Growing Instructions: Banana Fertilizer (2023)

Index:

1. Main functions of plant nutrients.
2. Nutritional Functions and Symptoms of Banana Deficiency
3. nitrogen (N)
4. Phosphor (P)
5. Potassium (K)
6. Magnesium (Mg)
7. Calcium (Ca)
8. Azurblau (S)
9. micronutrients
10. Ferro (Fe)
11. Manganese (Mn)
12. Zink (Zn)
13. copper
14. salt sensitivity

Low soil fertility is one of the main limitations for optimizing plant growth and yield. Soil fertility can be controlled by fertilization, but the farmer needs to be fully aware of their nutrient issues in order to make the right decisions about the type and amount of fertilizer to apply. Numerous diagnostic techniques to assess the nutrient status of the soil and to determine the fertilization needs of plants, i.e. nutrient deficiencies, field and pot experiments, soil tests and plant analyses.

The improvement in banana yield and banana quality due to balanced fertilization is well documented. Information on how to improve the storage quality of the fruit and the storage properties of bananas through the proper use of nutrients is also crucial as large volumes of the fruit are sold in remote markets.

• The banana root system extends to the top 2 feet of soil. Being a tiresome crop, proper application of fertilizers must be used to produce good yields.
• The choice of fertilizers, nutrient dosages, application times, etc. varies greatly depending on the agroclimatic regions and the varieties.

The effects of adequate banana fertilization are:

• Increased crop yield by improving sorting or bundle weight,
• Reducing the time required for the bunch of bananas to ripen
• Greater number of good quality, marketable grapes per hectare,
• Improving the quality in terms of physical and chemical properties that bring high yields to producers.

2.1 Main functions of plant nutrients

Table 4: Summary of the main functions of plant nutrients:

2.2 Nutrient functions and deficiency symptoms of the banana

Table 5: Role of specific nutrients

Nutritional deficiencies impair banana growth (Table 6). It should be noted that potassium deficiency has clear negative effects.

Table 6: Number of leaves produced in 158 days and intervals between leaf budding ("Dwarf Cavendish" in sandy soil)

2.2.1 Nitrogen (N)

Function:Nitrogen is one of the main nutrients taken up by banana roots, preferably in the form of nitrate (NO₃^-) ion. Nitrogen is a component of amino acids, amides, proteins, nucleic acids, nucleotides and coenzymes, hexosamines etc. This nutrient is also essential for proper cell division, growth and respiration.

• Nitrogen is the most important growth promoter. Induces vegetative growth of the pseudostem and leaves, giving them a desirable, healthy green color.
• A robust and healthy vegetative structure is essential for high yields, and nitrogen is primarily responsible for this vegetative structure. Bananas poorly fed with N produce only 7 leaves compared to 17 leaves produced by bananas fed with sufficient N.
• When banana plants are N-deficient, it takes 23 days for leaves to develop, compared to 10 days when banana leaves receive adequate N.
• Nitrogen deficiency causes slow growth and paler leaves with reduced leaf area and leaf production rate. The N has a positive effect on the growth in length of the petioles.
• It was observed that the more large and healthy leaves produced in the first 4–6 months, the larger the size of the fruit clusters.
• Nitrogen increases grape quality and bud production.
• A lack of N results in thin, short, compressed petioles, thin, lush roots, and fewer shoots. Phosphorus uptake is higher due to N deficiency.

