Verification of Nutrients Standards for Diagnosis of Yuhebao Lychee (litchi Chinensis Sonn.)

The steady production of Yuhebao lychee (Litchi chinensis Sonn.) is involved in accurate fertilization management. The critical period of nutrient requirement for Yuhebao lychee is during January to June every year in Taiwan because the period is from flowering to fruiting stage. It would serve the references of fertilization if there is an accurate standard for nutrient management of Yuhebao lychee. This study was conducted to establish the accurate standard of sampling period and location for nutrient diagnosis of Yuhebao lychee by analyzing essential nutrient elements of leaves from pre-anthesis to harvest stage. The leaves were sampled every month on middle of January to June for the estimation of leaf nutrients by inductively coupled plasma spectrophotometer (ICP). The results revealed that the appropriate sampling position and period of leaves should be from the leaves below flower spike during the flowering period. On the other hand, the mature leaves from either the branch of flowering or non-flowering terminal for nutrient management of Yuhebao lychee is recommended. Key words: Agricultural management, climate variations, lychee, nutrient diagnosis.