Extension Agronomist - Soil Testing & Plant Analysis
Plant Part and Time:
Healthy mid-terminal leaves on current season's growth taken in mid season. (8 to 10 weeks after full bloom)
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Nitrogen (N)
1.80-2.10% (Golden Delicious)
1.90-2.30% (All other varieties)
Deficiency due to inadequate N fertilization and/or ineffective N fertilization. No additional N fertilizer should be applied until next spring. When N leaf level is greater than 2.4%, possible fruit disorder may occur. If N is low, for next year's crop, apply 0.30-0.60 lbs. N/tree. If this year's terminal growth was less than 8 inches on trees that set a good crop, use the higher N rate; if terminal growth was 8 inches or more, lower the rate of N. Where vigor is low, N can also be supplied by spraying low biuret urea at 6 to 12 lbs. N/A after bloom but not in late cover sprays. If N is within the sufficiency range, or slightly high, for next years crop , 0 to 0.60 lbs. N/tree. If this year's terminal growth was less than 8 inches on trees that set a good crop, use the higher N rate; if terminal growth was 8 inches or more, lower the rate of N. If terminal growth was greater than 15 inches, do not apply any nitrogen.
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Phosphorus (P)
0.15-0.50%
Deficiency is generally due to low soil test P. Low P in leaves can also be due in part to a low soil pH. For best P availability, maintain soil pH between 6.0 to 6.5. If the leaf level is less than 0.15% and the soil test P level is also low, for next year's crop, apply 60 lbs. P2O5/A. If the soil test P level is medium, apply 30 lbs. P2O5/A; if the soil test level is high, do not apply additional phosphorus fertilizer next year. If the leaf P level is within the sufficiency range, no additional phosphorus fertilizer will be required for the next crop, irrespective of the soil test P level.
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Potassium (K)
1.25-1.80%
Deficiency is due to low soil test K. Do not apply excessive K or more than recommended rates of K fertilizer as Mg deficiency may result. If leaf and soil K levels are both low, for next year's crop, apply 60 lbs. K2O/A. If leaf K levels are low and the soil test K levels are medium or higher do not apply additional K2O. If the K content is within the sufficiency range, no additional potassium fertilizer will be required for the next crop, irrespective of the soil test K level.
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Calcium (Ca)
1.00-2.00%
Low Ca leaf levels will result in poor fruit quality and a physiological disorder called "Bitter pit" in apple. If the Ca level in apple tissue is less than 1.0%, apply calcium chloride at 2 lbs./100 gallons (maximum of 3 to 6 lbs./A) or calcium nitrate at 3 lbs/100 gallons (maximum 4.5 to 9.0 lbs./A) in all cover sprays. Higher rates can cause foliage burn and should not be re-applied unless at least 1/2 inch of rain has fallen since previous application. Do not apply foliar sprays when temperatures exceed 90oF. Since apple acts as a low accumulator of Ca, take care to ensure the soil pH is adequate and the other elements are applied in their proper amounts. In some cases, supplemental application of Ca to the soil as gypsum or the use of calcium nitrate to supply the N requirements may be desirable.
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Magnesium (Mg)
0.20-0.50%
Deficiency is due to low soil test Mg and/or low soil pH. Soil test and lime using dolomitic limestone. If soil test Mg level is low, apply 20-25 lbs. Mg/A. When K2O is to be applied also, the use of SUL-PO-MAG or K-MAG to meet the K and Mg requirements is suggested. Apple is not considered a Mg sensitive crop; therefore, the proper maintenance of soil pH using dolomitic limestone should be sufficient to meet the Mg needs.
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Manganese (Mn)
25-200 ppm
Deficiency is not a common problem while excessive Mn is frequently a problem. Low subsoil pH (or surface soil pH) results in the uptake of large quantities of Mn and produces a physiological disorder in apple called "measles."
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Iron (Fe)
50-400 ppm
Deficiency not a problem in Georgia. High Fe test results normally indicate soil or dust contamination. An accurate Fe determination can only be obtained with washed leaves (See section - Washing to Remove Contaminates).
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Boron (B)
25-60 ppm
Deficiency is a common problem with apple resulting in physiological disorder called "Internal Cork." Boron deficiencies can be corrected by applying foliar applications of B, using 0.2 to 0.4 lbs. of B/100 gallons (0.4 to 0.8 lbs./A) at both petal fall and first spray. CAUTION: Do not exceed the recommended rate as excessive B may cause injury or death to trees. If the B content is within the sufficiency range,apply a maintenance application of B using 0.2 to 0.4 lbs. of B/100 gallons (0.4 to 0.8 lbs. B/A) at petal-fall spray.
