“…However, most current protocols for apple pollen range between 100 g L −1 and 150 g L −1 . Boron is believed to stimulate ATP hydrolysis and H + transport as shown by Obermeyer et al [ 43 ] on ungerminated lily pollen, and several studies have reported that endogenous boric acid promotes pollen germination and tube length in numerous plant species, including almond [ 44 ], pineapple [ 45 ], apricot [ 46 ], apple [ 46 ], cherry [ 46 ], kiwifruit [ 47 ], lychee [ 48 ], mango [ 49 ], peach [ 46 ], pear [ 46 ], plum [ 46 ], and pomegranate [ 50 ].…”