Table 7: Nitrogen (N) in bananas

Table 8: Optimum nitrogen dose for plant growth* - Cv. Pioneer (2 x 3 m)

I - First cycle

II – Second Cycle

** - Fertilization:P and K, dolime. N degradation (35, 75, 115, 155 days after sowing).

Solo: pH 5,4; P 2 ppm; K 0,5 meq/l; Ca+Mg 7 meql/l; Al 1 meql/l

* Brazil and others (2000) Brazil

Figure 4: Effects of nitrogen on TSS, sugar and sugar/acid ratio (uniform P and K ratio)

Babu (1999) If

deficiency symptoms:

Typical symptoms of nitrogen deficiency in the banana plant are general yellowing of the leaves, pink tints on the petioles (Figs. 5, 6) and leaf sheaths, stunting, redefinition, thin pseudostem, small petioles, and reduced shelf life of the banana. plants leaves. Bananas are more sensitive to nitrogen deficiency than any other element, e.g. Nitrogen deficiency leads to a noticeable reduction in yield.

Figure 5:Severe symptom of nitrogen deficiency in bananas

Figure 6:Symptoms of nitrogen deficiency: leaf stalks turn pink to purple and the distance between them becomes extremely short

Figure 7:Severe symptom of nitrogen deficiency in banana leaf stalks

Figure 8:Excess Nitrogen: Heavy burning of banana leaves from over-application of urea (damage clusters near center of rib)

2.2.2 Phosphor (P)

Function:Phosphorus contributes to the formation of healthy rhizomes and a strong root system. It also affects flower establishment and vegetative growth in general. It is one of the three main nutrients and is obtained from banana roots mainly in the form of orthophosphate (H₂AFTER₄^-). It is a component of sugar phosphates, nucleic acids, nucleotides, coenzymes, phospholipids, phytic acid and more. It plays a key role in reactions involving ATP. This element is necessary for many vital processes such as photosynthesis, carbohydrate metabolism and energy transfer within the plant. It helps plants store and use energy from photosynthesis, develop roots, accelerate maturity and resist stress.

deficiency symptoms:Symptoms of phosphorus deficiency appear on old leaves as chlorosis on their edges. Purplish-brown spots also develop. With a severe deficiency, the affected leaves curl, leaf stalks break, and younger leaves turn a deep green. Production is reduced and marginal chlorosis occurs and, in severe cases, premature death.

Figure 9:Severe phosphorus deficiency, symptom on banana leaves (Cv. Dwarf Cavendish). Leaf margins become necrotic.

2.2.3 Potassium (K)

Due to the high K content in banana fruits and leaves (see Fig. 1, page 5), K is considered the most important plant nutrient in banana production.

The amount of K taken from the soil and field in the harvested grapes is very high. Estimated annual soil losses from fruit removal alone can amount to 400 kg of elemental K (equivalent to 480 kg K₂O) per ha with a production of 70 tons of fruit. Therefore, the banana plant needs a good supply of K, even in soils with high K levels.

Function:Potassium is required as a cofactor for more than 40 enzymes. It plays a role in stomata movements by maintaining electroneutrality in plant cells. It is necessary for many other physiological functions such as B.: sugar and starch formation, protein synthesis, normal cell division and growth, neutralization of organic acids, participation in enzymatic reactions, regulation of carbon dioxide supply by controlling the opening of the stoma and improved efficiency in use of sugars, increasing the resistance of plants to biotic and abiotic stresses , such as z and turgor, regulation of Na entry and/or exit into the plasmalemma of root cells, chloride exclusion through the selectivity of fibrous roots for K over Na, and conferring salt tolerance on cells by increasing the ability to store K in the vacuole against leakage hold when Na occurs outside.

Potassium does not play a direct role in plant cell structure, but it is essential because it catalyzes important reactions such as respiration, photosynthesis, chlorophyll formation, and water regulation. The role of K in the transport and accumulation of sugars within the plant is particularly important, as these processes enable fruit filling and hence higher productivity.

