eChapters

Plant propagation techniques refer to the methods by which the plants are multiplied and increased in number.

Methods of Propagation

i) Sexual Method of Propagation - Seeds are used as propagating material.

ii) Asexual Methods of Propagation - Plant parts, other than seeds are used for plant propagation.

Plant propagation is the science of generating new plants. Basically, in plant kingdom, the plants multiply themselves either asexually or by sexual means. In asexual propagation methods, plants use any of the vegetative part of the plant to produce offspring such as stem, root, buds, etc. The plants thus produced are having exactly the same genetic blueprint as that of the parent plant. However, in the sexual method of propagation, the specialized parts of the plants which have undergone meiosis takes parts such as pollen and ovule to produce seed which on germination produces the plants having characters encoded on its genome. Such plants may have a blend of characters of both the parents. The seed production is a complex phenomenon which takes place after fertilization (Bhatnagar and Johri, 1972).

Spices play important roles in daily life and India is a rich repository of spices. Various biotechnological approaches like micropropagation, somaclonal variation, in vitro conservation, synseed technology, protoplast fusion, production of flavor and coloring components, and development of novel transgenics have great significance in conservation, utilization and increasing the production and productivity of spices. Protocols for micropropagation and production of disease free planting materials are available for many spices. Efficient plant regeneration protocols are also available for exploiting somaclonal variation ,where the available natural variability is relatively low. Technologies for isolation and culture of protoplasts were reported in a few spices. Development of transgenics for disease resistance is gaining momentum. Synseed and Micro-rhizome technology are also available for many spices for safe propagation, conservation, movement, and exchange of germplasm. In vitro and cryo preservation technologies for conservation of spices germplasm are available for many spices.

Since the dawn of civilization, the human species had an intimate association with fruits, roots, nuts and other vegetables that sustained them through the ages. This mutualism continued and flourished through domestication and organized culture of horticultural crops. Pretty long before, homestead gardening had been evolved in different parts of the globe independently to become a part of tradition in almost every society. Plant domestication by all likelihoods started around the human settlements. The obvious reasons for this were man’s need, better supply of water and organic household wastes and protection against destruction or grazing by animals, that’s why the prospective horticultural enterprise of homestead gardens all over the world is still the most enduring and sustainable form of family food production system and very important micro-units for conservation of plant genetic resources. The traditional and indigenous endeavour of the tribal people for conservation of land races also noteworthy contribution from one generation to the next. Though cereals are staples for most of the world population, there has been sustained emphasis on horticultural crops, particularly vegetables, all over the world during last few decades. The possible reasons are:

The Indian arid zone is characterized by high temperature and low and variable precipitation which limit the scope for high crops productivity. However, these conditions greatly favour the development of high quality in a number of fruits such as date palm, ber, aonla, bael, pomegranate, kinnow, lasoda and in vegetables cucurbits, legumes and solanaceous crops, spices, medicinal and aromatic plants. The existing low productivity could be increased by following improved technologies and inputs. It is now realized that there is a limited scope for quantum jump in fruit and vegetable production in the traditional production areas. The amelioration of the extreme conditions is also considered vital for life support to the inhabitants of this area. The recent awareness regarding the potential of these ecologically fragile lands for production of quality produce has not only opened up scope for providing sustainability for the people of this region, but also for bringing in new areas to increase horticultural production. The area expansion and yield potential of arid horticultural crops has increased many folds because of development of new varieties and advancement in production techniques in arid region.

Introduction

The green revolution technologies involving the greater use of synthetic agrochemicals with adoption of nutrient responsive, high yielding varieties of crops have boosted the production output. However, this increase in production has slowed down and in some cases there are indications of decline in growth of productivity and production. Environmental and health problems associated with agriculture. These questions have given rise to a process of serious thinking to safeguard the environment and the quality produce.

7.1 INTRODUCTION

Production of temperate-zone fruits in subtropics may seem fanciful to be initiated, but it is a practice that has existed in localized regions for generations. Seedling peaches are grown in Venezuela, Northern Thailand, and Southern Mexico. No one knows precisely when these species were introduced, but local selection has produced cultivars adapted to areas with little or no chilling temperatures. Rest either does not occur or is sufficiently shallow to be broken by stress induced by defoliation or drought. Commercial cultivations of temperate-zone fruits are well-established in subtropical areas, where winter temperatures allow partial breaking of the rest period. In areas of Northern Mexico, Southern Africa, and Israel, for example, chemical treatments are regularly applied to supplement the effects of limited chilling. Because temperature declines with increasing elevations, many microclimates exist in the subtropics where temperate-zone fruits are not currently grown, but could be. Subtropical regions where temperate fruits are grown include the southern past of California (Mediterranean type), the low deserts of the Southwest USA (hot arid type), the Gulf Coast and most of Florida (humid type), the Southern Mediterranean and Northern Sahara, Northern India, Southeast China, the middle part of South America, and much of Australia. Similar potential climatic conditions are also available in subtropics of India.

