PDC LESSON 3.5 SEEDS – CROSS POLLINATION

  

PERMACULTURE COURSE AGRO-ECONOMYN

PDC LESSON 3.5 SEEDS – CROSS POLLINATION

 

Cross-pollination

Other types of complete flowers require crosspollination. They need insect or the wind to create fertile seeds. Some plants such as from the brassica family have a chemical barrier that prohibits self-pollination within the flower. They require bees or other insects to bring pollen from another plant to effectively carry out cross-pollination. If one plant were grown on its own it would have hardly any seed. Pollen from other brassica varieties can easily cross with each other to form broccoli- cauliflower crosses etc.

Rouging with cross-pollination will of course contaminate the true types. 

Natural cross-pollination

Plants such as lettuce, tomatoes, peas, and beans are self-pollinated and do not rely on insects or pollen from other plants to produce fertile seed. They are called in-breeders. However, in a garden situation, a certain amount of natural cross-pollination happens because of curious and hungry insects. Pollen often sticks to the body and legs of insects. Some pollen of the same family is more dominant in one variety than another. E.g. Chilli is more dominant than capsicum and it can therefore revert easily to a chilli type capsicum in the garden if these are kept in the garden at the same stage of maturity. Also, hot chillies will compete, and one will dominate the other, so several chilli types in the home garden may eventually turn into one variety! The same is said for basil. For this reason, self-pollinators should be kept as isolated as is possible from each other for seed saving.

Text from the roots, Elisabeth Ferkonia (Aus.) PDC studied with Bill Mollison,