UNIT-II
Climatic Requirement for the cultivation of horticultural Crops
Climate
The climate is the most important factor on which choice of the crop for a region depends climate is defined as the whole of average atmospheric phenomena for a certain region calculated for a period of thirty years. These phenomena are light, heat, water and air.
Light
Intensity and duration are the two aspects of light which are important for plant development. The light intensity can be judged from the number of hours of bright sunlight or of the cloudiness of the sky. Usually, horticultural crops need a lot of light and need to be grown in a sunny climate, but there are few crops which can tolerate shade eg. ginger and turmeric.
• A third group requires permanent shade like carambola, salak palm & duku.
• Photoperiod or Day length is the duration of light for the time elapsing between dawn and dusk.
Heat
It is a non-mechanical energy transfer with reference to a temperature difference between a system and its environmental surrounding
• Heat-average temperature of a place gives an idea about heat units available based on which crop can be decided. Temperate fruit crops like almond, apple, peach, pear and plum become dormant due to short-day conditions in the region and need chilling of various lengths to break dormancy
• On the other hand very high temperatures observed in the arid region cause sunscald, wilting, necrotic spot and even death of plants.
Water-
• Water is vital for plant growth and development as a substrate in photosynthesis, distribution of metabolites and nutrients, regulation of plant temperature.
• It is also present in the atmosphere as humidity in the form of vapour. This atmospheric humidity also influences the growth and development of plants. High humidity: Sapota, Banana, Mangosteen, Jackfruit and Breadfruit. Low humidity (Dry): Ber, Grape, Date palm, pome
• Air -
Air is a mixture of oxygen, nitrogen and other gases that encompasses the earth and forms its atmosphere. Air is one of the climatic factors Determining plant growth.
Horticultural Zones of India
The Indian subcontinent is bequeathed with a great variety of climate and soil conditions.
India can be divided into tropical, subtropical and temperate regions.
In each broad category, there are variations due to rainfall, humidity, altitude etc. Reflecting these aspects six different horticultural zones have been recognised
Temperate:
(i) Kashmir, Himachal Pradesh, North Uttaranchal, Sikkim and part of Arunachal Pradesh.
(ii) N. W. Subtropical: Rajasthan, Punjab, Haryana, Central Uttar Pradesh and North Madhya Pradesh (MP).
(iii) N. E. Subtropical: Bihar, Jharkhand, Assam, Meghalaya, Nagaland, Manipur.
(iv) Central tropical: South Madhya Pradesh, Chattisgarh, West Bengal, Orissa, Gujarat and Maharashtra.
(v) Southern tropical: Andhra Pradesh, Karnataka and Tamil Nadu.
(vi) Coastal tropical humid: Konkan, Goa, Kerala, Western Ghats, the Eastern Ghats in Tamil Nadu, Andhra Pradesh and Orissa.
Agroclimatic zones of India
1. Western Himalayan Region: This zone consists of Punjab and Haryana, Union Territories of Delhi and Chandigarh and Sriganganagar district of RajasthanThis consists of three distinct sub-zones of Jammu and Kashmir, Himachal Pradesh and Uttar Pradesh hills.
2. Eastern Himalayan Region: Arunachal Pradesh, Sikkim and Darjeeling hills, Assam and Jalpaiguri, Meghalaya, Manipur, Mizoram, Tripura, Nagaland and West Bengal fall under this region, having high rainfall and high forest cover.
3. Lower Gangetic Plains: The Lower Gangetic Plains region in West Bengal consists of four sub-regions. This zone values for about 12% of the country’s rice production.
4 Middle Gangetic Plains: This zone consists of 27 districts of Bihar plains & 12 districts of eastern UP.
5. Upper Gangetic Plains: This zone consists of 32 districts of UP divided into 3 sub-zones of Central, North-West and South –West.
6. Trans-Gangetic Plains: This zone consists of Punjab and Haryana, Chandigarh & Delhi.
7. Eastern Plateau and Hills: The eastern Plateau and Hills the region consists of the following Sub-region of Wainganga, Orissa inland & MP Eastern hills.
8. Central Plateau and Hills: This zone comprises of 46 districts Uttar Pradesh, Rajasthan & Madhya Pradesh.
9. Western Plateau and Hills: This zone comprises of major parts of Maharashtra and some parts of MP.
10. Southern Plateau and Hills: This zone comprises of 35 districts of Tamil Nadu, Karnataka & Andhra Pradesh.
11. East Coast Plains and Hills: This zone includes Orissa coastal, North Coastal Andhra and Ganjam & South Coastal Andhra.
12. West Coast Plains and Ghats: This zone runs along the west coast, covering parts of Maharastra, Goa Karnataka, Kerala & Tamil Nadu.
13. Gujarat Plains and Hills: Consists of 19 districts of Gujarat
14. Western Dry Region: This region covers 9 districts of Rajasthan
15.Islands Region: This zone covers the island territories of the Lakshadweep & Andaman and Nicobar.