Micronutrient deficiencies in Macadamia integrifolia Maiden & Betche seedlings.

摘要

Micronutrient concentrations were assessed in Macadamia cultivars Keauhou and Ikaika, grown with 6 nutritious solutions: one complete, the 5 others with individual omission of a specific element. The results showed that lower leaves of seedlings grown in complete solution contained 12.9 and 18.6 mg B, 2.6 and 2.7 mg Cu, and 28.3 and 18.1 mg Zn/kg for cultivars Keauhou and Ikaika, respectively. In the lower leaves of plants grown in B- and Zn-free solutions, cultivars Keauhou and Ikaika contained 5.7 and 6.1 mg B and 20.3 and 18 mg Zn/kg, respectively. In the complete solution, lower leaves of cultivars Keauhou and Ikaika contained 221.7 and 289.3 mg Mn and 129.8 and 121.4 mg Fe/kg, respectively, compared with 145.5 and 91.1 mg Mn and 38.6 and 48.9mg Fe/kg, respectively, in the Mn- and Fe-free treatments. The young Macadamia plants did not differ in symptoms of Fe, B, Cu and Zn deficiency or in the levels related to these symptoms, although a difference between cultivars was detected for Mn concentrations. The elements that most limited dry matter production were, in decreasing order, Fe, Cu and Mn.