Modern horticulture may be defined as an agricultural science which treats of the production, utilization and improvements of fruits, vegetables and ornamental plants. The term is derived from the Latin word hortus ‘garden’ and cultura ‘cultivation’.
Development of Horticulture in India:
Indian Council of Agricultural Research’s Vision for Development of Horticulture:
The ICAR is an apex body at the national level mainly responsible for adding, promoting and coordinating agricultural research in the country. It has the concurrent responsibility of research, education and extension education.
The objectives of the ICAR during the IX Five Year Plan are as follows:
1. Conservation, planned enhancement and utilization of agro-biodiversity.
2. Enhancing productivity through evolution of high-yielding hybrids and varieties.
3. Research on diversification, quality improvement, post-harvest technology, value addition and export-oriented commodities.
4. Sustaining enhanced productivity of irrigated agriculture and judicious development and use of energy, especially renewable sources of energy.
5. Characterization and development of sustainable land-use models for rainfed agriculture in high-rainfall areas.
6. Development of the integrated pest management (IPM) and integrated nutrient management system (INMS) approaches and systems for sustainable agriculture.
7. Fostering excellence in relevant basic and strategic research.
8. Generating research and technologies geared to promote equity among regions, sectors of society and gender.
9. Strengthening social science, policy planning, agri-business, research monitoring mechanisms, administration and personnel reforms, publications and information dissemination system.
10. Strengthening Agricultural Research Information System (ARIS).
11. Promoting Agricultural Human Resource Development (AHRD).
12. Linking scientists with the farmers through Institute-Village Linkage Programme (IVLP)-an innovative technology transfer model.
13. Institutionalization and strengthening linkages/partnership with the CGIAR and other national and international agencies and research and development establishments, non-governmental organizations (NGOs), farmer organizations, private sector etc.
14. Optimization of resources through planning, prioritization and coordination.
The translation of these objectives into programmes and activities would certainly develop horticultural research in India.
Role of Indian Institute of Horticultural Research:
Dr. I. S. Yadav, Director of Indian Institute of Horticultural Research, Bangalore has recently projected the role of the institute. The institute undertakes research in fruit production since 1968.
The institute is working on the following objectives:
1. Enrichment of germplasm from indigenous and exotic sources for tropical fruit – mango (south and western India), banana, grape, papaya, litchi, jackfruit, macadamia nut, avocado, mangosteen, longan, rambutan, custard apple, fig, lime and jamun.
2. Screening of germplasm for various traits like high yield, dwarfness particularly in tree fruits, high nutritive value, processing and export qualities.
3. Breeding varieties for desirable traits like high yield, dwarfness particularly in tree fruits, high nutritive value, processing and export qualities through conventional breeding techniques and also biotechnological approaches.
In mango, focus will be on dwarfing and freedom from spongy tissue while it is on resistance to canker in acid lime, resistance to Fusarium wilt in banana, resistance to mildews in grapes, F1 hybrids for fruit drop in papaya, deep red and bold arils in pomegranate, better keeping quality and more pulp to peel ratio in custard apple.
4. Maintenance of field gene banks of mango, fig, papaya, pomegranate, jack fruit and other minor fruits at IIHR, Bangalore, litchi and certain citrus species like pummelo, lemons and citrons at Ranchi; sapota and passion fruit at Chettalli (Karnataka); ber and aonla at Godhra (Gujarat).
5. High density planting in mango, guava, ber and pomegranate.
6. Efficient nutrient management through orchard efficiency, leaf nutrient standards, fertigation and integrated nutrient management.
7. Determination of water requirements of different fruit crops like mango, acid lime, pomegranate and standardisation or water management practices including micro-irrigation and rain water harvesting.
8. Standardisation of agro-techniques for those promising from new introductions like rambutan, macadamia nut, avocado, mangosteen and longan for increased productivity.
9. Developing fruit based cropping systems for mango, sapota, litchi and ber.
10. Work on war footing on improved measures to prevent post-harvest losses which include studies on storage, packing and transport and popularization of fruit products.
11. Intensive work on all aspects to produce export suitable fruits.
12. Concentrated research on fruit crops suitable for dry land conditions and arid and semi-arid regions.
13. Introduction and cultivation of fruits with export potential like mangosteen, macadamia nut and Kiwi fruit.
Job Carrier:
The ornamental industry provides a wide variety of jobs for many categories of people, directly or indirectly. Conducting a computer search via the Internet reveals a wide variety of advertised jobs.
