Short communication

J. Hortl. Sci.
Vol. 10(1):107-108, 2015

Manipulation of bunch development in banana to
ensure uniformity in fruit size and high yield was achieved
in different varieties of banana by Kotur et al (2012) using
direct nutrient-feeding to the de-navelled distal end of rachis
after fruit set. Using 15N-labelled urea, it was demonstrated
earlier (Kotur and Keshava Murthy, 2008) that over 42%
of N blended in cow-dung slurry enriched with urea and
sulphate of potash (SOP) could be mobilized into the bunch,
with concomitant inflow of other nutrients present in the
enriched cow-dung. Improvement in Fe and Mn content
from 53 and 4.8µg g-1, respectively, in the whole banana
fruit (pulp + peel) under ‘Control’, to 115 and 14.9µg g-1,
respectively, was obtained in direct nutrient-feeding with a
blend of 7.5g each urea and SOP in cow-dung in ‘Robusta’
banana (Kotur and Keshava Murthy, 2010). Therefore,
further enhancement in bunch weight, and fruit bio-
fortification with these micronutrients important for human
nutrition (Nair and Iyengar, 2009; INSA, 2011) was
attempted by enriching the blend with FeSO4 (heptahydrate)
and MnSO4 (monohydrate). ‘Control’ bunches retained the
male flower until harvest, while, other treatments involved
direct nutrient-feeding of the de-navelled distal end of rachis
(after shed of 15-18 spathes) with 500g fresh cow-dung
enriched with 7.5g each of urea and SOP dissolved in 100ml
of water.  Uniform bunches carrying 10 hands (with average
number of fingers at 132 ± 6.8) were selected for receiving

Bio-fortification with iron and manganese for enhanced bunch yield in ‘Robusta’
banana through direct nutrient-feeding

S.C. Kotur
Division of Soil Science and Agricultural Chemistry

ICAR-Indian Institute of Horticultural Research,
Hesaraghatta Lake Post, Bengaluru - 560089, India

E-mail: sckotur@gmail.com

ABSTRACT
Enhancement of bunch weight together with bio-fortification with Fe and Mn was attempted in ‘Robusta’ banana by

enriching with 0-1.25g bunch-1 each of FeSO4 (heptahydrate) and MnSO4 (monohydrate). Bunch yield and content of Fe
and Mn in the pulp substantially increased by direct nutrient feeding of bunches with 7.5g each of urea and SOP
besides 0.75g each of FeSO4 and MnSO4. The improved technique holds promise for combating anemia in humans by
bio-fortification of banana with Fe besides supplemental Mn in diet.

Key words: Bunch size, direct nutrient feeding, ‘Robusta’ banana, Musa sp., Bio-fortification, Fe and Mn content
of pulp

the treatments. The blend was further enriched with FeSO4
and MnSO4 in the range of  0-1.25g each (Table 1) used in
3 replications. After harvest, fruit and bunch weight was
recorded. Pulp from fruits ripening at ambient conditions
was sampled, sliced, held in on oven at 70oC to dryness,
and powdered. The powder was digested in 9:4
nitric:perchloric acid mixture.  Iron and manganese in the
digest were determined using an atomic absorption
spectrophotometer. Data was analyzed taking the experiment
design as a completely randomized unit.

Table 1. Effect of de-navelling and direct feeding of Fe and Mn
blended with urea, SOP and cow-dung in ‘Robusta’ banana bunch
Treatment Fruit Bunch Fe M n

weight weight content content
(kg/bunch) (kg) (μg g-1) (μg g-1)

Control 13.934 14.685 25.8 1.1
Cow dung + Urea + SOP 19.551 20.621 31.8 2.4
Cow dung + Urea + SOP + 20.702 21.833 35.2 2.8
0.25g each of FeSO4 and MnSO4
Cow dung + Urea + SOP + 22.329 23.496 48.5 3.0
0.50g each of FeSO4 and MnSO4
Cow dung + Urea + SOP + 24.466 25.806 59.9 3.8
0.75g each of FeSO4 and MnSO4
Cow dung + Urea + SOP + 19.413 20.465 58.9 4.3
1.00g each of FeSO4 and MnSO4
Cow dung + Urea + SOP + 17.246 18.194 43.5 3.2
1.25g each of FeSO4 and MnSO4
SEm (±) 0.4459 0.4730 1.74 0.21
CD (P=0.05) 1.3013 1.3803 5.08 0.35



108

Direct nutrient feeding using cow-dung enriched with
urea and SOP increased fruit and bunch weight by 40% to
76% over the ‘control’ owing to enrichment with FeSO4
and MnSO4 (Table 1). This accounted for 25% enhancement
over application of cow-dung enriched with only urea and
SOP. Significant decline in fruit and bunch weight occurred
at 1.00 and 1.25g each of FeSO4 and MnSO4, but, fruit and
bunch weight was similar to that obtained in just urea +
SOP blended with cow-dung. With regard to Fe and Mn
content of pulp, significant increase was observed in enriched
cow-dung with up to 1.0g each of FeSO4 and MnSO4 per
bunch, declining significantly at 1.25g each of the two
nutrients. However, these values were smaller than reported
earlier (Kotur and Keshava Murthy, 2010), as, only the pulp
was studied which has much lower nutrient content relative
to the fruit peel. These results indicate that it is possible to
increase bunch yield further as also the content of Fe and
Mn in pulp substantially, by direct nutrient-feeding of
‘Robusta’ bunches with 7.5g each urea and SOP along with
0.75 each of FeSO4 and MnSO4. There is also a scope for
adding nutrients other than N, K, S, Fe and Mn to the blend
of cow-dung to optimize the use of direct nutrient-feeding
of banana bunch. This can help maximize bunch yield and
improve nutrient status in the pulp, to boost the food-value
of banana fruit. However, neutraceutical implication in terms
of bio-availability of Fe and Mn to humans remains to be
seen through suitable clinical trials. This improved technique

holds promise for combating anemia among humans besides
supplementing Mn in their diet. Nair and Iyengar (2009)
opined that food-based approaches for increasing iron and
other haematopoietic nutrient content are important for
correction of iron deficiency anemia in humans.

REFERENCES
INSA. 2011. Micronutrient security for India – priorities

for research and action. Indian National Science
Academy, New Delhi, pp. 1-19

Nair, M.K. and Iyengar, V. 2009. Iron content, bioavailability
and factors affecting iron status of Indians. Indian
J. Med. Res., 130:634-645

Kotur, S.C. and Keshava Murthy, S.V. 2008. Enhancing the
fruit yield of ‘Robusta’ banana (Musa×paradisiaca
L.) by de-navelling and feeding nitrogen, potassium
and sulphur through the distal-end of the bunch. Indian
J. Agril. Sci., 78:109-115

Kotur, S.C. and Keshava Murthy, S.V. 2010. Influence of
de-navelling and stalk-end nutrient application on
nutrient composition of ‘Robusta’ banana fruits. J.
Hortl. Sci., 5:148-150

Kotur, S.C., Ramesh, P.R. and Venugopalan, R. 2012.
evaluating  direct feeding of de-navelled banana bunch
with nutrients for enhancing fruit quality yield and
nutrient contents. J. Hortl. Sci., 9:166-171

(MS Received 07 December 2013, Revised 17 November 2014, Accepted 20 November 2014)

J. Hortl. Sci.
Vol. 10(1):107-108, 2015

Kotur