan kualitas umbi ‘Palasa’, ‘Palu’ dan ‘Sumenep’ pada semua ketinggian tempat.

The ‘Palasa’ in the highlands areas (more than 700 m asl.) and ‘Palu’ in the lowland areas of Lembah Palu (less than 300 m asl) produce low production shallot bulb which have not been able to fulfill the bulb demand of fried shallot production. The low yield of bulbs due to low water availability in that areas. The research was conducted to identify the physiological characters, growth, yield and the bulbs quality of ‘Palasa’, ‘Palu’ and ‘Sumenep’ in different altitude levels and different the conditions of soil moisture, and the application of plastic tunnel and mulches to modify the environmental factors. The greenhouse pot trials were carried out in Yogyakarta in three altitude levels (100, 400 and 800 m asl) with the three varieties (‘Palasa’, ‘Palu’ and ‘Sumenep’) and three levels of soil moistures (50,100 and 150 % field capacity). The pot trials of six different locations (three locations in Yogyakarta and three locations in Central Sulawesi) using three varieties (‘Palasa’, ‘Palu’ and ‘Sumenep’) for second research. The field trials were conducted in Central Sulawesi at three locations with different altitude levels (100, 450 and 750 m asl.) using the three varieties (‘Palasa’, ‘Palu’ and ‘Sumenep’) with plastic tunnel (without tunnel and with tunnel) and mulch (without mulches, rice straws and black plastics) for the third research. The series of research were conducted from February 2009 to June 2010. The results showed that (1) the ‘Palasa’ growth and yield were not affected by the different altitude level and soil moisture. The ‘Palu’ and ‘Sumenep’ at the altitude level of 800 m asl (low temperature) required low to optimum soil moisture (50-100 % field capacity). However, at the low to moderate altitude level (100-400 m asl) the ‘Palu’ and ‘Palasa’ needed optimum to high soil moisture (100-150 % field capacity). In all altitude levels the ‘Palasa’, ‘Palu’ and ‘Sumenep’ showed low physiological characters, growth, yield and bulbs quality at the low soil moisture (50 % field capacity), and (2) ‘Palasa’, ‘Palu’, and ‘Sumenep’ produced fresh weights of bulb is 13.68 t.ha -1 , 7.67 t.ha -1 and 12.67 t.ha -1 , respectively. The application of rice mulch and black plastic mulch were able to increase the fresh weight of bulbs per hectare of 29.3 % and 24.7 % compared to those with no mulch, respectively. In conclusions, ‘Palasa’, ‘Palu’ and ‘Sumenep’ can be cultivated in all altitude levels (100 to 800 m asl) with adequate water irrigation (100 % field capasity). The application of clear color plastic tunnel of 0.13 mm and rice straw-based mulches of 5 cm depth ware able to increase the quality of the ‘Palasa’, ‘Palu’ and ‘Sumenep’ bulbs in all altitude levels.

Kata Kunci : Bawang merah, ketinggian tempat, lengas tanah, sungkup, mulsa