Name the plant growth regulator which upon spraying on sugarcane crop, increases the length of stem, thus increasing the yield of sugarcane crop.

Gibberellin is used for spraying on sugarcane crop to increase the length of stem. This happen because gibberellin helps to increase the internodal distance. Spraying sugarcane crop with gibberellins increases the length of the stem, thus increasing the yield by as much as 20 tonnes per acre.