A. Direct Jobs:
A large number of jobs require knowledge and training in horticulture. The level of training could be vocational or at the college level. The work may be indoors or outdoors. Intense manual labor or paperwork in the office may be involved.
Many jobs in horticulture require a high school diploma and a short course in horticulture or agriculture. A college education provides more in- depth knowledge of the field and offers job opportunities at supervisory or managerial levels and to conduct research.
The following are selected categories of jobs that require varying degrees of familiarity with horticulture:
1. Greenhouse manager or worker
2. Nursery manager or worker
3. Florist
4. Golf course manager or worker
5. Landscape designer or architect
6. Tree surgeon
7. Groundskeeper
8. Garden center manager or technician
9. Vegetable
10. Fruit grower
11. Flower grower
12. Researcher
13. Extension officer
14. Sales or marketing officer
15. Teacher, and
16. Farm manager.
Certain jobs do not require any familiarity with horticulture by way of formal training. For example, one can find numerous fobs in the greenhouse that require only an ability to follow directions and instructions directions and instructions and a sense of responsibility. Many workers in the greenhouse perform jobs such as watering, transplanting, filling pots with media, harvesting produce, and so on. Job prospects for those who pursue formal training in agriculture or horticulture are very bright.
B. Indirect Jobs:
The ornamental industry has spawned a number of supporting or service industries, including the following:
i. Research:
Many scientists are engaged in developing new and improved types of vegetables, fruits, and ornamentals. These new cultivars may have wider and better adaptation, be higher yielding and of higher nutritional quality, and have other qualities depending on breeding objectives. Research is conducted in both private and public sectors (at universities, research institutes, and research companies) to find solutions to problems in the horticultural industry.
College-level training (often graduate level) is required to adequately prepare for a career in research. Research institutes invest a great amount of human and financial resources in developing new cultivars, which is why commercial seed companies sell their improved seed (such as hybrid seed) at premium prices. Apart from improving the agronomic and nutritional qualities of plants, horticultural scientists also devote considerable time to improving the aesthetics of ornamentals and the quality of products.
ii. Chemical Industry:
The horticulture industry depends on large amounts and varieties of chemicals, including fertilizers, pesticides and growth hormones. Many companies involved in producing chemicals that are used to enhance plant production and the quality of produce. Chemicals are an integral part of modern high- input production practices.
The increasing trend toward ensuring a safer environment has been the impetus for the creation and enforcement of laws and guidelines for the judicious and safe use of chemicals. Crop production using little or no chemicals, called organic farming, is gradually gaining popularity.
iii. Machinery:
Engineers design and produce tools and machinery for use in the production of horticultural plants. Machinery and implements are available for preparing land, planting cultivating, spraying, harvesting, storing, and packaging. These aids enable large-scale production of horticultural plants to be undertaken. Home garden versions of some of this machinery and equipment are available.
Horticultural products are transported from the areas of production to marketing outlets. Because of their largely perishable nature, horticultural produce and products require special handling in transportation to retain their quality for a long time. Certain items require refrigeration during storage. Horticultural has spawned an elaborate transportation and distribution network.
Because most horticultural products are harvested and used fresh, the ability to preserve quality in transit is critical to the industry. In certain cases, the produce is harvested before it ripens in order to increase its shelf life. Home gardeners have the advantage of ready access to vine-ripened and fresh produce.
Numerous jobs are available in these four general areas at various levels. These jobs can be obtained by persons trained in fields other than horticulture, such as basic science, engineering, economics, marketing, agribusiness, genetics, and post-harvest physiology.
Climatic Zones of Horticultural Crops:
Agro-ecological zones (AEZs) are geographical areas exhibiting similar climatic conditions that determine their ability to support rained agriculture. At a regional scale, AEZs are influenced by latitude, elevation, and temperature, as well as seasonality, and rainfall amounts and distribution during the growing season.
Agro ecological zoning (AEZ) defines zones on the basis of combinations of soil, landform and climatic characteristics. The particular parameters used in the definition focus attention on the climatic and edaphic requirements of crops and on the management systems under which the crops are grown.
Each zone has a similar combination of constraints and potentials for land use, and serves as a focus for the targeting of recommendations designed to improve the existing land-use situation, either through increasing production or by limiting land degradation.
Climatic conditions of a particular region are complex and with varied environmental factors which influence the fruit production. It includes several basic environmental conditions such as temperature, rain fall, humidity, and lights.
