Executive Summary

To achieve nutrition and income security for the people, particularly in arid region, suitable horticultural production technology is of vital importance. Although the Indian Council of Agricultural Research (ICAR) started multilocation collaborative research in 1976, major initiative on this aspect was taken in 1993 with the establishment of National Research Centre for Arid Horticulture (NRCAH now as CIAH) at Bikaner. This strategic plan for arid zone horticultural research updates the ongoing programme nder the CIAH which is a part of the ICAR system under the Department of Agriculture Research and Education (DARE). 

"To conduct basic and applied research for improvement in productivity of horticultural crops and development  of horticulture-based cropping system under arid environment; and to act as a repository of information related to arid horticulture, so as to achieve the following objectives:

To introduce, collect characterize, conserve and evaluate biodiversity of horticultural crops under arid environment.

To utilize the available biodiversity and improve tyhe target crops to develop high quality and productive types having tolerance to biotic and abiotic stresses.

To study the factors related to rapid multiplication of propagules in case of established as well as new drops and the problems related to their growth and development.

To standardize agrotechniques with respect to efficient use of soil, water and nutrients for increased horticultural productivity.

To study the ecophysiological parameters of cropping system models for utilization of high temperature and radiation resouces alongwith studies on mechanisms of physiological adaptation of horticultural crops to drought, heat and salt.

To develop postharvest technology package for extended use of the horticultural produce of arid region.

To develop integrated pest and disease management technologies for horticultural crops under arid environment."

   The programme will be built on the basis of multidisciplinary projects comprising a series of activities. The developed technologies will be tested at relevant locations under the instrument of an All India Coordinated Research Project already in operation under the CIAH. Linkages to augment and strengthen execution of the programme will be maintained with several national and international organisations and developmental agencies.

   The present provision of professional staff of 21 will need to be raised to a level of 60 during 1997-2002 to support the expanded activities. Accordingly, the budgetary requirements will rise to Rs. 1800 lakhs from teh present level of Rs. 350 lakhs. Efforts will be made to generate internal resources to met part of the funding. Activities such as human resources development for research and development activities will also need to be strengthened.

1. Preamble

            During the V plan and ad hoc Project under AP Cess Fund Scheme was started by the Indian Council of Agricultural Research (ICAR) in 1976 at ten centres for research on some selected fruits in the semi-arid areas in India. After relocation and addition of some centers during the VI Plan, this became a component of an ongoing All ndia Coordinated Fruit Improvement Project of the ICAR. With further strengthening and modifications during the VIII Plan, this component was carved out to form the All India Coordinated Research Project on Arid Zone Fruits (AICRP on AZF) to conduct multilocational experiments on various aspect of fruits like ber, pomegranate, date palm, aonla, fig custard apple, bael, etc. at 12 centres in India, viz., Abohar in Punjab, Aruppukottai in Tamil Nadu, Anantapur, in Andhra Pradesh, Bangalore in Karnataka, Bawal in Haryana, Rahuri in Maharashtra, Faizabad in Uttar Pradesh, Mundra and Sardarkrushinagar in Gujarat and Bikaner, Jodhpur and Jobner in Rajasthan. The work programme of this Project was thus confined to multilocational testing of the technologies on some selected fruits being generated by the rather inadequate manpower and infrastructure inputs either in the ICAR Institutes such as Central Arid Zone Research Institute, Jodhpur (CAZRI) and Indian Institute of Horticultural Research, Bangalore (IIHR) or in the State Agricultural Universities (SAU’s) particularly in Rajasthan, Haryana and Gujarat.

            Realizing the potential of horticultural productivity or arid zones, the compatibility of these crops to the arid zone ecosystem and the need to achieve nutrition and income security for the people, the Indian Planning Commission, as recommended by the Working Group on Agricultural Research and Education, approved establishment of a National Research Centre for Arid Horticulture (NRCAH) during the Seventh Five Year Plan and upgraded to Central Institute for Arid Horticulture (CIAH) on September, 2001. Consequently, a Task Force, constituted by the ICAR in 1987, identified specific missions for its work. The Project Coordinator (Arid Fruits) was assigned additional responsibility of Officer on Special Duty to monitor the progress of the NRCAH in November, 1990. a site for its establishment was then selected and 125 ha land was acquired in November, 1992 close to thepremises of Rajasthan Agricultural University, Bikaner (RAU) on national highway 15. Eight posts of scientists were redeployed from IIHR to provide scientific manpower to the NRCAH. In April, 1993 the Project Coordinator (Arid Fruits) alongwith the establishment of AICRP on AZF was hifted from Haryana Agricultural University, Hisar (HAU) to Bikaner to ensure the growth of the NRCAH which actually started on creation of the required administrative, technical and supporting manpower in September, 1994.