1. Introduction

As purveyors of ornamentation, inciters of attraction, symbols of inspiration and peace as well as repositories of beauty, flowers hold special roles worldwide. Flowers have always been associated with mankind since time immemorial because they were used in religious offerings and other social ceremonies. Today; floriculture has emerged as one of the most lucrative business profession and as a major diversification options in the agri-businessin many countries of the world due to higher income per unit area. Floriculture is also known as sunrise sector of agriculture because of its fast growing and increasing demand. In India, about 3,09,000 hectares across the country was used for floriculture and produced 23,88,000 metric tonnes (MT) of loose flowers. India is second largest flower producer after China.

Vegetables are short duration crops and provide more returns per unit area and time besides, they play a major role in balancing human diet, thus, helping in alleviating hunger and malnutrition (Annon., 2009). In the previous few years, India has attained quantum jump in vegetable production and present estimated vegetable production is around 162.9 mt in an area of about 9.4 mha (NHB, 2014), and holds second position at global level. But this level of vegetable production is insufficient to meet the recommended daily intake (~300 g per capita per day) for a huge population of the country. This is mainly due to lower average productivity (17.5 t/ha) of the nation. There are several crop diminishing factors such as soil borne- and foliar- diseases, insect-pests and nematodes as biotic factors, and soil or water salinity, alkalinity, metal toxicity and heat and moisture stress as abiotic factors, which greatly affect vegetable crops yield in almost all growing areas, especially in fragile arid and semi arid regions.

Abstract

Floriculture is the fast emerging sector in horticulture sector and people are changing very fast from the traditional field crops to flowers because of high returns per unit of area and better price. The flowers are being used during all the occasions. Though the art of growing flowers is not new to India, large scale commercial cultivation and protected cultivation in polyhouses is relatively new in India. With the opening up of world market in the WTO regime, there is a free movement of floriculture products worldwide. India is having a better scope in future as there is a shift in trend towards tropical flowers and this can be gainfully exploited by countries like India with high amount of diversity in indigenous flora. The major flowers grown under protected cultivation are rose, chrysanthemum, gerbera, carnation and lilium. Even some of the flowers are location specific and made a dent on the state economy, the best examples are carnation in Himachal Pradesh and gerbera in Maharashtra. Now with market trend is changing and biotechnological tools must be exploited for the crop improvement to evolve novel varieties with desirable colour traits. The other major area of work is on protected cultivation of cut flowers which is coming up on a large scale and value addition in floriculture i.e. extraction of pigments, essential oils, pharmaceutical and nutraceutical compounds have emerged as frontline avenues in floriculture. We have many challenges ahead like trained HRD, quality planting material, technical knowhow, limited choice of the varieties and products in the market to compete in global market.

The beginning of protected cultivation in the country has paved the way for export of horticultural produce, especially of flowers to earn valuable foreign exchange. The technology also became handy for quality production of flowers and F₁ hybrid seeds for domestic and export markets. In view of the globalization of international market and tremendous boost that is being given for export of flowers, there has been a spurt in the demand for protected cultivation technology. Low-cost polyhouses are quite popular in the North-East and in the northern plains, flowers are being raised in polyhouses either for capturing the early markets or to improve the quality of seedlings. Several commercial floriculture ventures are coming up in Uttrakhand, Maharashtra, Karnataka and Tamil Nadu to meet the demands of both domestic and export markets. There has been a substantial increase in area under protected cultivation of different flower crops. Though there were initial hitches owing to the cost sharing, farmers of some states have taken maximum benefits of the existing schemes and adopted the technology. Protected cultivation technology is one of the most useful technology inputs which hold promise to transform Indian floriculture and bring in the “Colour Revolution”.

Nearly, 40 countries are involved in protected cultivation of flower and vegetable crops. New production centers are being added constantly, mostly from developing nations. Today, majority of production is from developing countries like Zimbabwe, Morocco, Kenya, Ecuador, Costa Rica, Mexico, Singapore, Malaysia and India. In developed world, USA has an area of about 6,000 ha under greenhouses which are mostly used for floriculture. The Netherland is traditional exporter of greenhouse grown flowers all over the world. Israel, the largest exporter of cut flowers, has wide range of crops under greenhouses. About 1,000 ha area is under protected cultivation. Approximately, 98% of flowers are grown under open field cultivation and hardly 2% under the greenhouse cultivation.

