After permanent irrigation had been introduced, and partly replaced the
former basin irrigation under Mohammed Ali, there was a decisive change in
the structure of agricultural production. Some crops lost their importance or
disappeared completely, like barley, leguminous plants, flax and dye-providing
plants. The areas on which crops like maize, bersim, cotton, rice and vegetables
were grown were greatly expanded.
Various factors determine the times at which crops are grown, or crop
rotation, such as availability of irrigation water, farm size, profit margins