  "to conduct basic and applied reasearch for improvement in productivity of horticultural crops and development  of horticulture-based cropping system under arid environment; and to act as a repository of information related to arid horticulture”,

and to achieve this, the following objectives have been identified:

·        The first objective is to introduce, collect, characterize, conserve and evaluate the biodiversity of horticultural crops under arid environment.

·        The second objective is to utilize the available biodiversity and improve the target fruit crops such as ber, pomegranate, aonla, date palm and cucurbitaceous, leguminous and solanaceous vegetables to develop high quality and productive types having tolerance to biotic and abiotic stresses.

·        The third objective is to study the factors related to rapid multiplication of propagules in case of established as well as new crops and the problems related to their growth and development

·        The fifth objective is to study the ecophysiological parameters of cropping system models for utilization of high temperature and radiation resources.

·        The sixth objective is to develop postharvest technology package for extended use of the horticultural produce of arid region.

·        The seventh objective is to develop integrated pest and disease management technologies for horticultural crops under arid environment.

3. GROWTH
3.1  Infrastructure
3.1.1  Research set up
A. Divisions

A.1 Crop improvement
            
            Fruit Breeding Laboratory: This laboratory is to work on improvement of selected fruits or arid region such as ber, pomegranate and indigenous under exploited fruit yielding plants. The laboratory will also work on commercial crops such as grapes, citrus, guava etc. through collaboration with relevant Institutions.

            Vegetable Breeding Laboratory: The laboratory is to work on improvement of vegetable crops of cucurbitaceae, Leguminosae and Solanaceae. Besides this, the laboratory will work on development of drought, heat and cold tolerant varieties for crops such as tomato, cauliflower, cabbage, pea etc.

            Biotechnology Laboratory: This laboratory will work on tissue culture, micro-propagation and genetic engineering for improvement of horticultural crops.

            Genetic Conservation Laboratory: This laboratory will work on conservation of genetic resources of horticultural crops in vitro and in field genebanks.

A. 2 Crop production

            Fruit Culture Laboratory: This laboratory is to work on agrotechniques wuch as propagation, planting systems, pruning, fruit growth and development, orchard floor management, etc.

            Vegetable Culture Laboratory: This laboratory is to work on nursery techniques, planting systems, crop rotations, interculture, off-season production, etc.

            Plant Pathology and Nematology Laboratory

            Entomology Laboratory

A 3. Water Managemetn

            Water Management Laboratory: This laboratory is to work on efficient use of water both under rainfed and irrigated systems.

            Meteorology Laboratory: This laboratory will collaborate in research activities related to efficient use of water and climatic resources.

            Soil and Plant Nutrition Laboratory: This laboratory is to work on integrated plant nutrient management.

            Plant physiology Laboratory: This laboratory is to work on adaptations to stress caused by drought, cold, heat and salt.

B. Units

B.1  Postharvest Technology

            Studies on postharvest techniques to improve storage life and quality of produce and on standardization of processing techniques of fruits and vegetables will be done.

B. 2 Social Sciences and Extension

            The unit will consist of Economics, Computer Centre, Statistics, Extension and AICRP Coordinating Unit.

B.3 Library

            The library of NRCAH (CIAH) subscribes national and international journals and has a collection of a large number of reference books.

B.4 Research Farm

            The research farm of CIAH has 124.58 ha land area. The farm has canal irrigation facility for more than 50 ha area. To ensure regular water supply, two water reservoirs with a storage capacity of 30 lakh litres of water have been provided.

            Facility of two tubewells to ensure water supply to the laboratories, residences and the research fields in case of erratic water supply from the lift canal has been developed.

