Documenting Symptoms and Critical Values for Nutrient Deficiencies in Wine Grapes

Photographic images of nutrient deficiency symptoms were gathered for this project

IPNI-2013-USA-WA15

16 Apr 2014

2013 Annual Interpretive Summary


A study was conducted from 2009 to 2011 where nutrient deficiencies were imposed on replicated red and white wine grape plants grown in pots. Deficiencies of N, P, K, Ca, Mg, S, B, Cl, Cu, Fe, Mn, and Zn were imposed on 10 replications of Cabernet Sauvignon and of Semillion plants. In addition, 30 control (full nutrition) Cabernet Sauvignon and Semillion plants were also grown for comparison. In 2010, just prior to commercial harvest, three plants for each cultivar and nutrient treatment and three control plants were destructively harvested. The plants parts were divided into components (roots, trunk, shoots, petioles, leaves, and, if present, fruit and rachis). The components were dried, weighed, ground, and analyzed for nutrient concentration. The remaining plants were over-wintered in a cold storage area, and in 2011 the treatments were continued, with weekly photographs of the developing nutrient deficiency symptoms. At bloom, another three plants of each cultivar/nutrient combination were destructively harvested and in later September, at commercial harvest, all remaining plants were destructively harvested and handled as described above.

Nutrient deficiency symptom images are being processed and will soon be made available for viewing on the IPNI website. While all photographs were taken early in the morning, and a large umbrella was used for shading, there was still variation in the plant color in the photographs due to light interception created by the changes in the sun’s position as well as plants being photographed from an eastern or western exposure depending on their position. All photographs were taken with the plant placed in front of a black background to use for color adjustment. This project resulted in over 5,000 photographs. Using the program Adobe Lightroom, each photo was adjusted to a uniform “exposure” using the black background as the constant for adjusting the image. Additionally, photos were cropped to remove any edges beyond the black background and to strive for fairly uniform sizing. As the image processing is completed, the photographs will be added to the IPNI nutrient deficiency gallery for public viewing.