Fluorine uptake by fruit and leaf in relation to fruit disorders in mango.
Zhang ChengLin, Huang HuiBai, Chen HouBin
Author Affiliation: Department of Land Resources and Environmental Science, South China Agricultural University, Guangzhou 510642, Guangdong, China.
Acta Horticulturae Sinica 24 : 111-114
Abstract : The uptake and distribution of atmospheric fluorine by mango fruits and leaves were studied in an orchard where black tip and stunted fruit disorders had appeared. Results showed that fluorine was absorbed by the fruits throughout the season via the stomata on the skin. As the cuticle wax thickened, absorption decreased. A small amount of fluorine absorbed by the leaves was translocated to the fruit. Fluorine accumulated mainly in the skin of the fruit rather than in the flesh or the seed. Fluorine absorbed early in fruit development inhibited cell expansion causing the stunted fruit condition. Fluorine in raindrops gathered at the stylar end of the fruit was one reason for the black tip disorder. The fluorine was absorbed into the tissue and caused necrosis. In a field experiment where the fruits were deliberately held upside down, black tip disorder occurred on the shoulder of the fruits. The fruits were much more sensitive to fluorine pollution than the leaves. However, young leaves were more sensitive than older ones. Leaves absorbed fluorine throughout the growing season and injury began with necrosis at the leaf edge.