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Copper (Cu)
5-20 ppm
Deficiency is not likely to occur.
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Zinc (Zn)
20-50 ppm
Deficiency is not an uncommon problem resulting in small fruit size and lack of good fruit color. For corrective treatment, apply a foliar application of Zn in mid-October using 3 lbs. of zinc sulfate per acre in 100 or more gallons of water per acre.
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Aluminum (Al)
0-200 ppm
High Al levels are not likely to occur. When both high Fe and Al values are obtained, probably due to soil or dust contamination. See Fe discussion above.
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Molybdenum (Mo)
0.10-0.20 ppm (tentative)
Sufficiency range is not firmly established for apples. =====================================================
Plant Part and Time:
Mature leaves from mid-portion of current season's growth (lateral shoots, position 4, 5 and 6), taken during first two weeks after harvest.
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Nitrogen (N)
1.20-1.70%
Deficiency due to inadequate or ineffective N fertilization. Generally, application of 30 lbs. N/A in early spring and 30 lbs. N/A after harvest will maintain N within the sufficiency range. If N is less than 1.20% increase the post harvest application rate to 40-50 lbs. N/A. If N is greater than 1.70%, apply 20 lbs. N/A in early spring and a similar amount after harvest. N levels of approximately 2.00% can result in reduced yields.
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Phosphorus (P)
0.08-0.20%
Deficiency may be due to low soil P, inadequate P fertilization, or poor root development. If P is less than 0.08% and the soil test level is low and no root damage is evident, apply 25-50 lbs. P2O5/A in next year's fertilization program. If the higher rate is used, split the application, applying one half at post-harvest and one half in early spring. If leaf P is between 0.08 - 0.20% and the soil test P level is medium or higher application of P2O5 can be omitted the following year. If the soil test P level is low apply 25 lbs P2O5/A as a maintenance application.
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Potassium (K)
0.35-0.60%
Deficiency due to low soil K, inadequate K fertilization, and/or heavy crop load. If the leaf K level is less than 0.35%, apply 25-50 lbs. K2O/A in next year's fertilization program. If the higher rate is used, split the application, applying one half in early spring and the other half harvest. If the K level is between 0.35% and 0.60%, continue with present fertilization practices. If the K level is 0.6l% or higher, application of K2O can be omitted in next year's fertilization program.
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Calcium (Ca)
0.25-0.70%
Deficiency is rarely detected since the soil test Ca level must be extremely low for a deficiency to occur.
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Magnesium (Mg)
0.14-0.20%
Deficiencies may occur at very low soil test Mg levels. If leaf Mg is less than 0.14%, apply 15-25 lbs. Mg per acre as magnesium sulfate or other forms of soluble Mg.
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Sulfur (S)
0.11-0.25%
Sulfur levels are generally within the sufficiency range. If S is low, use sulfur containing materials such as ammonium sulfate, ordinary superphosphate, potassium-magnesium sulfate, or magnesium sulfate in the fertilization program.
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Manganese (Mn)
25-100 ppm
Low Mn levels are not likely to occur except on very sandy low organic matter soils. If leaf Mn levels are less than 25 ppm, low Mn can be corrected by soil application of 25 lbs. manganese sulfate/A.
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Iron (Fe)
25-70 ppm
Iron deficiency in blueberries is a common occurrence and is very difficult to correct in established bushes. Foliar applications may be partially effective if applied in early season. If the leaf level is less than 25 ppm, next spring apply a foliar application using a chelated iron source such as NaFeEDTA plus a surfactant. Apply at a rate of 1 to 2 quarts per acre in sufficient water to completely wet the foliage. Soil application of 10 lbs. of chelated iron per acre has also been partially effective in correcting iron deficiency symptoms.
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Boron (B)
12-35 ppm
Low levels may occur on very sandy and low organic matter (<1%)soils. If the B level is less than 12 ppm, soil apply 0.5 lbs. of actual B/A in next year's fertilization program.
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Copper (Cu)
2-10 ppm
Cu levels of 2 to 4 ppm are of common occurrence in blueberries. Effective corrective treatments have yet to be developed.
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Zinc (Zn)
10-25 ppm
Low zinc levels may occur on very sandy low organic matter soils. If the Zn level is less than 10 ppm soil, apply 10 to 15 lbs. zinc sulfate per acre in next year's fertilization program. =====================================================
Plant Part and Time:
Most recent mature leaves adjacent to fruit cluster taken in mid to late summer but before final swelling of fruit.
