AGRONOMY OF ZEA MAYS

WHAT IS AGRONOMY???

Is the science and technology of producing and using the plants for food, fuel, and fiber.

AGRONOMY OF ZEA MAYS

Quality Of Seeds Producti

on

Insect and

diseases

harvesting

treatment

CULTIVATION OF ZEA MAYS

STEPS IN CULTIVATION OF MAIZE

PLANTING

SILKING

DENTING

MATURING

DOUGHING

MATURED

• Planting : Spread seed during crop planting

• Silking : Crop pollination

• Doughing : Thick substance start to form

• Denting: Plant use all it’s resources and lastly break

• Maturing: When green leaves disappear it is considered as matured

• Collection: Crop mature within 3-4 monts.

How to get quality seed in maize hybrids…

SUITABLE CLIMATE-Cultivate In February- Sowing In November- Seed Production In December

ISOLATION DISTANCE- Isolate by distance if different varieties

LAND REQUIREMENT- Well drained and sandy or black soil is suitable

SEED TREATMENT- treat seed with thiram in order to control diseases.

QUALITY OF SEED

PRODUCTION

GROWTH AND DEVELOPMENT STAGE 0: (FROM PLANTING TO SEE EMERGENCE)

↓Under warm, moist conditions seedlings emerge after about six to 10 days. If cool and hot condition, the seed will take longer time to germinate.

STAGE 1 : (FOUR LEAVES COMPLETELY UNFOLDED) ↓Grow point is still below soil surface and aerial part are limited to leaf sheath and blades.

STAGE 2: (EIGHT LEAVES COMPLETELY UNFOLDED) ↓ Leaf area increase 5 - 10 times, while stem mass

increase 50-100 times. Tillers begin to develop under the soil.

STAGE 3 : (TWELVE LEAVES COMPLETELY UNFOLDED) ↓ Tassel begins to develop rapidly.

STAGE 4: (SIXTEEN LEAVES COMPLETELY UNFOLDED) ↓

Stem lengthen and tassel already fully developed

STAGE 5 : (SILK APPEARANCE AND POLLEN SHEDDING)

↓All leaves completely unfolded and demand for water

and nutrients is high.

STAGE 6: (GREEN MEALIE STAGE) ↓

lateral shoot and bracts are fully develop. Starch begin to accumulate in the endosperm

STAGE 7 : (SOFT DOUGH STAGE) ↓

Grain mass continues to increase and sugars are converted into starch.

STAGE 8: (HARD DOUGH STAGE) ↓

Sugars in the kernel disappear rapidly. Starch accumulates in the crown of the kernel and extends

downwards.

STAGE 9 : (PHYSIOLOGICAL MATURITY) ↓

kernel reach maximum dry mass, layer of black cell develop at the kernel base. Grain is matured

STAGE 10: ( DRYING OF KERNEL (BIOLOGICAL MATURITY)

↓ Under favourable conditions, drying takes place at

approximately 5 % per week up to the 20 % level, after which there is a slowdown.

ADAPTATION AND PRODUCTION POTENTIALWater - Approximately 10 to 16 kg of grain are produced per milimetre of water. A yield of 3 152 kg/ha requires between 350 and 450 mm of rain per annum.

Soil requirements - good effective depth, favourable morphological properties, good internal drainage, an optimal moisture regime, sufficient and balanced quantities of plant nutrients and chemical properties.

MAIZE HARVESTING PROCESS

Harvest time

Harvesting process

requirement

Before Harvesting

After Harvesting

Losses due to poor storage

Conditions that favour aflatoxin

contamination in maize grains

Losses due to mould

Harvest timeThe optimum time of

harvesting maize is when the stalks have dried and moisture

of grain as about 20-17%.

Harvesting process requirement•Harvest maize as soon as it is dry but not overstay in field it will be attacked by weevils if does and lodge. In addition to reducing post harvest losses, this will also release the field for early land preparation.•Keep the grain as clean as possible. Dry maize on cement floor or use tarpaulin to reduce chance of contamination.•Dry on concrete or canvas not on bare soil.

Before Harvesting•Make sure the drying place or equipment is clean and disinfected, ready to receive the cobs.•Remove old grain and dirt from anything that will come in contact with the good or new grain. This includes harvesting tools, carts, wheel barrows, bags and baskets.•Where possible, fumigate them or at least treat them with boiling water to kill insects or their eggs. This is done in order to avoid infection of new grain by insects and their eggs.•Organize enough labour to reap and carry the cobs to the drying place.

