Phenology of Rice

Phenology is the study of event in life cycle of plants and influence of physical factors like season, climate, soil, topography. Identification of each phase of rice crop play vital role in the management of nutritions , pests , diseases,fertilizers, in rice crops.

Advantages of phenological identification:

Help farmer to identify the appropriate period for the fertilizer application.eg urea is insert at time of field manipulation and foliar stage.
Preemergence and post emergence weedicides is easily detected and removed by effective distinction. Specially mimicry weeds needs appropriate attention.
Helps in research purpose for pest resistant or high yielding gene insertion.

The lifecycle of Rice plant consists of different 3 phase.They are as follows:

Germination to emergence phase: In germination stage ,at first radical appearsand then plumule appears which gives raises to seadling.

1.Vegetative phase:
This phase includes from seed germination to panicle initiation. This stage is accomplished within 60-70 days. It includes different stages:

Seedling stage: Leaf develops at the rate of one per 3-4 days.Upto 5 l eaf stage the seedling becomes autotropic.
Transplanting stage: Found in only transplanted rice but not in DSR.20-25 days old seedling are ready for translanting. Transplanting shocks for 5-10 days for development of secondary roots.
Tillering stage: 30-40 days seedling are visible in tillering .It is continued from primary to tertiary stages.

2.Reproductive phase:

It is carried from panicle initiation to flowering stage. It is observed in 35 days of seedling. It includes following stages:

Panicle initiation stage: flower premodium initiation at the tip of growing shoot.
Booting stage: This stage is also known a stem elongation or internode elongation stages. Production of auxin accelerates growth of internodes. Panicle cause buging in the leaf sheath.
Heading stage: This stage is also known as panicle emergence stage.Panicle tips emerges out of the flag leaf sheath. Its occurs 15 days after booting.
Flowering stage: It occurs 25 days after booting and 5 days after heading. Lodicules becomes turgid pushing lemma and palea apart thus open the flower out of pollination.After pollination ,lemma and palea are closed. Pollination is followed by fertilization.

3.Ripening phase:

It includes the flowering to fully mature stage. It starts from 25-30 days of seedling.It includes following stages:

Milky stage: The content of caryopsis are first watery then turns into white milky fluids which can be squeezed out. Time duration about 7- 12 days takes place.

Dought stage: 2- 3 days weeks duration take place . there are soft dought and hard dought stage. Soft dought stage is about 5-7 days. Hard dought stage is about 5-7 days.

Maturity stage: Physiological maturity: there is maximum dry matter accumulation in the seed. 80% grains in panicle are matured.

Harvestable maturity: Moisture content of the seed is reduced 90% grain in a panicle are matured.

Writer: Smirti Sharma (Student, Bsc. Ag IAAS Paklihawa Campus)