The most crucial period in the life of a coffee orchard is the first five years. During this period the trees must be fertilized, protected from weeds and pests, and pruned for efficient growth and future production.
Fertilizer
Coffee requires nutrients to grow and produce a crop. The crop growth stage determines the types and amounts of fertilizers necessary, and they must be applied at correctly spaced intervals in order to produce optimal growth.
The main purpose of applying fertilizer to young trees is to supply the nutrients necessary to support vigorous and continuous growth of roots and leaves. Young trees in particular need a fertilizer with a high phosphorus (P) content to promote root production.
Bearing coffee trees have different nutrient requirements, as described below. A harvested crop of 10,000 pounds of cherry contains about 63 pounds of nitrogen (N), 13 pounds of phosphorus (P, but calculated as P2O5), and 68 pounds of potassium (K, but calculated as K2O). The trees producing that much cherry contain 250 pounds of N, 60 pounds of P, and 200 pounds of K in their leaves, stems, and roots. Additional quantities of nutrients are utilized in the orchard system, including nutrients in coffee leaf litter, wood that is pruned, windbreak trees, and weeds. In addition, nutrients are lost by leaching, erosion, and volatilization.
The suggested fertilizer schedule given at right was developed for farmers who broadcast fertilizer by hand, but the 
amounts can be adjusted for banded applications or “fertigation” (injection through an irrigation system). An example for fertigation is also given at right, below.
Year 1
As described in the section on planting, a liberal amount of fertilizer high in P is placed in the bottom of the planting hole before transplanting. The next fertilizer application is made approximately two months after transplanting. Traditionally, a 10-30-10 (percent N:P:K) formulation is used, but this should be modified according to recommendations based on soil analysis. A handful (2 oz, 1/4 cup) per tree of this fertilizer should be evenly spread over a zone beginning a few inches from the trunk and extending to the tip of the lateral branches (leaf drip line). This application is repeated at intervals of about three months during the first year.
Year 2
During the second year the vertical branches will grow taller and the roots and side branches will extend laterally. The quantity of fertilizer should be increased to approximately two handfuls (4 oz, 1/2 cup) per tree at three-month intervals.
Leaf sampling for tissue analysis
The second year the trees have been in the ground is the time to begin sampling leaves for tissue analysis to correct any nutrient imbalances. Pick the most recently fully matured pair of leaves (usually the 3rd or 4th pair from the terminal) from lateral branches at mid-height of the tree. Sample leaves after flowering but before the cherries are full size. Take one or two pairs of leaves from 20 “average” trees per acre. If the farm is large and uniform, 20 pairs of leaves from 5 acres is sufficient. If parts of the orchard are managed differently, sample them separately. If in parts of the orchard trees are doing poorly, collect samples from both normal and poorly growing trees.
Soil and plant tissue analyses can be done by commercial laboratories or by the CTAHR Agricultural Diagnostic Service Center (ADSC). ADSC also analyzes insect and plant disease problems. Contact the nearest CTAHR Cooperative Extension Service office for information on analysis fees and the best time to bring in samples for shipment to ADSC at UH-Manoa.
The tissue analysis report will indicate the concentration of nutrients (elements) in the leaves. The table above is a guide, indicating the desired levels of nutrients in recently matured leaves of coffee plants.
A regular program of plant tissue analysis is a recommended part of an efficient coffee farm’s operation. Tissue analyses can often pinpoint “hidden” deficiencies before they cause observable symptoms in the field. By the time visual symptoms become apparent, plant growth usually has been seriously affected. Signs of nutrient deficiencies in coffee are described in the key at right. The most frequently seen deficiency symptom in coffee is nitrogen deficiency, followed by, occasionally, zinc.
Year 3
The trees will be 4-6 ft tall in the third year. At this stage, the coffee plant needs less phosphorus and more potassium, which is needed for flowering and seed formation. Various fertilizer formulations have been tailored to the needs of the coffee industry. Coffee CherryR (10-5-20) has been the traditional mix for many years.
Key to identifying nutrient deficiency symptoms
I. Problem seen on older leaves or generally on the entire plant. If not, go to II.
A. Uniform leaf chlorosis (yellowing) or light interveinal chlorosis (yellowing between green veins). If not, go to B.
Lower leaves exhibit slight chlorosis, young leaves remain darker green; faint interveinal chlorosis of older leaves at advanced stages; small necrotic (dead) spots (usually brown) may be present. Phosphorus
Phosphorus Deficiency
Figure 19. Leaf showing P deficiency, faint interveinal yellowing of older leaves, necrotic (dead) spots may develop on the edge and within the leaf.
B. Localized necrosis or interveinal chlorosis evident on older leaves.
1. Marginal chlorosis followed by development of dark brown necrotic spots on the leaf margins; necrotic areas coalesce until entire margins are dark brown, while the areas along the midrib remain green. Potassium
Potassium Deficiency
Figure 20. Older leaf showing K deficiency, initial symptoms are chlorosis on margins which can become necrotic areas. Leaf color is darker that P deficiency. Young leaves are not affected.
