Effects of magnesium foliar application on pericarp coloring of Litchi chinensis Sonn. cv. Feizixiao and contents of potassium, calcium and magnesium in pericarp

ObjectiveThe experiment was conducted to study the effects of magnesium(Mg) foliar application on peri-carp coloring and contents of potassium(K), calcium(Ca) and Mg in pericarp, and provided references for reasonable fer-tilization measures of Litchi chinensis Sonn. cv. Feizixiao. MethodAdult trees of Litchi chinensis Sonn. cv Feizixiao (16-year-old) were used as materials. After physiological fruit-falling period, the trees were sprayed with Mg fertilizer, in parallel with clean water for control(CK). Hue angle, anthocyanin content, chlorophyll content, sugar content in flesh, total K, total Ca, total Mg, water soluble K, water soluble Ca and water soluble Mg in pericarp were recorded and correlation analysis was conducted. ResultMg foliar fertilizer application promoted the coloration of pericarp in advance by promoting accumulation of anthocyanin in pericarp, and significantly increased contents of water soluble Ca, total Mg and water soluble Mg(P<0.05, the same below). Linear partial correlation coefficient between total K and water soluble Ca, between water soluble K and total Mg, between water soluble K and total Ca, and between total Mg and total Ca in pericarp reached significant level in spraying Mg fertilizer treatment and CK. There was significant difference between total Ca content and water soluble Ca content in linear partial correlation coefficient in spraying Mg fertilizer treatment. During pericarp coloring , unary exponential functions between total Ca, water soluble Ca, total Mg, water soluble Mg in pericarp between anthocyanin content in both Mg spraying treatment and CK were positive correlated. There was mutual gain effects between Ca content and Mg content in pericarp. ConclusionMg foliar application can increase anthocyanin accumulation of L. chinensis Sonn. cv. Feizixiao pericarp by increasing the contents of Ca and Mg, promote the coloration of pericarp in advance and overcome stay-green problem. Therefore, it can be promoted in actual planting.