Accurate assessment of crop vegetative state is crucial for agricultural management, particularly under varying environmental conditions. However, detailed field experiments face logistical and cost challenges. The Normalized Difference Vegetation Index (NDVI) and other vegetation indices offer non-invasive and large-scale solutions for assessing plant health. The integral of the NDVI curve over time aggregates NDVI values, providing a comprehensive view of vegetation dynamics, surpassing the insights from individual NDVI measurements. Developing robust methodologies to calculate the vegetation activity index (VAI) based on NDVI integral is essential for efficient vegetation evaluation, aiding sustainable agriculture. Biostimulants enhance plant growth and resilience against stressors. Sugarcane, vulnerable to various stresses, can benefit from biostimulants, especially under drought conditions. Studies on biostimulant effects on sugarcane's metabolism, yield, and quality have been limited. Analysis of NDVI data indicated significant variations between treated and untreated areas over time. Polynomial regression models (R² between 0.921 and 0.959) demonstrated a strong ability to explain vegetation variability. Normality tests confirmed that VAI and Tons of Sugar per Hectare (TSH) data follow a normal distribution. There was no significant difference in VAI between treated and untreated areas during the plant development cycle, but a significant increase in VAI was observed in treated areas post-treatment (p=0.021). No significant difference in TSH was found, indicating no impact on sugar productivity. L-alpha biostimulant increased vegetation activity during critical growth periods but did not affect sugar yield. Return on investment analysis suggested high profitability of the treatment.