Iron, zinc and boron deficiency in papaya

Abstract

Papaya ( Carica papaya L.) cultivar ‘Honeydew’ was grown in refined sand with complete nutrition and at deficient levels of iron (0.014 or 0.056 mg l −1), zinc (0.0065 or 0.013 mg l −1) or boron (0.0033 or 0.033 mg l −1). The symptoms of deficiencies of iron and boron appeared in young leaves, and those of zinc in middle leaves. The depression in growth was maximum in iron deficiency and least in zinc deficiency. The affected leaves from plants which were acutely deficient in iron, zinc or boron contained as little as 85 μg iron, 13 μg zinc and 6.7 μg boron g −1 dry matter, respectively, whereas comparable leaves from normal plants contained 140 μg iron, 22.4 μg zinc and 17.3 μg boron g −1 dry matter, respectively.