India has diversified climates right from temperate to tropical climates. So, India has been divided into 3 horticultural zones.
They are:
1. Tropical zone.
2. Subtropical zone.
3. Temperate zone.
Entire South India below the Vindhya hills comes under this zone. This zone is again sub-divided in to 3 sub-zones.
They are:
(i) Central tropical zone,
(ii) Southern tropical zone, and
(iii) Coastal tropical humid zone.
(i) Central Tropical Zone:
States of Maharashtra, Orissa, Southern part of Madhya, Pradesh (Chhattisgarh) and Telangana area of Andhra Pradesh comes under this zone.
Fruit crops recommended – Mango, Cashew, Citrus, (Sweet Orange, Mandarin orange, and limes), Grape, Guava, Sapota, Banana, Sitaphal, Fig, Ber, Pomegranate, Jamun, and Jackfruit.
(ii) Southern Tropical Zone:
Andhra Pradesh excluding Telangana, Tamil Nadu, Kerala and Karnataka states comes under this zone.
Fruit crops recommended – Mango, Coconut, Banana, Cashew, Sapota, Pineapple, Mangosteen, Breadfruit, Jackfruit, Sitaphal, Areca nut, Rubber, Pepper, Turmeric, Clove, Nutmeg, Cocoa, Coffee, Citrus (Sweet Orange, Mandarin orange, and limes).
(iii) Coastal Tropical Humid Zone:
Areas covering all along the coast of different states of peninsular India up to about 160 km inside to the sea shore line. The climate will be always humid and warm. Temperature will not be mild in winter when compared to southern tropical zone.
Fruit crops recommended – Coconut, Banana, Cashew, Jackfruit, Mango, and Pineapple.
The area above the Vindhya hills comes under this zone. Occasionally frost occurs in this zone. This zone is sub-divided into two sub-zones basing on the direction.
They are:
(i) North-Western Subtropical Zone:
States like Rajasthan, Punjab, Haryana, Gujarat, Parts of Bihar, U.P, M.P and west Bengal comes under this zone.
Fruit crops recommended – Litchi, citrus (sweet orange, mandarin oranges), dates, guava, sapota, Papaya, phalsa, fig are some typical subtropical fruits grown but other tropical fruits like Mango, jack, banana can also be grown etc.
(ii) North-Eastern Sub-Tropical Zone:
Areas like parts of UP, Bihar, West Bengal, Assam, Meghalaya, Manipur, Nagaland, Mizoram, Arunachal Pradesh, and Tripura.
Fruit crops recommended – Litchi, Citrus (Sweet Orange, Mandarin oranges), Dates, Guava, Sapota, Papaya, Phalsa, Fig, Mango etc.
Areas comes in this zone are Jammu and Kashmir, Kullu, Katrain, Kangra valleys of Punjab, parts of Himachal Pradesh and Kumaon hills and also high altitude regions in South India- Nilgiris and Palani hills of Tamil Nadu. This zone frequently experiences frosts. This zone is further sub-divided in to two sub zones based on elevation.
They are:
(i) Higher elevation, and
(ii) Lower elevation.
(i) Higher Elevation:
This elevation ranges from 1500—2500 m MSL.
Fruit crops recommended – Apple, Pears, Walnut, Almond, Cherry and Strawberry etc.
(ii) Lower Elevation:
This elevation ranges from 1200—1500 m MSL.
Fruit crops recommended – Peaches, Persimmons, Japanese plum etc. Although Peach is a temperate fruit crop, a no. of varieties like Sharbati, Honey stone, Sunred and Safeda can be successfully grown in the northern plains of subtropical zone. Similarly Rome beauty an apple variety is grown around Bangalore.
Elevation is not only the factor which decides the prospects of fruit cultivation in temperate zone. Other factors like hail storms, rainfall etc. which should also be considered for selection of site for fruit cultivation in temperate zone. Eg. Simla and Solan at 2100 and 1400 m of elevation from sea level respectively.
But they are not suitable for growing fruits because of hail storms. But Kullu valley and Kotagarh regions in Punjab are free from hailstorms and are suitable for growing temperate fruits.
Fruits growing zones are based on the climatic factors. These zones are tropical, sub- tropical, temperate and arid zone. However, there are certain to exceptions to this, e.g., grape can be grown in temperate and sub-tropical regions, while papaya can be grown in tropical and sub- tropical condition.
