To avoid in breeding depression/to encourage cross pollination ,
i) pollen is released before the stigma becomes receptive or stigma becomes receptive much before the release of pollen. Blind
ii) the anther and stigma are placed at different positions so that the pollen cannot come in contact with the stigma of the same flower.
iii) self-incompatibility is a genetic mechanism and prevents self-pollination (from the same flower or other flowers of the same plant) from fertilising the ovules by inhibiting pollen germination or pollen tube growth in the pistil.
iv) the production of unisexual flowers- If both male and female flowers are present on the same plant such as castor and maize(monoecious) ( Any two)
