Crop Guide: Citrus Tree Fertilizer Recommendations

Index:

1. Many benefits with Haifa quality fertilizers
2. Summary of recommended applications with Haifa fertilizers
3. Plant nutrients requirements
4. Soil analysis
5. Plant analysis data
6. Nitrogen
7. Phosphorus
8. Potassium
9. Nutrigation™ (fertigation)
10. Nutrigation™ Recommendations for Young trees
11. Nutrigation™ recommendation of bearing trees
12. Nutrigation^™Schedule
13. Proportional Nutrigation™
14. Nutrigation™ practice in Israel
15. Multicote™ Agri Controlled Release Fertilizers
16. Foliar nutrition

 

3.1 Many benefits with Haifa quality fertilizers

Either soil application, fertigation or foliar treatments, Haifa provides quality products to benefit of any citrus grower.

 

Soil application:

Multi-K™ in prilled form, can be applied manually or by fertilizer spreader, a source of nitrogen in nitrate (NO3-) form and chlorine free potassium. Prevents salinity injuries and is quickly up-taken by tree roots.

Multicote™ Agri most suitable when labor is not available or affordable, or where leaching of plant nutrients may occur, this control release fertilizer (CRF) is an ideal solution.

Nutrigation™ (fertigation) Multi-K™, Poly-Feed™, Haifa MAP™ and Haifa MKP™ are water soluble fertilizers, containing major macro and minor plant nutrients. Due to the compatibility and the solubility of these fertilizers, can be fertigated in the most effective way and with most beneficial results.

 

Foliar applications: 

Haifa Bonus™ affects the external and internal fruit quality: increases size and weight, prevents creasing and splitting, improves soluble solids and vitamin C content. In addition, correct quickly and effectively plant nutrient deficiencies.

Tank mix of Haifa Bonus™ with plant growth regulators, improves their functions.

In addition to nutritional functions, Haifa Bonus™ suppresses scale population, like Floridian Wax Scale, an environmental friendly and economical treatment.

Poly-Feed™ available in many N-P-K ratios to deal with an effective way to prevent and to cure plant nutrient deficiencies.

Magnisal™ will cure in a very quick and effective way magnesium (Mg) deficiencies.

 

The recommendations appearing in this document should be regarded as a general guide only. The exact fertilization program should be determined according to the specific crop needs, soil and water conditions, cultivar, and the grower’s experience. For detailed recommendations, consult a local Haifa representative.

 

Disclaimer: Any use of the information given here is made at the reader’s sole risk. Haifa Chemicals Ltd. provides no warranty whatsoever for "Error Free" data, nor does it warrants the results that may be obtained from use of the provided data, or as to the accuracy, reliability or content of any information provided here.

In no event will Haifa Chemicals Ltd. or its employees be liable for any damage or punitive damages arising out of the use of or inability to use the data included.

 

3.2 Summary of recommended applications with Haifa fertilizers*

Table 10: Summary of recommended applications with Haifa fertilizers*

A - Leaf analysis determining fertilization requirements
Leaf analysis	N (%)	P (%)	K (%)
Deficient	2.2	0.09	0.7
Low	2.2-2.4	0.09-0.11	0.7-1.1
Optimum	2.5-2.7	0.12-0.16	1.2-1.7
High	2.8-3.0	0.17-0.30	1.8-2.4
Excess	>3.0	>.30	>2.4

* For detailed recommendations, refer to the relevant paragraph in the following chapters.

 

B - Plant nutrients requirement
Growing stage	First yield	Production 70%	Full production
Expected Yield (T/ha)	8 - 21	18 - 49	25 - 70
N	47 - 97	79 -1 92	95 - 247
P2O5	63 - 75	74 - 100	77 - 116
K2O	45 - 105	83 - 221	102 - 293
CaO	20 - 39	33 - 74	38 - 92
MgO	6 - 12	12 - 25	13 - 31

* For detailed recommendations, refer to the relevant paragraph in the following chapters.

