Influence of Agro-ecology on Growth and Performance of Several Potential Mutants of Cassava

Cassava (Manihot esculenta) is an important source for food, feed, and raw material for industries in Indonesia. In order to develop new high yielding and high starch content varieties, two national varieties (i.e. Adira-4 and Malang-4) and introduced variety (UJ-5) were irradiated with gamma ray to induce genetic variety. Evaluation of potential cassava mutants was needed to learn their growth and performance in two different agro ecologies, which were acid upland and optimum upland, in order to select adaptive mutants. Cuttings from sixteen mutants and three parent lines (UJ-5 (V3), Adira-4 (V4), and Malang-4 (V5)) were planted in two different locations which were Technical Implementation Unit Field Tenjo, Bogor (pH 4,8; 57 m asl) and Cikabayan Experimental field IPB, Dramaga, Bogor (pH 5,6; 200 m asl). Destructive observation was done at 4 months after planting to observe root length, tuber length, tuber diameter, and tuber mass. There was no significant difference between mutants and their parent lines on every observed variable. Number of leaves, stem diameter, tuber diameter, and tuber mass on every mutant and parent lines in acid upland were not significantly different with those planted in optimum upland. Plant height and tuber length in some mutants in acid upland were significantly higher than those planted in optimum upland. Disease incident of brown leaf spot (Cercospora sp.) was 90% and 47% and disease severity was 25-50% and 0-25% infected part of plant in acid upland and optimum upland respectively.