HORTICULTURE

Detailed explanation-1: -Examples of mechanical defenses include thorns on the leaf or stem, bark on a tree, and trichomes or barbs on the leaf. In some instances, a plant will protect its seeds with a tough shell (think of a coconut, a jackfruit or a pineapple).

Detailed explanation-2: -The two major mechanical defences of plants are toughness and hardness. These have different material causes and ecological functions. In any non-metal, high toughness is achieved by composite construction (i.e. by an organized mixture of components).