Changes of Inorganic Nutrient Contents in Leaf of 'Niitaka' Pear and Inorganic Nutrient Contents of Leaf Influenced by Meteorological Elements

This study was conducted to investigate inorganic nutrient contents in spur leaf and shoot leaf of 'Niitaka' pear during the growing season and leaf inorganic nutrient contents as influenced by meteorological elements. The contents of N, P, K, and Mg were decreased in spur leaf during their vegetative growth, while Ca and Mn increased. The contents of N, P, K, Mg, and Fe showed no differences between spur leaf and shoot leaf. However Ca, Mn, Zn, and Cu contents were higher in spur leaf than those in shoot leaf, but B content was lower in spur leaf than those in shoot leaf. The content of N in shoot leaf was positively correlated with mean temperature, whereas negatively correlated with maximum temperature. The content of P in spur leaf was negatively correlated with maximum temperature. The content of Ca in spur leaf was negatively correlated with mean temperature, whereas positively correlated with maximum and minimum temperature. The contents of Mg and B in shoot and spur leaf were positively correlated with mean temperature, whereas negatively correlated with maximum and minimum temperature. The contents of Ca and Mn showed significant differences between spur leaf and shoot leaf at mid-July to early August. These results suggest that sampling is important to distinguish between spur leaf and shoot leaf for diagnosis of nutrient conditions in pear trees.