Growth Stages of Rice
Updated: Apr 6, 2018
The plant growth stages identify growth periods in their lifecycle and can be separated into the vegetative and reproductive stages of growth. Germination and development are the initial phases in the vegetative phase of expansion and are significant growth events since they provide the foundation on which plant further flourishes. Germination starts as young shoot originates through the seed coating at one end of the seed. Since the shoot reaches and elongates on the ground surface, the growth begins. The reproductive stage is normally connected to the creation of the panicle and grain or flowering.
Elaborating this concept with example of rice, when it is planted on the ground, germination and development occur nearly simultaneously as when a foliage has fully exerted, another is generally emerging, and it is possible to consider the emerging foliage from the count. Seedling phases occur during the initial two to five weeks. As rice passes the 3- to 4 foliage stage, tiller creation may start, sparking the tillering stages. Tillers seem as shoots those are secondary to the shoot. They are started at the base of the plant, appearing from the interior of the seedling leaves on the primary shoot.
The number of tillers is mainly decided by plant population, and tiller creation occurs over a 2 to 3 weeks period. Generally, a stand of 10 plants per sq ft will average two to four tillers per plant. When a rudder appears, the expansion stage is considered as first stage. Tillering phases therefore are numbered according to the number of rudders present, and, generally, with a stand of 10 plants per sq ft, plants in the fourth tiller stage are common. Panicle initiation is the initial stage in the reproductive phase of expansion and denotes the beginning of panicle creation. The developing panicle has been microscopic in size in the stem, and panicle initiation can generally be connected with the beginning of stem internode creation.
As the internode elongation stage starts, an accumulation of chlorophyll occurs between the nodes. This accumulation of chlorophyll imparts a green colour that surrounds the developing internode, producing a green ring or band. Therefore, this internode elongation stage has been sometimes referred to as this green ring stage. This stage can be referred to as first green ring since additional internodes those form at the top of the first internode may also have the green ring impact as they start to form. A total of five internodes could be produced from the creation of a stem of rice. As internode and panicle creation continue, the panicle differentiation stage occurs.
Renu Joshi, Ph.D.