Potassium improves performance

Table 9: Impact of K on Yield** – (Cv. Grand Naine, 3 x 4 m)

* fertigation: daily K&N (total 400 g/plant) for 6 months, weekly P, Mg, S (4 months), weekly Zn, Mn (3 months)

** Saad and Atawia (1999): Egypt

* - N 250 g/Plant, P₂Ö₅125 g/Pflanze; N&K in 3 Split Shots

** Abu Hasan et al.(1999) If

Table 11: Impact of K on Yield** - Pioneer Cv (2 x 3m)

I - Second Cycle

II - Third Cycle

* Fertilization: P and N, dolomite lime. K-Split (35, 75, 115, 155 days after sowing)

Solo: pH 5,4; P 2 ppm; K 0,5 meq/l; Ca+Mg 7 meql/l; Al 1 meql/l

** Brazil et al.(2000) Brazil

Table 12: Influence of K on yield and quality*

* Bhargava y ai. (1993)

Table 13: Effect of K applied to soil on yield*

* with a plant population of 1800 plants / ha

K-Absorptionsdynamik:

• Intensive K uptake in the first vegetative phase
• General decrease in K concentration in the plant from shoot to fruit
• High K in the soil allows for a good intake even in the last phase
• The K uptake stabilizes after the burst appears
• Low K supply, limits transfer of minerals (N, P, Ca, Mg, Cu, Zn) into the xylem
• Low K supply, limits carbohydrate transfer

Table 14: Effect of Multi-K application on banana quality

(Jambulingam et al. 1975)

Figure 10: The effect of foliar K content on yield when applying Multi-K by drip

deficiency symptoms:The symptoms of potassium deficiency in bananas become noticeable quickly if it is not used continuously in intensive banana cultivation. The classic symptoms of K deficiency are:

leaves

• Leaf chlorosis: The most characteristic symptom of K-deficient plants is yellowing of the tips of older leaves (Fig. 11-12). Yellowing and necrosis spread rapidly toward the base of the leaf until the entire leaf wilts back to its normal position.
• Rapid yellowing of older leaves, which become orange and dry; Leaves can become frayed and curl down; Leaves are wrinkled in appearance, divisions develop parallel to the secondary veins, and the leaf blade flexes downward while the midrib flexes and breaks, causing the distal half of the leaf to droop.

Figure 11:Slight potassium deficiency - old leaves turn orange-yellow

Figure 12:Moderate potassium deficiency: Necrosis begins at the leaf edges

Figure 13:Severe potassium deficiency: necrotic streaks reach midrib of leaf

Figure 14:Extreme potassium deficiency - most leaves wither and the typical curling begins

Figure 15:Deadly potassium deficiency: necrosis and folding of a large part of the leaf

Over time, the leaves curl inward and die off shortly thereafter (Fig. 16).

Figure 16:potassium-deficient banana; older leaves become chlorotic, then necrotic, and the midrib tip curves downward.

• Purple-brown spots appear at the base of the petioles and in severe cases the center of the tuber may show areas of broken down, brown, water-soaked cell structure.

fruit

• Bunch malformation: Fruit clusters on K-deficient plants are short, slender and misshapen due to low fruit filling, poorly filled cluster.
• Deformed fruits, badly filled and not for sale.

Figure 17:Deformed fruits, badly filled and not for sale.

plant growth

• Stunted Growth – It is common for K-deficient banana plants to exhibit slow growth, shorter internodes, and a stocky appearance.
• Longer than normal intervals between the appearance of new leaves, much smaller leaves, premature yellowing of the plant.

excess potassium

High Potassium:

• create a MgO/K imbalance₂Or proportions on the floor
• Symptoms: "bluish"
• magnesium deficiency
• calcium deficiency

Figure 18:Symptoms of high potassium levels

2.2.4 Magnesium (Mg)

Function:Magnesium is a secondary macronutrient that is absorbed as Mg²⁺. Magnesium is a crucial part of the chlorophyll molecule. It is required, non-specifically, by a large number of enzymes involved in phosphate transfer. It is involved in photosynthesis, carbohydrate metabolism, nucleic acid synthesis, is associated with the movement of carbohydrates from the leaves to the upper parts, stimulates the uptake and transport of P, and is an activator of several enzymes. .

