Preface India is the largest producer of many fruit crops in the world. Among them, perennial fruit crops have immense scope in domestic and export market. The country also provides suitable climatic conditions for these fruit crops, but the productivity is low due to interactive effect of many dependent and independent factors. The lack of awareness and required knowledge about the successful production system of fruit crops of perennial nature lead to push them in unproductive and declining phase. The old senile unproductive trees which become problematic to the orchard growers, need to uproot and replace them with new plantation, which is a long-term venture. The developed rejuvenation technology and its successful implementation, can transform the old senile unproductive phase to young productive phase in a sustainable manner through the integration of medium-term strategic plan in a scientific and skilful manner by utilizing the benefits of existing rhizosphere, without any economic loss. This vital aspect of rejuvenation in old unproductive fruit trees, presents many (a variety) cross-cutting issues on the theme of restoration of youthful vigour, enhancement of quantum of quality fruit production, period of sustainability and above all the economic feasibility. This necessitated that a comprehensive book on this aspect be written, which has collective information with critical reviews and practical concerns to avoid the hitch at initial level of adoption for the invasive rejuvenation technology for old senile fruit trees. With this idea in mind, the present book ‘ Rejuvenation in Fruit Trees (Tropical and Subtropical)’, would be highly useful to students of Agriculture/Horticulture, at B.Sc, M.Sc. and Ph.D. levels, academic experts, researchers, scientists, administrators, policy-makers, farmers, exporters, entrepreneurs and other stakeholders in fruit production. The book consists of 17 chapters. The first 6 chapters deal with the concept, cause, need and strategic steps involved in technique of rejuvenation, while the rest 11 chapters takes care of high-value commercial fruit crops of woody perennial nature describing present status, various prospects and constraints, involved implementation strategies with integration of multipronged approaches where aftercare practices including nutrition, irrigation, canopy management have been given proper attention along with damages caused by disorders, pests and diseases. The current trends and requirements have also been brought within purview in addition to critical perspectives that foster a better understanding of its R&D issues for this technique, which is based on possible updated information vis-à-vis the long research and field experience of the author. The author acknowledge the help of scientists, experts and research workers in consulting their opinion, reports, research papers, books, bulletins etc., published in India and abroad. The author is also thankful to those fruit growers, where the successful implementation of the technology and success stories gave the courage to write this book. I am more thankful to Dr. Som Dutt, Editor, Indian Journal of Agricultural Sciences, and Indian Horticulture, DKMA, KAB-I, New Delhi, for critically editing and preparing the manuscript in an easily readable mode.

India is endowed with abundant natural resources and diverse agroclimatic conditions, which are ideal for cultivation of a number of annual or perennial crops, in different areas. Meticulous planning, extraordinary scientific support, judicious use of inputs and focused policy thrust have led to manifold increase in production and productivity of fruit trees. The horticultural crops, particularly fruit crops, are high-value and technology- intensive crops. Appropriate technologies are gaining popularity in entire country in view of their high potential of productivity, land utilization and more income. Today, our country is producing different kinds of fruits, but quantum of total fruit production is unable to cope with the present day demand. Various constraints, biotic and abiotic in nature, pose hindrances to meet the fuel potential. The poor productivity of fruit trees is the main reason of low availability of fruits. The low productivity of fruits is compounded by several environmental, genetic and conditional factors. Besides, productivity and quality of perennial fruits continued to remain low and there exists a wide gap in between actual and potential production. Visualizing the problems of perennial commercial fruit production, the main reason comes in forefront/top is a large number of old and senile orchards turning even unproductive, due to lack of information regarding non-adoption of appropriate agro-techniques and canopy management (Hare Krishna, 2012). Though, we have made rapid strides in fruit production, the productivity is very low compared to developed countries. The present scenario of production in our country is still technology deficit and what so ever the technologies are available very poor in adoption level and the situation still go worse even in the era of climate change. Present situation demands that new technologies are needed to push the yield frontiers further by utilizing inputs more efficiently, diversifying to more sustainable and yielding higher quantum of quality production, particularly by integration of invasive and non-invasive medium-term strategic technologies. There are still challenges ahead in the way of the research which require concerted efforts in organizing, conducting and developing the technology as well as the proper way they are transferred to growers. The new generation of technologies will have to be much more site-specific, based on high quality science and a heightened opportunity for end-users, participation/adoption in identification of targets and achieving the objectives. These must be not only aimed at increasing the growers/farmers technical knowledge and understanding of science-based timely operations. It will also need to take on challenges of integrating the socio-economic context and role of markets for profitability and economic viability.