3.1.2 Buildings

            The NRCAH (CIAH) has a provision for one double story Lab-cum-Office building covering a floor area of about 350m². A farm laboratory and farm sheds covering a floor area of 600m² have also been provided besides two security guard rooms, one at the gate and other in the heart of the farm complex. Seven residential quarters (1 Type V, 2 Type III, 2type II and 2 type I) have been provided.

3.2 Budget

            The budget provisions on arid horticultural research started towards the end of V Plan which grew considerably from VII Plan onwards as a result of provision of an independent All India Coordinated Research Project on Arid Fruits followed by establishment of the National Research Centre for Arid Horticulture at Bikaner. The details are given below:-

 3.3 Manpower

           The manpower provision for arid horticultural research grew from 52 in 1978 to 158 in 1992 (Fig. 1 and Table 1)

Fig 1. Growth and Manpower For Arid Horticultural Research

4. SALIENT RESEARCH ACHIEVEMENTS

            The research achievements monstly emanating from AICR on AZF are listed below:

4.1 Genetic resources and crop improvement

·        Collection of Annona, Carissa, Cordia, emblica, Ficus, Morus, Phoenix and Ziziphus and cultivars/germplasm of Aegle marmelos (bael), Annona squamosa (Custard apple), Emblica officinalis (aonla), focus carica (fig), Grewia subinaequalis (phalsa), Pheonix dactylifera (date palm), Punica granatum (pomegranate) and ziziphus mauritiana (ber) are being maintained in field genebanks at different locations of ndia. Collection of Prosopis cineraria (khejri), Citrullus lanatus (watermelon), Cucumis callosus (kachari), Opuntia ficus-india (cactus pear) have been made.

·        In ber, the early maturing cultivar, Gola performed well all over the country and the late maturing Umran had longer shelf life.

·        In pomegranate, cultivar selection Jyothi and IIHR Selection from Bassein Seedless, G-137 from Ganesh and P-23 and P-26 from Muskat have been made. Some hybrids (e.g. Mridula) having better quality attributes have been developed.

·        In aonla, besides the commercial cultivars Banarasi, Francis, Balwant and Chakaiya, new selections, viz., Kanchan, Krishna, NA-6, NA-7 and NA-9 have been made.

·        In bael, selection NB-5 has been found precocious and superior in fruit quality.

·        In date palm, early maturing cultivar Halawy has been recommended. Some promising palms bearing large, non-astringent doka fruits have been identified from the seedling groves in Kachchh district of Gujarat.

·        In custard apple, cultivar Balangar, Washington (PI 198797 and 107005) and interspecific hybrids Island Gem and Bullock’s Heart were recommended. Hybrid Arka Sahan has been developed.

4.2 Production techniques

·        propagation techniques have been standardized for ber (I-budding in polytubes), aonla (patch budding), bael (path budding) and custard apple (softwood grafting).

·        High density plantation (5x2m) has been standardized in pomegranate.

·        Pruning technique in ber (after 6 secndaries or 10-25 buds) and phalsa (at 100 to 150 cm height) have been standardized.

·        Black polythene in ber, local organic materials like baddy husk and groundnut shells in pomegranate and bui (Aerva tomentosa) in date palm were identified for mulching

·        Leaf sampling techniques have been standardized for ber (5^th and 6^th leaf from secondary shoots), pomegranate (8^th to 10^th leaf from tip), aonla (middle porition of 3 month old indeterminate shoots), custard apple (5^th leaf from growing tip and phalsa (4^th leaf from tip).

·        Nutritional doses have been recommended for pomegranate (625g N+250g P+250g K) and fig (900g N+250g P+250g K).

·        Fruit thinning in date palm (one-third strands from centre of bunch) and pomegraante (retaining 50 fruits per tree) and preharvest sprays in ber (750ppm Ethephon) and date palm (1000ppm Ethephon) have been recommended fro fruit quality improvement).