 

 

C - Soil application	Young trees (g/tree/year)
	Age of tree	N rate	Rate of Multi-K™
N	Year 1	70 - 140	500 - 1000
	Year 2	140 - 280	1000 - 2000
	Year 3	280 -  420	2000 - 3200
K	Year 1	70 - 140	150 - 300
	Year 2	140 - 280	300 - 600
	Year 3	280 - 420	600 - 900
	4-7 years (kg/ha/year)
		N rate	Rate of Multi-K™
N	Grapefruit	120 -160	900 -1200
	Orange, Tangelo or Tangerine	120 - 200	900 - 1500
K	Grapefruit	120 -160	260 - 350
	Orange, Tangelo or Tangerine	120 - 200	260 - 430
	Eight years and older (kg/ha/year)
		N rate	Rate of Multi-K™
N	Oranges	140 - 250	1000 - 1900 kg
	Grapefruit	120 - 160	900 -1200 Kg
	Tangerine/Tangelo	120 - 300	900 - 2300 Kg
K	Oranges:	140 - 250	300 - 540
	Grapefruit	120 - 160	260 - 350
	Tangerine/Tangelo	120 - 300	260 - 650
CRF	Multicote™ Agri 16-5-12	In planting hole	300 - 500 g/tree
		Non-bearing trees	250 - 600 g/tree
		Bearing trees	1 - 1.5 kg/tree

* For detailed recommendations, refer to the relevant paragraph in the following chapters.

 

 

D - Nutrigation™
	Young trees
Age (yr)	N	Urea	Multi-K®	Annual Multi-K®
	Daily supply (g/tree)				Kg/tree
1	1.5 - 2.5	2.3 - 4.0	3.2  -  5.4		0.768  -  1.296
2	2.5 - 3.5	4.0 - 5.4	5.4 - 7.6		1.296  -   1.824
3	4.0 - 4.5	6.2  - 7.0	8.7 - 9.8		2.088  -  2.352
4	4.5 - 5.0	7.0 - 10.5	9.8 - 10.8		2.352  -  2.592
	Bearing trees (Kg/ha)
		N	P2O5		K2O
		200 - 300	60		180-300
Fertilizer	Urea	400 - 600
	Multi-MAP		100
	Multi-K®				400-650
	Bearing Trees - higher yield (Kg/ha)
		N	P2O5		K2O
		650 - 950	250		650  - 1000
Fertilizer	Urea	950 - 1250
	Multi-MAP		400
	Multi-K®				1400  -  2000

* For detailed recommendations, refer to the relevant paragraph in the following chapters.

 

 

E - Proportional Nutrigation™ (ppm)
N (20-30% as NH4+)	35
P (as orthophosphate*)	10
P2O5	22.7
K	25
K2O	30.1

* For detailed recommendations, refer to the relevant paragraph in the following chapters.

 

 

F - Foliar feeding - young trees
Poly-Feed™	2%

* For detailed recommendations, refer to the relevant paragraph in the following chapters.

 

 

G - Foliar feeding
		Product	Concentration
Correct deficiency	K	Haifa-Bonus-npK™	4%
	Mg	Magnisal™	1.4%

* For detailed recommendations, refer to the relevant paragraph in the following chapters.

 

 

H - Foliar treatments with  Haifa Bonus-npK™
Yield & Quality	Parameter	Concentration	No. of Applications
External fruit quality	Increases size	2 - 6 %	2 - 4
	Increases fruit weight	2 - 6 %	2 - 4
	Improves rind color	2 - 6 %	2 - 4
Rind Disorders	Reduces creasing	2 - 6 %	2 - 4
	Reduces splitting	2 - 6 %	2 - 4
Internal juice quality	Increases juice content	2 - 6 %	2 - 4
	Increases of soluble solids	2 - 6 %	2 - 4
	Increases of acid	2 - 6 %	2 - 4
	Increases vitamin C	2 - 6 %	2 - 4
Floridian Wax Scale	Suppression	4%	1 - 2
Growth regulator	Fruit size & productivity	4%	Growth regulators
			2,4-D + 2,4-DP
			NAA
			TPA

* For detailed recommendations, refer to the relevant paragraph in the following chapters.

 

 

3.3 Plant nutrients requirements

The tree age and the expected yield are two important parameters in determining the required plant nutrients (Table 11).

 

 

Table 11: Required rates of macro and secondary plant nutrients according to growing stages and expected yield

Growing stage	First yield	Full production	Production 70%
Expected Yield (T/ha)	8 - 21	25 - 70	18 - 49
N	47 - 97	95 - 247	79 -1 92
P2O5	63 - 75	77 - 116	74 - 100
K2O	45 - 105	102 - 293	83 - 221
CaO	20 - 39	38 - 92	33 - 74
MgO	6 - 12	13 - 31	12 - 25

 

3.4 Soil analysis

This is useful for measuring pH, available P and certain exchangeable cations, notably Ca and Mg.