Today, our country is the second largest producer of fruits in the world, yet the per caput availability of fruits is below the recommended level (Chadha et al., 2013). The major reason for low availability of fruits is poor productivity. In addition, pressure of burgeoning population and ever increasing demand also result in reduced availability of fruits. The production of fruit crops is still nature dependent. The problem of low productivity of fruits is compounded by several environmental, genetic and conditional factors. At present, there exist a wide gap in between actual fruit yield and their potential yield in almost all tropical and subtropical fruit species, particularly in perennial and woody trees of fruits. There is a great diversity in perennial fruit crops which permits considerable manipulation for various purposes and desirable outcome. For achieving even the average productivity in many fruit crops, the production constraints like lack of information regarding canopy management, non-adoption of appropriate agro-techniques and timely management practices are required, while the concern about existing a large number of old and senile orchards which has turned or are turning even unproductive needs attention (Hare Krishna, 2012). Though, the country’s fruit production status is showing an increase, but far below the potential production requires immediate attention to critically analyze the situation by revisiting the problems and its causes, identifying the gaps and development of need- based technologies in the present context.

The low productivity of perennial fruits has been attributed to various factors, like small size of holdings, preponderance of old and senile trees and poor management of inputs such as water, nutrients and pesticides. Thickly-shaded mango orchards in Malihabad areas of Uttar Pradesh (Kalloo et al., 2005; Mishra, 2013), lanky as well as sick tall unproductive litchi orchards in Muzaffarpur and its adjoining areas in Bihar (Kumar, 2008), seedling orchards of guava and citrus fruits throughout the country, including disease-affected aonla and other perennial fruit plantations are commonly seen in large tracts in different parts of the country (Pandey et al., 2013; Singh 2007). In pomegranate, the old orchards become non- productive due to incidence of pests and diseases, and negligence (Hiwale, 2009). The traditional trend of orcharding for most of the tropical and subtropical evergreen perennial fruit trees, in general, are regarded as not responsive to pruning. However, a number of observations made in recent decades have conclusively proved the effectiveness of this important operation in maintaining the sustained fruit yield and keeping the plant well within manageable limits. The efforts have been made to deal perennial fruits in quite details wherever deemed necessary. Climatic factors have been found to affect significantly on fruit bearing as a result of pruning treatments. Though, this aspect is one of the most misconceived and least understood when seen with shoot emergence and shoot physiology for perenation and phase change from vegetative to reproductive. Correct pruning may easily spell the difference between success and failure, yet many growers undertake infinite pains to get the best out of their trees but the neglect to give their consideration to important practice. It is obviously needless to mention here that their such efforts end in futility. For better understanding of principles and practices of pruning, it would be imperative to trace out its historical background. The present level of understanding about pruning has been developed through ages with the increased understanding of growth and developmental processes of fruit plants.

Rejuvenation of fruit trees is visionary approach to save the old senile declining trees for future sustainable quality fruit production through unique integration of invasive exhaustive operations in scientific manner and skilful management. Since unproductive and uneconomic orchards are in abundance, a large-scale uprooting and replacement with new plantations (rehabilitation) will be a long-term and expensive strategy. Therefore, research efforts have been initiated at various pioneer institutes/ SAUs to standardize. The technology for restoring the production potential of existing plantations by a technique called rejuvenation. Rejuvenation of old orchard is very vital under orchard management. Reiterative pruning and canopy re-building of perennial fruit trees is medium- term strategy requiring scientific skill and technique, for bringing back the youthful vigour with enhanced quantum of quality production in sustainable way within a time gap of three years for mango, litchi and cashew (Lal et al., 2000; Kumar, 2008), while two years for guava, aonla and pomegranate (Singh, 2007; Hiwale 2009) without any economic loss to growers. The old fruit orchards need to be rejuvenated since they show decline in yield and quality of produce. These trees/plants need to be rejuvenated which have attained a stage where they are no more profitable from the grower ’s point of view (Singh, 2007; Srivastava, 2007).

