Abstract. Musyarofah N, Susanto S, Aziz SA, Suketi K, Dadang. 2020. The diversity of ‘kristal’ guava (Psidium guajava) fruit quality in response to different altitudes and cultural practices. Biodiversitas 21: 3310-3316. The current study aimed to compare the quality of ‘kristal’ guava fruit harvested from different altitudes under different cultural practices. The study was conducted from January to March 2019. Four treatments were examined, i.e., fruit from low altitude-intensive cultural (LI), low altitude-less intensive cultural (LI), middle altitude-intensive cultural (MI), and middle altitude-less intensive cultural (ML). All treatments were arranged in a completed randomized design and each treatment had five trees as replicates The findings of the study showed that there was a variation of fruit quality in response to different altitudes and cultural practices. The fruits harvested from low altitudes were significantly bigger and heavier than the fruits harvested from middle altitude, irrespective of cultural practices. With regard to fruit softness, the fruits from middle altitudes were crispier than fruits from the low altitude. The chemical qualities of the fruits, indicated by TSS/TA ratio and vitamin C, were better in guava orchard under intensive cultural practice than less intensive cultural practice. The intensive cultural practice also improved the guava fruit size as compared to the less intensive cultural practice. This finding may be attributed to pruning which is performed in intensive cultural practice. More beneficial metabolites for human health such as vitamin E and caryophyllene were found in fruit from low altitude.

Information on scar incidence and its effect on fruit quality of ‘Kristal’ guava (Psidium guajava L.) grown on different altitudes is currently limited. The aim of this study was to evaluate the fruit scar incidence and fruit quality of 'Kristal' guava var. grown on low- and middle-altitude orchards. The research was conducted by collecting 50 samples of fruit harvested from each orchard from January to June 2019. Fruit quality evaluation was carried out at Postharvest Laboratory, Department of the Agronomy and Horticulture, IPB University, whereas scarring pest observation was conducted at Insect Biosystematics Laboratory, Department of Plant Protection, IPB University. Our results showed that the low-altitude orchard produced more fruits with medium, high, and very high scar intensity, while the middle-altitude orchard produced more fruits with low and very low scar intensity. Fruit scar was caused by fruit scarring pests, especially thrips and mites. Fruit tissue damage only occurred on the epidermis of fruit pericarps where the tissue turned brownish and thickened. Additionally, there was no expansion of the damage into the pulp. The peel damage did not affect the fruit taste as indicated in the level of total soluble solids (TSS), titratable acidity (TA), TSS/TA ratio, vitamin C, and total flavonoids content. Fruit external quality was varied in response to altitude, where middle-altitude orchard produced a heavier, a bigger and a lower fruit softness than low-altitude ones. Present findings could be the baseline information for determine the best growth site and adjustment of pest control to maintain fruit quality.