Effects of calcium and boron on quality and browning spot disease of Huangguan pear

The foliar sprayings of 0.3% H3BO4 (B), 0.5% CaCl2 (Ca) and 0.3% H3BO4＋0.5% CaCl2 (B＋Ca) before the fruit bagging stage for 3 times at 7 day intervals were carried out respectively to study effects of calcium and boron nutrition on quality and browning spot disease of Huangguan pear. The results show that polyphenol oxidase(PPO) activity of peel during prophase of storage is significantly decreased in the three treatments (B, Ca and B＋Ca), while peroxidase(POD) activity is increased, and browning spot of peel is decreased during the cold storage at 0℃. These effects are obvious in the spraying of B＋Ca; and fruit weight per fruit, Ca content, Ca/Mg and Ca/K of peel at harvest are significantly increased in the spraying of B＋Ca. Soluble phenol content is reduced in the Ca and B+Ca treatments, and B contents of fruit peel and flesh are significantly increased in the spraying of B. Therefore, quality and storability of Huangguan pear are significantly improved for spraying of B+Ca.