 

 

Table 12: A standard soil test, using Mehlich-1 extractant, interpretation and phosphorus recommendations for commercial citrus orchards, 1-3 years of age

Soil test Phosphorus, ppm	0 - 10	10 - 15	16 - 30	31 - 60
Interpretive Classes	Very Low	Low	Medium	High
Recommendation for P2O5  application (g/tree)	Apply at 100% of the N  rate	Apply at 75% of the N rate	Apply at 50% of the N rate	0

Application of high rate of magnesium (Mg) fertilizers, may suppress the uptake of potassium (K) due to their cationic competition.

 

 

Table 13: The standard Mehlich-1 soil test interpretations and magnesium recommendations for commercial citrus orchards.

Soil Test Magnesium, (ppm)	15	15 - 30	> 30
Interpretive Classes	Very low - Low	Medium	High - Very High
Recommendation	Apply Mg fertilizer with MgO at 20% of the N rate	Apply Mg fertilizer with MgO at 20% of the N rate	No Mg recommended

However, because citrus trees are grown on a wide range of soil types, it would be difficult to establish standards for all soils. They are therefore usually developed for certain soil types in a given region.

It is usually more difficult to assess the N and K status in the soil because both these elements are subject to leaching, especially in humid regions.

 

3.5 Plant analysis data

Leaf analysis is an essential tool to determine the required plant nutrients (Table 14). According to leaf analysis results, the fertilization rates and the correct ratio of plant nutrients can help to schedule the fertilization program.

 

 

Table 14: Leaf analysis standards for mature, bearing citrus trees based on 4 to 6-month-old, spring-cycle leaves from non-fruiting terminals

Element	Deficient	Low	Optimum	High	Excess
N (%)	2.2	2.2-2.4	2.5-2.7	2.8-3.0	>3.0
P (%)	0.09	0.09-0.11	0.12-0.16	0.17-0.30	>.30
K (%)	0.7	0.7-1.1	1.2-1.7	1.8-2.4	>2.4
Ca (%)	1.5	1.5-2.9	3.0-4.9	5.0-7.0	>7.0
Mg (%)	0.20	0.20-0.29	0.30-0.49	0.50-0.70	>0.70
Cl (%)	?	?	0.05-0.10	0.11-0.25	>.25
Na (%)	-	-	-	0.15-0.25	>.25
Mn (ppm)	17	18-24	25-100	101-300	>300
Zn (ppm)	17	18-24	25-100	101-300	>300
Cu (ppm)	3	03-אפר	מאי-16	17-20	>20
Fe (ppm)	35	35-59	60-120	121-200	>200
B (ppm)	20	20-35	36-100	101--200	>200
Mo (ppm)	0.05	0.06-0.09	0.10-1.0	2.0-5.0	>5.0

 

3.6 Nitrogen

The form of a nitrogen, either ammonium (NH₄⁺), nitrate (NO₃^-) or amide (NH₂), plays an important role when choosing the right fertilizer for Nutrigation of citrus trees.Nitrate-nitrogen is a preferable source of nitrogen as it suppresses the uptake of chloride (Cl^-) and at the same time promotes the uptake of cations, such as potassium (K⁺), magnesium (Mg²⁺) and Calcium (Ca²⁺). In addition, the nitrate form of nitrogen increases the pH of soil solution near the root system, especially important in acidic soils.

 

The nitrogen in Multi-K^™ (potassium nitrate, KNO₃) is entirely in nitrate form, which makes it a suitable fertilizer for Nutrtigation™.

 

 

Table 15: Nitrogen requirements and recommendations for the first three years after planting

Age of tree	N rate (g/tree/year)	Rate of Multi-K™  (g/tree/year) as a single N source*
Year 1	70 - 140	500 - 1000
Year 2	140 - 280	1000 - 2000
Year 3	280 - 420	2000 - 3200

* Other water-soluble N fertilizer may be added and Multi-K^™ rate should be reduced accordingly.

 

 

Table 16: Nitrogen requirements and recommendations for trees aged 4-7 years, by variety

Variety	N rate (kg/ha/year)	Rate of Multi-K™/ (kg/ha/year) as a single N source*
Grapefruit	120 -160	900 –1200 kg Multi-K™ / Ha
Orange, Tangelo or Tangerine	120 – 200	900–1500 kg Multi-K™ / Ha

* Other water-soluble N fertilizer may be added and Multi-K^™ rate should be reduced accordingly.

