PERTANIKA JOURNAL OF TROPICAL AGRICULTURAL SCIENCE

Rafflesia zollingeriana is one of the endemic species in the eastern Java Region of Indonesia that has gained much attention from researchers. R. zollingeriana has not been studied for its flower bud development, mortality, and population dynamics. The present study investigated the flower growth, mortality, flowering success, sex ratio, and life cycle of R. zollingeriana in the Papring Forest, Kalipuro Banyuwangi, East Java, Indonesia. Five populations of R. zollingeriana with 412 individuals were observed visually every two weeks for 12 months. Each bud was observed to determine the growth dynamics, growth rate, life cycle, distribution size, bud sustainability, mortality, and sex ratio of R. zollingeriana. The bud phase development was recorded to determine its population structure and life cycle. The results showed that R. zollingeriana required between two and three years to complete its life cycle. The smaller buds grew more slowly than the larger buds. The bud mortality rate was quite high at 73.54% and occurred during the cupule and bract transition phase. The blooming success rate of its buds was only 17.71%, with a higher proportion of female flowers than male flowers. R. zollingeriana in Papring Forest was flowering throughout the year, with the most frequent flowering incidents occurring during the high rainfall months of January, February, March, and June. There is a relationship between the number of flowering incidents and environmental factors such as rainfall, temperature, and length of irradiation. This study underscores the species’ vulnerability, low blooming success, and high mortality, which inform conservation strategies for R. zollingeriana in Papring Forest, Banyuwangi