4.3    Crop protection

·        Chemical control schedule have been developed against major disease such as powdery mildew in ber (2-4 sprays of 0.1% dinocap or carbendazim), black leaf spot of ber (3-4 sprays of 0.2% captafol or mancozeb or copper oxychloride or 0.1% carbendazim), fungal leaf and fruit spot in pomegranate (4 sprays of 0.3% mancozeb or 0.4% copper oxychloride or 0.1% carbendazim), bacterial leaf and fruit spot in pomegranate (3 sprays of 500 ppm paushamycin+0.2% copper oxychloride), Graphiola leaf spot in date palm (4 sprays of 0.4% copper oxychloride), rust in fig (4 sprays of 0.2% chlorothalonil or 0.4% copper oxychloride).

·        Chemical control schedules have been developed against the major insect pests such as fruitfly in ber (prophylactic spray of 0.3% dimethoate or oxydemation at 70-80% fruit st; 2-3 sprays of 0.05% malathion + 0.5% gur or sugar), fruit borer in ber (0.08% monocrotophos or 0.01% fenvalerate), pomegraante butterfly (one spray of 0.002% deltamethrin and one spray of 0.2% carbaryl 50 WEDP) and fig midge (2 sprays of 0.05% monocrotophos 40EC or fenitrothion 50 EC or 0.1% carbaryl 80 WP).

·        Chilochorus nigritus has been identified as an important predator of Parlatoria scale in date palm.

4.4    Postharvest technology

Techniques for preparation of chhuhra  and pind khajoor (soft date) from doka fruis (hard ripe yellow) have been developed.

4.5    Publications

363 research papers, 154 popular articles and 36 technical documents were brought out.

4.6    Techniques/technologies generated

Thirty two agrotechniques were standardized at different centers in peninsular and north India. Three strategic technologies were also generated.

5. IMPACT ASSESSMENT

            As a result of research for the last two decades, considerable knowledge in arid horticulture has accumulated and thus the sector has already assumed great importance for development of the vast drought prone arid zone of India.

            There has been definite impact in terms of (i) awareness regarding potential of income generation by growing fruits and vegetables in arid region, (ii) increase in area and production of these fruits and vegetables in arid region and (iii) supply of fruits and vegetables for internal as well as export markets.

5.1 Growth of the commodities

            There has been spectacular increase in the production of fruits and vegetables in India during the past decade. The current annual fruit and vegetable production in India is respectively 39.5 and 70 million tones. In the arid region, the production of fruits increased from 0.6 million tones in 1984-85 to about 0.7 million tones in 1993-94 and that of vegetables from 0.6 million tones to 1.1 million tones during this period. Thus, even in the arid region the production increased rapidly. However, the availability of fruits and vegetables is very low in this region compared to the requirement of 1.1 and 1.9 million tones respectively considering the per capita per day dietar needs of 8.5g fruits and 250 g vegetables.

            The growth of area under fruits and vegetables in the arid region has been rather slow considering the potential. Area under fruits increased from about 50 thousand ha in 1984-85 to about 66 thousand ha in 1993-94 and that of vegetables increased from about 63 thousand ha in 1984-85 to 85 thousand ha in 1993-94. Considerable area has come up under ber in different parts of the contry. Its area increased from 243 ha in 1984-85 to 757 ha in 1994-95 in Rajasthan, from 626 ha in 1991-92 to 1432 ha in 1995-96 in Haryana and from 907 ha in 1980-81 to 1108 ha in 1994-95 in Karnataka. Area under pomegranate also increased from 92 ha in 1984-85 to 370 ha in 1994-95 in Rajasthan and from 1418 ha in 1980-81 to 1746 ha in 1984-85 in Karnataka (Fig. 2).

                                                                                                        FRUITS                                                     VEGETABLES

                        Fig. 2 Area and Production of Fruits and Vegetables

The growth of area under fruits and vegetables in the arid region has been rather slow considering the potential. Area under fruits increased from about 50 thousand ha in 1984-85 to about 66 thousand ha in 1993-94 and that of vegetables increased from about 63 thousand ha in 1984-85 to 85 thousand ha in 1993-94. Considerable area has come up under ber in different parts of the country. Its area increased from 243 ha in 1984-85 to 757 ha in 1994-95 in Rajasthan, from 626 ha in 1991-92 to 1432 ha in 1995-96 in Haryana and from 907 ha in 180-81 to 1108 ha in 1994-95 in Karnataka. Area under pomegranate also increased from 92 ha in 1984-85 to 370 ha in 1994-95 in Rajasthan and from 1418 ha in 1980-81 to 1746 ha in 1984-85 in Karnataka (Fig. 2)

