Applications of cold compensators in pecan trees (Carya illinoienensis Wangenh. K. Koch)

Resumen

Objective: In northern Mexico, pecan cultivation is a key economic activity; however, in recent years, climate change has led to a reduction in nut yield due to insufficient chill hour accumulation during increasingly mild winters. This study aimed to identify effective chill compensators to mitigate this issue and improve early-season development and productivity in pecan trees.

Design/methodology/approach: The experiment was conducted in Aldama, Chihuahua, during the 2020 growing cycle using a randomized complete block design. Various conventional chill compensating products were applied to evaluate their effect on yield and quality parameters.

Results: The average yield was 2.21 t ha⁻¹, with 184 nuts per kilogram and 57.1% edible kernel content. The mean Alternate Bearing Index (ABI) was 29.56%, and the Long-Term Productivity Index (LTPI) was 14.56%. Treatments that produced the greatest positive impact on these variables were, in order of effectiveness: hydrogen peroxide (H₂O₂), Erger® + Ca(NO₃)₂, TA + TO + TDZ (Tecno Agro + Tecno Oil + Thidiazuron), and Dormex.

Limitations/implications: Although not explicitly addressed in the study, results may vary depending on regional climate, orchard age, or cultivar, suggesting a need for site-specific evaluation before broad application.

Findings/conclusions: The application of chill compensators significantly improved pecan productivity and quality. H₂O₂ was the most effective treatment, increasing yield by 100%, kernel percentage by 2.64%, and LTPI by 135.82%, while reducing nut count per kilogram by 17.37% and ABI by 51.69%. Conversely, CaSO₄ increased ABI by 107.69% relative to the control, leading to higher alternate bearing intensity and substantially reduced productivity.