Corn growing guide

Recommended types:

Starter Fertilization

Top dressing

1 Introduction

1.1 Importance and Uses of Corn

Corn is ranked among the most versatile crops, with different uses depending on the type of crop and how it is processed.

1.1.1 Corn for Fruit (Dry Seed)

Human

Nutrition:
- Corn flour,semolina , corn flakes.
- Production of glucose syrup and starch.
Feed:
- A key component of compound feed due to its high energy value.
Industrial Use:
- Production of bioethanol and biogas.

1.1.2 Silage Corn

Feed:
- Full exploitation of the plant (seed, leaves, shoot).
- High in energy and digestible fiber.
Silage:
- Suitable for ruminants such as cows and sheep.
- Promotes milk production due to its nutritional value.

1.1.3 Other Uses

Bioenergy:
- Production of ethanol from corn starch.
- Use of residues for biogas production.
Industry and Cosmetics:
- Production of polymers from starch (biodegradable plastics).
- Production of oils for cosmetics and pharmaceuticals.

1.2 Climatic Requirements and Cultivation Suitability

The growth of corn is significantly affected by climatic conditions and requires a proper selection of varieties depending on the environment and the purpose of the crop.

1.2.1 Temperature Requirements

Optimum germination temperature: 10–12°C.
Optimal Growth Temperature: 20–30°C.
Critical Sensitivity Stages:
- Flowering: High Temperature (>35°C) may cause fertilization failure.
- formation: Temperatures below 10°C slow growth.

1.2.2 Water and Humidity

Total water requirement: 500-800 mm during the growing season.
Stages of high water requirements:
- Vegetation and leaf growth.
- Flowering and grain formation.
Corn is highly susceptible to drought, especially in the flowering and grain filling stages.

1.2.3 Light and Photoperiod

Corn belongs to C4 type crops, with high photosynthesis efficiency.
It requires 6-8 hours of direct sunlight per day for optimal growth.

1.2.4 Soil Requirements

Ideal Soils:
- Deep, well-drained, high in organic matter.
pH: 5.8-7.2 (also suitable for slightly acidic to neutral soils).
Requirements: Sandy
- soils allow good root growth but require more intensive irrigation.
- soils need good drainage to avoid water holding.

1.3 Advantages of Growing Corn

Productivity and Performance:

Suitable for extensive and intensive crops.

Trace elements:

Wide geographical spread due to resilience in different environments.

Trace elements:

Ideal for animal feed, industrial use and energy production.

Trace elements:

Possibility of incorporation into crop rotation.
Reuse of plant residues for soil improvement or energy production.

2. Botanical Characteristics and Physiology

2.2 Radical System

Primary Roots:
- They grow from sperm during germination.
- They serve the initial absorption of water and nutrients.
Secondary (Fibrous) Roots:
- They extend along the stem and reach a depth of 1.5-2 m.
- They provide support and stability to the plant, especially important for silage crops.
Aerated (Supporting):
- They grow from the lowest nodes.
- They support high plants and absorb surface water.

2.1.2 Shoot

Straight and concave, with obvious knots and intercostal intervals.
raised to 1.5-3 m for grain corn and can reach up to 4 m for silage corn.
The diameter ranges between 2–5 cm, offering resistance to winds.

2.1.3 Sheets

Elongated, lanceolate with a length of 30–100 cm and a width of 3–12 cm.
Interchangeable arrangement along the shoot.
They contain a high concentration of chlorophyll for maximum photosynthetic ability.

2.1.4 Flowering and Reproduction

Corn is a monogenous and solitary plant.
- Flowers male :
  - Placed at the top of the shoot.
  - They produce pollen for pollination.
- flowers:
  - They are found in the underarms of the leaves.
  - They grow the fruits (seeds) after fertilization.
- Pollination:
  - It is done with the wind (anemophilous pollination).
  - Successful pollination depends on the time of release of pollen and the receptivity of the female flowers.

2.2 Development Stages

Corn growth

is divided into distinct stages that affect water, nutrient, and plant protection requirements.

2.2.1 Stage 1: Germination (0–10 days)

Development of primary roots and first leaves.
Sensitive to water shortages and low temperatures.

