Difference Between Self Pollination and Cross Pollination

In self-pollination, the plant effectively fertilizes itself. The pollen from the anther falls directly onto the stigma of the exact same flower, or another flower on the exact same plant.

• Requirement: The flower is usually 'bisexual', meaning it contains both male and female organs right next to each other.
• Agents: It happens automatically when the flower moves in the wind. It does not require any bees, butterflies, or external agents to carry the pollen.

In cross-pollination, the plant mates with a completely different plant. The pollen from a flower on Plant 'A' must physically travel through the air to land on the stigma of a flower on Plant 'B' (of the same species).

• Agents: This cannot happen automatically. It strictly requires an external pollinating agent like the wind, water, or insects (like honeybees) to physically carry the pollen across the garden from one plant to the other.

• Self-Pollination produces exact genetic clones of the parent plant. Because there is zero mixing of DNA, the species becomes genetically weaker over time, producing smaller fruits and failing to adapt to new diseases.
• Cross-Pollination is evolution's greatest trick. By mixing the DNA of two entirely different plants, it creates massive genetic diversity. The resulting seeds are highly robust, disease-resistant, and produce far superior, massive fruits and flowers.