Effect of Leaf Shading on Flowering Processes of Sugarcane

Abstract

The effect of leaf shading on the regulation of sugarcane flowering processes by young expanding leaves was investigated. A severe flowering repression produced by shading the leaves with aluminum foil, for one week at the onset of expansion, suggests that the leaf is highly capable of perceiving the critical photoinductive light and of producing a flowering stimulus during its emergence from a tightly rolled spindle. Both floral induction and time of tassel emergence were significantly affected. A persistently significant suppression of floral induction as a result of leaf shading in stools having variable proportions of treated and untreated stalks demonstrated that individual stalks proceed more or less independently with their flowering processes within a stool complex. No evidence was found of interstalk transport of a flowering stimulus. It is suggested that the effectiveness of leaf shading within treated stalks is very possibly a translocation phenomenon.