 

 

Table 17: Nitrogen requirements and recommendations for trees eight years and older

Variety	N rate (kg/ha/year)	Rate of Multi-K™/ (kg/ha/year) as a single N source*
Oranges	140-250	1000 – 1900 kg
Grapefruit	120-160	900 -1200 Kg
Tangerine/Tangelo	120-300	900 – 2300 Kg

* Other water-soluble N fertilizer may be added and Multi-K^™ rate should be reduced accordingly.

 

3.7 Phosphorus

 

 

 

Table 18: Test interpretations and phosphorus recommendations for commercial citrus orchards, ages 4 and above

 

P level in leaf tissue	Soil test P level	P recommendation
High or Very High	Soil test P not applicable	0 Kg of P2O5 for 12 months until re-evaluation
Optimum	Sufficient	0 Kg of P2O5 for 12 months until re-evaluation
Optimum	Less than sufficient	8 Kg P2O5/ha for every 9,500 kg of fruit produced per ha during one year
Low	Less than sufficient	12 Kg P2O5/ha for every 9,500 kg of fruit produced per ha during one year
Deficient	Less than sufficient	16 Kg P2O5/ha for every 9,500 kg of fruit produced per ha during one year

 

3.8 Potassium

Potassium recommendations also depend on the age of citrus trees. During the first 3 years after planting, K₂O should be applied at the same rate as N (g K₂O/tree). For orchard ages of 4 years and above, K₂O should be applied at the same rate as N (in Kg K₂O/ha). 

 

 

Table 19: K recommendations for the first three years of orchard-age

Age of tree	Rate of K2O (g/tree)	Rate of Multi-K™ (g/tree)
Year 1	70 - 140	150 - 300
Year 2	140 - 280	300 - 600
Year 3	280 - 420	600 - 900

 

 

Table 20: K requirements and recommendations for trees aged 4-7 years

Variety	Rate of K2O (kg/ha/year)	Rate of Multi-K™  (kg/ha/year)
Grapefruit	120 -160	260 - 350
Orange, Tangelo or Tangerine	120 - 200	260 - 430

 

 

Variety	Rate of K2O (kg/ha/year)	Rate of Multi-K™ (kg/ha/year)
Oranges	140 - 250	300 - 540
Grapefruit	120 - 160	260 - 350
Tangerine/Tangelo	120 - 300	260 - 650

 

3.9 Nutrigation™ (fertigation)

Application of water soluble fertilizers through the irrigation system is the optimal method for providing balanced plant nutrition throughout the growth season.  A balanced Nutrigation™ regime ensures that essential nutrients are placed precisely at the site of intensive root activity and are available in exactly the right quantity - when plants need them.

 

 

3.9.1 Nutrigation™ Recommendations for Young trees

• Soil type: Light to medium
• 240 irrigation (application) days per year. If more application days, calculated daily rates should be reduced, accordingly 
• Rates are based on N: K₂O ratio 1: 1

 

Table 22: Nutrigation™ recommendations for young trees

Year	N	Urea	Multi-K™	Annual Multi-K™
	Daily supply (g/tree)*			Kg/tree
1	1.5 - 2.5	2.3 - 4.0	3.2  -  5.4	0.768  -  1.296
2	2.5 - 3.5	4.0 - 5.4	5.4 - 7.6	1.296  -   1.824
3	4.0 - 4.5	6.2  - 7.0	8.7 - 9.8	2.088  -  2.352
4	4.5 - 5.0	7.0 - 10.5	9.8 - 10.8	2.352  -  2.592

^* In fertile soils and irrigated water with high content of plant nutrients, rates of fertilizers should be reduced, accordingly.

 

 

Table 23: Recommended applications of Haifa MAP™ (12-61-0) when soil test is not available

 

Year	P2O5	Haifa MAP	Haifa MAP
	(g/tree/day)	(g/tree/day)	(g/tree/year)*
1	0.5	0.8	192
2	1.0	1.6	384
3	1.5	2.4	576
4	2.0	3.2	768

^* Estimated 240 irrigated days.

