Gibberellins

Spraying sugarcane with plant growth regulators can significantly impact its growth, especially in terms of stem elongation, which directly relates to yield improvement. Among the options provided, Gibberellin is the most effective in increasing the length of the sugarcane stem.

Plant growth regulators, also known as phytohormones, play critical roles in the growth and development of plants. In the context of sugarcane cultivation, we focus on:

• Auxin: Primarily involved in cell elongation, apical dominance, and root initiation, rather than significant stem elongation.
• Gibberellin: Known for its ability to promote stem elongation by stimulating both cell division and elongation, thus having a pronounced effect on increasing plant height and yield. It is highly effective in sugarcane for boosting stem length.
• Cytokinin: Associated with cell division and differentiation, primarily influencing shoot development and delays in leaf senescence. It is not directly linked with increased stem length in sugarcane.
• Abscisic Acid: Generally involved in stress responses and inhibition of growth processes, rather than promoting them, hence not beneficial for increasing stem length.

Thus, for enhancing the length of the sugarcane stem and increasing yield, spraying with Gibberellin is the most suitable choice.