CROP NUTRITION
Wine grapes.
Plan by growth stage.
Explore a seasonal NABTA product example for mature wine grapes, with growth-stage timing, stage quantities and separate application amounts.
Planning example for agronomic review. These calculations use stated assumptions and are not field-validated NABTA recommendations. Adjust for block tests, crop load, water nutrients, salinity and irrigation capacity before field use. Use current product labels.
Mature-acre rates do not apply to young plantings. Missing information is identified in each program. No yield guarantee or UC endorsement is implied.
Wine grapesView growth stages, NABTA rates & application timing
Illustrative feeding program · agronomic review required
Example block: 7.0 fresh tons/ac. Mature commercial planting with zero assumed soil, water or other nutrient credits.
Seasonal fertilizer nitrogen41.3 lb K2O/ac
Seasonal potassium budget30.6 lb Ca/ac
Calcium supplied by CALTRATE
How to read this schedule: bold amounts are total product pounds per acre for the entire stage. Divide them across the separate applications shown. Dates are approximate; use actual crop stage. All rates shown are for root-zone fertigation, not foliar spraying.
| Growth stage / timing | NABTA CALTRATE 15.5-0-0 + Ca19 | NABTA SOP 0-0-52 |
|---|---|---|
| DormancyNov–Feb | No routine application0 lb/ac in this example | No routine application0 lb/ac in this example |
| After budbreakMar–Apr; after frost risk | 32.3 lb/acStage total: 2 separate applications × 16.1 lb/ac each | 11.9 lb/acStage total: 1 separate application × 11.9 lb/ac each |
| Bloom to fruit setApr–May | 48.4 lb/acStage total: 2 separate applications × 24.2 lb/ac each | 27.8 lb/acStage total: 2 separate applications × 13.9 lb/ac each |
| Berry growthMay–Jun; before veraison | 80.6 lb/acStage total: 3 separate applications × 26.9 lb/ac each | 39.7 lb/acStage total: 2 separate applications × 19.9 lb/ac each |
| Veraison to harvestJul–Oct; cultivar dependent | No routine application0 lb/ac in this example | No routine application0 lb/ac in this example |
| PostharvestWhile canopy stays active | No routine application0 lb/ac in this example | No routine application0 lb/ac in this example |
| Leaf fallEnd of season | No routine application0 lb/ac in this example | No routine application0 lb/ac in this example |
Assumptions & adjustments
- Medium-vigor drip example: 25 lb fertilizer N/ac before credits; UC range 10–25 for comparable drip conditions.
- K replacement example: 7 fresh tons × 5.9 lb K2O/ton. Confirm tissue K, wine-quality goals and soil fixation.
- The 20/30/50 N and 15/35/50 K stage splits are proposed planning assumptions, not UC trial treatments.
- No routine phosphorus or micronutrient dose is included. These examples assume adequate phosphorus; other nutrients require diagnostic evidence.
- Application counts are arithmetic subdivisions using 30 lb CALTRATE/ac and 20 lb SOP/ac as maximum example event sizes. Confirm current label directions, irrigation frequency, injection capacity, EC and calcium loading. Do not add irrigation solely to fit the schedule.
Product compatibility: apply CALTRATE separately from SOP, MKP, LIB and other phosphate or sulfate solutions, with appropriate flushing. Confirm the current California registration and label for SOP before purchase or use; its current status has not been verified for this example.
Research basis: UC / CDFA crop nutrition reference. Product analyses: CALTRATE label reference · SOP label reference. These references do not imply UC endorsement of NABTA products.
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