Abstract

Demand for horticultural commodities is increasing over a period of time. There is increasing pressure on available land for growing of such crops. The production of quality fruits, vegetables and other horticultural crops can be enhanced either by increasing productivity, use of improved cultivars/hybrids and effective production system, bringing additional land under horticultural crops or by promotion of protected cultivation which supports production in adverse climatic conditions and off seasons. Among horticultural crops, production of vegetables, flowers, medicinal and aromatic plants under protected condition is the best alternative to use the land and other resources more efficiently. Greenhouse cultivation is useful and is in practice in all kinds of climatic conditions, may it be severe and extreme cold (Canada and Russia), intolerant summer (Israel, UAE and Kuwait), excessive rains (Phillippines) and in moderate climate in several other countries. Nursery production of crops under protected conditions is highly economically viable.

The area under protected cultivation was only 0.23 per cent of the total area under horticultural crops in India in 2012. To boost up this, a number of varieties are bred for cultivation especially under polyhouse conditions. Greenhouse for vegetable production encompasses glasshouse, polyhouse, insect-proof net house, low tunnel polyhouse and zero energy polyhouse. Protected structures are of different kinds, viz. open-ventilated; closed polyhouse with fan and pad system; shade net house; sloped roof, rain shelter etc. Micro-irrigation has proved its efficacy in saving water, improving the yield and also is responsible for reducing diseases which develop in rather moist conditions. Protected structures appeared as the best means and are being used by many nursery growers for multiplication of healthy planting materials and are becoming popular especially in the hilly regions. Use of techniques like soilless culture, production of high value and low volume flowers and vegetables, hybrid seed of important vegetable crops and grafting of promising varieties on desirable root stocks can be made more efficiently under protected environment. Seed yield of many crops can be 3-4 times more under cover compared to their open field cultivation along with ensured quality.

Protected cultivation technologies in Himalayan high altitudes of India for the welfare of the soldiers and the society are a landmark in cultivation of horticultural crops in non-conventional areas. The protected production system has the potential to contribute greatly for achieving high productivity and stability to production in the present scenario of climate change. Extension of growing/harvesting period including off season is another desirable feature associated with protected cultivation.

Abstract

Protected cultivation technology in black pepper and cardamom offers distinct advantages over conventional farming. Production of quality planting materials irrespective of the season was made possible. Such propagating materials can be well maintained under polyhouse, irrespective of the seasons and can be used judiciously for replanting/ gap filling. In this era of climate change, protected cultivation assumes significance. In black pepper and cardamom, rapid multiplication techniques of planting materials were made possible. A novel idea of growing pepper, different from conventional system as “bush” that can be grown under potted and field conditions were also developed. Nutrition and water management studies could be undertaken with precision. In cardamom, quality planting material production and high quality capsule production are made possible all throughout the year by the adoption of protected cultivation. For optimizing production, prescriptions of fertilizers, using DRIS norms were developed for black pepper and cardamom based on critical soil and foliar nutrient concentrations. Typical deficiency symptoms of major and micro nutrients on black pepper were characterized to rectify the deficiency. Technology for propagation and cultivation of bush pepper in pots, under protected cultivation was also developed and popularized. Technology for using organic manures, non edible oil cakes, biofertilizers towards production of high quality zero defect black pepper and cardamom was also developed and popularized.

Protected cultivation can be defined as a cropping technique wherein the micro-climate surrounding the plant is controlled partially or fully as per the requirement of the plant species during their growth period. This cropping technique is the most modern approach to grow different horticultural crops mainly, vegetable crops and flowers for enhancement of both productivity and product quality. This technology has spread extensively the world over in the last few decades. This technology involves the cultivation of different crops particularly, horticultural crops in a controlled environment wherein the environmental parameters like the temperature, humidity, light, soil, water, plant nutrition, etc. are manipulated for enhancement of production as well as product quality even during off-season which ensures additional return to the growers.

Growing population, rapid urbanization and changing climate have created a global challenge to meet the food and nutritional needs. In India, rapid urbanization is not only taking place in larger cities, but satellite towns are competing for food, water, transportation and above all adding to pollution of the environment. As warming of the climate gathers alarming pace, posing a danger to agriculture, greenhouse cultivation is the only answer to save crops of flowers and vegetables. The yield under polyhouse cultivation can be achieved to the level of 5-8 times as compared to open field cultivation.

PROTECTED STRUCTURES

Protected cultivation is unique and specialized form of agriculture. Protected or greenhouse cultivation of vegetables is one of the means for clean vegetable production in peri-urban areas. The protected cultivation facilitates year-round production of high- quality produce with minimum labour and irrigation water, and almost wards off pest problem. In peri-urban regions, where climate prevents or does not favour year-round production of crops in open field, vegetable production can be taken up in protected environment. Use of protected structure for cultivation of crops as a commercial venture is a recent phenomenon, especially in the tropical areas.

