Adsorption of Cadmium by Brassica juncea (L.) Czern. and Brassica pekinensis (Lour.) Rupr in Pot Experiment

Heavy metal pollution in farmland threatens human life. It is not clear whether crops can adsorb heavy metals. In this study, the cadmium accumulation and tolerance in Chinese cabbage Brassica pekinensis (cv. Xiaoza-56) and the known Cd-accumulator Brassica juncea in hydroponics and pot experiment were investigated. Furthermore, we evaluated their potential on the phytoextraction of Cd-contaminated soil. The hydroponics with 1–50 μM Cd concentrations showed that both B. juncea and B. pekinensis had high Cd accumulation and tolerance with translocation factor closed to 1 at Cd levels < 25 μM. The pot study conducted with 5 to 100 mg Cd kg−1 soil indicated that B. juncea showed less tolerance and accumulation to Cd than B. pekinensis, especially at higher Cd levels. The bioconcentration factor was much higher than 1 in both B. juncea and B. pekinensis grown in <40 mg Cd kg−1 soil without showing biomass reduction. In the model evaluation, the ability of B. juncea and B. pekinensis to reduce the initial soil Cd concentration of 20 and 5 mg kg−1 to specific targets with a lower or higher biomass of 4 or 20 t ha−1, respectively. The above results indicate that B. juncea and B. pekinensis (cv. Xiaoza-56), which the latter is a better candidate for Cd phytoextraction in moderated Cd-contaminated soil. The results provide a reference for Cd pollution control.

Pengaruh Kombinasi Pupuk NPK dengan Suplemen Pupuk Organik Cair terhadap Jumlah Bakteri dan Jamur Total di Rizosfer serta Hasil Tanaman Sawi Putih (Brassica pekinensis L.) pada Andisols Lembang

Large P fixation on Andisols can be overcome by adding P fertilizer into soil. However, to support good plant growth required the provision of nutrients N, K, micro nutrients and hormones. Research objective was to find out effect of NPK fertilizer with liquid organic fertilizer on total bacteria and fungi in the rhizosphere and plant yield of chinesse cabage (Brassica pekinensis L.) grown in Andisols. Experiment was conducted from March until May 2011 at experimental field of PT. Multiguna Indah Lestari, Kayu Ambon village, Lembang subdistrict, Bandung regency, West Java, with altitude of 1000 m above sea levels. The experimental design was Randomized Block Design with nine treatments and three replications which consisting of combination. The fertilizer rates were without treatment (A), 1dose of NPK (B), 1 dose of liquid organic fertilizer (C), 1 dose of NPK + ½ dose of liquid organic fertilizer (D), 1 dose of NPK + ½ dose of liquid organic fertilizer (E), ½ dose of NPK + 1 dose of liquid organic fertilizer (F), ½ dose of NPK + 1 dose of liquid organic fertilizer (G), 1 dose of NPK + 1 dose of liquid organic fertilizer (H), 1 dose of NPK + 1 ½ dose of liquid organic fertilizer (I). The results showed that NPK fertilizers and liquid organic fertilizer influenced total bacterial as well as fungi in the rhizosphere and plant yield of chinesse cabage. Fertilization treatments that demonstrated the best effect on both microbial population and chinese cabbage yield was application of ½ recommended dose of NPK with 1 recomended dose of liquid organic fertilizer gives the best result of 54,72 kg per plot (54,18 ton ha-1).

EFEKTIVITAS INSEKTISIDA EMAMEKTIN BENZOAT TERHADAP HAMA Plutella xylostella L. DAN HASIL TANAMAN SAWI PUTIH (Brassica pekinensis) DI LAPANGAN

Tujuan dari penelitian ini adalah untuk mendaptkan konsentrasi yang efektif dari insektisida dengan bahan aktif Emamektin benzoate dalam mengendalikan ulat Plutella xylostella dan menghasilkan tanaman sawi putih yang tinggi.Percobaan dilakukan di desa Wangunharja, Kecamatan Lembang, Kabupaten Bandung Barat yang berlangsung dari bulan Oktober sampai Desember 2018. Percobaan menggunakan Rancangan Acak Kelompok dengan 5 perlakuan dan 5 ulangan. Perlakuan konsentrasi insektisida yang diaplikasikan yaitu A = 0 ml/ l , B = Bestfast 250 EC dengan konsentrasi2 ml/ l, C = Siklon 5,7 WG dengan konsentrasi 0,1 g/l, D = Siklon 5,7 WG dengan konsentrasi 0,3 g/l, dan E = Siklon 5,7 WG dengan konsentrasi 0,5 g/l. Pengamatan yang diukur adalah intensitas serangan dan bobot bersih sawi putih.Hasil penelitian menunjukkan insektisida dengan bahan aktif Emamektin benzoat dengan dengan konsentrasi 0,3 g/l (D) dan 0,5 g/l (E) efektif untuk pengendalian hama ulat Plutella xylostella dan menghasilkan sawi putih yang tinggi di lapangan.