Diagnosis and Recommendation Integrated System Norms for Jackfruit (Artocarpus heterophyllus Lam.) Nutrient Status Evaluation

In China, the balanced fertilization was neglected in jackfruit orchards from lack of monitoring nutrient status. Therefore, for identification deficiency or excess of nutrients and determination the order of nutrient requirement, the jackfruit diagnosis and recommendation integrated system (DRIS) was provided. The jackfruit DRIS norms about N, P, K, Ca, Mg, S, Fe, Mn and B were developed using 2 years data of high-yielding orchards and low-yielding orchards of Hainan, China. Based on the DRIS norms, the DRIS indices of low-yielding orchards were defined, and then determined the order of nutrient requirement. Meanwhile, the DRIS norms were used to derive the standard of DRIS index grade, which identified deficiency or excess of nutrients for jackfruit orchards. Eventually, we found that the order of low-yielding orchards nutrient requirement was Ca > K > Fe > P > N > S > Mg > B > Mn, and the deficient nutrients were Ca, K and Fe. Therefore, the establishment of the DRIS approach is very important for jackfruit nutrient status diagnosis. It may be beneficial to fertilizer plan of Hainan jackfruit orchards.