Viticulture Newsletter May 2002 PDF Version

From the Viticulture Staff at Oregon State University

Contributors: Jessica Howe, Jessica Cortell, Anne Connelly, and Carmo Vasconcelos

In This Issue

Mineral Nutrients: a summary

Nutrient Management Tools

Part 1 Soil and Petiole Sampling

Part 2 Resources for Interpreting Soil and Tissue Analysis

Making Choices on Fertilizer Applications

Introduciton

Welcome to the Oregon State University Viticulture Extension Newsletter. This first edition is dedicated to nutrition. Thanks to the efforts of Jessie Howe and Jessica Cortell, the information provided here is designed to help wine grape growers make decisions regarding nutrition management. We are fortunate to have Jessie Howe on board because she just completed her Masters at OSU. The title of her thesis, The Effects of Soil Moisture and Nitrogen Application on Leaf Gas Exchange, Fruit Composition, and Carbohydrate Storage of Pinot noir and Chardonnay Grapevines in the Willamette Valley, was under the supervision of Carmo Vasconcelos. OSU Extension will be providing quarterly newsletters with a designated theme through the Northwest Berry and Grape Information Network. We will make a limited number of hard copies available for individuals who do not have Web access. If you have any suggestions, comments, or questions regarding content please contact us at OSU, Department of Horticulture, 541-737-5453 or e-mail me at connella@bcc.orst.edu. If you have any comments regarding the Web format please contact the Web Master, Ben Exstrom at the North Willamette Research and Extension Center at ben.exstrom@oregonstate.edu. Thank you, Anne Connelly

Upcoming Events

Mineral nutrients: a summary

Plant growth and development depend on mineral nutrients. Nutrients are divided into two categories: macronutrients and micronutrients. Macronutrients are constituents of organic compounds and are required by plants in substantial amounts. Micronutrients are most commonly constituents of enzyme molecules and are required in small amounts.

Plants obtain mineral nutrients from the soil. The mobility of each individual nutrient varies both in the soil and within the plant. This is important to consider when deciding how to manage nutrients within a given system (i.e. fertilizer application, source, and timing). Each nutrient has functions that it serves in the plant. Table 1 summarizes the different mineral elements, their unique functions, the quantity in which they are present within a plant, and their mobility.

When mineral nutrients become limiting in plants both physiological and biochemical processes are affected and deficiency symptoms can be observed. Table 2 illustrates some of the common deficiency symptoms for each of the mineral nutrients.




Table 1: Nutrient functions, quantity, ionic forms, and mobility

				Quantitiy
Macronutrient			Function	% dry weight	Ionic forms	Soil mobility	Plant mobility
	Carbon	C		45.00%
	Oxygen	O		45.00%
	Hydrogen	H		6.00%
	Nitrogen	N	amino acids, proteins, nucleic acid, nucleotides, chlorophyll, coenzymes, yeast need nitrogen to remain viable during fermentation	2.0-5.0%	NH4+	Immobile	Immobile
					NO3-	Mobile	Mobile

	Phosphorus	P	ATP (energy metabolism), nucleic acids, coenzymes, phospholipids, cell multiplication and tissue growth depend on sufficient phosphorus	0.2-0.5%	HPO4--	Very immobile	Mobile
					H2PO4-	Very immobile	Mobile


	Potassium	K	Osmosis and ionic balance (reduces transpiration and maintains cell turgescence), stomatal function, enzyme activation, plays a role in the assimilation of carbon by leaves	1.00%	K+	Immobile	Mobile



	Sulfur	S	amino acids (cysteine, methionine), proteins, coenzyme A	0.2-0.5%	SO4-	Mobile	Slightly mobile
			amino acids (cysteine, methionine), proteins, coenzyme A
	Calcium	Ca	cell walls, enzyme cofactor, membrane permeability	0.50%	Ca+	Immobile	Very immobile
			cell walls, enzyme cofactor, membrane permeability
	Magnesium	Mg	chlorophyll, enzyme activation, phytin (a reserve substance rich in P and Ca)	0.20%	Mg++	Immobile	Mobile


Micronutrient				ppm
	Boron	B	plays a role in the migration and use of sugars, nucleic acid synthesis, membrane integrity, influences Ca use	20	H3BO3	Mobile	Very immobile


	Zinc	Zn	enzyme activation, enzyme component	100	Zn++	Very immobile	Immobile
	Iron	Fe	chlorophyll synthesis, cytochrome, nitrogenase	100	Fe++	Very immobile	Immobile
					Fe+++	Very immobile	Immobile
	Copper	Cu	enzyme activation, enzyme component, oxidation/reduction	6	Cu++	Very immobile	Immobile
			enzyme activation, enzyme component, oxidation/reduction
	Manganese	Mn	integrity of chloroplast membrane, oxygen release in Photosynthesis, cofactor of enzyme reactions	50	Mn++	Very immobile	Immobile


	Molybdemum	Mo	nitrogen fixation, nitrate reduction	0.1	MoO4-	Very immobile	Immobile
	Chlorine	Cl	Osmosis and ionic balance	100	Cl-	Mobile	Mobile

Other
	Sodium	Na			Na+	Mobile	Mobile

sources: Righetti, T. Oregon State University. Marschner, H. Mineral Nutrition of Higher Plants. 1986. Galet, P. Grape Diseases. 1996



Table 2: Nutrient deficiency symptoms

Macronutrient			deficiency symptoms
	Nitrogen	N	reduced vigor, enchanced senescence of older leaves, yellow leaves, upright leaf petiole angle, uniform chlorosis in mature leaves, reddish petioles, premature shoot lignification