crop nutrition advice
crop nutrition advice
Everything you need to know about banana fertilization, best practice, suitable products, field trials, and more.
Advice for growing bananas (Musa spp.)
Bananas grow well in a wide range of soils.
Soil pH should be between 5.5 and 6.5, and the soil must not be compacted.
The optimum temperature for leaf emergence is about 25-30⁰C. Banana crops are sensitive to low temperatures.
The banana crop cycle in tropical environments may be as short as seven months.
Chilling occurs below 10⁰C, and irreversible frost damage happens when leaves are exposed to -2⁰C for just 10-15 minutes.
Estimated nutrient uptake (kg/t):
50 t/ha fresh fruit at 2000 plants/ha.
Source: IPI Bulletin 7 – Fertilizing for High Yield – Banana (1989).
Dynamics of banana nutrient uptake over a crop season
|40 t ff*||60 t ff*|
* ff = fresh fruit
Source: Research Data INIAP-IPI (2020)
Role of nutrients
|Total soluble solids||+||+|
|Ascorbic acid (Vit. D)||+|
+ = improving; – = decreasing;
Source: Banana Crop Guide, Haifa.
Deficiency symptoms appear rapidly and simultaneously show on leaves of all ages. Leaves become very small and are pale green. Mid-rib, petioles, and leaf sheaths become reddish pink, and the leaf production rate markedly decreases. Distance between successive leaves reduces, producing a ‘rosette appearance’ and poor growth, resulting in stunted plants. Fruit bunches become small with a reduced number of bunches.
Reference: Rahul Mane BSc.
Reduced vigor, stunted growth, and poor root development, leaf margins of the oldest 4-5 leaves become chlorotic. Under severe P deficiency, leaves develop purple-brown flecks and eventually produce ‘saw-teeth’ necrosis of the leaf edges. Affected leaves curl and petioles break; young leaves have a deep bluish-green color. Fruit maturity is delayed.
Potassium deficiency symptoms usually appear at flowering time. Rapid appearance of orange/yellow color on older leaves which subsequently get dry and die. The mid-ribs of these leaves are often bent or broken at two-thirds of their length, making the leaf point downwards. Plants produce small leaves and exhibit delayed flowering. The reduced bunch size shows prior to the effect on plant growth.
Symptoms appear on the younger leaves due to low calcium mobility in the plant, generally after a flush of growth or as a result of unbalanced potassium application.
Interveinal chlorosis near leaf margins. ‘Spike leaf’ deformation or absence of leaf blade, fruit cracks readily upon fruit maturation, fruit bends up, producing a more concave form. The fruit diameter and biomass are reduced.
Deficiency causes chlorosis of leaf margins of older leaves. The yellowing extends towards the mid-rib, with a green band remaining near the mid-rib. The chlorosis is more severe in leaves exposed directly to sunlight, with purple mottling of the petioles. The leaf-sheath separates from the pseudo-stem, the plant height is reduced, and fruits do not ripen well and become tasteless.
Symptoms are similar to nitrogen deficiency, but chlorosis is uniform and general throughout the entire plant, including younger leaves. The heart leaf becomes white, and other leaf blades become very soft and tear easily. Thickening and leaf creasing, plants with advanced deficiency will be stunted.
Recommendations for growing bananas
Step 1: Seedlings
Seedlings can be obtained from nurseries producing reputable micro-propagated seedlings or self-produced by experienced fruit growers.
Step 2: Planting
Separate seedlings to standardize plots and simplify crop management. Plant new seedlings in holes where the seedlings didn’t germinate approximately 30 to 40 days after planting.
Step 3: Crop Management
- Weed control should be carried out, especially in the initial phases.
- Thinning aims to eliminate excess shoots from the clump, leaving one daughter per plant and, later, the granddaughter. Each clump usually has three plants: mother, daughter, and granddaughter.
- Defoliation eliminates broken, dry, disease-infected leaves and those that will cause damage to the bunch. It improves shoot development, reduces disease incidence, increases aeration and luminosity, and facilitates harvesting.
Step 4: Eliminate Heart and Flowers
The “heart” of a banana must be eliminated 10 to 20 cm below the last lot soon after opening. This speeds up the development of the bunch, improves fruit quality, and reduces pest incidence. Flowers must be eliminated soon after the elimination of the “heart” and carried out only in varieties with persistent male flowers below the last bunch to also reduce pest incidence.
Step 5: Bag the bunch
Bagging banana bunches protects fruit against pests and physical damage and accelerates and evens out bunch development. Carry out bagging after removal of the “heart” (the male flowers) and the last bunch.
Carry out fertilizer application according to the crop stage, soil contents, nutrient extraction, and weather conditions.
For different countries, fertilizer application may vary from 4 to 24 times per year according to wet periods or irrigation frequency. The number of applications can be reduced when using slow or gradual-release fertilizers while still achieving increases in yield, quality, and profitability.
An approximate recommendation to obtain a medium to high production would be around 400-60-600-130-60-60 kg/ha/year of N, P2O5, K2O, CaO, MgO, and S, respectively, plus a reasonable rate of micronutrients based on the yield levels of the farm.