This class of fruits is grown successfully in cold regions where the temperature falls below freezing point during winters. During the cold season, the trees, sheds their leaves and goes into rest period. For breaking this rest period, a definite chilling period is required. This class of fruits includes fruits like apple, pear, walnut, almond, plum, peaches, strawberry etc.
This class includes fruit crops which are unable to endure cool temperature. Some of them are being severally injured by even the temperature somewhat above the freezing point. This class of fruits required hot and humid climate in a summer and mild winter. This class includes only evergreens such as mango, Sapota, papaya, cashew, pineapple, banana etc.
This class includes fruit crops intermediate in character to tropical and temperate. These fruits are grown mostly in plains where the climate is hot, comparatively dry and winter less severe. This class of fruits include fruits lie citrus, phalsa, fig, guava, and pomegranate.
Besides these zones, the arid region has extreme climatic conditions. In arid zones rain is very greatly low and its distribution is erratic leading to low plats stand and productivity. To make it still worse, the water storage capacity of soils in these areas is very low, being mainly poor textured and shallow soils, and is compared with high evaporative losses.
The arid fruit crops can be grouped in two categories:
1. Deep rooted and short flowering and fruit set on the commitment of the monsoon and complete apple fruit development before the soil moisture stress, such crops are custard apple, ber tamarind, aonla, marking nut etc.
2. Fruits, flowering starts after rainy season and harvesting will be during summer season, such crops are very handy. Ex. Mango, Beal, jamun, phalsa, wood apple, charoli, cashew nut, jackfruit, kokum, karvanda, mulberry, etc.
Fruit Growing Areas and Varieties in India:
The nature has given to India diverse geographical soil and agro-climate conditions in various regions. Thus it is possible to grow different kinds of fruits in the different states of India. The climate ranges from typical tropics in Kerala to extreme temperate in the high hills of Kashmir, Himachal, U.P., Arunachal Pradesh and Meghalaya. Similarly, Meghalaya get the highest rainfall in the world and Rajasthan get very little rain.
It is therefore, possible to grow tropical sub-tropical and temperate fruits in the different regions. The total production of fruits estimated to be about ten million tonnes. Fruits like banana, mango, citrus etc., are indigenous to India. Similarly there are many minor fruits which may be indigenous to this country.
The fruit industry in India must receive attention to solve some problems like citrus decline, mango malformation, wilt of Guava, banana bunchy top, papaya mosaic etc. It is desirable that dwarf and early varieties of the major fruit crops should evolve. The manuring and fertilization of the fruit trees should be on scientific basis as it is done by empirical formula. Leaf analysis should be basis for nutrition of fruit trees.
Every nursery catalogue mentioned various varieties under each fruit crop but whether they are clone or variety is not yet established. Much advance has not been done in fruit breeding in India. Mallika in Mango and Lucknow-40 in Guava have been introduced from abroad and some indigenous, clones.
Besides the above major fruit crops, there are several small or minor fruits growing in sub-tropical climate in Assam, West Bengal, Meghalaya, Arunachal, Nagaland, Tripura, Kerala, Orissa and Tamil Nadu in home gardens. Some of these fruits have local importance.
Some of the minor fruits are-Rose apple, Watery rose-apple, Wax apple, Carambola, Longan, rambutan, Governor’s plum, jambolan, Surinam cherry, passion fruit, Sour soup and many citrus species, Mulberry and Tree tomato etc.
Besides the above important varieties, the total germplasm available in India of various important fruits are as follows:
(a) Almond – 48
(b) Apple – 502
(c) Apricot – 52
(d) Cherry – 68
(e) Grape – 816
(f) Guava – 114
(g) Mango – 813
(h) Peach – 119
(i) Pear – 112
(j) Plum – 177
(k) Walnut – 23
The collections are scattered in the different states and research stations. In India there are 41 Fruit Research Stations.
India is blessed with variety of fruits and vegetables of tropical, sub-tropical and temperate. In fact with the growth of research, facilities intensive work has been undertaken at various places in the country and at the Indian Agricultural Research Institute, New Delhi on various facets of the improvement of fruit crops.
The opportunities for the improvement of fruit and vegetable crops are almost unlimited. The development of new and better plants by hybridization is by no means limited to those plants now being grown in home and commercial plantings.
It is well known that wild plants have been the source of most cultivated plants. Naturally, the most striking and outstanding fruits and superior strains alone make many worthy and a few tremendously valuable selections.