Figure 19:The effect of magnesium on banana production

N: 276 kg/ha, K2O: 585 kg/ha, MgO: 122 kg/ha (+ S: 96 kg/ha)

Fuente: REF: Potash & Salt (2002) Ecuador

deficiency symptoms:Magnesium deficiency manifests itself in a yellowish chlorosis of the central area of ​​the blade, while the edges and midrib remain green; Other symptoms include purple spots on the petioles and detachment of the leaf sheaths from the pseudostem.

Lack:

• common with bananas
• Occurs in old plantations that have been fed low Mg
• Or where excess potassium is applied
• Edge yellowing (Fig. 20).
• Bluing: purple spots on the petioles ("blue disease")
• Separation of the leaf sheath from the stem.

Result

• Low income
• poor plant growth
• Potassium and calcium malabsorption

Figure 20:Magnesium deficiency symptoms

2.2.5 Calcium (Ca)

Function:Calcium is another secondary plant nutrient that is taken up by the plant roots as Ca²⁺. Calcium, as Ca pectate, is a component of the middle layer of the cell walls. Calcium is required as a cofactor by some enzymes involved in the hydrolysis of ATP and phospholipids. It is an important element for root development and function; a component of cell walls; and is necessary for chromosome flexibility and cell division.

Calcium deficiency is a widespread problem in banana cultivation and significantly reduces the quality of the fruit. Water stress is the main cause of calcium deficiency as it disrupts calcium uptake in the root and leads to local deficiencies in the fruit. Boron is necessary for maintaining perspiration (water absorption) and thus also for the absorption of calcium. Excessive use of nitrogen fertilizers and excessive plant vigor also aggravates calcium deficiencies. Calcium and boron are also essential for plant vigor, which is why deficient plants are more likely to suffer from fungal diseases and environmental stress. Calcium deficiency is common in both acidic and alkaline soils, even when the soil's levels of exchangeable calcium are high. This is largely due to the low mobility of soil calcium and competition with other nutrients such as ammoniacal nitrogen, potassium and magnesium.

Calcium deficiency caused by:

• Little sweat, e.g. in high humidity
• The fruit has a low rate of transpiration:
  a) Decreased Ca uptake in ripening fruit can lead to Ca deficiency
  b) Ripe spots on bananas (e.g. reinforced by plastic bags on the waistband)
• Rapid leaf growth can lead to Ca deficiency
• Cold winters in the subtropics
• Imbalances with K and Mg
  a) high levels of K, Mg or NH₄⁺reduces the availability of approx
  b) optimal uptake of Ca in the soil ratio Ca:(K+Ca+Mg) of 0.7

Source: Lahav & Turner (1989 - IPI Bulletin #7), C.B.I Banadex (1998 - AIM Database)

Figure 21:Effect of calcium application on banana productivity

Tasse N: 200 kg/ha, Tasse K: 498 kg/ha

Those: Moreno et al. (1999) - Venezuela

deficiency symptoms

Typical symptoms that indicate a calcium deficiency in the banana plant are: generalized dwarfing, reduced leaf length, reduced leaf emission rate; the leaves are curled; tissue near midrib thickens, may turn reddish brown. In subtropical growing areas, calcium deficiency usually occurs in early summer after the spring flood. It manifests itself as typical chlorosis and necrosis and, in severe cases, in the form of a "tip of the leaf".

Point:

• The symptoms are found on the youngest leaves and cause leaf spikes in which the young leaf blade is deformed.
• black Sigatoka(Mycosphaerella fijiensis)the disease is worse
• Intervenous chlorosis near the leaf margins
• Creates a "split blade" appearance when the new blade is warped or missing
• Symptoms appear after a growth spurt
• Or where high levels of potassium are applied

Plantar:

• It causes heart rot in newly planted tissue culture seedlings.

