In the present case, a mature leaf exhibits irregular light brown lesions, bordered by a dark brown margin.
Zinc deficiency
Affected plants are paler in colour than normal and the leaves have a purplish tint. Necrotic spots (often light brown with dark margin) occur on the older leaves.
Growth is also reduced due the affect of zinc on chlorophyll function. Internodes are shortened.
Zinc deficiency
Medium leaves show interveinal chlorosis.
Zinc deficiency on durum wheat
Cereals: 1 to 3 l/ha from the 2 leaf stage to second node detectable (Zadok's G.S. 12 to 32). Repeat applications at 10 to 14 day intervals, within this timing, if necessary. For autumn sown crops, an application prior to winter dormancy may also be beneficial. In addition, 1 l/ha from second node detectable to flag leaf fully emerged (Zadoks G.S. 32 to 39). Water rate: 50 to 200 l/ha. Seed Dressing: 3 to 6 litres per tonne.
Cereals: 1 l/ha at 2 leaf stage to second node detectable (Zadok's G.S. 12 to 32). Water rate: 200 l/ha. For severe deficiency, increase to 2 l/ha or repeat at the above rate. For autumn-sown crops, an application prior to winter dormancy is strongly recommended. Seed Dressing: Typically 3 litres per tonne. Rate can be increased up to 6 litres per tonne if necessary.