Techniques:

Sufficient soil moisture for uniform germination.
Basic fertilization with phosphorus to strengthen the roots.

2.2.2 Stage 2: Leaf and Stem Growth (10–40 days)

Rapid increase in leaf area and photosynthetic ability.
Creation of nodes and development of air gasses.

Techniques:

Surface application of nitrogen to enhance vegetation.
Irrigation for a stable water supply.

2.2.3 Stage 3: Flowering and Fertilization (40–65 days)

Start flowering and pollination.
Development of female flowers and formation of cinders.

Techniques:

Decisive stage for final performance.
Ensure adequate moisture and application of potassium for fertilization aid.

2.2.4 Stage 4: Grain Formation and Filling (65–90 days)

Transfer of nutrients to the granules.
Beginning of fruit ripening.

Techniques:

Maintain adequate amounts of potassium and water.
Reduction of nitrogen to prevent excessive foliage growth.

2.2.5 Stage 5: Maturation and Harvesting (90–120 days)

Final filling of the grains and hardening of the seed.
Reduction of moisture in the granules.

Techniques:

Correct harvesting time to minimize losses.
Grain drying under 14% humidity for safe storage.

2.3.1 Corn for Fruit

Emphasis on maximum seed production and starch content.
Requires gradual application of nitrogen to increase fruiting.
Harvest at full ripeness (humidity 15–20%).

2.3.2 Silage maize

Emphasis on biomass, digestibility and energy content.
Requires higher planting density and increased potassium doses.
Harvest at the stage of milky-waxy ripeness for better digestibility.

3. Soil Preparation and Seeding

3.1 Suitable Soils and pH

Corn is demanding in terms of soil quality, as it needs good drainage and adequate aeration.

Ideal Soils:
- Deep and fertile soils with a high organic matter content (>2
- Well-drained, with moderate water holding capacity.
Types:
- Sandy loamy soils for better root system development.
- Clay loam soils for areas with high moisture requirements.
Optimal pH:
- 5.8-7.2 (slightly acidic to neutral).
- In acidic soils (<5.5) addition of lime is required to increase the pH.

3.2 Soil Preparation

Soil preparation should aim at improving structure, destroying weeds and incorporating key nutrients.

Macroelements:

Deep treatment (25–30 cm) to improve ventilation and drainage.
Destruction of perennial weeds and incorporation of organic materials.

Environmental Benefits:

- Disc harrowing to create a good seeding surface.
- Incorporation of fertilizers for nutrient enhancement of the substrate.

1. Ισοπέδωση Εδάφους:

- Ensure uniformity in irrigation and avoid water accumulation.

1. Ανάλυση Εδάφους:

- Check nitrogen (N), phosphorus (P), potassium (K) and microelement levels (Zn, B).

Lubrication

scheduling based on results.

3.3 Sowing and Planting Density

The sowing must be uniform and ensure a good distribution of plants in the field. The planting density may vary depending on the purpose of the crop (fruit or silage).

3.3.1 Sowing season

Fruit:
- Late March to mid-May (depending on soil temperature >10°C).
Silage:
- Early sowing (late March-April) to maximize biomass.

3.3.2 Seeding Depth

3–6 cm, depending on soil moisture and seed size.
In heavy soils, a smaller depth is preferred to avoid vegetation problems.

3.3.3 Planting Density

CropPlanting Planting Silage

Usage	Density (plants/acre)	Distances
Corn for Fruit	7,000-8,000 plants	70 cm between lines, 15–20 cm in-line.
Corn	9,000-10,000 plants	60–70 cm between lines, 10–15 cm in-line.

Remarks:

For fruit, a lower density is preferred for better grain formation.
For silage, greater density increases biomass but requires increased fertilization.

3.4 Selection of Varieties and Hybrids

The choice of varieties depends on the purpose of cultivation, climatic conditions and soil fertility.

Macroelements:

Hybrids high in starch and protein.
Adapted to dry conditions for greater resistance to drought.
Producer varieties with resistance to diseases (rust, fungi).

for Fruit:

Hybrids with high biomass production and high sugar content.
varieties with increased digestibility.
Use of varieties that produce larger ears and thicker stems.