Fruit:

• The skin breaks when the fruit is ripe.
• Fruit clusters - scratch others into clusters
• The weight and diameter of the fruit are reduced.
• The quality of the fruit is inferior and the skin breaks during ripening.

Figure 22:Calcium deficiency symptoms

Figure 23:Early leaf symptoms (yellow stripes parallel to leaf midrib)

Figure 24:Chlorotic (white) and/or necrotic cardiac leaves

Figure 25:Early leaf symptoms of calcium boron deficiency (wrinkled leaves)

2.2.6 Azur (S)

Function:Sulfur, also a secondary plant nutrient, is essential for protein formation as a component of the three amino acids cystine, cysteine ​​and methionine.

Sulfur is necessary for the formation of chlorophyll and for the activity of ATP sulfurylase. These essential functions enable the production of healthy and productive plants, which are a prerequisite for high yields and superior quality.

deficiency symptoms:

The leaves are chlorotic and small, with thickening of the secondary veins; wavy leaf margins; Necrosis on the edge of the lower leaves.

Sulfur deficiency is rare as sulfur is often supplied with fertilizers containing sulfur:

(N. H₄)₂SO₄, superphosphate or MgSO₄

Point:

• Symptoms appear on young leaves.
• The leaves turn yellowish-white.
• With severe infestation, necrotic spots appear on the leaf edges.
• The leaf veins are thickened.

Fruit:

• Clusters are small or "strangled"
• Yields can be reduced

Figure 26:Schwefelmangel

Figure 27:Sulfur deficiency, yellowing of the entire leaf

2.3 Micronutrients

The availability of micronutrients is strongly influenced by soil pH.

• Above pH 7, the uptake of Fe, Mn and Zn is significantly reduced
• Below pH 5 there is a significant reduction in Mo and P uptake and an increase in Mn and Al uptake.

High levels of Na and Mg in the soil reduce the uptake of micronutrients

2.3.1 Boro (B)

• Boron deficiency is not common in bananas. It occurs, although in some Latin American countries (e.g. Ecuador)
• Boron deficiency is common in acidic soils
• Bormangelsymptome:
  - Corrugation and deformation of the sheet metal
  -White bands perpendicular to the ribs on the lower part of the blade
• The uptake rate of B in the field is constant from seedling to harvest: 40 mg/plant/month

Figure 28:Effect of different boron rates on yield

Planting density: 2123 plants/ha

Fertilization [kg/ha]: N 224, P 35, K 336, Mg 62, Zn 24
Source: Silva (1973), Plantains of Puerto Rico

Symptoms of boron deficiency include: chlorotic streaks on leaves, oriented vertically and crossing main veins (Fig. 29); Leaf malformation (Fig. 30), intervenous chlorosis. This deficiency can develop slowly over time.

Boron deficiency can lead to reduced grape weight and size, as well as insufficient filling of individual fruit units.

Figure 29:Boron deficiency: parallel whitish stripes in the center of the leaf

Figure 30a-c:Boron deficiency - deformed foliage

Boron deficiency occurs in a variety of soils, but boron availability decreases with increasing pH. Boron is essential for flowering, fruit set and sugar translocation. Boron is necessary for the absorption and movement of calcium, and calcium deficiency can be significantly reduced with the use of boron. Boron plays a similar role to calcium in plant nutrition and is therefore essential for quality factors such as peel strength, fruit firmness and shelf life. Since boron is necessary for root development and plant strength, deficiencies often increase the likelihood of fungal diseases and reduce plant tolerance to various environmental stresses.

2.3.2 Ferro (Fe)

Function:Iron is a component of cytochromes, non-heme iron proteins, participates in photosynthesis and N₂Dehydrogenases related to fixation and respiration. Iron is also involved in the reduction of nitrates and sulfates and in the processes of peroxidase and adolase reduction. The total amount of iron absorbed by healthy plants is only 1-3 g. 80% of this is taken up in the first half of plant life.

deficiency symptoms:General chlorosis of the whole blade, especially of the young leaves; delayed plant growth; small curls. The color of the leaf becomes whitish-yellow.