Area under vegetable increased from 48315 ha in 1984-85 to 66553 ha in Rajasthan in 1994-95, from 39249 ha in 1985-86 to 79500 ha in 1994-95 in Haryana and from 111628 ha in 1980-81 to 147683 ha in 1984-85 in Karnataka. Plantations of regular aonla, bael and date palm orchards have started coming up in different parts of the country. Area under date palm, however, has not increased to that extent owing to lack of a fast multiplication technique to true-to-type plants. The economics return potential from these fruits in now well known even from areas with precarious resource endowments.

5.2 Input/output assessment

            In case of ber under irrigated conditions, the benefit cost ration comes to about 6:1 whereas, in rainfed conditions, it is nearly 2.4:1. In case of pomegranate, aonla and date palm the benefit ratio is 2.4:1, 2:1, 3.2:1 respectively.

5.3 Item by item assessment

            Fruit crops

            In ber, the identified varieties are in great demand. Tube method of propagation ahs been adopted by the nursery men for large scale multiplication. As a result, area under ber has considerably increased all over the dry areas of the country including peninsular region where it was almost non-existent earlier. The other production technologies relatred to pruning, moisture conservation by mulching, management of pests and diseases, etc. have not yet been fully adopted.

            In pomegranate, the identified cultivars as well as the new hybrids are being planted by the farmers on large scale. The production technologies related to nutrient application, training and optimum fruit load, control schedules against insect pests and diseases, water use and moisture conservation by mulches have not yet become  very popular.

            In aonla, the identified cultivars are spreading in different locations in India. Propagation technique is already being used by the farmers. The cultural techniques related to planting on saline wastelands and nutrient application are being popularized.

            In date palm, the identified varieties have not yet spread in spite of great demand because the available multiplication technique is too slow. The cultural techniques related to fruit thinning and control of insect pests and Graphiola disease have not been adopted by the farmers.

            In other fruits also wherever varieties have been identified, these are becoming popular. However, their regular cultivation in still negligible.

            Other horticultural crops

            Technologies specific to arid areas for other horticultural crops such as vegetable, medicinal, aromatic and ornamental crops are required by the farmers.

5.4 Lessons Learned, Suggestions and Options for Future

6. SCENARIO
6.1 Strength
Vast land resource
    The  vast area under the arid lands is a great resource  for the production of horticultural crops.  The Indian arid zone is spread over  nearly 31.7 million hectare land area of which 41.5 per cent  is  arable and 19 per cent is culturable wasteland (Fig.3 and Table 2).

Table 2. Arid regions in different zones of India.

Indira Gandhi Canal Project Area:

The  region has a major canal irrigation programme to  cover 15.37lakh ha area under the Indira Gandhi canal Project having a total feeder canal length of 649 Km.

Genetic resources

    Indian subcontinent is an important gene centre being origin of  nearly  166 cultivated plant species and rich in diversity  of  as many  as  320 species and their wild relatives.  The arid  region  has comparatively  fewer  plant species but several of them are  of  great horticultural value.  Ziziphus mauritiana (ber), Z. nummularia (jharber),  Cordia  myxa (gonda) yield edible fruits.   Seeds  of  Salvadora oleoides  (pilu)  yield oil.  The seeds of Acacia senegal  mixed  with unripe pods of Prosopis cineraria (khejri), unripe fruits of  Capparis decidua  (ker) and ripe fruits of Cucumis callosus (kachri),  commonly found  in  arid  region, are used to  prepare  a  delicious  vegetable (panchkuta).  Similarly, clusterbean, cowpea, amaranth, Cucurbitaceous crops  are  common vegetables.  Fully ripe pods of  khejri   are  very nutritious and contain nearly 56% carbohydrates and over 10%  protein. 

