Variation rules of nutrition content in Palayinda mango leaves and nutrition diagnosis

ObjectiveVariation rules of nutrition content in Palayinda mango leaves was analyzed, in order to provide reference for determining nutrition diagnose indexes and guiding scientific fertilization. MethodHealthy Palayinda mango trees in well managed and high-yield Palayinda mango gardens in Baoshan, Yunnan were randomly sampled. Contents of nitrogen,phosphorus,potassium,calcium,magnesium and sulfur in the first blade were studied. Appropriate sampling time and nutrition diagnosis indexes for leaf nutrition diagnosis were determined based on annual deviation from mean, coefficient of variation and stability between different years of each nutrition. ResultCoefficient of variations of nitrogen, calcium, magnesium and sulfur were the smallest in January of 2013-2015, which were 9.46%,22.76%,1.84% and 3.58%respectively. Therefore, January was suitable for sampling for Palayinda mango leaf nutrition diagnosis. The diagnosis in-dexes were as follows: nitrogen 12.68-15.34 g/kg, phosphorus 1.05-1.19 g/kg, potassium 4.88-8.92 g/kg, calcium 14.10-22.40 g/kg, magnesium 2.13-2.21 g/kg and sulfur1.24-1.34 g/kg. ConclusionIn Baoshan, Yunnan, it is recommended that collecting first blade in January for Palayinda mango leaf nutrition diagnosis.