Perennial fruit trees build their woody architecture with some building blocks, i.e. modular units, known as metamer or phytomer (White 1979; Room et al., 1992; Hare Krishna, 2012). It consists of meristems initially an apex. When a meristem faces periods of dormancy during low temperature or pruning, later it appears as bud, whenever active, as such bud produces a growing point with sequence of meristematic tissues simultaneously called a sprout, i.e. extension unit or growth unit (Halle et al., 1978; Bell, 1991). The driving mechanism behind the pattern appears to be auxin production (and basipetal transport) when new shoots and leaves developed and are exposed to light (Sterck, 2005). Other feature of trees are to produce more xylems relative to phloem, accumulate xylem over time and may thus produce thick woody branches and stems. Further, attaining reproductive phase and reproduction processes compete with vegetative functions, depleting resources necessary for maintenance and growth (Fakhri et al., 1987). The idea that reproduction, growth and defence interact within the individual and compete for limited resource is now considered an established principle. Because there are trade-offs between a plant’s various functions and the concept of source, and sink helps to explain allocation patterns at both the physiological and evolutionary levels. Logical approaches have extended this hypothesis to an explicit as source and sink framework in which the effects of defence allocation on rates of consumption can be weighed against the effects on growth (Coley et al., 1985; Mooney and Gulmon, 1982; Fakhri et al., 1987). The allocation to vegetative structures has compounding interest for plant growth, as plant life-cycles begins with pure vegetative growth (Abrahamson, 1979), also consistent with the idea that perennials must forego some reproductive expenditure to retain sufficient resources for perennation.

There is an urgent need to take up productivity improvement programmes in the senile plantations, with fresh stock supported with appropriate and integrated combination of inputs, pruning and grafting as well as training techniques taking care of health, vigour and productiveness. This require proven technology implementation through individual farmers, farmers’ cooperatives, self-help groups, NGOs, growers’ associations and commodity organizations. However, technology depends upon the nature and requirement of a particular fruit crop. The rejuvenation technology for transformation of old senile orchards into young productive ones in sustained manner requires well-planned and concerted efforts. Though processes and procedures require scientific skill with precision in application/implementation as these important commercial crops have been associated with livelihood of many farmers/growers, i.e. why economic production is of utmost important for the growers as it holds true for all the region specific important commercial fruit crops in general. The successful translation of rejuvenation technology in old senile orchards includes sequential operational steps. They should be followed in scientific manner for different category/group of fruit crops.

Aonla or Indian gooseberry (Emblica officinalis Gaertn), belongs to family Euphorbiaceae, is indigenous to Indian subcontinents (Morton, 1960). It has become an important commercial fruit crop in India, due to its hardy nature, suitability to various waste lands, high productivity, nutritive and therapeutic values (Singh et al., 2003). In its processed form, is very popular among the social elites (Singh, 2012). As an indigenous fruit, it has extensive adaptability to grow in diverse climatic and soil conditions ranging from plain lands to hills. The climate ranging from hot tropical plains to humid subtropical mid-elevation hills has been found suitable for its cultivation. It is successfully raised in arid, semi-arid, coastal and warm temperate conditions. Similarly it grows well in saline, alkaline and degraded as well as in sandy, red and clay soils (Singh, 2012). It is not merely a source of nutrients and medicines but its cultivation is also highly remunerative for small and marginal farmers. Traditionally, aonla has been a common crop of forest or household, but during the last decade or two, unprecedented expansion has been witnessed in the sphere of aonla cultivation across the country, utilizing the wasteland. Many small and big orchards have been established. This has resulted in efficient utilization or resources culminating in increase in farmers’ income and nutritional security coupled with enhanced employment and better utilization of wastelands.

Bael [Aegle marmelos (L) Correa.], a native fruit of religious importance, is well known to the Indian people for its nutritional and medicinal values. Leaves are used as sacred offering to ‘Lord Shiva’. All parts of plant viz., leaves, roots, bark, fruits, seeds etc. are used in preparation of various Ayurvedic medicines. Bael fruit is rich in protein, fat, minerals (Ca and Fe) and vitamins (riboflavin, β carotene and Vitamin C). Fruits are used to improve the digestive system and to cure stomach diseases. Fruits can be processed into various beverages and preserves (Jauhari and Singh, 1971). In spite of its Indian origin and high medicinal and nutritional values, well organized orcharding of bael is not commonly seen in the country. It is mainly found in wild and semi-wild condition throughout the India. Besides, it is also grown in the homestead gardens, backyards, religious places and farmer’s fields (Misra and Uniyal, 2013).

Ber (Zizyphus mauritiana Lamk), is an ancient fruit crop of India. It is relished for its sweet and sour fruits. The fruits are nutritious containing high amount of vitamins like C, A and B complex. The genus Zizyphus belongs to the family Rhamnaceae, consisting of 40 species of tropical and subtropical regions of northern hemisphere (Yadav et al., 2005). The one Zizyphus jujube (Chinese jujube) and the other Zizyphus mauritiana (Indian ber) are the two important species grown widely in temperate, tropical and subtropical regions of the world. The ruggosa and nummalaria are other important species. PRESENT STATUS Ber, a popular fruit, is being grown as almost commercially important fruit crop. It has better adaptability in marginal soils in arid region of subtropics. It is mainly grown in India as well as different countries in central Asia, China and Taiwan. It has been truly called as poor man‘s fruit/poor man‘s apple. Ber can suitably be grown almost in all the parts of north Indian plains in Uttar Pradesh, Haryana, Punjab and Rajasthan. Seedling ber trees are found extensively growing widely in arid and semi arid areas.