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Nitrogen (N)
1.65-2.15%
If the leaf N is between 1.65 and 2.15%, continue the present N fertilization program. Generally, 80-100 lbs. N/A (50-60 lbs. applied in the spring and 30 lbs. applied after fruit set) will maintain the leaf N within the desired range. If the leaf N is below 1.65%, apply 60 lbs. N/A after fruit set. If the leaf N is in excess of 2.15% reduce the normal application rate by one half.
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Phosphorus (P)
0.12-0.18%
Phosphorus levels are generally within the sufficiency range. If the P level is less than 0.12%, apply,100 lbs. P2O5/A in next year's fertilization program. If the P level is between 0.12 and 0.16%, apply 40-50 lbs. P2O5/A in next year's fertilization program. If the P level is 0.16% or higher, P2O5 can be omitted next year.
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Potassium (K)
0.80-1.20%
Leaf K levels below 0.80% generally indicate low soil K or a heavy fruit set. If the K level is below 0.80%, apply 100-125 lbs. K2O/A next year. If the K level is between 0.80 and 1.20%, apply 40-60 lbs. K2O/A next year. If the K level is greater than 1.20%, K2O may be omitted from next year's fertilization program.
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Calcium (Ca)
0.70-1.10%
Low Ca levels are usually corrected by application of limestone based on soil test recommendations. Maintaining the soil pH between 5.5 and 6.0 will generally supply sufficient Ca to keep the Ca level within the sufficiency range.
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Magnesium (Mg)
0.15-0.25%
If the Mg level is below 0.15% and the pH is below 5.5, apply dolomitic limestone based on soil test recommendations. If the soil pH is between 5.5-6.0, apply a soluble source of magnesium such as potassium-magnesium sulfate or magnesium sulfate (Epsom salt) at a rate to supply the equivalent of 25 lbs. Mg/A.
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Manganese (Mn)
60-150 ppm
Manganese is generally sufficient due to sprays with Mn based fungicides such as Maneb.
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Iron (Fe)
60-120 ppm
Iron levels are usually sufficient.
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Boron (B)
15-25 ppm
If the B level is less than 15 ppm, broadcast 1/2 lb. B/A (5 lbs. Borax or 2 1/2 lbs. Solubor/A) every two years. (Note: This can be mixed with water and sprayed on the soil surface). The boron requirement can also be met by spraying the foliage with Solubor at the rate of 1 lb. (0.2 lb. B/A) per acre just prior to bloom. Do not exceed the suggested rates.
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Copper (Cu)
5-10 ppm
Copper levels are usually sufficient.
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Zinc (Zn)
18-35 ppm
Zinc levels are usually sufficient. =====================================================
Plant Part and Time:
Mature leaves from mid portion or near base of current season's terminal growth taken in mid season.
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Nitrogen (N)
2.75-3.50%
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 lbs. N/A after harvest, but no later than September, and 40-60 lbs. N/A 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 lbs. N/A and the January or February application to 30-60 lbs. N/A. Apply and adjust the N application as described in the previous paragraph.
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Phosphorus (P)
0.12-0.50%
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 lbs. P2O5/A. 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.
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Potassium (K)
1.50-2.50%
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 lbs. K2O/A; if between 1.50-1.74% K, apply 50-70 lbs. K2O/A; if between 1.75-2.50%, apply 30-50 lbs. K2O/A. 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.
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Calcium (Ca)
1.25-2.50%
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.
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Magnesium (Mg)
0.25-0.50%
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 a Mg deficiency from occurring.
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Sulfur (S)
0.12-0.40%
Low sulfur levels have been detected in peaches growing on the sandy soils of Georgia. If sulfur is low, include a minimum of 10 lbs. of S/A in the fertilizer program until satisfactory S levels are detected in the tissue.
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Manganese (Mn)
20-150 ppm
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.
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Iron (Fe)
60-400 ppm
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.
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Boron (B)
20-45 ppm
Low boron levels are not frequently encountered. If boron is low, apply 1/2 lb. B/A in the fertilizer program or apply a foliar application using 0.2 lbs. B/A 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.
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Copper (Cu)
5-20 ppm
Deficiency not likely to occur. If low Cu levels are encountered, apply 3-4 lbs. Cu/A (12-16 lbs. of copper sulfate/A).
