Crop Physiology Lesson Introduction and Crop Growth Analysis

Original video: https://youtu.be/LTqGPldxdbI

Lecture on: 13 October 2025

The first part of this lecture establishes the difference between plants (multicellular photosynthetic life-forms) and crops (plants grown in large quantities for commercial purposes). All crops are plants, but not all plants are crops.

Key Focus of Crop Physiology

Crop Physiology is the study of how plant organs (stems, roots, leaves, flowers, fruits, seeds) function, and the complex chemical processes that allow crops to grow, live, and reproduce. Its three main tasks are to describe and explain:

Processes: Natural events like Photosynthesis, Respiration, Transpiration, Flowering, Seed Formation, and Stomatal Opening and Closing.

Functions: Natural activities of a cell, tissue, organ, or chemical substance, such as capturing energy, assimilating carbon, distributing nutrients, and responding to the environment.

Environmental Response: How these processes and functions change in response to external factors like light and temperature.

Understanding Growth and Development

The video then clarifies the stages of a crop's life:

Growth: Defined as the irreversible change in size of cells and organs due to both cell division and enlargement. It can be determinate (stops growing at a certain size, like bush tomatoes) or indeterminate (continues to divide indefinitely, like vine tomatoes). Growth is attained primarily by net photosynthesis.

Cellular Growth Stages: Growth occurs in meristematic regions and involves three phases: Cell Division (Formation Phase), Cell Enlargement (Elongation Phase), and Cell Differentiation (Maturation Phase).

Development: The progression from earlier to later stages in maturation, involving growth, morphogenesis (acquiring form), and differentiation (specialization)

The lecture introduces the concept that growth is a quantitative phenomenon measured in relation to time. It can be measured in terms of increase in length (for organs like stem and root) or increase in area or volume (for leaves). The typical growth pattern of an annual plant is often represented by a Sigmoid Curve.

Keywords: Crop Physiology, Plant Physiology, AGR3301, Crop Growth Analysis, Plant Growth Stages, Growth Curve, Determinate Growth, Cell Division, Cell Differentiation, Photosynthesis, Transpiration, Plant Development, Measurement of Growth.

Location:

Faculty of Agriculture, Universiti Putra Malaysia

Fakulti Pertanian, Universiti Putra Malaysia, 43000 Seri Kembangan, Selangor

2.983567621706455, 101.73466120334834

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