2. Introduction of high temperature and short day crops D)High latitude to low latitude duration shortened 2) Low latitude to high latitude duration elongated 3)Introduction of crops between high altitude and low altitude duration shortened(downward) /elongated(upward2. Introduction of high temperature and short day crops 1) High latitude to low latitude duration shortened 2) Low latitude to high latitude duration elongated 3) Introduction of crops between high altitude and low altitude duration shortened (downward) /elongated (upward)