Appraisal of the Diagnosis and Recommendation Integrated System and Nutrient Status of Pineapple (Ananas Comosus L.) Growing Fields

Abstract

ABSTRACT The diagnosis and recommendation integrated system (DRIS) has such high reliability that it can be used to evaluate many crops. Therefore, in order to have a practical database for these norms, this study was conducted to evaluate the established DRIS norms for plant pineapples (Ananas comosus L.) and to assess their nutrition status in an acid sulfate soil. Healthy and disease-free leaf samples of 8-month-old pineapple plants without fruits were collected from experimental fields with nutritional omission trials and from farmers’ fields at four cultivating sites. Nutrient concentrations were analyzed to determine DRIS indices. The result showed that the + 7 leaf was highly reliable to diagnose the macro-nutrition status, while the + 1 leaf and + 3 leaf lacked the nutrient ratios pair to assess P and Mg nutrition status. Based on the average DRIS indices of the four sites, the nutrient surplus was observed in the order P>Mn>Fe>Ca (81.7 > 52.8 > 15.7 > 13.3), while nutrient deficiency varied in the order K>Zn>N>Mg (−88.2<-20.3<-16.4<-10.7) at the + 7 leaf. The DRIS norms needed to be calibrated to obtain nutrient ratio pairs for P in the + 1 leaf, and P and Mg at the + 3 leaf.