Diurnal Variations of Carbohydrate Contents and Activities of Related Enzymes in Leaves in Response to Defruiting in Peach Trees Diurnal Variations of Carbohydrate Contents and Activities of Related Enzymes in Leaves in Response to Defruiting in Peach Trees Study on photosynthetic property of Cucurbita maxima Effects of Fruit Thinning on Fruit Sugar Accumulation and Leaf Photosynthetic Characteristics of Pear Effects of potassium on plant growth, potassium cycle and distribution in different maize genotypes Effects of Fruit Thinning on Fruit Sugar Accumulation and Leaf Photosynthetic Characteristics of Pear