EFFECTS OF TEMPERATURE, RELATIVE HUMIDITY AND RAINFALL ON LEAF FLUSHING, FLOWERING AND YIELD OF LONGAN GROWN IN CHIANG MAI PROVINCE, THAILAND

T. Jaroenkit, B. Buamasung, S. Ussahatanonta, P. Manochai
The effects of environmental factors, including temperature (T), relative humidity (RH), and rainfall (R) on leaf flushing, flowering and yield of longan grown in Chiang Mai Province, Thailand, were investigated. Data, such as leaf flushing, flowering, fruit setting and yield were collected from 10-year-old ‘Daw’ longan trees. The data were collected from the date of pruning (June 1, 2010) to harvesting (June 9, 2011). Leaf flushing started 31 days after pruning. The leaves were allowed to flush twice before potassium chlorate (KClO3) was applied on November 1, 2010 to induce flowering. The inflorescence started to emerge 36 days after the application and fruits were harvested 185 days from flowering. The environmental data were grouped according to specific development stages before being analyzed. The period of leaf flushing (Y1) correlated negatively with T (r=-0.94), but positively with RH (r=0.92) and R (r=0.52). Percentage of leaf flushing (Y2) correlated positively with RH (r=0.75) and R (r=0.64), but negatively with T (r=-0.75). Temperature and relative humidity showed positive relationship with the logarithm of the induction period (Y3) (r=0.95 and 0.96, respectively) and percentage of flowering (Y4) (r=0.92 and 0.91, respectively). Rainfall during induction period seems to play no crucial role. Harvesting time (Y9) correlated well with T, RH, and R, with correlation coefficients of -0.99, 0.98 and 0.58, respectively. The correlation coefficients of male (Y5) and female flower (Y6), blooming periods (Y7), percentage of fruit set (Y8) and yield per tree (Y10) were relatively low. Therefore, there might be other confounding factors that contributed to these responses. The predicted models of the effects of environmental factors on each parameter analyzed by a statistic program (SPSS) were also evaluated in this study.
Jaroenkit, T., Buamasung, B., Ussahatanonta, S. and Manochai, P. (2014). EFFECTS OF TEMPERATURE, RELATIVE HUMIDITY AND RAINFALL ON LEAF FLUSHING, FLOWERING AND YIELD OF LONGAN GROWN IN CHIANG MAI PROVINCE, THAILAND. Acta Hortic. 1029, 169-175
DOI: 10.17660/ActaHortic.2014.1029.19
https://doi.org/10.17660/ActaHortic.2014.1029.19
environmental factors, flushing, flowering, correlation coefficient
English

Acta Horticulturae