Effects of Short-term Pre-tapping Meteorological Factors on Latex Quality of Hevea brasiliensis

Taking the latex of Hainan rubber trees from July to December 2025 as the research object, the dry rubber content (DRC) and the nitrogen, phosphorus, potassium and ash contents of raw rubber were continuously monitored during the tapping period, and meteorological data (average temperature, extreme high temperature, extreme low temperature, precipitation, relative humidity and sunshine hours) were collected simultaneously for the 1, 3 and 5 days prior to tapping. The Kruskal-Wallis test was used to compare differences in latex quality among different tapping periods, and the Dunn test was used for multiple comparisons between groups. Spearman correlation analysis was used to screen key meteorological factors and sensitive time windows, and redundancy analysis (RDA) was used to quantify the comprehensive effects and relative contributions of various meteorological factors to latex quality. The results showed that latex quality indices differed significantly among different tapping periods. The DRC showed a decreasing trend and exhibited a lagged response to meteorological conditions 3-5 days before tapping, being significantly positively correlated with the average temperature and extreme low temperature in the 5 days before tapping and with precipitation in the 3 and 5 days before tapping. The nitrogen, phosphorus, potassium and ash contents of raw rubber showed a trend of first decreasing and then increasing: they decreased to a trough from August to September, then rose continuously and peaked in December. These contents responded immediately to meteorological conditions one day before tapping and were significantly negatively correlated with precipitation, extreme high temperature and relative humidity one day before tapping. The changes in DRC and mineral element contents were regulated by different physiological mechanisms; the effect of sunshine hours was relatively minor, and temperature was the dominant meteorological factor regulating latex quality.