4. Lubrication

4.1 Introduction to Corn Fertilization

The nutrition of corn must fully cover the needs of the plant in all macroelements (N, P, K) and microelements (Zn, B, Mg) to ensure:

High yield in seed (fruit) or biomass (silage).
quality with high energy value and starch or fibre content.
Resistance to disease, drought and mechanical stresses.
Optimal exploitation of the soil and reduction of environmental impact.

4.1.1 General Principles of Lubrication

1. Προγραμματισμός με Βάση την Ανάλυση Εδάφους:

- Estimation of nutrient reserves and soil pH.
- Determination of deficiencies in macroelements and microelements.

Fertilizer

Distribution By Development Stage:

Basic fertilization: Incorporation before sowing for the growth of roots and shoots.
Surface lubrication: Administration of supplementary doses during development.

Trace elements:

- Gradual nitrogen supply to avoid sloping or excessive vegetation.

Potassium

boosting for stress resistance and quality improvement.

Trace elements:

Fruit: Emphasis on seed production and high starch content.
Silage: Emphasis on biomass and energy requirements of plants.

4.1.2 Nutrition Differences for Fruit and Silage

Corn for Fruit

Nutrition

Goals:
- Development of a strong root system and shoots.
- High grain production with high starch content.
Focus on Nitrogen Fertilizers:
- Promoting shoot growth in the early stages.
- Gradual transfer of nutrients to the granules.
Requirements:
- Zinc (Zn) for speckling.
- Magnesium (Mg) for chlorophyll synthesis and sugar transport.

Corn

Nutrition

Goals:
- Development of high biomass (shoots, leaves).
- Enhancement of digestibility and content of easily digestible fibers and sugars.
Focus on Potassium (K):
- Improve plant strength and increase carbohydrate content.
Increased Nitrogen (N) Requirements:
- Enhancement of foliage and chlorophyll growth.
- Gradual application to maintain growth until harvest.

4.1.3 Application of Fertilizers in Basic and Surface Fertilization

Pre-plant Application:

Incorporation before sowing to strengthen the root system.
Use of fertilizers with a high concentration of phosphorus (P) and potassium (K).

Suggested Installments (kg/acre):

Cultivation

Direction	Nitrogen (N)	Phosphorus (P₂O)	Potassium (K₂O)
Fruit	5–7	3–5	6–8
Silage	7–8	3–4	8–10

Surface lubrication (Top-dressing):

Application of nitrogen during germination (20–40 days).
Potassium supplementation before flowering.

Suggested Installments (kg/acre):

Cultivation

Direction	Nitrogen (N)	Potassium (K₂O)
Fruit	6–8	4–5
Silage	8–10	6–8

4.2 Nutritional Needs and Macroelements

The cultivation of corn presents high nutrient requirements due to its fast growth and high productivity. These requirements vary depending on whether the crop is intended for fruit or silage, which requires strategic management of macroelements (N, P, K) and microelements.

4.2.1 Nitrogen (N)

Role in Corn:

Promotes rapid growth of shoots and leaves.
Enhances photosynthetic activity and protein production.
It increases grain production (for fruit) and biomass (for silage).

Techniques:

Crop Installment Silage Nitrogen

Usage	Total Dose (kg/ha)	Management
Corn for Fruit	11–15	50% base lubrication, 50% surface in 2 doses.
Corn	14–18	40% basic lubrication, 60% superficial in 3 doses.

Management by Stage:

Macroelements:

Administration of nitrogen before sowing to enhance germination.

First Surface Application (20–30 days):

Support vegetative growth and the formation of cinders.

Second Surface Application (Flowering):

Meeting the needs during fertilization and filling of the grains.

Techniques:

Water fertilization: Application of soluble nitrogen fertilizers through irrigation to avoid losses.
Fertilizers with urease/nitrification inhibitors: They provide gradual nitrogen release, reducing the need for multiple applications.

4.2.2 Phosphorus (P)

Role in Corn:

Strengthening the root system in the early stages of development.
Support flowering, fertilization and grain formation.
Improving energy transmission through ATP.

