Nutrient distribution, dynamics, and sampling in coconut and Canary Island date palms

All leaves from 10 replicate Cocos nucifera L. 'Malayan Dwarf' (COC) and Phoenix canariensis Chabaud (CID) trees were sampled for leaf nutrient analysis. In addition, the leaflets of the youngest fully expanded leaves and the third oldest leaves were divided into five groups along the primary leaf axis and these leaflets were then cut into thirds to determine nutrient distribution patterns within leaves and leaflets. Nutrient remobilization rates were calculated for N, P, K, Mg, and Mn. Results showed that N, P, and K were highly mobile within and between leaves of both species of palms. Up to 31% of the N, 66% of the K, and 37% of the total P in the oldest leaves were ultimately remobilized to newer leaves within the palm. Magnesium remobilization rates averaged approximate to 71% for CID but only approximate to 10% for COC. The middle-aged leaves appeared to be the primary sink for Mg in COC, rather than the youngest leaves as in CID. Manganese was also quite mobile in both species, with up to 44% of the total Mn remobilized in CID. Samples consisting of recently matured leaves were determined to be the most appropriate for Ca, Fe, Mg (COC only), and Zn, but oldest leaves are more suitable for N, P, K, and Mn analysis.