Expert System for Paddy

About Rice

A staple food for over 2.7 billion people, rice is one of the world's three most important crops. Across India, rice is grown on 44.6 m ha for a total production of 80 million tonnes (paddy) with an average yield of 1855 kg/ha. It is grown in almost all the states. The states of West Bengal, Uttar Pradesh, Madhya Pradesh, Bihar, Orissa, Andhra Pradesh, Assam, Tamilnadu, Kerala, Punjab, Maharashtra and Karnataka account for 92% of rice production and area.

Kingdom	Plantae
Division	Magnoliophyta
Class	Liliopsida
Order	Cyperales
Family	Gramineae
Genus	Oryza
Species	Sativa
Sub-species	Indica

Roots	The root system is fibrous. Rice seeds give out seminal roots soon after sowing. These are temporary in nature. Secondary adventitious roots produce from the lower nodes of the culm are the real functional roots.
Stem (Culm)	The rice stem known as culm is hollow and is made up of nodes and internodes. Each node bears a leaf and bud, which may grow into a shoot or tiller. Primary tillers grow out of the main culm. Tillering continues in rice upto vegetative phase. Some tillers die during the reproductive phase due to competition for water and nutrients. Panicles bearing tillers are known as fertile or productive tillers.
Leaf	Each node of the culm bears a leaf. The leaf is composed of the following parts: Leaf sheath: It originates from the node of culm and many a times encloses it and sometimes even the next upper node and a part of the leaf sheath of the upper leaf. Leaf blade: It is the upper expanded part of leaf and begins at node, where it is joined with leaf sheath. At the joint there is a thick collar. Auricles: These are hairy appendages at the base of the leaf blade. Ligules: It is a thin papery structure just above the auricles. Different parts of leaf are of importance in identifying the varieties. Flag leaf: It is the uppermost leaf just below the panicle. It is generally shorter in length and remains erect at an angle
Panicle	The inflorescence of rice plant is born on terminal shoot and is known as panicle. It is determinate type and at maturity it is droopy in nature. Panicle bears the spikelets. Spikelet: A spkelet is the floral unit and consists of two sterile lemmas, a lemma, a palea and the flower. Lemma: It is a 5 nerved hardened bract with a filiform extension known as awn. Rice varieties may or may not have an awn. Palea: It is a three nerved bract slightly narrower than lemma. Flower: It consists of 6 stamens with two -celled anthers and a pistle with one overy and two stigmas. The pistil consists of one ovule.

Rice is a crop of tropical climate. However, it is also grown successfully in humid to sub-humid regions under subtropical and temperate climate. Rice is cultivated in almost all types of soils with varying productivity. The major soil groups where rice is grown are riverine alluvium, red-yellow, red loamy, hill and sub-montane, Terai, laterite, costal alluvium, red sandy, mixed red, black, medium and shallow black soils.

Latitude	39°S latitude (Australia) to 45°N latitude (Japan) and 50°N latitude (China)
Latitude (India)	8 to 35°N latitude
Temperature	20° to 40°C 30°C during day time and 20°C during night time (more favorable for the development and growth of rice crop)
Solar radiation	500-700 cal /cm-2 /day
Rainfall	150 cm to 200 cm

Agroclimatic situations	Seasons	Period
Agroclimatic situations	Seasons	From	To
General	Virippu (I crop/autumn)	April-May	Sept-Oct
	Mundakan (II crop/winter)	Sept-Oct	Dec-Jan
	Puncha (III crop/summer)	Dec-Jan	Mar-Apr
Onattukara	Virippu (I crop/autumn)	April	August
	Mundakan (II crop/winter)	Aug-Sept	Dec-Jan
	Third crop (where HYVs come up)	Feb-Mar	April
Kuttanad	Additional Crop	May-June	Aug-Sept
Kuttanad	Puncha	Oct-Nov	Feb-Mar
Kari soils	Additional Crop	June-July	Sept-Oct
Kole (Single cropped area)	Mundakan (Kadumkrishi)	Aug-Sept	Dec-Jan
Pokkali	Virippu (I crop/autumn)	May-June	Sept-Oct
Pokkali	Oorumundakan	Aug-Sept	Dec-Jan
Kaipad	Virippu (I crop/autumn)	April-May	Sept-Oct
High ranges	Nancha	May-June	Oct-Nov
High ranges	Puncha	Dec-Jan	Apr-May