Techniques:

Crop Installment Silage Phosphorus

Usage	Total Dose (kg/ha)	Management
Corn for Fruit	3–5	Integration of 100% into the base lubrication.
Corn	3–4	Integration of 100% into the base lubrication.

Management:

Phosphorus is applied before sowing, as it is a stable element in the soil and is difficult to absorb if not placed near the root system.
Placement at a depth of 5–7 cm to improve uptake.

Techniques:

In acidic soils (<5.5 pH), phosphorus is inactivated. Application of minerals is required to adjust the pH.
In phosphorus-poor soils, it is recommended to use foliar applications with phosphate solutions.

4.2.3 Potassium (K)

Role in Corn:

Regulation of water management and stress resistance (drought or salinity).
Improve fruit quality (starch) and digestibility of biomass (silage).
Enhance the transfer of sugars from the leaves to the granules.

Techniques:

Crop Installment Silage Potassium

Usage	Total Dose (kg/ha)	Management
Corn for Fruit	10–12	60% basic fertilization, 40% surface (before flowering).
Corn	12–15	50% base lubrication, 50% surface in 2 doses.

Management:

Administration in base fertilization to support early development.
Surface application before flowering to enhance grain formation and biomass.

Techniques:

Use of potassium sulfate (K₂SO₂) instead of potassium chloride (KCl) in soils with high salinity.
Combination with foliar application of potassium for quick correction of deficiencies.

4.3 Fruit and Silage Fertilization Program

The development of an effective fertilization program for corn is based on the direction of cultivation (fruit or silage), the nutritional status of the soil and the needs of the plant at its different stages of development.

4.3.1 Fertilizing Program for Corn Fruit

Target:

High seed production with high starch and protein content.
Improvement of the quality of the fruit for industrial and animal feed uses.

Basic Lubrication (Before Seeding):

Target:

Strengthening the root system and initial growth.
Provide sufficient phosphorus and potassium reserves for critical development stages.

Item	Dose (kg/acre)	Method of Application
Nitrogen (N)	5–7	Integration by tillage or soil treatment.
Phosphorus (P₂O)	3–5	Apply 5–7 cm under the seed.
Potassium (K₂O)	6–8	Uniform integration into the soil.

Surface Lubrication (During Development):

Target:

Support shoot growth and flowering.
Improvement of fertilization and filling of the granules.

FertilizationGrain

Stage	Nitrogen (N)	Potassium (K₂O)	Remarks
3–4 sheets (20–30 days)	4–5 kg	2–3 kg	Stimulate shoot and leaf growth.
7–8 leaves (before flowering)	4–5 kg	2–3 kg	aid and initial grain development.
formation (50–60 days)	2–3 kg	—	Final reinforcement for optimal filling and grain quality.

Foliar Nutrition (Special Applications):

Zinc (Zn):
- Dosage: 150–200 g Zn/acre sprayed during leaf growth.
- Improves the flowering and growth of cinders.
Boron (B):
- Dosage: 100–150 g B/acre sprayed before flowering.
- Supports fertilization and seed formation.

4.3.2 Silage Corn Fertilizer Program

Target:

High biomass production with high digestibility and energy value.
Enhance plant resistance and sugar content.

Basic Lubrication (Before Seeding):

Target:

Development of a strong root system and enhancement of biomass.

Item	Dose (kg/acre)	Method of Application
Nitrogen (N)	7–8	Integration by tillage or soil treatment.
Phosphorus (P₂O)	3–4	Apply 5–7 cm under the seed.
Potassium (K₂O)	8–10	Uniform integration into the soil.

Surface Lubrication (During Development):

Target:

Support biomass growth and increase resistance to drought and stress.

Drip

Stage	Nitrogen (N)	Potassium (K₂O)	Remarks
3–4 sheets (20–30 days)	4–5 kg	3–4 kg	Enhancement of biomass and root growth.
7–8 leaves (before flowering)	5–6 kg	3–4 kg	Enhance photosynthesis and shoot growth.
formation (50–60 days)	3–4 kg	2–3 kg	Supporting sugar production and digestibility of biomass.

Foliar Nutrition (Special Applications):

Magnesium (Mg):
- Dosage: 200–300 g Mg/acre sprayed during leaf growth.
- Enhances photosynthesis and carbohydrate transport.
Sulfur (S):
- Dosage: 100–150 g S/acre sprayed before flowering.
- Improves the digestibility of silage biomass.