    Euphorbia antisyphilitica and Simmondsia chinensis have performed well in  the region.  The region is also rich in medicinal plants  such  as Balanites aegyptica (hingota), Commifera wightii, Catharanthus  roseus (periwinkle),  Withania somnifera (ashwangandh), Aloe barbadensis  and Cassia angustifolia (senna).

 Promising germplasms

    The  native  species such as  Prosopis  cineraria  (khejri), Ziziphus nummularia (jharber), Z. mauritiana var. rotundifolia  (boradi),  Capparis  decidua (ker), Citrullus  lanatus  (mateera),  Cucumis callosus (kachari) have considerable variability.  Fruit species  such as Ziziphus mauritiana, Punica granatum, Emblica officinalis,  Phoenix dectylifera  (date  palm),  Psidium guajava (guava),   Aegle  marmelos (bael), Morus spp. (mulberry), Carissa carandas (karonda), Cordia myxa (gonda) have performed well.

     Under the irrigated conditions, excellent quality production from fruits such as grape, sour lime, sweet oranges,  kinnow,  mango, papaya,  vegetables such as cucurbits, beans, tomato, brinjal,  chillies, okra, onion and leafy vegetables, medicinal plants such as Ocimum sanctum,  O.  basilicum,  Solanum sp., Opium  sp.,  isabgol,  vetiver, liquorice,  henbane and anise flower crops such as Damask rose,  marigold, jasmine, etc.

 Agroclimate conducive for quality production:

     The  peculiar agroclimatic conditions of the region  imparts unique quality in fruits such as ber, sweet oranges, papaya and  vegetables such as chilli, cumin, fenugreek and cucurbitaceous crops. Arid region  is  the  only area where commercial date  palm  production  is possible.

 Surplus family labour:

     Owing  to long slack seasons and low intensity of  cropping, there is considerable surplus family labour available in the arid zone farming communuities which can be put to use for increasing production of high value horticultural crops.

  Research infrastructure

The National Research Centre for Arid Horticulture alongwith the All India Coordinated Research Project Centres located in 8  State Agricultural Universities and 2 ICAR Institutes now provides a  strong infrastructure for research on various aspects of arid horticulture.

6.2 Weaknesses

Low productivity of horticultural crops:

    Considering that the small area under horticultural crops in the  region is mostly under assured irrigation and farily  good  care, the productivity of these crops is low (Fruit‑11.04 t/ha.; Vegetables 13.36  t/ha.).  The production of the fruits and  vegetables  in  arid region is respectively 0.7 and 1.1 million tonnes.

    This is mainly because of inadequate production  technology, related  to adaptable genotypes and optimum management.  Although  the region  has great potential for quality production of fruits  such  as grapes,  pomegranate,  ber  etc, vegetables  and  other  horticultural crops,  the suitable package of practices for these crops  to  achieve high  productivity under its peculiar agroclimatic conditions are  not available.     

 Poor soil conditions

     The  arid zone soils are very poor in fertility.  The  soils of the north‑western arid region described as 'desert soils' and 'grey brown soils' of the Order Aridisols are light textured.  The solum  of these soils is moderately calcarious (0.2% CaCO3) and below this solum at depths of 40‑120cm, a sharply differentiated zone rich in  alkaline earth carborates (5‑45% CaCO3) is present in the form of hard crystalline  concretions which may be many metres thick.  Most of arid  areas (about  64.6%)  is duny where the soils often contain 3.2‑4  per  cent clay and 1.4‑1.8 per cent silt.  The brown light loam soils occupy 1.7 per  cent  area which has loamy fine sand to fine sandy  loam  on  the surface  and a  heavier subsoil underlain with calcium carbonate  concretions.   Besides this, about 5.9 per cent area is covered by  soils having  hard pan, 5.6 per cent is under hills and pediments,  6.8  per cent  area  is alluvial duny and 1.6 per cent is  sierozems  extending from the soils of Haryana and the Punjab.  In Gujarat also, grey brown soils are widespread besides a large area having deltaic alluvium with small  area in Kachchh having deep black and medium black  soils.   In the peninsular India, a considerable part of arid region has red sandy soil and some parts have mixed black soils.