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Zinc (Zn)
15-50 ppm
Low Zn levels have become more prevalent in recent years. When low Zn levels are encountered, apply 9-11 lbs. of Zn/A (e.g. 25-30 lbs. zinc sulfate/A) in the fertilizer program. High Zn can be a sign of "peach decline" and the trees should be carefully examined for other symptoms.
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Aluminum (Al)
0-400 ppm
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). =====================================================
Plant Part and Time:
Healthy mid-terminal leaves on current season's growth taken in mid season.
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Nitrogen (N)
1.80-2.50%
Deficiency due to inadequate N fertilization and/or ineffective N fertilization. If the leaf N level is less than 1.80%, for next year's crop, apply 0.3 to 0.6 lbs. of N/tree. If this year's terminal growth was less than 8 inches on trees that set a good crop, use the higher N rate; if terminal growth was 8 inches or more, lower the N rate. Where vigor is low, nitrogen can also be supplied by spraying low biuret urea at 6 to 12 lbs./A after bloom but not in late cover sprays. If the N level is greater than 1.80%, for next year's crop, apply 0 to 0.6 lbs N/tree. If this year's terminal growth was less than 8 inches on trees that set a good crop, use the higher N rate; if terminal growth was 8 inches or more, lower the N rate accordingly. If terminal growth was more than 15 inches, do not apply any nitrogen.
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Phosphorus (P)
0.12-0.30%
Phosphorus deficiency is rare in pear trees under field conditions. Low phosphorus is generally due to very low soil test P levels and low soil pH. Phosphorus should be adequate if the soil test P level is maintained at medium or higher levels and the pH maintained between 6.0 and 6.5. If the leaf P level is low and the soil test P level is low or medium, apply 60 to 30 lbs. P2O5/A . If the soil test P level is high, do not apply any phosphorus fertilizer.
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Potassium (K)
1.00-2.00%
Low K levels are generally due to low soil test K. If the leaf level is low, and soil test K level is low or medium, apply 60 lbs. K2O/A. If the soil test K level is high, do not apply any potassium fertilizer.
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Calcium (Ca)
1.00-2.00%
Deficiency not likely to occur under normal orchard conditions. Less than sufficient level due to very low soil Ph and low soil test Ca level. Soil test and lime to adjust the soil pH to 6.0 to 6.5.
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Magnesium (Mg)
0.20-0.50%
Deficiency due to low soil test Mg and/or low soil pH. Soil test and lime using dolomitic limestone. If soil test Mg level is low, the use of SUL-PO-MAG or K-Mag to meet the K requirement is desirable. However, pear is not considered a Mg sensitive crop; therefore, proper maintenance of soil pH using dolomitic limestone should be sufficient to meet the Mg needs.
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Manganese (Mn)
20-200 ppm
Deficiency is not a common problem, but excessive Mn (<200 ppm) is sometimes encountered. Excessive Mn levels are generally observed in pears when grown on low pH soils (<5.5). Soil test and lime to pH 6.0 to 6.5.
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Iron (Fe)
30-150 ppm
Deficiency not a problem in Georgia. High Fe test results normally indicate soil or dust contamination.An accurate Fe determination can only be obtained when the leaves are properly washed (See section - Washing to Remove Contaminates).
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Boron (B)
20-60 ppm
Boron deficiency causes fruit pitting, blossom blast and spur die-back. Deficiencies of B can be corrected by soil application of 2 lbs. of actual B per acre once every 3 to 5 years, or annual foliar applications using 0.4 to 0.8 lbs. of actual B per acre in sufficient water to completely wet the foliage.
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Copper (Cu)
5-20 ppm
Deficiency not likely to occur. Copper deficiency results in die-back and a disease of pear known as exanthema. Deficiencies can be alleviated by soil applications of 1/2 to 2 lbs. of copper sulfate per tree.
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Zinc (Zn)
20-50 ppm
Little-leaf, rosette and leaf mottle are associated with low leaf Zn concentrations. For corrective treatment, apply a foliar application of Zn in mid-October using 1 lb. of actual Zn (3 lbs. of zinc sulfate per acre in 100 or more gallons of water per acre).
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Aluminum (Al)
0-200 ppm
High Al levels are not likely to occur. When both high Fe and Al values are obtained, they are probably due to soil or dust contamination. See Fe discussion above.
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Molybdenum (Mo)
0.5-1.50 ppm (Tentative)
Sufficiency range is not firmly established for pear trees. =====================================================
Plant Part and Time:
Middle pair of leaflets from the mid-portion of terminal growth taken 56 to 84 days after catkin fall. (In Georgia July 7 through August 7).