Protected cultivation is a specialized agricultural system in which a certain control of the soil–climate ecosystem is exercised modifying its conditions (soil, temperature, solar radiation, wind, humidity and air composition). Plants are cultivated by means of these techniques modifying their natural environment to prolong the harvesting period, alter the conventional cropping cycles, increase yields, improve product quality, stabilize production and provide products when open field cultivation is limited (Wittwer and Castilla, 1995). It is the most contemporary approach to produce mainly, horticultural crops qualitatively and quantitatively and has spread extensively the world over in the last few decades. Protected cultivation also known as controlled environment agriculture (CEA) is highly productive, conservative of water and land and also protective of the environment (Jensen, 2002). Protected cultivation is now becoming popular in Kerala experiencing humid tropical climate with the adoption of locally suitable green house technologies.

Protected cultivation has rapidly expanded in many regions across the globe as early as 1960, when plastics were introduced/used in agriculture and subsequently during 1970’s, when the rise in oil prices resulted in increase of energy costs. About 115 countries in the world are into greenhouse vegetable production commercially (Sabir and Singh, 2013). The world scenario shows the area under protected cultivation to be nearly 6,23,302 ha. while total estimated world greenhouse vegetable production area is 4,02,981 ha. Of the total world greenhouse vegetable area, soilless/hydroponic culture systems account for 95,000 ha (Hickman, 2011).

The advent of protected cultivation technology in India materialized during the early nineties, post globalization. In India, area under protected cultivation is presently around 25,000 ha while the greenhouse vegetable cultivation area is about 2,000 ha. Faced with constraints of land holdings, rapid urbanization, declining crop production, declining biodiversity and ever increasing population, demand for food, especially vegetables has increased manifold and protected cultivation has offered a new dimension to produce more in a limited area. Today Dutch protected cultivation is one of the most intensive farming systems in the world with high levels of output by using the latest technologies (Goncharova, 2004).

Abstract

Keeping in view the increasing demand of off-season and high value vegetables in several big cities of the country, there is an urgent need for diversification from the traditional agriculture by production of high value vegetable crops under different protected conditions for increasing their productivity and quality not only for getting high returns but in a Horti-Business / Veggie-business model. Nursery raising under protected cultivation is highly suitable for such Horti-business model or can be adopted as an agri entrepreneur business in major vegetable growing areas of the country by unemployed youths who are graduates in agriculture or post graduates in horticulture. Low cost protected technologies like plastic low tunnels or walk in tunnels, shade net houses can be used for off season vegetable cultivation for getting high returns. Similarly, insect proof net houses can be used on a large scale for safe vegetable cultivation by way of minimizing the use of pesticides in vegetable cultivation and virus free quality seed production in large number of vegetables in a horti-business model. Some of the technologies like low pressure drip irrigation and low cost nursery raising technology can also be replicated in other parts of the country even among the resource poor and tribal farmers.

Greenhouse

It is constructed by plastic, polythene, and fibreglass material having temperature control and ample light availability needed for propagating plants by seed, cutting and grafting.

Types of greenhouse

1. Based on shape and style: The commonly followed types of greenhouse based on shape are lean–to, even span, uneven span, ridge and furrow, saw tooth and quonset greenhouse.

Lean–to type greenhouse:

• It is limited to single or double–row plant benches with a total width of 7–12 feet.
• It is typically facing south side. It should face the best direction for adequate sun exposure.
• This design makes the best use of sunlight and minimizes the requirement of roof supports.
  • It has the disadvantages: limited space, limited light, limited ventilation and temperature control.

Greenhouses are frames or inflated structures covered with a transparent or translucent material in which crops can be grown under partially controlled or totally controlled conditions of atleast. It is large enough to permit persons to work within, to carry out cultural operations. Greenhouse cultivation as well as other modes of controlled environment cultivation has been evolved to create favourable microclimate, for the crop production all through the year or during off season, when the produce is highly priced and remunerative. Green house is a broader term of protected structures which includes different types of structures according to the need. Green houses vary in size and complexity from small home or hobby structures to large commercial units, from solar green house to sophisticated environment controlled ones.

1. Which type of vegetable is often grown in shade net house?

a) Tomato

c) Radish

b) Lettuce

 d) Cucumber

2. What is the primary advantage of greenhouse cultivation for vegetable production?

a) Increased exposure to natural elements

 b) Protection from pests and diseases

 c) Lower cost of production

 d) Reduced need for irrigation