|Plant Part and Time:||Mature leaves from mid portion or near base of current season's terminal growth taken in mid season.|
|Element and Sufficiency Range||Interpretation and Recommendations|
Deficiency due to inadequate N fertilization and/or ineffective N application. Low N is also a sign of "peach decline" and the trees should be carefully examined for other symptoms. High leaf N can result in excessive twig growth and winter injury. If the N level is low (<2.75%), for next year's crop apply 30-60 pounds N per acre after harvest, but no later than September, and 40-60 pounds N per acre in the herbicide band in late January in extreme south Georgia or early- mid February for the remainder of the state. If the nitrogen is broadcast, increase the application rate by 30%. If the N level is within the sufficiency range (2.75-3.50%), reduce the post harvest application to 20-50 pounds N per acre and the January or February application to 30-60 pounds N per acre. Apply and adjust the N application as described in the previous paragraph.
Less than sufficient generally due to low soil P test level and/or inadequate P fertilization. If the leaf content is less than 0.12% and the soil test P level is low, apply 60 pounds P2O5 per acre. If the leaf content is less than 0.12% and the soil test P level is medium or higher, do not apply any additional phosphorus fertilizer.
Less than sufficient due to low soil K test level and/or inadequate K fertilization. If the leaf content is less than 1.50% K, apply 80-100 pounds K2O per acre; if between 1.50-1.74% K, apply 50-70 pounds K2O per acre; if between 1.75-2.50%, apply 30-50 pounds K2O per acre. If the leaf content is greater than 2.50% K, potash application can be omitted from the fertilizer program for one crop year. Pull samples again the following year to monitor the K status of the trees.
Less than sufficient due to low soil pH. Soil test and lime to adjust the soil pH to 6.0-6.5. Low Ca may also be a sign of "peach decline" and the trees should be carefully examined for other symptoms.
Less than sufficient due to low soil pH (less than 5.4) and/or low soil test Mg level. Soil test and follow lime recommendation using dolomitic limestone to correct soil acidity. Adequate liming using dolomitic limestone should prevent Mg deficiency from occurring.
Low sulfur levels have been detected in peaches growing on the sandy soils of Georgia. If sulfur is low, include a minimum of 10 pounds of S per acre in the fertilizer program until satisfactory S levels are detected in the tissue.
Deficiency is not likely to occur in Georgia. When the Mn concentration exceeds 150 ppm, this is a good indication that soil pH is low. Check soil pH and lime according to soil test recommendations.
Deficiency is not likely to occur. High Fe test results indicate soil or dust contamination. An accurate Fe determination can only be obtained with washed leaves (See section - Washing to Remove Contaminates).
Low boron levels are not frequently encountered. If boron is low, apply 1/2 pound B per acre in the fertilizer program or apply a foliar application using 0.2 pound B per acre in sufficient water to completely wet the foliage. Boron levels greater than 50 ppm can be toxic. When B exceeds 45 ppm, discontinue applications of B in the fertilizer or foliar spray program.
Deficiency not likely to occur. If low Cu levels are encountered, apply 3-4 pounds Cu per acre (12-16 pounds of copper sulfate per acre).
Low Zn levels have become more prevalent in recent years. When low Zn levels are encountered, apply 9-11 pounds of Zn per acre (e.g. 25-30 pounds zinc sulfate per acre) in the fertilizer program. High Zn can be a sign of "peach decline" and the trees should be carefully examined for other symptoms.
High Al concentrations in leaf tissue may be a sign of "peach decline" and the trees should be carefully examined for other symptoms. Aluminum does not normally enter the trees unless through damaged roots. If both Fe and Al are high, probably due to soil and dust contamination (see Fe discussion above).