Improvement of Light Interception by a Plant Canopy to Increase

Maize Yield

I. Komang Damar Jaya

, Sudirman

, Jayaputra

Postgraduate Program, University of Mataram. Jl. Pendidikan 37 Mataram 83125, Lombok. INDONESIA.

Keywords: Double Row, Planting Orientation, Population, Single Row, Vegetative.

Abstract: The ability of a maize plant canopy to intercept sunlight during grain filling determines its yield. This

research explored options to increase the ability of maize plants to intercept sunlight, especially at the end of

vegetative growth. A field trial to study the effect of row planting orientations (north-south and east-west)

and row patterns (single row and double row) was conducted under rainfed conditions in Lombok,

Indonesia. In the single row treatment, the spacing was 70 cm between rows and 20 cm in the row (70 x 20

cm). A spacing of 35 x 20 cm was used for the double row treatment with 70 cm apart of the two double

rows. Treatments were arranged in a Split-plot design with planting orientations as main plots and planting

models as sub plots. Each treatment was replicated three times, and the size of each plot was 3.5 x 3.5 m.

Results of the experiment showed that the canopy of the plants with north-south row orientation intercepted

much more sunlight than that of the east-west orientation. At the end of the vegetative stage, the canopy of

the plants planted in double rows intercepted 15% more sunlight than that in the single row. Maize grain

yield in the double row was 25% higher than that grown in a single row

1 INTRODUCTION

World maize production has been increasing in

response to rising demand, particularly for animal

feed. In addition to its use for animal feed, maize is

also a staple food in much of South America and

Africa, and its use extends to many other food

products (Shiferaw et al., 2011). The highest maize

production is dominated by the USA, followed by

China, Brazil, India and Argentina. In South-East

Asia region, Indonesia is the country with the highest

maize production, above The Philippines and

Vietnam (World Atlas, 2016) and it ranks eighth in

word production. As in China, most of maize

produced in Indonesia is utilized as animal feed.

In tropical countries that grow significant amounts

of maize, such as Brazil, Mexico, Indonesia and

South Africa, the crop is mainly produced by small

scale farmers in dryland areas. Smallholder farmers in

these regions are exposed to high climatic variability

and have low adaptive capacity to climate change

impacts. The occurrence of climate change has

brought about rainfall reduction in some regions

accompanied by some extreme weather events that

influence maize yield (Li et al., 2011). Hence, rain

water harvesting technology and its management have

become important considerations in maize production

in dryland areas. In addition to water availability,

sunlight and photosynthetic capacity are important

determinants of maize yield, and need to be optimized

to improved yields in dryland areas.

Most smallholder farmers in Indonesia still use

plant populations of traditional varieties of maize

when they grow modern hybrid varieties. The modern

varieties have been engineered to accommodate

higher plant populations due to their narrow leaf angle

(Pugano, 2007). With high plant populations and a

narrow leaf angle, the modern maize hybrid can

maximize light interception, especially during grain

filling, which can increase maize grain yield (Andrade

et al., 2002). Therefore, it is necessary to develop

high yielding maize production technology by

maximizing sunlight interception, particularly in

dryland regions that are being negatively impacted by

climate change.

Light interception by the maize canopy can be

increased by planting seed in narrow rows or

increasing plant population to bring about complete

canopy cover (Westgate et al., 1997). For modern

hybrid varieties, intraspecific competition among

plants after canopy cover can increase plant yield

(Toler et al., 1999). This may be due to the leaf

Komang Damar Jaya, I., Sudirman, . and Jayaputra, .

Improvement of Light Interception by a Plant Canopy to Increase Maize Yield.

DOI: 10.5220/0009900000002480

In Proceedings of the International Conference on Natural Resources and Sustainable Development (ICNRSD 2018), pages 189-192

ISBN: 978-989-758-543-2

189

architecture of modern maize varieties tending to have

a narrow angle (upright), permitting high

photosynthesis activity (Stewart et al., 2003). The

result of a high photosynthesis activity on maize with

upright leaves is a high grain yield. This paper reports

the results three experiments aimed at finding an

appropriate technique to increase sunlight interception

and maize grain yield through exploring planting

orientation and planting pattern in rainfed maize.

2 MATERIALS AND METHODS

A field experiment was conducted at Gumantar

village, Kayangan sub-district, North Lombok

(8.253654 S, 116.285695 E). The experimental site

was dominated by soils with a high sand fraction and

very low organic matter. Since the experiment was

conducted during the dry season (May to August

2016), irrigation water was required. Water was

supplied by a deep pump well located near the

experimental units. This practice has been considered

as very expensive by the local farmers and only

dryland farmers that have sufficient money are able to

grow maize during the dry season in that area. The

experimental location was an open area with full

sunlight to replicate normal field conditions of light

interception, evaporation and transpiration.

This experiment evaluated two row planting

orientations (north-south and east-west) and two

planting models (single row and double row). In the

single row treatment, the spacing was 70 cm

between rows and 20 cm in the row (70 x 20 cm). A

spacing of 35 x 20 cm was used for the double row

treatment with 70 cm apart of the two double rows.