 

3.9.2 Nutrigation™ recommendation of bearing trees

• Soil type: light to medium 
• Tree population:  400-600 trees/ha
• Expected yield: 40 t/ha

 

The recommended average rates of nutrients (Kg/ha):

N	P2O5	K2O
200-300	60	180-300

Nitrogen:The recommended amount is based on the nitrogen consumption of 4-6 Kg N/ ton of fresh fruit. 75% of the entire amount of nitrogen should be applied from early spring to the mid-summer. It is recommended to split this amount of nitrogen and to apply it proportionally in each one of the irrigation cycles.

The rest 25% can be applied in autumn, after color breaking, or as post-harvest fertilization.

Phosphorus:One or two applications at the beginning of spring.

Potassium: It is recommended to divide the entire amount of potassium and to apply it proportionally in each one of the irrigation cycles from early spring to early summer irrigations.

 

 

Nutrigation^™Schedule:

Table 24: Nutrigation schedule on bearing trees

Fertilizer	Application time	No. of applications	Total amount
Multi-K™	Spring to early summer	Weekly	400-650 Kg/ha
Urea	During the season	Weekly	400-600 Kg/ha
Haifa MAP™	Spring	1-2	100 Kg/ha

 

 

Recommendations for Bearing Trees (higher yield)

• Soil type: light to medium
• Plant population: 440 trees / ha
• Expected yield: 60 ton / ha

 

 

The recommended average rates of nutrients (Kg/ha):

N	P2O5	K2O
650 - 950	250	650  - 1000

 

 

	Kg. / ha	N	P2O5	K2O
Urea	950 - 1250	430 - 570	0	0
Haifa MAP™	400	50	240	0
Multi-K™	1400  -  2000	175 - 280	0	650 - 1000

 

 

Table 25: Nutrigation™ schedule of total plant nutrients per seasonal application

Fertilizer	kg / ha	kg/ha
		N	P2O5	K2O
First irrigation  (spring)
Multi-K™*	400 - 700	52 - 91		184 - 322
Urea*	300 - 500	138 - 230
Haifa MAP™**	150	18	92
Spring - Summer
Multi-K™*	650 - 900	85 - 117		299 - 414
Urea*	600 - 950	276 - 437
Haifa MAP™**	100	12	61
Late Summer - Fall* (Last irrigation)
Multi-K™*	350 - 500	45.5 - 65		161 - 230
Haifa MAP™**	150	18	92
Total		644 - 988	244	644 - 966

^* Split into low rates and applied weekly ; ^** Split into 1-2 applications

 

In case of magnesium deficiency, it is recommended to spray with 2% Magnisal^™ (Haifa's magnesium nitrate product) when the leaves of the early spring flush have reached 2/3 of their final size. This Nutrigation™ programshould be adjusted according to leaf analysis data.

 

3.9.3 Proportional Nutrigation™

Proportional Nutrigation™, (constant concentrations of plant nutrients during the entire irrigation session) is a beneficial tool, mainly when growing on sandy soils (Table 26).

 

 

Table 26: Proportional Nutrigation

 

Nutrient	mg/l (ppm)		Nutrient	mg/l (ppm)
N (20-30% as NH4+)	35		Cu (as chelates)	0.012
P (as orthophosphate*)	10		Fe (as EDTA chelate)	0.088
P2O5	22.7		Mn (as chelate)	0.088
K	25		Zn (as chelate)	0.056
K2O	30.1		Mo	0.0006
Ca	20		B	0.088
CaO	28.2
Mg	10
MgO	16.7
S	13
SO3	32.5

* P in orthophosphate form serves as a buffer.

 

3.9.4 Nutrigation™ practice in Israel

Non-bearing citrus trees

 

Table 27:  Recommended rates of N, P and K, on young – non-bearing citrus trees:

Age of tree	N-P-K g/tree			Actual fertilizers
	N g/tree	P2O5 g/tree	K2O g/tree	Multi-K™	Urea	Haifa MAP™
First year	0.4	0.2	0.4	0.9	0.3	0.4
Second year	0.8	0.4	0.8	1.8	0.6	0.7
Third year	1.6	0.8	1.6	3.5	1.2	1.3
Forth year	3.2	1.6	3.2	7.0	2.4	2.6

When proportional fertigation is used, the concentration of N, the irrigated water in non-bearing orchard should not exceed 200 ppm (200 g N in 1000 L water).