Cashew (Anacardium occidentale), is an evergreen tree in the family Anacardiaceae. It is grown for its edible fruits (nuts). Cashew originates from North-East Brazil (Salam and Peter, 2010). As a fast growing woody perennial, is characterized by spreading branches. Cashew trees can reach a height of 12 m and have an economic lifespan of 25 years. A Canopy of cashew develops irregular if not checked properly. In later stage, its canopy shape and size become difficult to manage (Nalini et al., 1999). Manipulation of canopy size and shape by means of pruning and training for its containment and better yield was not felt as a necessary orchard management technique for cashew. Majority of the older plantations are of seedling origin of non-descript material and have poor genetic potentiality. They have become senile. Such plantations can be rejuvenated provided they are managed properly and not very old (Gurupasand et al., 2012). If the plantations are of improved varieties having good genetic make-up such plantations can be rejuvenated by limb pruning or if they are genetically low yielders they need to be top-worked by beheading and grafting with better material for improving the yield performance.

Genus Citrus (Citrus spp.) belongs to family Rutaceae and subfamily Aurantioedae. Citrus fruits are cultivated over a wide range of agroclimatic conditions because of their ability to adapt to different situations. Citrus is considered to be one of the most remunerative fruit crops in India, having a lasting niche in the international trade and world finance. Most of the Citrus species are believed to be native to tropical and subtropical regions of southeast Asia, particularly, northeastern India and the region between China and India (Ghosh, 2007). Trees belonging to genus Citrus are comparatively small in size (other perennial fruit crops) and evergreen in nature that are grown in tropical, subtropical and even mild temperate climates. Citrus fruits are nonclimacteric so they do not ripen further once removed from the trees. So it is important that they are picked at the right stage of maturity.

Guava (Psidium guajava L.), belonging to family Myrtaceae, is cultivated and naturalized in the tropical and subtropical regions of the world. It occupies fifth place in area (0.15 million ha.) and fourth place in fruit production (1.80 million tonnes) in India. It has gained considerable prominence owing to its high nutritive value, availability at moderate price, a pleasant aroma and good flavour. Its fruits are used for both, fresh eating and processing. It excels most other fruit crops in productivity, hardiness, adaptability and vitamin C content. Besides its high nutritive value, it bears heavy crop every year and gives handsome economic return involving very little inputs. This has prompted several Indian farmers to take up guava cultivation on a commercial scale (Chadha, 2003). Guava trees are not difficult to grow and can survive in a range of soil and climatic conditions. However, precise management is required to produce a highly profitable crop.

Jackfruit (Artocarpus heterophyllus Lam.), belonging to the family Moraceae, is indigenous to the rain forests of the Western Ghats of India (Menon and Peter, 2011; Amma anbd Kumaran, 2011; Alila and Sanyal, 2011). It spread early onto other parts of India, south-east Asia, the East Indies and the Philippines. It is often planted in central and eastern Africa and is fairly popular in Brazil and Surinam (Menon, 2011). Its tree is adapted to humid tropical and near-tropical climates. The jackfruit tree is handsome and stately. In the tropics, it grows to an enormous size. One of the popular cultivar, Ceylon, was introduced into India from Ceylon and planted extensively in our country. PRESENT STATUS India is the second largest producer of jack fruit in the world and better known as the motherland of jackfruit (Verhji and Coronel, 1992; Chadha, 2003; Amma and Kumaran, 2011). Though, it is indigenous to India, but also found widely grown in Bangladesh, Burma, Sri lanka, Malaysia, Indonesia, the Philippines, Brazil and other tropical countries (Milan, 2011). In India, it has wide distribution in Asam, Tripura, Bihar, Uttar Pradesh, foothills of the Himalayas and Kerala, Tamil Nadu and Karnataka. Jackfruit is the national fruit of Bangladesh. It is one of the three auspicious fruits of Tamil Nadu along with mango and banana. Jackfruit is very extensively grown all over the state of Tripura. As per the records of the Department of Horticulture and Soil Conservation, Government of Tripura, the area under jackfruit is about 9,012 ha with a total production of 2,69,404 tonnes (2012-13).