Treatments were arranged in a Split-plot design with

planting orientations as main plots and planting

models as sub plots. Each treatment was replicated

three times, therefore there were 12 experimental

units of 3.5 x 3.5 m plots.

At planting time, Phonska N-P-K (15-15-15)

fertilizer was applied at a rate of 300 kg ha

-1

along

with Urea fertilizer at a rate of 100 kg ha

-1

. Thirty-five

days after planting (DAP) Phonska was reapplied at

the same rate as at planting time. Then Urea was

reapplied 56 DAP at a rate of 200 kg/ha. Before

application of the second fertilization, hand weeding

was done in all the experimental plots.

Watering was done with a gradient system,

namely by supplying small water canals between

experimental plots. In the early stages of growth,

watering was performed once per week and as plants

grew bigger, watering was undertaken twice per

week up to cob maturity stage. The irrigation

practice in this experiment provided an optimum

water requirement for maize crops to grow on a

dryland and that condition only can be achieved

when the rainfall during the rainy season (December

to March) is normal at about 700 mm. Pest and

disease control was done only when necessary.

Plant variables observed were plant height,

number of leaves, leaf area, and percentage of light

interception at the end of the vegetative growth.

Light interception was measured by using AccuPAR

(PAR/LAI Ceptometer Model LP-80, Decagon

Devices), during a bright day, full sunlight from

12.00 to 13.00, by measuring PAR

(Photosynthetically Active Radiation) light at the

above and below canopy in each treatment. Plant

yield variables consisted of: cob length, cob

diameter, cob weight, seed weight per cob, seed

weight per plant, and seed weight per plot. Cob

length, cob diameter, cob weight was determined

immediately after harvest. Seed dry weight was

measured after the seeds were dried with about 14%

moisture content. Maximum and minimum

temperatures were recorded daily.

3 RESULTS AND DISCUSSION

The results showed that plant height and leaf area

index, which were measured at the highest rate of

vegetative phase (42 days after planting = DAP) and

at the end of vegetative phase (60 DAP), were not

significantly influenced by plant row orientation.

Plant row orientation had a significant effect only on

percentage of light interception by the plant canopy

(Table 1). Canopies of plants in north-south row

orientation intercepted much more light than those in

east-west row orientation. At 42 DAP, plants in

north-south row orientation intercepted 11% more

sunlight than those in east-west row orientation. The

ability of the plant canopy to intercept sunlight

increased as the age of plants increased as the

difference in light interception between plants in

north-south and east-west row orientation was 15%

greater at 60 DAP than at 42 DAP.

Plant height was not significantly influenced by

row pattern. Table 1 shows that row pattern

significantly influenced leaf area index and

percentage of light interception. Plants grown in

double rows resulted in much higher leaf area index

and light interception than those grown in single row.

The higher leaf area index of plants grown in double

rows compared with that in single rows was merely

due to higher plant population per unit area.

ICNRSD 2018 - International Conference on Natural Resources and Sustainable Development

190

Table 1: The effect of row orientation and planting pattern

on plant height, leaf area, and percentage of sunlight

interception by plant canopy at 42 and 60 DAP.

Observ

ation

time

Treatment

Variables

Plant

height

(

)

Leaf

area

index

% light

inter-

tion

DAP

Orientation

North-South 149,7 1,94 47,30

East-West 149,2 1,96 42,37

LSD

0.05

- - 0,42

Rows

Sin

le row 149,0 1,70

a*)

42,98

Double rows 149,8 2,20

46,68

LSD

0.05

- 0,0013 0,42

DAP

Orientation

North-South 225,5 3,24 81,35

East-West 198,5 3,16 70,95

LSD

0.05

- - 0,62

Rows

Single row 212,0 2,68

73,08

Double rows 212,0 3,71

79,21

LSD

0.05

- 0,0046 0,62

*) Numbers in the same column with the same treatment,

followed by different letters are significantly different.

Table 2: The effect of row orientation and row pattern on

maize yield variables at harvest.

Treatments

Variabel

Fresh

cob

weight

(g)

Fresh cob

weight

/plot (kg)

Cob

length

(cm)

Cob

diamet

(mm)

Orientation

North-South 254,50 12,13 17,27 46,87

East-West 281,97 12,23 18,17 44,67

LSD

0.05

- - -

Rows

Single row 265,33 10,42

17,93 45,77

Double rows 271,13 13,95

17,50 45,77

LSD

0.05

- 0,029 - -

*) Numbers in the same column with the same treatment,

followed by different letters are significantly different.

The canopy of plants grown in north-south row

orientation intercepted more light than those grown in

east-west orientation. This was in accordance with the

results of Jaya et al. (2001) who reported that light

interception coefficient of plants grown in north-south

row orientation was higher than that of plants grown

in east-west row orientation. Consequently, to

maximize sunlight interception, maize planting

orientation will be better in north-south direction. In

this experiment, however, light interception at the end

of the vegetative phase reached just 79%. This value

is still far below that suggested by Jeschke (2014)

who asserted that 95% light interception was

achievable from the end of the vegetative phase until

grains filling. The lower light interception found in

this study was not due to low plant population but

rather by low leaf area index resulting from less than

maximum plant growth.

