Agronomic Response of Habanero Pepper (Capsicum chinense Jacq.) to Different Phosphorus Fertilization Strategies

Phosphorus (P) management can influence habanero pepper growth and productivity, but crop response may depend on the strategy used to supply this nutrient. This study evaluated five phosphorus fertilization strategies in Capsicum chinense Jacq. grown under shade house conditions: granular diammonium phosphate + urea (T1), soluble diammonium phosphate + urea (T2), soluble orthophosphate with steric protection (T3), phosphoric acid (T4), and a control without additional fertilization after 40 days after transplanting (T5). Four experimental sections per treatment were analyzed, with ten sampled plants distributed among the sections. Vegetative and reproductive traits were evaluated between 72 and 134 days after transplanting. The area under the curve (AUC) was calculated from repeated measurements of plant height, branching, leaf traits, and reproductive variables to assess their cumulative responses over the corresponding evaluation periods. At 134 days after transplanting, T3 and T4 showed greater plant height than T2 and T5, although plant-height AUC did not differ significantly among treatments. T3 had the highest final fruit set (62.0 fruits plant−1) and estimated yield (0.765 kg plant−1 and 0.849 kg m−2), whereas T5 had 35.7 fruits plant−1 and estimated yields of 0.296 kg plant−1 and 0.329 kg m−2. The first two principal components explained 68.93% of the total variation. PC1 (54.71%) was mainly associated with plant height, stem diameter, petiole length, leaves per branch, fruit set, and internode length, whereas PC2 (14.22%) was more closely related to leaf dimensions and branching. T3 and T4 tended toward positive PC1 values, while T5 was positioned toward negative values. Greater vegetative growth did not necessarily result in higher productivity. T3 showed favorable final vegetative growth, the highest numerical final fruit set, and greater estimated yield than T1, T2, and T5, although its yield did not differ significantly from T4. These findings highlight the importance of considering both vegetative growth and reproductive performance when evaluating phosphorus fertilization strategies for habanero pepper.