Hi: Browning at the edges of grape leaves usually signifies potassium
deficiency. I would spread about l/2 pound of potassuium chloride per
plant. It should be applied in a straight line (concentrated) about one
foot on each side of the trunk. It can be applied any time. Potasium
chloride is usually sold at the fertilizer distributors as potash muriate.

Joe.
> On some of my largest, older cab franc leaves (basal), I am noticing what
> appears to be a slight burning on the tips of the leaves. Otherwise the
> leaves look good. Good color. Good size, etc.
>
> Any ideas to suggest what might cause this? A deficiency of some sort?
> "General Viticulture" has a paragraph that suggests high sodium, but I'm
not
> sure how that would happen.
>
> Regards
> Jeff Chorniak
>
>