Plant yield variables at harvest, such as fresh cob

weight, fresh cob weight per plot, cob length, and cob

diameter were not significantly influenced by row

orientation (Table 2). Meanwhile, plants grown in a

double row pattern resulted in cob weight per plot

significantly higher than those grown in a single row

pattern due to the difference in plant populations.

Dry yield variables such as seed weight per cob,

percentage of seed per cob, seed weight per plot, and

weight of 1000 seeds were not significantly

influenced by planting orientation. Maize yield (seed

weight per plot) was only significantly influenced by

row pattern. Plants grown in double row pattern

resulted in yield about 25% higher than those in single

row did (Table 3).

Results presented in Table 3 show that the

increase in plant population by using double rows was

not sufficient to proportionately increase plant yield.

The yield increase was 25% compared with a plant

population increase of 28% from planting in double

rows. Less than optimum plant growth is suggested

as the main cause of the proportionately lower yield

increase, as the plant canopy was only able to

intercept 79% of the light at the end of the vegetative

phase. As mentioned previously that percentage of

light interception at this phase should achieve 95%

(Jeschke, 2014). High sunlight interception at the

grains filling phase can increase plant photosynthetic

capacity in such a way that plant yield increase

(Andrade et al., 2002). The other possibility is that the

plant population used was not optimum enough for

NK22, a variety with a narrow leaf angle.

Table 3: The effect of row orientation and row pattern on

dry maize yield variables

Treatment

Variable

Seed

weight/c

(g)

% seed/

cob

Seed

weight/p

lot

(

Weight

of 1000

seeds

(g)

Orientation

North-South 154,77 78,06 7,97 393,83

East-West 162,67 77,55 7,65 388,67

LSD

0.05

- - - -

Rows

Sin

le row 167,93 77,30 6,93

a*)

399,67

Double rows 149,50 78,31 8,68

382,83

LSD

0.05

- - 0,024 -

*) Numbers in the same column with the same treatment,

followed by different letters are significantly different.

Improvement of Light Interception by a Plant Canopy to Increase Maize Yield

191

4 CONCLUSIONS

It can be concluded that improvement of sunlight

interception can be achieved by using a north-south

plant row orientation and increasing plant

populations up to 98.000 plants/ha through using

double row planting. In this study, the increase in

plant population from 71.000 (single row) to 98.000

plants/ha (double row) could increase maize yield by

25%. This has the potential to significantly improve

productivity of smallholder farmers growing maize

in tropical, dryland farming systems.

ACKNOWLEDGEMENT

The authors would like to thanks reviewers for their

constructive comments. This research was funded by

University of Mataram 2016 under contract number

64S/SPP-UPT/UN 18.12/PL/2016.

REFERENCES

Andrade, F.H., Calviňo, P., Cirilo, A., Barbieri, P., 2002.

Yield responses to narrow rows depend on increase

radiation interception. Agron J. 94: 975-980.

Jaya, I.K.D., Bell, C.J., and Sale, P.W., 2001.

Modification of within-canopy micro-climate on

maize for intercropping in the lowland tropics. Proc.

Australian Agronomy Conference, Hobart,

Australia. 29 January-1 February 2001. Retrieved

from http://www .regional.org.au/au/asa/

2001/6/b/jaya.htm.

Jeschke, M.R., 2014. Managing corn for greater yield.

Crop Insights. 24 (2). Retrieved from

http://www.pioneer.co.nz/assets/Managing_Corn

_for_Greater_Yield_CI170309.pdf.

Li, X., Takahashi, T., Suzuki, N., and Kaiser, H.M., 2011.

The impact of climate change on maize yields in the

United States and China. Agr Syst. 104: 348-353.

Pugano, E., and Maddonni, G.A., 2007. Intra-specific

competition in maize: Early establishment hierarchies

differ in plant growth and biomass partitioning to ear

around silking. Field Crops Res. 101: 306-320.

Shiferaw, B.B., Prasannam, B., Hellin, J. and Bänziger.

M., 2011. Crops that feed the world 6. Post success

and future challenges to the role played by maize in

global food security. Food Secur. 3: 307-327.

Stewart, D.W., Costa, C., Dwyer, L.M., Smith, D.L.,

Hamilton, R.I. and Ma, B.L., 2003. Canopy structure,

light interception, and photosynthesis in maize. Agron

J. 95: 1465-1474.

Toler, J.E., Murdock, E.E., Stapleton, G.S., and Wallace,

S.U., 1999. Corn leaf orientation effects on light

interception, intraspecific competition, and grain

yields. J. Prod. Agric. 12: 396-399.

Westgate, M.E., Forcella, F., Reicosky, D.C., and Somsen,

J., 1997. Rapid canopy closure for maize production in

the northern US cornbelt: Radiation-use efficiency and

grain yield. Field Crops Res. 49: 249-258.

World Atlas. 2016. World Leader in Corn (Maize)

Production by Country. Retrieved from

www.worldatlas.com/articles/world-leaderin=corn-

maize-production-bycountry.html.

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