Phosphorus and Potassium Deficiencies
Figure 21. Both P and K are deficient on this lateral which has a heavy crop, laterals without crop on the same tree appeared normal.
2. Faint marginal chlorosis with sunken, yellow-brown to light brown necrotic spots developing in a wide band along leaf margins; interveinal chlorosis evident in affected leaves, particularly along the midrib. Magnesium
Magnesium Deficiency
Figure 22. Spots along the margins of older leaves are signs of magnesium deficiency.
II. Problem seen on younger leaves near shoot tips.
A. Uniform chlorosis to faint interveinal chlorosis; plants have sparse vegetative growth.
1. Leaves rapidly becoming pale green; emerging leaves uniformly pale green with a dull green sheen. Entire plant becoming pale green, with sparse vegetative growth; leaves becoming yellow-green at advanced stages; whitish veins may be present in lower leaves. Nitrogen
Nitrogen Deficiency
Figure. 23. In nursery, the plant on left had adequate fertilizer, on right had insufficient N.
Nitrogen Deficient Branch
Figure 24. Branch below is deficient for N, note yellow, without N fertilizer it will dieback.
2. Leaves light green to yellow-green, with faint interveinal chlorosis; deficient leaves retain shiny luster. Sulfur
B. Sharp interveinal chlorosis of youngest leaves; older leaves unaffected.
1. Leaves expanding normally, with vein network remaining green and clearly visible against the light green to yellow-green background; background becoming nearly creamy white at acute stages. Iron
Iron Deficiency
Figure 25. Iron deficiency is seen on new leaves, as a interveinal chlorosis which can in severe cases become almost white.
2. Leaves not expanding normally; narrow, often strap-shaped; veins visible against a yellow-green background; failure of internodes to elongate properly, giving plants a rosetted appearance. Zinc
Zinc Deficiency
Figure 26. Zinc deficiency is seen on the younger leaves, which show a fine interveinal chlorosis. Note the new leaves are more narrow than normal. Commonly seen on new growth from trees recently regrowing from stump pruning, frequently later growth will become normal.
C. Bronzing, mottling, or necrosis of youngest leaves; dieback of terminal buds.
1. Leaves bronzed along margins, cupped downward; emerging leaves necrotic; eventual dieback of terminal buds. Calcium
2. Youngest leaves light green, mottled, with uneven margins and asymmetric shape; emerging leaves with necrotic spots or tips. Boron
Boron Deficiency
Figure 27. Boron deficiency is seen on younger leaves. Leaves have a mottled green and yellow not an even green or interveinal chlorosis. Necrotic spots may develop in severe cases, lea_ margins become irregular as does the growing point.
Other fertilizers sold for coffee in Kona are Coffee SuperR (14-7-28) and “plus” formulations containing N-P-K with zinc (Zn), magnesium (Mg), and iron (Fe). If a 10-5-20 formulation is used, a total application of 1000 pounds per acre per year is considered enough in year 3.
The fertilizer is applied by broadcasting by hand four times a year. The first application is made at the beginning of the growing season following the semidormant period. The second application is given immediately after the flowering period, and the third is given when the crop is making its most rapid development and vegetative growth is at its maximum. The fourth application is made just before harvest.
Year 4
As the trees grow larger, the amount of fertilizer applied per year is increased to approximately 1500 pounds per acre (based on 10-5-20), split into four or more applications. As the amount of fertilizer increases, care should be exercised to broadcast it evenly over the entire area under the branches and no closer to the trunk than 6 inches away.
If the orchard is located in a sunny, relatively unclouded area, as are coffee orchards in Kona below the Belt Road, additional N fertilizer is recommended, split into two applications. Up to 500 pounds per year of ammonium sulfate should be applied (or 230 pounds of urea, which would provide the same amount of N). These two applications are given between the first and second, and the third and forth applications of 10-5-20.
Where there is excessive rainfall and cloudiness, supplementary nitrogen fertilization is not necessary. The usual practice among experienced coffee growers whose orchards in Kona are located in areas that fall between the excessively cloudy section and the sunny section is to apply an additional 200-300 pounds of ammonium sulfate.
Year 5
Fertilizer is increased to 2000 pounds per acre per year as production increases in the fifth year. However, if the orchard is established on exceptionally rich soil, 1500 pounds or even less will probably be sufficient. By this time, the trees should be bearing a commercial yield, and a target of 10,000 pounds of cherry per acre is feasible.
Fertilizer application calendar
The fertilization calendar on p. 15 for bearing coffee grown in Kona is revised from an earlier CTAHR recommendation (Anon. 1961) and is meant to be used as a starting point and modified by the grower based on crop performance and tissue analysis. A target yield of 10,000 pounds of cherry per acre is assumed.
Farmers who are “fertigating” must use soluble formulations. Urea and potassium nitrate (KNO3) are frequently used. Farmers who are fertilizing organically should start with overall nutrient targets similar to those suggested here and then adjust applications based on the products available and the condition of the crop.