Iron deficiency mainly occurs with:

• Lime beds
• Soils with a high water table
• Soils with high manganese content

Lahav & Turner (1989 - IPI-Bulletin No. 7)

Figure 31:Symptoms of iron deficiency

2.3.3 Manganese (Mn)

Function:Manganese is one of the micronutrients absorbed by plant roots in the form of Mn²⁺. It is required for the activity of dehydrogenases, decarboxylases, kinases, oxidases, peroxidases and is not specific to other enzymes activated by divalent cations. It is necessary for the photosynthetic development of O₂, as well as involvement in the production of amino acids and proteins. Manganese plays an equally important role in photosynthesis, chlorophyll formation and nitrate reduction. A concentration of metalloenzyme peroxidase is considered a marker for Mn deficiency.

deficiency symptoms:Manganese deficiency in its mild form manifests itself as "comb-tooth" chlorosis, beginning at the leaf margins and extending along the leaf veins to the center of the leaf with occasional narrow green margins. Chlorosis first appears on the second or third youngest leaf.

Figure 32:Symptoms of manganese deficiency.

Toxicity:Manganese toxicity is a known problem in acidic soils. In severe cases, manganese levels in the leaves can reach 6,000 ppm. High levels of Mn reduce calcium absorption by 30%, magnesium absorption by 40%, and zinc absorption by 20%, and may increase the onset of the disorder known as "mature mixed."

2.3.4 Zink (Zn)

Function:It is an essential component of alcohol dehydrogenase, glutamic acid dehydrogenase, lactic acid dehydrogenase, carbonic anhydrase (which regulates carbon dioxide metabolism), alkaline phosphatase, carboxypeptidase and other active enzymes such as dehydropeptidase and glycylglycine dipeptidase in protein metabolism. It also regulates fluid relationships, increases cell membrane integrity, and stabilizes sulfhydryl groups on membrane proteins involved in ion transport. With low Zn availability, the cluster mass quadruples in response to a higher Zn ratio. At high concentrations, Zn has low mobility in the phloem from leaves to fruits.

deficiency symptoms:Zinc deficiency is a very common problem in bananas, occurring in all growing regions. It is more common in young plants without a mother plant that acts as a nutrient reservoir. Symptoms can appear in one year without affecting production but reduce fruit production in the second or third year. Zinc deficiency occurs in bananas when they are grown in zinc-deficient soil. Symptoms can be severe, especially in sandy soils and in soils with high pH due to fixation, or in acidic and degraded soils with low zinc levels. Zinc can leach under acidic conditions. Zinc is also inactivated at high phosphorus concentrations in the soil.

On the paper:

• The leaves become narrow.
• Yellow to white bands appear between the secondary veins.
• Elongated brown necrotic spots appear on the yellow stripes
• Appears as narrow prickly young leaves, chlorotic striate leaves, chlorosis of striate leaves or spots;
• A zinc-poor leaf is significantly smaller than a normal leaf, and a high concentration of anthocyanin pigmentation develops on its underside.

Dummy:

• become very thin
• The curls have little crooked fingers.
• Bananas have a characteristic light green tip
• Plant growth shows stunting and restarting.

2.3.5 Copper

Function:Copper plays an active role in the enzyme that performs key functions such as respiration and photosynthesis, and Cu proteins are involved in lignification, anaerobic metabolism, cell defense mechanism, and hormonal metabolism. Known forms of Cu in plants include: cytochrome oxidase, diamine oxidase, oxidized ascorbate, phenolase, lecase, plastocyanin, protein with ribulose bisphosphate carboxylase activity, ribulose bisphosphate oxygenase activity, superoxide dismutase, plant acyanine and quinol oxidase . Copper proteins show electron transfer and oxidase activity. Copper is also a component of cytochrome oxidase and heme in equal proportions. It also acts as a terminal electron acceptor of the mitochondrial oxidative pathway.

deficiency symptoms:The midrib and main veins curve backwards, giving the plant an umbrella-like appearance. The leaves turn bronze yellow.

