Respon anatomi struktur sekretori getah kuning, morfologi, dan fisiologi buah manggis (garcinia mangostana l.) Terhadap aplikasi kalsium secara eksternal

Abstract

Yellow latex (gamboges) in mangosteen (Garcinia mangostana L.) resulted from the damage of epithelium wall secretory duct in the pericarp is presumably caused by deficiency of calcium. The application of Ca to the soil in previous experiment didn’t increase calcium content on the fruit’s pericarp sufficiently. Therefore, the alternative method may need to be tried to improve Ca content. The objective of this research was to study the effect of calcium spraying to the growing mangosteen fruit on the anatomical structure of yellow latex secretory duct, morphological and physiological response. The Randomized Block Design with three replications was applied on fruit surface of ±30 years old mangosteen trees in Leuwiliang sub district. The treatments were CaCl2 0.25 M, CaCl2 0.5 M, CaCl2 1 M, Ca(OH)2 0.25 M, Ca(OH)2 0.5 M, and Ca(OH)2 1 M that was performed at the 2nd, 4th, 6th, 8th weeks after anthesis (WAA). The parameters analyzed were the thickness, length and wide of epithelium secretory duct cell wall, yellow latex score, physical and chemical characteristics, calcium content and. The result showed that Ca application was generally able to decrease yellow latex score on the skin as well as in the aril, but there was different respond between CaCl2 and Ca(OH)2 treatment. The reduction of yellow latex score on skin was highest on Ca(OH)2 1M treatment (26%) while on the aril it was CaCl2 0.5 M treatment (28%). The physiology respond showed that the increase Ca pectat was in accordance to the reduction of yellow latex score on the skin fruit. The application of Ca didn’t influence physical and chemical characteristics of the fruit neither total Ca content of the pericarp significantly.