Senescence as an active developmental cellular process in the...

Senescence can be defined as "the sum of deteriorative processes, which naturally terminate the functional life of an organism". Senescence is not confined only to whole plant, it may be limited to a particular plant organ such as leaf and flower or cells such as phloem and xylem. Abscission is natural shedding of leaves, foliage branches, fruits, floral parts etc. According to Leopold (1967) abscission is a senescence phenomenon. Senescence as an active developmental cellular process in the growth and functioning of a flowering plant, is indicated in leaf abscission. Whole plant senescence also known as overall senescence occurs in annuals (eg, rice, wheat, gram, mustard) biennials (eg, henbane) or perennials.