Pollination, Pollinizers, and Pollinators in Horticultural Crops

1. Introduction

• Pollination is one of the most important processes in the reproductive cycle of flowering plants.
• It directly influences fruit set, fruit quality, seed development, and crop yield in both annual and perennial horticultural crops.
• In many fruit crops, cross-pollination is essential for successful fertilization and fruit development.
• Hence, knowledge of pollination biology, pollinizers, and pollinators is crucial for scientific orchard management and productivity.

2. Definition of Pollination

• Pollination is the transfer of pollen grains from the anther (male part) of a flower to the stigma (female part) of the same or another flower.
• It is the first essential step leading to fertilization and subsequent fruit and seed formation.

3. Types of Pollination

Pollination is classified mainly into two types, based on the source of pollen.

• Self-Pollination (Autogamy) Transfer of pollen grains from the anther to the stigma of the same flower or another flower on the same plant.

Types:

1. Autogamy – within the same flower (e.g., Tomato, Pea).
2. Geitonogamy – between flowers on the same plant (e.g., Mango, Banana).

Characteristics:

• Genetic uniformity.
• No dependence on external agents.
• Less variability, but may cause inbreeding depression.

Examples: Peach, Apricot, Tomato, Brinjal, Chilli.

• Cross-Pollination (Allogamy); Transfer of pollen grains from the anther of one flower to the stigma of a different plant of the same species.

Characteristics:

• Promotes genetic variation.
• Ensures hybrid vigor (heterosis).
• Requires external agents (wind, insects, etc.).
• Common in most fruit trees.

Examples: Apple, Pear, Plum, Almond, Mango, Citrus.

• Types of Cross-Pollination Agents

Cross-pollination requires external agents for pollen transfer known as pollinating agents.

• Importance of Pollination in Fruit Crops

Pollinizers

• Definition
• A pollinizer is a plant or cultivar that provides viable and compatible pollen for the fertilization of another plant’s flowers.
• Pollinizers are essential in self-incompatible or cross-pollinated crops.

• Characteristics of a Good Pollinizer

Importance of Pollinizers

• Ensures effective cross-pollination and fertilization.
• Improves fruit set percentage and quality.
• Maintains regular bearing and prevents unfruitfulness.
• Used for hybrid seed production and breeding programs.

Examples of Pollinizers in Major Fruit Crops

Pollinizer Planting Design in Orchards

• Pollinizers should be planted systematically to ensure adequate pollen transfer.

Pollinators

• Definition
• Pollinators are living agents (mostly insects, birds, or animals) that carry pollen from the anther of one flower to the stigma of another, resulting in pollination.
• They play a vital role in cross-pollinated and insect-pollinated crops.

• Types of Pollinators

• Importance of Pollinators

• Honeybees as Major Pollinators
• The most efficient natural pollinators in horticultural crops.
• Bees visit flowers for nectar and pollen and transfer pollen between flowers during their visits.

Advantages:

1. Promote cross-pollination and fertilization.
2. Improve fruit shape, size, and seed content.
3. Increase yield up to 30–50% in crops like apple, citrus, and cucurbits.

Management Practices:

• Introduce 2–3 honeybee colonies per hectare during flowering.
• Avoid pesticide spraying during bloom.
• Ensure flowering overlap between varieties.

• Artificial Pollination (Hand Pollination)

When natural pollinators are absent or insufficient, manual pollination is practiced.

• Pollination Management in Orchards

• Factors Affecting Pollination Success

• Examples of Pollination Systems in Fruit Crops