Litchi (Litchi chinensis Sonn.), a member of the Sapindaceae family, originated in China. An arillate fruit, it is widely cultivated in subtropical regions of the world, providing livelihood security to millions of people in south-east Asia (GalanSauco and Menini, 1989; Menzel and Waite, 2005). Litchi is important commercial fruit crop in India. It is popularly known as “queen” of fruits due to its attractive colour, taste, flavour and excellent quality. Nutritionally, it is rich in sugar content with appreciable content of protein, minerals, fibres, vitamins and calorific value. Litchi is consumed mainly as fresh and little as processed form. The juicy aril is an excellent thirst quencher. It is highly perishable in nature. The short span of fruit availability coupled with poor shelf-life, limits duration of its availability in the domestic as well as international market. Till date, it is meagrely exploited for potential production and due R & D support is still lacking. PRESENT STATUS At present annual fruit production is around 585,300 metric tonnes from an area of 84,170 ha and the national productivity is 6.95 tonnes/ha. In India, main production region is concentrated in Bihar, West Bengal, Uttar Pradesh, Uttarakhand, Assam, Jharkhand, Tripura, Punjab, Haryana and Himachal Pradesh. The area under this crop has undergone substantial expansion in the past 64 years with plantation increasing from 9,400 ha in 1949 to 78,000 ha, in 2013 (NHB, 2013). Till date, the present level of production is unable to cope up with the ever-increasing demand. Its fruits are available from early-May to July in different areas.

Mangoes (Mangifera indica L.) belong to the family Anacardiaceae, has become naturalized and adapted throughout the tropics and subtropics. There are over 1,000 varieties throughout the world, which is a testament to their value to mankind. Popularly known as ‘King of Fruits’, mango is eaten throughout the world. Commercial mango cultivation is based on locally adapted and recommended cultivars. There is a great diversity in mango fruit which permits considerable manipulation of various purposes and markets such as juice, candy, chutney, amchur, pickles, jam, jelly, fresh fruit, canned and/or dried fruit etc. Given the multiple products, it is therefore a potential source of foreign exchange for a developing country as well as a potential source of employment for a considerable seasonal labour force. PRESENT STATUS India is the leading country sharing 42.1 % of the world mango production. Currently, it is cultivated in 22,97,000 ha with a total production of 1,51,88,000 tonnes. In India, all fruits share 29.25 % of total land and 31.13 % of total fruit production of which, 36 % of land and 20.3 % of production is under mango. Mango prefers a warm, frost-free climate with a well defined winter dry season. Rain and high humidity during flowering and fruit development reduces fruit yield. The tree generally flowers in mid- to late winter, while fruits mature during early to mid-summer. Mango trees are usually between 3-10 m (10–33 ft) tall but can reach up to 30 m (100 ft) in some forests. The canopy is evergreen with a generally spreading habit. The heavy canopy of the mango is a source of shelter and shade for both animals and human beings. It occupies a pre-eminent place among sub-tropical fruits grown in some states.

Pomegranate (Punica granatum L.) commonly known as ‘Anar’, is an ancient favourite table fruit of tropical and subtropical regions of the world. It belongs to family, Punicaceae. There is a great diversity in pomegranate. Originated in southern Asia and said to be native from Iran to the Himalayas in the northern India (Sandhu and Gill, 2013). The orcharding of pomegranate is somewhat expansive and skilful job. The perennial nature of fruit take longer period to come to bearing stage (3-4 years). Thereafter due to neglect in management practices the annual production, many a times compels the orchardist have to go for distress sale of entire poor quality produce. But, the successful commercial fruit production with increased quality production has made significant contribution to economic development of the grower and ultimately those in the growing region in sustainable manner.

Sapota or sapidilla or bully tree or chiku (Manilkara achras (Mill.) Fosberg) is a delicious tropical fruit crop, was introduced from tropical America. Among lesser-known fruits, area expansion and production of sapota have been observed spectacular. During as the area under sapota is fast increasing and this crop is attaining the status of major fruit crop. PRESENT STATUS India is considered to be the largest producer of sapota in the world, though it is considered to be a minor crop in India (Bal, 1997). The area under sapota in India during 2000-01 was 69,400 ha with a production of 6.74 lakh tonnes, while during the year 2012-13, it was 164000 ha with a production of 14.95 lakh tonnes (ICAR-DataBook 2014). The area under sapota is increasing so rapidly owing to a wider range of adaptability. In many regions, cultivation of sapota is preferred over mango (Bal, 1997). The important sapota growing states are Maharastra, Gujarat, Andhra Pradesh, Karnataka, Tamil Nadu, Kerala, Uttar Pradesh, West Bengal, Punjab and Haryana. Recently, our country has made a beginning in export to Middle East countries.

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