     The soils are poor in organic matter having per cent organic carbon of 0.03 in bare sand dunes to 0.1 in the stabilized dunes.  The soils are generally rich in total potassium (8250‑18980ppm) and  boron (1.9‑12.2ppm)  but  are low in nitrogen  (185‑150ppm)  and  phosphorus (285ppm) and micronutrients such as copper (10‑11ppm), zinc  (2.07ppm) and iron (20ppm).  The soils often have high salinity.

     Poor ground water resource

    The ground water resource is not only limited owing to  poor surface and sub‑surface drainage but is also generally highly  saline.  The  depth  of water ranges from 10m to as high as  140m.   The  other irrigation  water  resources  in the region are  seasonal  rivers  and rivulets  in  Gujarat,  surface wells and some  runoff  water  storage devices  (e.g.,  tanks, khadins).  Thus the water  resources  in  arid region are limited and can irrigate hardy 4% of the area.

    Low rainfall  
    
    The  mean annual rainfall in the Indian arid region is  very low  and  varies from 100mm in north‑western sector  of  Jaisalmer  to 450mm in the eastern boundary of arid zone of Rajasthan.  In  Gujarat, it  varies  from 300 to 500mm and in Haryana and Punjab  from  200  to 400mm. In peninsular region, the rainfall varies from 520 mm in Bellary (Karnataka)  to 748mm in Cuddappa (Andhra Pradesh).  Most of the  precipitation  in north western arid region occurs during  July - September in  about  19-21 rain spells. The moisture balance  scenario  in  arid region is given below:

Table 3: Moisture balance scenario in arid regions.

 6.3 Threats

    The  arid  zone ecosystem is very fragile and  is  prone  to serious imbalances even with slightest disturbance owing to mismanagement of resources or influx of external factors.

 Unscientific use of irrigation water:

     Indiscriminate  use  of  water has already led  to  rise  in ground  water  table and salinisation of soils in  the  region  making large areas unfit for horticultural production.

  Genetic erosion:

                With  the  growing population pressure the  indigenous  genepools are getting eroded. Since this trend is continued to grow  there is  danger of extinction of native gene pools. Also most part of  arid region is on international boarder, aggrevating such a threat for  the region.

     Recurrent drought and high potential evapotranspiration

     Arid  environment poses constraints to  productivity  mainly because  of abiotic stress owing to scanty rainfall, high summer  temperature,  high  solar radiation and high wind  velocity,  low  winter temperature, low soil fertility and high salinity in irrigation  water and soil. 

     Potential evapoptranspiration (PET)

    The potential evapotranspiration (PET) in the arid districts of Rajasthan varies from 2063.2mm at Jaisalmer to 1503mm at Sikar with a  moisture index value of ‑68.9 to ‑91.  In Gujarat, the  PET  varies from  1700 at Surendranagar to 2144.6mm at Rajkot with moisture  index value  of  ‑70 to ‑82%.  In Haryana and Punjab, the PET  value  ranges from 1615mm at Hisar to 1362.8mm at Ferozpur with moisture index value from  ‑58.9  to ‑72.9.  In the peninsular arid region, the  PET  value varies from 1857.1mm at Anantapur to 1738.1mm at Bellary with moisture index  value of ‑68.6 to ‑70.1.  This region is characterised  by  the extremes of temperature having dry and severe winter with  temperature as  low  as ‑4oC and very hot summer with temperature as high  as  48‑50oC.   In  summer,  hot winds (loo) are common and  sand  storms  are frequent.   Wind speed can be as high as 12 to 15.8km/hr  particularly during  the  summer.   The solar radiation both in  the  northern  and peninsular  India  is intense (from 414 cal/cm2/day in winter  to  612 cal/cm2/day  in  summer at Jodhpur).  Owing to these  conditions,  the atmospheric  vapour  pressure deficit reaches as high as  30mb  during May‑June.  These conditions get aggravated in the low rainfall years.

    Animal-bird-insect pests

The  presence of animal‑insect‑bird faunal complex  particularly concentrating in the localised green belts often poses problems.  The disease occurrences are comparatively fewer but are often observed to adversely affect.

6.6 Opportunities

Exploitation of indigenous variability

     Reserve  of  considerable variability of a number  of  hardy plant species which yield edible fruits and products of