Development and Improvement of Varieties:
All kinds of fruits and vegetables need further improvement is fully recognized. In general, the development and improvement of variety is done by the choice of chance seedlings, the procuring and utilization of worthy mutations (bud sprouts) and the selection of hybrids by hybridization investigations. Varieties are desired to have higher dessert, better shipping, storing and keeping qualities. Mutants are more suitable for particular purposes, and show easy adaptation to different regions and conditions.
It is well known that the perfect varieties do not exist. Yet, it is equally well understood that these are vast possibilities for improvement. A variety that may be particularly suited for home uses, because of its delicate texture, fine flavour and superior quality, may not possess satisfactory handling and shipping requirements.
Most of the important varieties now in cultivation originated as chance seedlings. Seeds dropped by chance in fields, gardens and other locations sprouted and developed into seedling trees, and vines. When these were worthy they attracted the attention and finally were reproduced by different methods and brought to the attention of producers.
When the cell division in the vegetation tissues of plants occurs for some reason to reproduce a new cell is not exactly like the parents. This results occasionally in the branch or bud that varies in some respects from other branches and buds of the parent tree.
If this variation is true mutation it may be reproduced when propagated vegetatively. These so called bud sports or mutations may occur in individual leaf, branch, entire tree or fruit. Worthy bud mutations, offer the most rapid method of improvement of the present standard varieties.
Hybrids results from the crossing of two or more varieties. It is generally concluded that hybridization offers the greatest possibilities for producing new types with incorporation of new characters to improve production, increase vigour and hardiness in fruits.
Vegetables in general require less time for improvement by hybridization than fruits. In facts, they are often designated as short term crops. From example, vegetable seed produced from controlled crosses may be planted the following year and crops are produced. In the case of fruits like mango and apples, seeds from crossing may produce plants and require 8 to 10 years to produce fruits.
By hybridization many new varieties with higher yields, better flavour, better storing and keeping qualities etc. have been evolved in both fruits and vegetables.
Planting System for Horticultural Crops:
Planting of horticultural crops is the process of transplantation of plants at prefixed place. The meaning of refers to transfer of a plant from a pot to its permanent place in the ground. It is the transfer of plants originally raised in seed beds for early intensive care to their permanent place in the ground. In transplanting seedlings, particularly of annuals, one has to avoid bunching and haphazard distribution.
During transplantation thinning of the plants is done according to need. The transplantation is beneficial to most plants whose seeds are very small and it also allows economy and convenience in the use of seeds. With normal care, a majority of the seedlings can be transplanted safely.
Planting Material:
Planting material plays an important role in the production of horticultural crops. Inadequate availability of quality planting material is one of the important deterring factors in development of a sound horticulture industry. At present 30-40% demand for planting material is being met by the existing infrastructure.
Any fruit crop is perennial in nature and takes a minimum of three years after planting to bear the first fruits. In spite of repeated cautioning, the farmers fail miserably in establishing their orchards due to faulty planting materials. Whenever due care is not taken to procure genuine planting materials, farmers will face a lot of problems in undertaking maintenance operations; thereby they lose their hope and incur heavy loss.
Farmers are keen in procuring genuine planting materials they are unaware of the techniques in identifying the correct nurseries to source the right planting materials from. There are certain guidelines to be followed for selecting planting materials.
Nurseries should have a well maintained mother block (scion bank), which should have proper labeling of the variety, the nursery should maintain the documents for the source of planting materials for the mother block, the grafts should have proper labels of the variety and the date of grafting should be displayed.
Normally farmers procure the grafts without seeing the plants at the nurseries. One should realize that the fruit plants will start bearing only after four or five years and if the fruits are of poor quality, faulty planting materials are responsible and whatever money and energy have been spent are a waste.
Identification of Planting Material:
An easy technique to identify the best quality planting material is that all the grafts of a particular variety should be uniform in their leaf characters. If variation is observed among the grafts displayed with the label of a particular variety, then these can be adjudged as faulty, poor quality planting materials. Further, the saleable grafts in the nurseries should be properly hardened before delivery which can be judged from the label displaying the date of grafting.
Planting is done in a small hole which is made in the centre of the pit which should be slightly larger than the ball of earth holding the roots of the plant. Before putting the plant in to the hole, all the damaged roots are pruned. The roots are spread out in the hole in their natural positions and covered with soil. The hole is then pressed down firmly.
