Mineral Nutrition for Muscadine Grapes
Dr. Mercy Olmstead, Extension Specialist University of Florida
Importance of Nutrition
Plants need essential elements to survive, produce high quality fruit Photosynthesis, cell wall growth, fruit set all depend upon optimum levels of nutrients
Pre-plant analysis: What can the soil provide?
◦ Amendments based on analysis since some elements are easier to fix before planting
Impact of pH on Nutrients
Soil pH is important pH affects nutrient availability
◦ Some nutrients more available in soil or solution
Areas with significant rainfall have lower soil pH
◦ Due to leaching of Ca2+, Mg2+, K+ and Na+ ◦ Replaced with H+
**The thicker the bar, the more available the nutrient
Impact of pH on Nutrients
Soil pH Adjustments
Acidic soils must be adjusted before planting Rate of pH change:
◦ Dolomitic lime (contains Mg) - Slow ◦ Ground limestone - Slow ◦ Pelletized limestone – Fast
Use combination of materials to sustain effect
http://web1.msue.msu.edu/monroe/soilweb2/raising%20pH.htm
Irrigation Water pH
Solutions for high pH water?
◦ Acidify the water source ◦ Monitor soil pH ◦ Apply fertilizers with sulfur to bring pH down
Required Elements
Macronutrients –
◦ Needed in large quantities ◦ Reported in % on plant tissue analysis
Micronutrients
◦ Needed in much smaller quantities ◦ Reported in parts per million (ppm)
Ppm = mg/L
◦ Easy to go from deficiency to toxicity with improper application
Nitrogen
Important in making amino acids & proteins, DNA and RNA, and chlorophyll Deficiency affects older leaves first
◦ Yellowing, small leaves
Excessive nitrogen promotes vigor and can leach into groundwater
◦ Increased pressure by environmental groups
EPA Numeric Nutrient Criteria in Florida
Sets numeric limit on P and N in bodies of water
Phosphorus
Important in cells that transfer energy
◦ ATP and ADP –...