Copper poisoning is possible, especially where Bordeaux mixture is still used for crop protection.

2.4 Salt Sensitivity

• High levels of salt in the soil or water can cause stress.
• Salt stress leads to marginal leaf chlorosis, stunted growth and thin, misshapen fruit.
• Type AAA dessert bananas (e.g. Cavendish) are more sensitive than plantains (types AAB/ABB).
• 100-500 ppm of total soluble salts in soil is satisfactory for banana growth. Plants and fruits are visibly affected at concentrations of 500-1000 ppm. If the total concentration of soluble salts exceeds 1000 ppm, plants will stun or die.
• Problems with salinity occur in the Caribbean, Latin America, Israel and the Canary Islands.
• Sodium and chlorine are not considered essential nutrients for banana plant growth.
• Bananas appear to be more sensitive to Na than to Cl (for example, bananas still grow up to 600 ppm Cl in irrigation water) (Israel).
• With high Na levels, the Na level in the roots can rise to up to 1.5% (3 times the normal value), particularly in the case of K deficiency.
• Excess Na causes nutritional imbalances
  -Na (or Mg), present in large quantities in irrigation water, reduces K uptake even in soils with high K content.
  - High levels of Na and Mg also reduce the absorption of micronutrients.
• If Cl is too high, sprout growth is restricted and the fruit does not fill up.

Figure 33:The salinity of the soil leads to a reduction in the biomass of plants and roots

Salinity affects root growth before crop stress becomes apparent

Nanicao (Cavendish Group) - Greenhouse test

Which: Araujo Filho et al. (1995) - Brasilian

Figure 34:Salinity slows growth

Which: Araujo Filho et al. (1995) - Brasilian

Bananas are sensitive to salinity and sodium toxicity.

• Bananas are sensitive to sodium (Na) and chloride (Cl)
• Salt problems arise when the chloride concentration in the soil solution exceeds 500 ppm.
• Cl toxicity reduces shoot growth and fruit does not fill out
• Sodium (Na) toxicity causes chlorosis
• Von⁺disturb K⁺Absorption

Figure 35:sodium toxicity

Salt damage occurs in banana trees irrigated with water at a concentration of 500 mg Cl/L. The problem is compounded when recycled irrigation water is used. In this case, use Multi-K^™Potassium nitrate is recommended as a nitrate source to suppress Cl uptake by banana roots.

Figure 36:The salinity of the water reduces agricultural production

Banana Monthan (ABB), India

Soil: sandy loam; pH 6.8, CEC 10.0 mol/kg, irrigation: 200 mm

The effects of salinity (0, 50 and 100 mM NaCl) can be observed in many banana varieties. With the increase in NaCl content, it shows injury symptoms such as: chlorosis and marginal necrosis of leaf, followed by leaf death. The effects on the leaves result in a reduction in leaf area by up to 50% and dry matter by 70%.

An increased salt content in the irrigation water reduces the yield (Fig. 37 - 40).

Figure 38:The effect of E.C. of irrigation water on bundle weight (two-year trial) Israeli et al, 1986

Figure 39:Salinity damage (reduction in water conductivity) after using KCl Source: Jones & Vimpany, 1999

Figure 40:Salinity damage (growth suppression) after KCl application Source: Jones & Vimpany, 1999

Because the banana plant is sensitive to salt, the fertilizer source must be carefully selected as a potential contributor to salinity. Haifa fertilizers are products of choice as a source of free chlorine, whether they are water-soluble fertilizers or CRF (Controlled Release Fertilizer). See pages 60-70 for more details.

Need more information about growing bananas? You can always return to the Banana Growing Index and Guidebanana fertilizer

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