The plant is then thoroughly irrigated. In the absence of rain the plant is watered once in three days liberally. The newly plant should be protected against severe sun especially during summer and provided with stake to avoid its shaking due to heavy winds.
Season for Planting:
The best season for planting and transplanting depends on the agro-climatic zones and species to species. Since the fresh planting material is environmentally sensitive, hence hot weather is generally avoided since there is a great risk about their establishment.
It is a common practice the transplanting should be done in rainy season, so that the transplanted plant can survive well. In heavy rainfall localities and water logging areas planting and transplanting operation are best postponed till about the close of the rainy season.
Carefully dig up a group of the small plants with a knife or plant label. Avoid tearing roots in the process. Let the group of seedlings fall apart and pick out individual plants. Gently ease them apart in small groups which will make it easier to separate individual plants. Handle small seedlings by their leaves, not their delicate stems. Punch a hole in the medium into which the seedling will be planted. Make it deep enough so the seedling can be put at the same depth it was growing in the seed flat.
After planting, firm the soil and water gently. Keep newly transplanted seedlings in the shade for a few days, or place them under fluorescent lights. Keep them away from direct heat sources. Begin a fertilization program.
When fertilizing, use a soluble house plant fertilizer, at the dilution recommended by the manufacturer, about every 2 weeks after the seedlings are established. Remember that young seedlings are easily damaged by too much fertilizer, especially if they are under any moisture stress.
Transplanting:
1. Transplanting Shrubs and Trees:
The shrubs and trees are raised from the seed stock. The seedlings are carefully transferred to polythene bags or pot of required sized, care should be taken to remove polythene cover at the time of transplanting. The plant is placed in a pit dug for planting and finally covered with soil. Seedlings of such plants are raised in earthen pots (10 cm diameter and 20 cm height) are used for raising seedlings.
After marking out of the positions for planting pits of appropriate size are opened well in advance at least a fortnight before planting, while digging the pits, the top soil which is generally good is kept on one size, unmixed with the rest of the soil. The soil is prepared along with the mixture of 3:2:1 part of manure and red earth.
If the soil is good it is mixed with manure alone. Sand is added to the soil if it is heavy. The top soil is used for filling up the upper portion of the pit. The pit is watered and gently pressed down a day prior to planting so that it would not further settle down after planting.
2. Transplanting Grafted Plants:
The grafts, before sale, should have been hardened for a minimum period of three months. In reputed nurseries, hardening is normally done by gradually exposing the grafts to open sunlight.
Another confusion which quite often bothers the farmers relates to what types of planting materials have to be used for different fruit crops. Except banana, acid lime and papaya most of the other fruit crops are cultivated by planting grafts.
Farmers usually prefer tall vigorous and two-year old approach grafts. But, considering the cost, difficulty in transport and poor field establishment, these grafts are not recommended for planting and at present it is recommended to plant soft-wood grafts. These two types of grafts exhibit good field establishment with less mortality and faster growth.
Since, these two methods are very easy and rapid; the nurserymen also have started producing these grafts. In recent times, the farmers have also realized that these grafts are better than the approach grafts.
3. Transplanting Corms, Bulbs and Tubers:
During dormancy (resting period) the underground corms (caladiums and gladiolus), bulbs (amaryllis and lily) and tubers (Begonia and dahlia) are to be separated. Washed, treated with plant protection chemicals and stored in sand until the next season. Runners or suckers of chrysanthemum (Perennials) and ferns, when overcrowded, can be transplanted by dividing the rooted side shoots to other pots especially in the beginning of the monsoon.
Methods of Digging:
Digging is dependent on the type of soil. For clay, digging is best undertaken in the autumn, leaving it exposed to the winter frost to break up the heavy clay sods. For light soils should be left until the early spring. If the soil has become hard and compacted, a fork may be the most useful tool. It is easier to insert into the ground than a spade and is effective at breaking up lumps and clods. You can opt for either a single or a double dig.
A. Single Dig:
1. This means taking out a single spit (spade’s depth) of soil. A single dig will be sufficient if the soil compaction is confined to the topsoil.
Proceed as follows:
2. Lay a string line across the width of the area to be dug, giving you a 1 ft. (30 cm) wide strip. Take out a spite of soil from one end, and place it in the corner diagonally opposite.