In fruit bearing orchards grow where leaf analysis is not available, it is recommended to apply 200 kg N /ha/yr, 180 Kg K₂O/ha/yr and once in three years 60 Kg P₂O₅/ha.

Applications of potassium may vary according to soil texture; in light texture soils, low rates of phosphorus in each fertigation may be added, similarly to N, while in heavier texture soils higher rates of P may be applied once a week.

 

 

Bearing citrus trees

Apply N throughout the irrigation period according to the harvesting time of the fertigated variety. Varieties that are having color breaking difficulties, it is recommended to complete the N fertigation in mid summer. When proportional fertigation is used, the concentration of N, the irrigated water bearing orchard, should not exceed 50 ppm N (50 g N in 1000 L water).

Phosphorus should be applied, as needed, during the entire fertigated period in equal rates. If orchard is not fertigated, phosphorous should be applied in one portion in either spring or fall.

Applications of potassium may vary according to soil texture; in light texture soils, low rates of phosphorus in each fertigation may be added, similarly to N, while in heavier texture soils higher rates of P may be applied; once a month.

 

Recommendations according to leaf analysis

 

 

Table 28: Recommended potassium application rates according to leaf analysis, for oranges, (Shamuti, Washington navels, Valencia), lemons and tangerines

K level in leaves (% of dry weight)	Low	Optimum	Excess
	Less than 0.45%	0.45% - 1%	Above 1%
Recommended rate of K2O kg/ha	300	180	0

 

 

Table 29: Recommended potassium application rates according to leaf analysis, for grapefruits

K level in leaves (% of dry weight)	Low	Optimum	Excess
	Less than 0.35%	0.36% - 0.75%	Above 0.75%
Recommended rate of K2O kg/ha	300	180	0

Potassium: should be applied in the same rates and methods as nitrogen.

 

 

Table 30: Recommended phosphorous application rates according to leaf analysis, for oranges, (Shamuti, Washington navels), lemons and tangerines

P level in leaves (%) in leaves	Low	Optimum	Excess
	Less than 0.35%	0.36% - 0.75%	Above 0.75%
Recommended rate of P2O5 kg/ha	120	60	0

 

 

Table 31: Recommended phosphorous application rates according to leaf analysis, for grapefruits and Valencia oranges

P level in leaves (%) in leaves	Low	Optimum	Excess
	Less than 0.03%	0.031%-0.040%	Above 0.041%
Recommended rate of P2O5 kg/ha	120	60	0

Phosphorous: When drip irrigation is practiced, it is recommended to apply the phosphorous as a full-soluble product, such as Multi-MAP or Multi-MKP, at a constant concentration, during the entire irrigation season.

When leaf analysis is unavailable, it is recommended to apply 200 kg/ha of nitrogen, 180 kg /ha of K₂O and once every three years, 60 kg/ha of P₂O₅.

Nutrigation^™with recycled water: this kind of water may contain substantial quantities of plant nutrients. Therefore, it is recommend analyzing the water in order to determine the available plant nutrient and to use the leaf analysis results as a guidance criterion for the real application of the fertilizers.

 

3.10 Multicote™ Agri Controlled Release Fertilizers

There are two main situations in which the use of Multicote™ Agri products are recommended:

 

1. In the planting hole: It is recommended to apply Multicote™ Agri in the planting hole, to ensure balanced and adequate plant nutrients that are essential during the root development stage and the initial growth. This is recommended both in the nursery, when the seedling is transferred to the growth pot, and when the young plant is transplanted to the new plantation.

 

2. In sandy soils and high precipitation conditions:  As a standard crop nutrition management, in order to minimize leaching problems and yet to feed the citrus trees with all essential plants nutrients, the grower has a choice of several longevities of Multicote™ Agri to suit crop needs according to local growing conditions.

 

 

Multicote™ Agri applications:

To select the right Multicote™ Agri formula and to set application rates, some guidelines have to be followed:

• Release longevity should consider soil temperatures. As the release rate increases with temperature, higher temperatures require formula with extended longevity. Note that the declared longevity refers to release at 21^oC
• Under heavy rainfall or intensive irrigation, formula with higher percentage of coated nutrients is required.
• In any case, the percentage of coated nitrogen must exceed the minimum of 25% of the total N in the product.
• The total rates of nutrients should consider
• Theoretical needs based on removal by the crop+expected losses
• Required/expected yield level
• Farmer’s common practice and experience

Under most conditions, Multicote™ Agri  enables reduction of 10-20% in application rates as compared to conventional fertilization.

