Background and Objective: Diagnosis and recommendation integrated systems (DRIS) are used to determine the nutrition status of several crops global. The study was conducted to determine a suitable leaf position to establish diagnosis and recommendation integrated system norms for N, P, K, Ca, Mg, Na, Cu, Fe, Zn and Mn nutrients in ratoon pineapple. Materials and Methods: On-farm research was designed in this study. Uninfected pineapple leaf samples were collected from 60 pineapple farms in Hau Giang. The t-test was used to compare mean values while F-test was used to compare variances between the high-yielding and low-yielding groups. Results: The results illustrated that the pineapple yield in the high-yielding group (>15.0 t ha–1, 26 farms) reached 18.4 t ha–1, higher than those in the low-yielding one (–1, 34 farms), producing 12.4 t ha–1. Concentrations of N, P, K, Ca, Mg, Cu and Zn in the high-yielding group outweighed those in the low-yielding group, while concentrations of Na, Fe and Mn in the low-yielding group were higher than those in the high-yielding one. A total of 18-24 out of 90 nutrient ratio pairs were selected to establish the DRIS norms at leaves +1, +3, +7, +14, +15, +18, +20, +22 and +24. The DRIS norms were set based on the leaf position with the number of ratios, which had statistically different means and variances >18 between the high-yielding and low-yielding groups. Conclusion: Nine norms were built at leaves +1, +3, +7, +14, +15, +18, +20, +22 and +24 from the high-yielding group to diagnose nutrients in ratoon pineapple.
Tạp chí khoa học Trường Đại học Cần Thơ
Lầu 4, Nhà Điều Hành, Khu II, đường 3/2, P. Xuân Khánh, Q. Ninh Kiều, TP. Cần Thơ
Điện thoại: (0292) 3 872 157; Email: tapchidhct@ctu.edu.vn
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