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Nitrogen (N)
2.50-3.30%
The N level for optimum production under non-irrigated conditions is in the range of 2.50-2.70%, under irrigated conditions the optimum range is 2.80-3.00%. If the N level is 2.30% or less, trees may be showing N deficiency symptoms. Low N is generally due to inadequate N fertilization and/or ineffective N application. If the N level is less than 2.50% apply 200 lbs. N/A; if between 2.50-2.70% apply 100-150 lbs N/A; if between 2.70-3.00% apply 100 lbs. N/A; if greater than 3.00% do not apply any nitrogen. In instances where variable rates are given the rate selected should be such that shoot growth on at least 50% of the trees is between 8-12 inches. For the Desirable variety, if the leaf content is greater than 2.30%, do not apply more than 100 lbs. N/A. If the N content is greater than 3.00% and early defoliation occurs, this may be a sign of excess N. In such instances check with pecan specialist before applying N fertilizer. (See potassium below.)
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Phosphorus (P)
0.12-0.30%
The P level for optimum production should be 0.14 to 0.30%. Less than sufficient due to low soil P level and inadequate fertilization. If the leaf content is less than 0.14%, apply 100 lbs. P2O5/A. If greater than 0.14%, do not apply P fertilizer. When the soil test P level is high or greater, do not apply P fertilizer.
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Potassium (K)
0.75-2.50%
Less than sufficient due to low soil K level and inadequate fertilization. Leaf K level for optimum production and tree vigor should be maintained between 1.25 to 2.50%. Although good yields may be produced when the K level is between 0.75 and 1.25%, maintaining the K level between 1.25 and 2.50% reduces winter injury damage and leaf scorch. If the level is less than 0.75%, soil apply 100 lbs. K2O/A. Also application of foliar sprays using 2 to 4 lbs. of potassium nitrate per 100 gallons of water with the second and third cover sprays may be beneficial in reducing K deficiency the first and second years after the deficiency is diagnosed. If the leaf K level is between 0.75 and 1.25% soil, apply 100 lbs. K2O/A . If the K content is between 1.25% and 2.50%, soil test and follow the soil test recommendation. Early defoliation can be a sign of K deficiency or an imbalance between N and K. If N is 3.00%, the K level should be greater than 1.25%.
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Calcium (Ca)
0.70-1.75%
The level of Ca for optimum production should be maintained between 1.00 to 1.75%. Low Ca levels are due to low soil pH. Soil test and lime according to soil test recommendations.
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Magnesium (Mg)
0.30-0.60%
Less than sufficient due to low soil pH (See Mn below), low soil Mg, and/or excessive K applications. If the Mg level is less than 0.30% and the soil pH is low, apply dolomitic limestone according to soil test recommendations. If no lime is needed apply 20 lbs. Mg/A, using a soluble Mg source. Also, apply a foliar application of Mg, using 3 to 5 lbs. of magnesium sulfate/100 gallons/A in the first three leaf sprays.
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Sulfur (S)
0.20-0.50%
Less than sufficient due to low soil S level. If the S level is less than 0.20%, S should be included in the fertilizer to supply a minimum of 20 lbs. S/A.
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Manganese (Mn)
100-800 ppm
Mn may not be toxic or reach toxicity levels but high Mn is an indicator of low soil pH. If greater than 800 ppm, soil pH may be 5.4 or less. If Mg is less than 0.30% and Mn greater than 500 ppm, liming with dolomitic limestone is essential. Soil test and lime according to the recommendation given. Mn deficiencies have not been observed in Georgia. Symptoms similar to "Mouse ear," a common problem in Florida due to Mn deficiency, has not been observed in Georgia. Mouse ear symptoms being seen with increasing frequency in Georgia are not Mn deficiencies.
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Iron (Fe)
50-300 ppm
Fe deficiency seems to be on the increase. It is associated with older trees and occurs only in certain trees. Fe deficiency may be genetically controlled and can be induced by excessive zinc application. It is difficult to correct. Foliar applications of Fe may or may not be effective. If Fe deficiency is suspected, leaves should be washed in a mild detergent solution before drying and sending to the laboratory for analysis. (See section on washing samples to remove contaminates). There are a number of foliar Fe spray materials available. Follow the label instructions.
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Boron (B)
15-50 ppm
Low B can occur on sandy soils that have been limed to pH 6.5 or higher. If leaf B is low, include 1 lb. B/A in next year's fertilization program. Boron concentrations of approximately 400 ppm have been associated with toxicity.
