Maize is believed to be originated in Central America. Maize ranks at the top of cereals on the basis of production in the world. Maize is followed by Wheat and Rice. In case of Nepal, maize is the second most important crop after rice. Total yield of maize for the fiscal year 2018/19 in Nepal was 2.84 Mt./Ha. Where, total production was 2,713,635 Mt. and area was 956,447 Ha.
Agro-ecology for maize in Nepal
|
|
High hills |
Mid hills dry |
Mid hills wet summer |
Mid hills wet spring |
Terai, inner terai and foot hills
valley summer planting |
Terai, inner terai, foot hills
valleys spring and winter planting |
|
Area |
64000 ha |
115,000 ha |
300,000 ha |
150,000 ha |
10,000 ha |
190,000 ha |
|
Location |
Runs throughout the country |
Far and mid west hills |
West, central and eastern hills |
|
|
|
|
Cropping system |
Sole maize or maize with millet |
Maize-wheat, Maize-barley,
maize-potato, maize-fallow |
Maize/Millet, Maize/Millet-
mustard, Maize-potato |
Maize-Rice |
Maize-mustard, maize-upland rice,
maize-millet, Maize/upland rice- black gram |
Maize-Rice, Maize-Rice- Buckwheat,
Maize-Rice-Mustard |
|
Important point |
Comprised of isolated pocket and
connected to mid hill ecology |
Maize on bari during summer |
Planted on bari on summer |
Planted on spring in khet |
Panted on onset of rain in bari |
Planted on khet with irrigation |
|
Problems |
Lack location specific High
Yielding Variety |
Lack of road network |
Post harvest and pest attack |
Early maturing variety requuired |
|
Drought problem in Spring Season.
Early maturing HYV required. |
Agronomy of Maize
|
|
Sowing
time |
Seed
rate |
Spacing |
Critical
growth stage |
|
Maize |
Kharif-
end of May to 1st week of July Rabi-
Mod Oct to Mid Nov Spring-
Mid March No
sowing in Dec –Jan. |
15-20kg/ha
for grain crop 20-30kg/ha
for forage crop |
60-75
cm x 20-30 cm |
Knee
high stage |
Yield of winter maize is higher
because
- More ripening period in winter
- Logging very low
- Low plant height
- Accommodate more plant in field
- Broad leaf and more LAI in winter maize
- Free of sterility problem as in summer maize
- winter maize yields are higher due to lower risk of pests and diseases and higher production of CHO/day/unit land among the cereals.
Yield of maize in hills is higher than in Terai
- Net assimilation Rate higher i.e. photosynthesis higher than respiration, night temperature in Terai is higher causing more respiration and reduced starch accumulation
- Less attack of pest and disease
Maize-finger millet cropping system of Nepal
In upper mountain either maize or millet is cultivated.
Classification of Maize
On the basis of growing habit:
- Kharif, rabi and Spring
On the basis of commercial types and endosperm
- Dent, Flint, Flour, Pop, Sweet, Waxy, pod maize
Growth stages of maize with special significance to intercultural operations
Typical corn plant develop 20 to 21 total leaves, silk in 65 days after emergence and mature around 125 days after emergence.
Seedling growth (Stage)- VE to V1
- Coleoptile reaches to soil surface.
- Seminal root growth slows and nodal root begins elongation.
- Growing point is below the soil surface.
- Moisture stress at seedling stage delays tasseling by 3-5 days and silking by 5-8 days. First irrigation at V2 if available.
Vegetative growth (Stage)- V2 to Vn
- Lateral root begins to grow from nodal roots in V3 and brace roots formation complete in V18.
- Stalk elongation occurs which pushes growing point upward.
- Ear and tassel initiation occurs at V5 followed by kernel number determination which is complete one week prior to silking.
Weeding:
- Two manual weeding 20 DAS and 30-35 DAS followed by Earthing up (not after V5) result better weed control.
- If weed problem is high, herbicides Mesotrione 1-1.5 a.i./ha at 70g/liter at V2 to V8 Stage
- 2,4-D at 1.5-2 kg a.i./ha in 800 litre water applied at 25-30 DAS
Fertilizer management
- 2nd dose on nitrogen can be applied at Knee high stage (30-40 DAS)
Water management
- Irrigation at knee high stage is very important.
Top 5 maize producing districts in Nepal
- Jhapa
- Ilam
- Bhojpur
- Syangja
- Khotang
Ecological requirement of maize crop
Ecological requirenment of maize can be discussed under following headings:
Climate
- Sea level to 3000m
- Requires moisture and warmth from germination to flowering
- Can be grown throughout the year except planting of Dec-Jan
Temperature
- Optimum for seed germination is 21¬0C.
- Most suitable for growth and development is 320C and 250C to 280C.
- 5-70C reduce photosynthetic rate for several days damaging
- C4 plant respond well to high temperature and intense sunlight.
- Extremely high temperature with low humidity and during flowering results in poor grain formation (desiccate pollen and interfere proper pollination).
Rainfall
- Can also be grown in areas receiving 60cm but should be distributed throughout its growing period.
- Also areas with 250-300 cm but no flooding or water logging.
- Early stage----------> No stagnant water
- Frost-------------> No at any stage
- 30-35 days after tasseling---------------> 50% water required
Ediaphic requirement
- Deep, fertile, rich in organic matter, well drain soil
- Sandy loam to silty loam
- pH 5.5 to 7.5
- Sensitive to water logging (stagnant for no more than 4-5 hours)
- Fertilizer add determined by soil analysis
Maturity indices
- Moisture 22-25%
- Hard grain, last grain at dough stage
- Black layer of husk start to senescence
- Upper layer of husk start to senescence
- Drying of silk, tassel, leaves (at least lower leaves)