Plant Anatomy and Agronomy Basics

• Basic agronomy is the science of managing crops and their environment to maximize productivity.
• It uses principles from biology, chemistry, physics, and environmental science.

Purpose of Agronomy

• Agronomy aims to understand plants.
• The soil is important in agronomy.
• Weather matters in agronomy.
• It utilizes science to improve crop yields.
• Reduce production costs.

Anatomy and Reproduction of Plants

• Plant anatomy or phytotomy studies the internal structure and tissues of plants.
• This includes organs like roots, stems, leaves, flowers, and fruits, and their functions.

Roots

• Roots anchor the plant, absorb water and minerals from the soil, and store nutrients.
• Fibrous roots exist.
• Taproots exist.

Stems

• Stems provide structural support.
• They transport water, nutrients, and sugars between roots and leaves.
• They can also store food and aid in the growth and development of leaves and flowers.

Leaves

• Leaves are the primary sites for photosynthesis, converting light energy into chemical energy (sugars).
• They facilitate gas exchange through stomata and regulate water loss through transpiration.

Flowers

• Flowers are reproductive structures involved in pollination and seed production.
• They attract pollinators and contain male and female reproductive organs (stamens and pistils).

Fruits

• Fruits develop from flowers and protect seeds, aiding in dispersal.
• They attract animals for seed spreading and provide nutrients to support seed growth.

Reproduction of Plants

• This is the biological process by which new plants are produced.

Asexual Reproduction

• It does not involve seeds or the fusion of gametes (sex cells).
• Offspring are genetically identical to the parent.

Types of Asexual Reproduction: Vegetative Propagation

• New plants grow from parts like roots, stems, or leaves.

Types of Asexual Reproduction: Cuttings

• Parts of a plant (like a stem) are cut and planted to grow a new plant.

Types of Asexual Reproduction: Grafting

• Joining parts of two plants so they grow as one is Grafting.

Types of Asexual Reproduction: Layering

• A stem is bent to the ground and covered with soil; it forms roots and becomes a new plant.

Types of Asexual Reproduction: Tissue Culture

• Growing plants from cells or tissues in a lab is called Tissue Culture.

Sexual Reproduction

• This involves male and female gametes, typically from flowers, and results in genetic variation.

Key Parts of a Flower

• Stamen (male part): produces pollen (male gamete).
• Carpel/Pistil (female part): contains ovary, which has ovules (female gamete).

Process of Sexual Reproduction: Pollination

• The transfer of pollen from stamen to carpel is termed Pollination.

Process of Sexual Reproduction: Fertilization

• Male gamete fuses with female gamete in the ovary.

Process of Sexual Reproduction: Seed Formation

• The fertilized ovule becomes a seed.

Process of Sexual Reproduction: Fruits Development

• Ovary develops into fruit containing seeds.

Process of Sexual Reproduction: Germination

• Seed grows into a new plant under the right conditions.

Factors Affecting Growth of Plants: Environmental Factors

• Light: Plants need adequate sunlight for photosynthesis.
• Temperature: Each plant has an optimal temperature range for growth.
• Water: Water is essential for nutrient absorption and photosynthesis.
• Air and Carbon Dioxide: Carbon dioxide is crucial for photosynthesis.
• Soil Quality: Soil composition, texture, pH level, and organic matter content influence root development and nutrient availability.

Factors Affecting Growth of Plants: Biological Factors

• Plant Genetics: Some plants naturally grow faster and are more resistant to diseases due to genetic traits.
• Pests and Diseases: Insects, fungi, bacteria, and viruses can reduce plant vigor, stunt growth, and lower yields.
• Competition from Weeds: Weeds compete with crops for nutrients, water, and sunlight, reducing crop productivity.
• Pollinators and Microorganisms: Beneficial insects like bees aid pollination, while soil microbes help break down organic matter and improve soil fertility.

Factors Affecting Growth of Plants: Human-Related Factors

• Fertilization and Nutrients Management: Proper application of fertilizers ensures plants receive essential nutrients.
• Crop Management Practices: Techniques such as crop rotation, intercropping, and pruning help maintain soil health and improve yields.
• Use of Pesticides and Herbicides: While these control pests and weeds, excessive use can lead to soil degradation and resistance in pests.
• Technological Interventions: Innovations like greenhouse farming, hydroponics, and genetically modified organisms (GMOs) enhance plant growth in controlled conditions.