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Copper (Cu)
6-30 ppm
Cu deficiencies or toxicities have not been observed in Georgia.
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Zinc (Zn)
50-100 ppm
Visual Zn deficiency symptom may occur when the leaf content is less than 30 ppm. Apply 100 to 150 lbs. zinc sulfate/A if the Zn content is less than 30 ppm. In addition, apply 2 lbs. zinc sulfate/100 gallons of water with the first three leaf sprays. If the Zn content is less than 50 ppm, but greater than 30 ppm, apply 30 to 50 lbs. zinc sulfate/A. If the Zn level is greater than 50 ppm, discontinue Zn treatment. Zn levels in excess of 250 ppm may induce an Fe deficiency. (See Fe above.) The Zn soil test is not as effective in determining Zn needs as a plant analysis. If Zn was foliar applied, the Zn analyses are invalid since some of the applied Zn may be on the surface of the leaves rather than in the leaves. Therefore, an evaluation of the Zn status of trees where foliar Zn applications have been made is difficult even if leaves are washed.
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Aluminum (Al)
0-2000 ppm
It is uncertain whether Al concentrations in excess of 2000 ppm are detrimental. High Al suggests low soil pH or poor aeration. If both Fe and Al are high, it is probably due to soil or dust contamination. See Fe discussion above. =====================================================
Plant Part and Time:
Young plants - Leaves adjacent to 2nd and 3rd clusters.
Older plants - Leaves from 4th to 6th clusters prior to or during fruit set.
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Nitrogen (N)
Young plants: 4.00-5.00%
Older plants: 3.50-4.00%
Deficiency is an uncommon problem in greenhouse tomatoes. Usually excesses occur which result in poor fruit set and increased susceptibility to disease and insect attack. Maintaining the nitrogen level at the lower end of the sufficiency scale is desirable. When N is high, no more N fertilizer should be applied and growth media should be leached to remove excess N if possible. For hydroponic solutions, reduce the N concentration in the nutrient solution.
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Phosphorus (P)
0.50-1.00%
Deficiency not likely to occur. Normally with a good fertility program, adequate P is supplied.
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Potassium (K)
3.50-5.00%
Deficiency is not likely to occur with a good fertility program. Frequently K levels may be too high for best cation balance with Ca and Mg. In such cases, no more K fertilizer should be applied and the soil media leached to remove excess K. For hydroponic solution, reduce the K concentration in the nutrient solution.
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Calcium (Ca)
0.90-1.80%
Deficiency is a common problem in greenhouse tomatoes. When the growth media is soil, it should be well limed. For artificial mixes, applications of calcium sulfate (gypsum) may be needed to provide the Ca essential to prevent the physiological disease known as blossom-end rot. The use of Ca (NO3)2 as a source of N is recommended. Foliar applications of Ca(NO3)2 or CaC12 (1.0 lb. in 100 gal. water) can provide some of the Ca needs when plants are deficient in Ca. For hydroponic solutions, special additions need to be made to insure an adequate Ca supply.
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Magnesium (Mg)
0.50-1.00%
Deficiency is a common problem usually due to inadequate Mg in the growth media. When deficient, Mg may be soil applied at the rate of 5 lbs. magnesium sulfate or equivalent per 1000 sq. ft. or foliar applied by dissolving 10 lbs. magnesium sulfate in 100 gals of water. Foliar applications are only temporary treatments and soil additions of Mg are recommended to control the deficiency for the length of growing period. For hydroponic solutions, special additions need to be made to insure an adequate Mg supply.
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Manganese (Mn)
50-500 ppm
Deficiency is not likely to occur. Manganese may be high, particularly on soils which have been steam sterilized.
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Iron (Fe)
50-300 ppm
Deficiency is not likely to occur. High Fe test results normally indicate soil or dust contamination. An accurate Fe determination can only be made with washed leaves.
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Boron (B)
35-60 ppm
Tomato has a high B requirement. Boron additions may be required to maintain the plant B level within the sufficiency range. Apply 0.5 lb. borax per 1000 sq. ft. for soil and artificial mixes if B has not already been applied. Care must be taken to insure that excessive B is not applied.
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Copper (Cu)
8-20 ppm
Deficiency is not likely to occur.
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Zinc (Zn)
20-100 ppm
Deficiency is not likely to occur.
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Aluminum (Al)
0-200 ppm
High Al levels are not likely to occur unless associated with soil or dust contamination (Fe will also be high).