Studies on the Breeding of High Yield Variety in Air-cured Tobacco. : I. Relations among Plant Type, Growth Habit and Yield in Some Bred Lines

Abstract

An investigation was made on the relation among plant type, growth habit and yield in some air-cured tobacco bred lines. High yield air-cured lines were developed from a cross between Shiroenshu, a commercial air-cured variety in Japan, and Burley 49, and from a cross among Shiroenshu. LA burle)" 21 and Coker 254. These lines had high productivity and varied in plant type. These plant types were classified as follows : PT 1 was a pyramidal plant t.vpe, ancl had larger leaves at lower parts of stalk, and smaller leaves at higher stalk position than Shiroenshu. PT 2 was similar in apperance to Shiroenshu. PT 3 was a cylindrical plant type having erected leaves, and its upper leaves were larger than those of Shiroenshu. PT 4 was a large cylindrical plant type, and had larger leaves at whole parts of stalk than Shiroenshu. The growth rate of PT I and PT 2 was high at the early growing stage, and then decreased in PT 1, but PT 2 kept high growth rate to the micldle growing stage. PT 3 and PT 4 were slow in early growth, but in the middle growing stage they grew more rapidly than the former two.