After Harvesting•Drying- the systematic reduction of crop moisture down to safe levels for storage, usually 12%-15.5% moisture content. It is one of the key post harvest operations since all down-stream operations depend on it.•Shelling- Shelling is commonly done by beating maize cobs with stick in a sack or a confined floor space where farmers can afford it.•Storage- to maintain the stored grains in good condition so as to avoid deterioration both in quantity and quality.

Losses due to poor storage•Mould•Microbial infection in storage occurs due to inadequate drying of produce. The situation is made worse when there are large numbers of insects present or when the stored crop is exposed to high humidity or actual wetting due to poor storage management. Fungal infection results into rots and development of aflatoxins, which are poisonous compounds to live stock and cause cancer in human.

Conditions that favour aflatoxin contamination in maize grainsAflatoxin contamination is encouraged by:• Physical damage due to poor shelling/threshing methods• Poor storage methods (exposure to moist condition)• Insect infestations.• Inadequate drying• Aflatoxin cannot be seen with a naked eye. However, suspect materials tend to:

• Be rotten• Be mouldy• Be discoloured• Have unpleasant smell• Have bitter taste• Have poor milling quality• Be warmer than room temperature

Losses due to mould•Loss of weight•Loss of quality (smell, taste, colour, nutritional value, germination)•Further increase in temperature and moisture, causing more grain deterioration.

PEST AND DISEASE OF MAIZE

Pests of maize :EarwormsCutwormsAphidsBirds

Solution for the pests:Earworms

• Fall and spring tilling helps by exposing the pupae to wind, weather, and predators, distroy earworms.

• Tight husks .Clipping a clothespin on the tip of each ear can help to keep husks tight.

• Wormwood Spray or a spray made from garlic and onion tea.

• A drop of mineral oil on the tip of each ear may help to suffocate any resident earworms.

• Blacklight traps will destroy earworms.

• Cosmos, smartweed and sunflowers are good trap crops.

Aphids• Plant alliums such as garlic and chives.

• Use yellow sticky traps or yellow dishes containing soapy water. Soap-Shield and mint tea spray is highly effective. Lacewings will eat 100 aphids per day

Cutworms • Interplant with onion, garlic or tansy to repel cutworms

• Plant sunflowers as a trap crop.

• Handpicking is easiest and most productive following a rain or thorough watering and should be done after dark. Cutworms can be spotted with a flashlight.

• Placing a cardboard collar around young seedlings.

• Molasses mixed with hardwood sawdust is an effective trap when spread around susceptible plants. The cutworms will get stuck in the molasses and can be destroyed in the morning.

• Adult moths are easily killed with bug zappers.

Birds • Use netting over the corn row. When harvest approaches, use net

bags over corn ears. Orange and onion bags will do nicely.

Disease management of maize:Black Bundle Disease and Late Wilt: Cephalosporium maydis, Caphalosporium acremonium

• The disease kills the plant prematurely after flowering. Infected plants do not show symptoms until they reach to tasseling.

• Wilting generally starts from the top leaves, Leaves become dull green, eventually loose colour and become dry.

• In advance stages the stalk loses its healthy green colour, lower portions become dry,shrunken with or without wrinklings, hardens and turn purple to dark brown which in more prominent on lower internodes.

• When split open diseased stalks, show brown vascular bundles starting in the underground portion of the roots.

• Diseased plants produce only ears with undeveloped shrunken kernels.

Bacterial Stalk Rot: Erwinia carotovora, Erwinia chrysanthemi

• High humidity especially overhead irrigation and waterloging, coupled with high temperature (30oC and above), are conducive for disease development.

• The basal internodes develop soft rot and give a water soaked appearance. A mild sweet fermenting odour accompanies such rotting.

• Leaves some time show signs of wilting or water loss and affected plants within a few days of infection lodge or topple down.

• Ears and shank may also show rot. They fail to develop further and the ears hang down simply from the plant

Charcoal-Rot : Macrophamina phaseolina

• The disease development is maximum during grain filling stage and is favoured by warm temperature (30-400C) and low soil moisture.

• Charcoal rot is found to be prevalent particularly in rabi season when summer temperatures during post flowering period becomes comparatively high (35 - 450C).

• The pathogen also attack many other hosts, which helps in its perpetuation. Since the fungus is a facultative parasite it is capable of living saprophytically on dead organic tissues, particularly many of its natural hosts producing sclerotial bodies.

• The fungus over winter as a sclerotia in the soil and infects the host at susceptible crop stage through roots and proceed towards stem.

Downy Mildews Downy mildews are an exciting group of fungi

which attacks many economically important crop

plants.

Ten downy mildew diseases are known on maize

caused by two genera viz., Peronosclerospora

and Sclerophthera.

Out of these, Sorghum Downy Mildew and Brown

stripe downy mildew are common in our country.