Nitrogen Deficiency in Grapes

How Nitrogen affects grapevines

Nitrogen drives canopy development, shoot vigour and the leaf area that fills bunches. Vines need most N between budbreak and fruit-set; excess after veraison delays ripening and softens berries.

Symptoms of nitrogen deficiency in grapes

Early: Uniform pale-green to yellow on the oldest basal leaves first (N is mobile and is withdrawn to feed young growth). Shoots are thin with short internodes.

Advanced: Whole-canopy chlorosis, early leaf drop, small pale bunches, poor cane maturity and weak return bloom the following season.

Why it happens

Sandy, low-organic-matter soils; heavy leaching after irrigation or monsoon; high C:N mulch tying up N; over-cropping.

How to confirm (petiole at full bloom)

Test	Sufficient range
Nitrogen in grapevine tissue	Petiole NO₃-N at full bloom 500–1200 ppm (deficient <350 ppm); blade total-N 1.6–2.8%.

Correction & timing in the vine cycle

Split-feed through drip from budbreak to fruit-set. Stop heavy N before veraison. A 1–2% urea foliar spray gives a quick lift on visibly pale vines.

Ranges are general guidance for Indian vineyards; always confirm with petiole analysis at full bloom and a soil test, and tailor doses to variety, stage and soil. Our agronomists can build a vine-specific programme free of charge.

Correction Products

Product	Method	Rate
Urea 46%	Soil	25–40 kg/acre
Calcium Nitrate	Drip	2–3 kg/acre/week

Treatment Steps

1. Confirm with soil test + leaf analysis. Check soil pH.
2. Apply Urea 46% at 25–40 kg as emergency foliar spray. Repeat after 7–10 days.
3. Apply drip or soil for lasting correction.
4. Include in regular nutrition program to prevent recurrence.

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