Please consult Haifa agronomist to customize Multicote™ Agri  fertilization program to suit your needs.

 

3.11 Foliar nutrition

Foliar feeding is a fast and highly effective method of supplementing and enriching plant nutrients when needed. Foliar application of Haifa water soluble fertilizers provides needed plant nutrients for normal development of crops when absorption of nutrients from the soil is disturbed, precision-timed foliar sprays are also a fast-acting and effective method for treating nutrient deficiencies.

Foliar application of the correct nutrients in relatively low concentrations at critical stages in crop development contributes significantly to higher yields and improved quality.

 

Determine safe foliar applied rate:

To verify the safe rate under local conditions, it is advisable to spray recommended rate on a few plants. After 3-4 days check the tested plants for scorching symptoms.

 

Preparation of tank-mix:

Dissolve Haifa water-soluble fertilizes in about half of the tank volume, and add to the spray tank. When applying together with crop-protection agents, addition of wetting agents is not necessary. To ensure compatibility of tank-mix components, a small-scale test should be performed prior to actual application.

 

 

 

Table 32: Haifa water-soluble fertilizers for foliar application

Fertilizer	Curing Treatment
Haifa-Bonus™	Potassium deficiency
Haifa MAP™	Phosphorus deficiency
Haifa MKP™	Phosphorus and potassium deficiency
Magnisal™	Magnesium deficiency
Poly-Feed™	N-P-K and micronutrients deficiency
Haifa Micro™	Micronutrients deficiencies

 

 

3.11.1 Haifa-Bonus™ increases yields and enlarges fruits

Foliar treatments with Haifa-Bonus™ proved to increase yield of many citrus species and varieties as well as increases fruit size, an important commercial parameter (Tables 33-35).

 

 

Table 33: Effect of Haifa-Bonus™ spray on size, yield and N & K levels in leaves of “Marsh” grapefruit

Treatment	Yield	Fruit size	Content in dry leaves (%)
	Boxes / tree	Fruit / box	N	K
Unsprayed	3.88	69.4	2.56	2.56
Sprayed* with Haifa Bonus-npK	4.38	65.7	2.68	2.68

* 3 % spray solution X 3 applications (April, June, and November)

 

 

Table 34: Effect of Haifa Bonus™ on Yield and Fruit Size of “Valencia” oranges

Treatment	Yield		Fruit size Fruit / box
	Boxes / tree	Fruits / tree
Unsprayed	7.54	976	130
Sprayed* with Haifa Bonus-npK	9.45	1135	120

* 5 % spray solution.

 

 

Table 35: Effect of Haifa Bonus™ sprays on fruit size of “Shamuti” oranges

Treatment	Yield kg / tree	Fruit Size
		Small	Medium	Large	Jumbo
		--------------  %  --------------
Control	102.8	63.94	19.39	14.26	2.4
4% Haifa Bonus-npK +18 ppm 2,4-D  (1 spray)	125.3	38.75	22.17	31.24	7.83
4% Haifa Bonus-npK +18 ppm 2,4-D (2 sprays)	122.63	30.22	22.42	33.52	13.36
4% Haifa Bonus-npK + 200 ppm NAA	79.1	18.26	12.66	40.66	28.41
4% Haifa Bonus-npK  + 300 ppm NAA	62.6	33.21	18.19	31.80	16.77

Foliar treatments with Haifa Bonus™ not only increases yield fruit size, but also reduces fruit splitting, a problem that may cause a sever reduction in marketable fruits (Tab. 11 - 13).

 

 

Treatment	No. of treatments	Fruit split (%)
Control		62.2
5% Haifa Bonus-npK	1	55.5
5% Haifa Bonus-npK	2	40.7
5% Haifa Bonus-npK	3	41.1
5% Haifa Bonus-npK + 20 ppm 2,4-D	1	35.4
5% Haifa Bonus-npK + 20 ppm 2,4-D	2	19.6
5% Haifa Bonus-npK + 20 ppm 2,4-D	3	20.1

 

 

Table 37: Effect of Haifa Bonus™ on “Nova” mandarins - R. Lavon (1992)

Treatment	Yield (kg/tree)	Fruits/tree	Mean weight of fruit (g)	Split (%)
Unsprayed	35 b	404 b	94 a	52 a
Ca-Nitrate 2%	43 ab	433 a	99 a	40 ab
Haifa Bonus-npK  3%	57 a	539 a	109 a	35 b
Ca-Nitrate 2%+ Bonus-npK  3%	49 ab	477 a	104 a	35 b

 

 

Figure 48: The Effect of Haifa Bonus™ on Yield & Fruit Size of Ruby-Red Grapefruit

 

Haifa-Bonus™ also reduces the fruit drop and affects the fruit quality (Tables 38-39).