4.4 Use of Trace Elements and Foliar Nutrition

Trace elements are essential for the normal growth of corn, as they are involved in important functions such as photosynthesis, protein synthesis and nutrient transport. Although they are required in small quantities, their deficiencies can significantly limit productivity and the overall health of plants.

Foliar nutrition is used to promptly correct deficiencies and improve the nutritional status of the plant during critical growth stages.

4.4.1 Role and Importance of Microelements

Zinc (Zn):

Role:

It participates in the synthesis of auxins, enhancing the growth of roots and shoots.
Promotes fertilization and seed formation.

Techniques:

Yellow or white necrotic marks on the edges of the leaves.
Reduce leaf size and delay growth.

Techniques:

- Basic Application: 0.5-1 kg Zn/acre (chelated).
- Foliar Application: 150–200 g Zn/acre during the leaf growth stage.

Boron (B):

Role:

Regulates the transport of sugars and the growth of wheat.
Enhances fertilization and grain formation.

Techniques:

Leaf

deformity and stunted growth.
Reduced fertility and low grain production.

Techniques:

- Basic Application: 0.2-0.3 kg B/acre.
- Foliar Application: 100–150 g B/acre just before flowering.

Magnesium (Mg):

Role:

Important component of chlorophyll and essential for photosynthesis.
Contributes to the transfer of sugars from the leaves to the grains.

Techniques:

Yellowing of old leaves (interleaf chlorosis).
Stunted growth and smaller fruits.

Techniques:

Basic Application: 1-1.5 kg Mg/acre (in sulfate form).
Foliar Application: 200–300 g Mg/acre during flowering.

Parsley (Petroselinum crispum):

Role:

Essential for the synthesis of proteins and enzymes.
Improves taste and digestibility in the production of silage.

Techniques:

Uniform yellowing of the younger leaves.
Reduced growth and low protein content.

Techniques:

- Basic Application: 1–2 kg S/acre (ammonium sulfate).
- Foliar Application: 100–150 g S/acre at critical stages of development.

Iron (Fe):

Role:

Involved in chlorophyll synthesis and breathing process.
Supports electron transport during photosynthesis.

Techniques:

- Interleaf chlorosis in young leaves.

Growth

retardation and a weak root system.

Techniques:

Foliar Application: 100–200 g Fe/acre with chelated forms (EDDHA).

4.4.2 Foliar Nutrition – Implementation Techniques and Strategies

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Immediate Correction of Deficiencies:

Especially in cases where the intake from the soil is insufficient.

Supplementary Nutrient Supply:

Reinforcement during critical stages such as flowering and fertilization.

Trace elements:

Combined with plant protection applications to reduce costs.

Steps:

Leaf

Growth (20–30 days):

Enhancement with Zn and Mg for foliage and shoot growth.

Flowering and Fertilization (40–50 days):

Application of B and Zn to enhance fertility and grain growth.

Formation (60–70 days):

Mg and K to improve sugar transport and grain growth.

Techniques:

Solution

Concentration: Do not exceed 1–2% to avoid burns.
time: Early morning or late afternoon for optimal results.
Combinability: Check compatibility with plant protection products.

5. Irrigation and Water Management

5.1.1 Total Water Consumption

Corn for Fruit:
- 500–700 mm/growing season.
Corn:
- 600–800 mm/growing season due to higher biomass.

5.1.2 Distribution of Water Requirements by Development Stage

DevelopmentWater Tightness Leaf Grain

Stage	Requirements (mm/day)	Sensitivity
Germination (0–20 days)	3–5	Moderate. Requires sufficient soil moisture.
Development (20–40 days)	5–6	High. Enhanced photosynthesis.
Flowering and Fertilization (40–60 days)	7–8	Very high. Critical stage for returns.
Filling (60–80 days)	6–7	High. Necessary for fruit growth.
Maturation and Drying (80–100 days)	3–4	Low. Reduction of irrigation for ripening.

5.1.3 Resistance to Drought

Corn is susceptible to drought during the flowering and fertilization phases.
Prolonged water scarcity at this stage can lead to low flower fertility and reduced grain production or reduced biomass in silage crops.

