Analisis Stabilitas Hasil Ubi 27 Genotipe Bengkuang (Pachyrhizus Erosus L. Urban) Di Jatinangor Jawa Barat Berdasarkan Model AMMI

Research aimed at estimating yield stability of 27 yam bean (Pachyrhizus erosus L. Urban) genotypes in Jatinangor was conducted at dry and rain seasons at the experimental station of Faculty of Agriculture Unpad, Jatinangor. Field trials at dry season was started from February to August 2006 and at rain season started from November 2006 to May 2007. Field plot consisted of four sets arranged in Randomized Block Design with 27 genotypes collected from various Indonesia regions and its ancestor from Central and South America as treatment and replicated twice. The four field trial sets were differed based on season and reproductive pruning treatment and considered as four different environment. Character observed was tuber weight per plant (g). Data was analysed with AMMI (additive main effect and multiplicative interaction). Result indicated that B-23/EC040 was highest yielding genotype, but less stable. In contrast, B-33/J, B-26/NS, B-10/EC550, and B-94/ENT were moderate yielded but had higher level of stability. Environment IV (rain season; pruning) was good environment where genotypic variation seemed more consistent with B-23/EC040 as best genotype. Best genotype in discriminating environment (I) was B-55/CJ, and in environment II was B-80/ENT. Whereas in Less discriminating environment III, B-15/EC104 was the best genotyp

Respons Tanaman Bengkuang Budidaya (Pachyrrhizus Erosus L. Urban) terhadap Pemangkasan Reproduktif untuk Karakter Hasil dan Kualitas Ubi

Percobaan yang bertujuan mengevaluasi respons dari 27 genotip bengkuang (Pachyrrhizus erosus L. Urban) terhadap pemangkasan sink reproduktif telah dilakukan di musim kemarau di Kebun Percobaan Fakultas Pertanian Unpad, Jatinangor. Percobaan lapang dilakukan mulai Februari hingga Agustus 2006. Percobaan terdiri dari dua set yang masing-masing set disusun dalam rancangan acak kelompok dengan 27 genotip bengkuang yang dikoleksi dari berbagai wilayah Indonesia and genotip leluhurnya dari Amerika Tengah dan selatan sebagai perlakuan dan diulang dua kali. Dua set percobaan tersebut dibedakan dengan perlakuan pemangkasan sink reproduktif. Karakter yang diamati adalah bobot ubi (g), bahan kering ubi (%), kadar pati ubi (%) dan kadar protein ubi (%). Data dianalisis dengan ANOVA dilanjutkan dengan uji gugus Scott-Knott, dan uji t-student. Hasil menunjukkan, bahwa tidak terdapat perbedaan antara 27 genotip bengkuang untuk semua karakter yang diamati pada populasi tanpa pemangkasan reproduktif. Sedangkan perbedaan respons 27 genotip pada populasi dengan pemangkasan hanya terlihat pada karakter bobot ubi. Perlakuan pemangkasan reproduktif hanya berpengaruh nyata terhadap bobot ubi