Rice growing zones

INTRODUCTION TO RICE

Rice is an essential food in the diet of one third of the world’s population. Its production and consumption is concentrated in Asia where more than 90% of the world’s rice is grown and consumed (David, 1991). In Pakistan, rice is an important food and cash crop, the second largest staple food crop after wheat and is the second major exportable commodity after cotton. Rice is planted on more or less 2.67 million ha (11% of the total cropped area), with total production of 6.68 million tones, and accounts for 17% of the total cereals produced annually (Anonymous, 2010). It accounts for 6.7 percent of value added in agriculture and 1.6 percent in GDP. Pakistan ranks 14^th in terms of rice production and 5^th country in the world for rice export. Every year around 1/3 of the total rice produce is exported and 2/3 is consumed locally.

Rice zones

In Pakistan, rice is grown under diverse climatic and edaphic conditions. Basmati predominates in traditional rice tracts of Punjab (Zone II). In Swat (Zone I) at high altitude mountain valleys, cold tolerant rices are grown. In the south of KPK, Sindh and Balochistan (Zone III and IV), IRRI type medium long grain heat tolerant tropical rices are grown (Figure 1).

            

                     Figure 1: Rice zones of Pakistan

Area, production and yield of rice

In Pakistan, rice is cultivated in all provinces under diverse climatic and soil conditions. The Punjab, Sindh, Khabir Pakhtoon Kuwa (KPK) and Balochistan, respectively account for 68, 24, 2 and 6 percent of the total area, and 59, 33, 2 and 6 percent production, respectively. Traditionally, two types of rice are grown (all irrigated) on flooded (puddled) soil through transplanting of 30-days old seedlings. The area under Basmati is the highest (51 %) followed by IRRI varieties (39%) and others varieties (10 %). The production of Basmati, IRRI and other traditional varieties is 37, 53 and 10 percent, respectively. Basmati is almost (96%) grown in Punjab, while IRRI type is shared 34, 52, 2 and 12 percent in Punjab, Sindh, KPK and Balochistan, respectively (Salim et al. 2003). The area under hybrids is increasing gradually and last year, the area under hybrid rice was almost 17 % in Sindh and 2-3 % in Punjab. During the current rice season (2011-12), hybrid area is expected to increase to 22 % in Sindh and 5-7 % in Punjab. A total of 22 % rice area is still under banned and low-yielding rice varieties.

Rice grain quality

Rice quality comes from a polygenic group of traits that are affected by environmental factors, crop management and the resulting interactions among these (Wrigley and Morris, 1997). Grain quality can be considered from several viewpoints: the grain’s external appearance, milling quality, cooking qualities, nutritional quality and quality related to food processing. Physicochemical properties of rice are the determinant of cooking and eating quality that effect overall acceptability of rice. The physical characteristics include gelatinization temperature. Gel consistency, alkali spreading, cooking and eating quality. Gelatinization temperature determine the time for cooking. Alkali spreading value is indirect measure of gelatinization temperature and is inversely correlated with gelatinization temperature. Aroma is special quality characteristics for rice acceptance

Definitions:
A) RICE: means milled rice which includes cargo rice, white rice, glutinous rice and boiled rice, whether it be whole grain, head rice, big broken, broken or small broken. 
1) Cargo Rice: (BROWN RICE, HUSKED RICE) means rice obtained from paddy of which only the husk has been removed. This includes its whole grain, head rice, big broken, broken, and small broken. 

2) Plain or White Rice: means rice obtained from paddy which has been husked and milled while by removing its bran layers. This includes its whole grain, head rice, big broken, broken, and small broken. 
3) Parboiled Rice: may be husked or milled rice processed from paddy or husked rice that has been soaked in water and subjected to a heat treatment so that the starch is fully gelatinized, followed by a drying process.

B) Grain Classification: means the proportional mixture of rice of difference classes to form a grade. Rice Kernal is divided into four classes namely: 
1) Extra Long Grain: shall be the head rice/whole grain having the average grain length of 6.90 mm or more. 
2) Long Grain: shall be the head rice/whole grain having the average grain length of more than 6.0 mm but not more than 6.90 mm. 
3) Medium Grain: shall be the head rice/whole grain having the average grain length of more than 5.0 mm but not more than 5.9 mm. 
4) Short Grain: shall be the head rice/whole grain having the average grain length of 5.00 mm or less. 
C) Yellow Kernel: means the kernel of which 25% or more of the surface area has turned yellow in color. 

D) Chalky Kernel: means the kernel of which 50% or more of the surface area is white like the color of chalk. 
E) Green Rice: means the kernel of green color in Cargo (Brown) rice which when broken is also green in color from inside or in the endosperm

F) Broken Rice: Broken of size ¾ length of grain and above shall count as head rice

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List of Pakistani rice varieties

Pakistan is blessed with multitude of agro-climatic conditions for growing several types of rice. Here are some of the common and popular varieties.

·         Super Basmati

·         Basmati 385 

·         Basmati 2000

·         Basmati 515

·         Shaheen Basmati

·         Basmati 198

·         IR-6

·         KS-282

·         KSK-133

·         NIAB IRRI-9

·         DR-82

·         Shahkar

·         JP-5

·         Swat-I,II

·         Fakhr-e- Malakand

Basmati has a distinct aroma in the field during milling, storage, cooking and eating. On cooking basmati almost doubles the length as compared to most of the non basmati varieties. Super basmati is the leading aromatic rice in the international market and fetch three to four times higher prices than the other long grain non aromatic varieties.

Basmati 385 is a short satured and short duration variety. Developed at KSK and released in 1988 for cultivation in Punjab. It attains height of 133cm and matures in 95-100 days yield is about 4000 Kg/ha. It is an aromatic variety and falls in long grain group (6.6 mm), breadth 1.6mm, with amylose content 23.18%.

IR-6 (Mehran-69) was officially released for cultivation in 1971 with the name IR-6 in the Punjab and Mrhran-69 in the Sindh. This is an introduction from IRRI. This variety is popular among growers due to its high yield. It is 115cm tall and matures in 115 days. Grain length of IR-6 is 6.60mm, breadth 2.0mm and the amylose content 26.4%.  Kernel of IR-6 has a chalky spot on the dorsal side.

KS-282 is a high yielding variety in the coarse group released by KSK. It matures in 100 days with about 6000kg/ha yields. It is 118 cm tall with clear and transparent kernel. A promising coarse rice variety for the southern Punjab. Kernel length is 6.70 mm and breadth 2.0 mm with amylose content 29.7%.