5.3 Water Saving and Precision Irrigation

1. Use of Ground Sensors:

Moisture

measurements to accurately determine irrigation time and quantity.
Improve performance by reducing water losses.

Environmental Benefits:

Control of plant growth with thermal cameras and color indicators.
Detection of areas with water scarcity and identification of inequalities.

Hydroponics with Substrate :

Adjustment of water quantities based on evapotranspiration (ET).
Efficient water use during critical development phases.

5.4 Proposals for Effective Water Management

Soil

Analysis for Permeability and Water Retention:

Application of irrigation techniques depending on soil properties.

Planning:

Targeted water and nutrient supply to increase efficiency.

Trace elements:

Use of sensors and software for more efficient water management.

Calcium (Ca):

Reduce water use and improve irrigation efficiency.

Planning:

Adjustment of water quantities based on evapotranspiration (ET) and weather forecasts.

6. Plant protection

6.1 Herbicide

Main Weeds:

Perennial weeds: Agriada (Cynodon dactylon), Kyperi (Cyperus rotundus).
Annual weeds: Savri (Setaria spp.), Bloodgrass (Digitaria spp.).

Methods:

Macroelements:

Ploughing and carving in the early stages of development.

Trace elements:

Pre-emergence Herbicides: Application before germination for weed seed control.
Post-emergence Herbicides: Application in the early stages of corn growth to combat weeds that have sprouted.

6.2 Fighting Enemies

Main Enemies:

Maize borer (Ostrinia nubilalis): The larvae of this lepidoptera enter the stems and cobs of the plant, causing damage that leads to reduced yield and quality.
aphid (Rhopalosiphum maidis): This aphid attacks the leaves, especially the top ones, and the fear of maize, sucking the juices and causing stunted growth.
Ironworms: These are soil insects that complete their biological cycle in one or more years. Their larvae feed on the roots of plants, causing damage to the root system.
Sesamia nonagrioides: The larvae of this lepidoptera attack the young leaves, the fear, but mainly the stems and cobs of maize, causing significant damage.
Farmers (Agrotis spp.): Larvae, known as caterpillars, feed on young plants, causing damage. Agrotis segetum is the most frequent enemy of this group.

7. Harvesting and Storage

7.1.1 Appropriate Harvest Stage

Harvest

time: 100–120 days after sowing (depending on the variety).
Moisture: 15–20%.
- Below 15% for immediate storage without drying.
- Over 20% requires drying to avoid fungal infections.

7.1.3 Moisture Management and Drying

The granules are dried at a temperature of 35–40°C to prevent cracks.
Target: Moisture <14% for safe storage.
Use of ventilated silos or dryers to reduce moisture and prevent fungal problems (e.g. aflatoxins).

7.1.4 Wrist Storage

Storage

Conditions:
- Temperature: 10–15°C.
- humidity: 60–70%.
- Regular ventilation to avoid condensation and fungal growth.
protection:
- Preventive disinfection of warehouses with insecticides.
- Use traps to control infestations.

7.2.1 Appropriate Harvest Stage

Development

Stage: Milky-waxy stage (70–80 days after sowing).
Moisture: 60–70% for optimal fermentation and storage.
Index:
- Stable grain formation but still soft (waxy stage).

7.2.3 Silage Packaging and Storage

Silo

Compression:
- Removal of air by compression to prevent fungal growth.
- Cover with plastic film for sealing.
Airtight Fermentation: Lactic acid
- is produced that stabilizes pH and retains nutritional value.
- Ideal pH: 3.8-4.2.
Use of Fermentation Additives:
- Microbial inoculations to accelerate fermentation and maintain quality.
- Reduce losses and increase digestibility.

7.3 Wrist and Ensilage Storage Comparison

Silage Harvest Storage Maintenance Protection

Parameter	Corn for Fruit	Corn
Stage	15–20% moisture in the granules	60–70% moisture in biomass
Method	Silos or ventilated warehouses	Airtight silos with compression
Duration	6–12 months with proper humidity	3–6 months for maximum quality
Requirements	Insect and fungal control	Check air tightness