 

 

Treatment	K in Leaves  (%)	Fruit Drop  (fruits/tree)	Yield (box/tree)
Unsprayed	0.47	193	1.14
Haifa Bonus-npK  4%	1.30	33	5.39

 

 

Table 39: Effect of Haifa-Bonus™ spray on “Lisbon” Lemons (USA)

Treatment	K concentration ( %  )		Acid in juice (% w/w) )	Fruit Color Rating
	Leaf	Peel
Unsprayed	0.39	0.51	6.40	1.72
Bonus-npK  spray*	0.50	0.70	6.88	1.88

* 3 % spray solution X 3 applications (April, June, and November)

 

 

3.11.2 Foliar feeding on young trees

Table 40: Foliar feeding with Poly-Feed^™ on young citrus trees to stimulate growth

Period	Frequency	Product	Spray concentration
May	Biweekly	Poly-Feed™*	2%
July-August	Biweekly	Poly-Feed™*	2%
September-October	Monthly	Haifa-Bonus™ + phosphoric acid	4% + 0.1%

* add surfactant

 

 

Table 41: Foliar feeding to correct deficiencies

Plant Nutrient	Period	Product	Spray concentration
Magnesium (Mg)	Spring, when leaves are 2/3 of their final size	Magnisal™	1.4 %
Potassium (K)	May-August, 1-2 applications	Haifa Bonus™	4 %

 

 

3.11.3 Foliar feeding prevents creasing and splitting, and improves fruit quality

For many years, foliar applications of Haifa-Bonus npK fertilizer proved to be an efficient treatment to reduce creasing in oranges (Tab. Xx).

 

 

Table 42: Foliar application of Haifa Bonus™ increases leaf K and reduces creasing in “Valencia” oranges

Treatment	Leaf K (%)		Creased fruits (%)	Severity index
	Before spray	After spray
Unsprayed	0.46	0.34	42.6	100
Sprayed* with Haifa Bonus-npK™	0.45	0.54	27.2	64

* 5 % spray solution.


Based on research results, the recommended treatment to reduce creasing is, to apply 4%-6% Haifa Bonus™ npK: 1st application on Mid June (after June drop), and 2nd application one month later (Table 43).

 

 

Table 43: Recommended foliar treatments with Haifa-Bonus™ npK

Treatment purpose	Application rate (kg/ha)	Conc. (%)	Spray vol. (liter/ha)	Timing	No. of sprays
Nutrition	100-240	4-6	2500-4000	Spring	1-3
Increase fruit size				Spring - Summer	1-2
Reduce fruit drop				After fruit-set	2-4
Reduce splitting and creasing				Spring - Summer	3-4
Suppress Floridian Wax Scale				Spring - Summer	1-2

 

 

Table 44: Growth regulators treatments, affecting fruit size and tree productivity, by variety

Varieties	Time of Treatment	Growth Regulator	Additives to growth regulators
Shamuti, Valencia Washington	End May - early June, Fruitlets 15-20 mm in diameter	2,4-D 20-40 ppm 2,4-DP 50-60 ppm	Haifa Bonus™ 4-6%
Michal, Clementines, Murkot, Dennis	End May - early June, Fruitlets 8-12 mmin diameter	NAA 200-300 ppm	Haifa Bonus™ 4-6%
Michal, Murkot	Fruitlets 21-25 mmin diameter	TPA-3,5,6  10-15  ppm	Haifa Bonus™ 4-6%
Valencia Washington	Fruitlets 15-18 mm in diameter	2,4-DP 50-60 ppm	Haifa Bonus™ 4-6%
Red Grapefruit, White Grapefruit	Fruitlets 15-20 mm in diameter	NAA 300 ppm	Haifa Bonus™ 4%

 

Need more information about growing citrus? You can always return to the citrus tree fertilizer & citrus crop guide table of contents