3. Facing this hole, and working backwards from it, drop a forkful of compost or well-rotted manure into the hole. Take out a spit of soil from the nest 1 ft. (30 cm) of earth in your strip and drop this on top of the organic material. Continue in this manner until you reach the end of the line and have dug a strip the width of your fork; you are left with a hole 1 ft. (30 cm) square.
4. Move the string on a spade’s width. Drop some organic material into the remaining hole in the first line. Take a spit of earth from the second line and drop it into the remaining hole in the first line. Continue in this manner along line two, and repeat until you have reached the end of the last line, dropping a forkful of organic material into each hole, until you reach the original spit of earth which will be waiting to be dropped into the last hole.
5. If you are using fine-quality, tilth-like compost, this is best reserved for the surface. If the soil is poor, you could incorporate some, and leave the rest for the surface.
B. Double Dig:
Double digging is the taking out or working on two spits of soil, down to the subsoil level. For new ground, or for the soil of poor state or overgrown with weeds, digging is the arduous task.
It will certainly be necessary if compaction has formed a hard pan at subsoil level. This will improve the structure of the subsoil. It is important, however, to take care that you do not allow the subsoil to be mixed with your topsoil. There are two ways to do a double dig.
1. The first is to take out your spit of topsoil as with a single dig. Then, before dropping in organic matter and filling the hole up with topsoil, use your fork to loosen the subsoil. This will help break up the compaction and aerate the subsoil.
2. The second method is more thorough, and even more arduous. It requires a spit of subsoil to be excavated, after you have taken out the spit of topsoil.
The technique is as follows:
(a) Proceed as for the single dig but start by removing two spits of topsoil to the far diagonal corner and also one spit of subsoil.
(b) Turn the exposed subsoil from hole two into hole one. Incorporate organic matter.
(c) Start hole three, taking a spit of topsoil and dropping it into hole one over the organic matter. Take a spit of subsoil from hole three and drop it into hole two.
(d) Proceed right through the area until the last two holes are reached.
(e) If weeds are being incorporated, take care to turn the topsoil spit over when incorporating so that any perennial weeds are buried at least 6 in (15 cm) deep.
Double digging, is hard work.
In subsequent years, it should not be necessary if:
1. You maintain the organic matter with enough compost to encourage the present of worms, whose movements have the same effect as your digging.
2. You take care not to trample the soil when it is wet, thus squeezing out the air and preventing water from draining away. In that event, you can look on it as a one-off tonic for poorly soil.
C. No-Dig:
Application of organic mulch to the soil surface can avoid digging. This may be a labor-saving device. It is a superior method of soil management because it avoids disturbance to its structure and micro life. For this continued and generous application of organic matter to the surface is necessary.
Beds:
The normal rectangular vegetable plot being broken up into a series of narrow beds, set between access paths. Digging may be needed to break up soil compaction. A key consideration in adopting the bed system is that it enables you to avoid this and to maintain a good soil structure. The beds can be anywhere from 3 to 5 ft. (90 to 150 cm) wide, to suit the individual.
The guiding principle is a width that enables you to reach all parts of the bed comfortably when sowing, tending or harvesting the crops. Most people find a width of 3 ½ to 4 ft. (105 to 120 cm) is adequate for their reach. The paths between can be narrow, to avoid undue waste of productive ground, but preferably of sufficient width to accommodate a wheelbarrow – 18 in (45 cm) is normally sufficient.
Size of the Beds:
The beds can be any length, but it is convenient to break them up with cross paths to facilitate access – and to avoid the temptation to walk across them. In this way, each bed will be accessible from a path on all four sides. This also provides a cordon sanitaire between the beds and any encroaching vegetation. They are best aligned north to south so that tall crops do not shade out lower, adjacent plants. Beds tend to be straight, but there is no reason why they should not be curved for aesthetic or other reasons.
Types of Beds – Flat or Raised Beds?
Flat beds are simple to prepare and involve putting the organic matter on the width of a bed, leaving path spaces between. In a dry area, or with dry soil, this has the advantage that less surface area is exposed to wind and sun, and the moisture will not drain down from the beds. Flat beds may also preferred for certain crops, such as potatoes, which benefit from earthing up and then being dug out.
Raised beds are built up higher than the surrounding paths. In many ways this is a logical progression from the decision to go for no-dig cultivation. It is often referred to as intensive raised bed gardening, because it can result in significantly higher yields. Horticulturists adopted this spacing too, quite inappropriately, and it became the yardstick – witness the standard instructions on most seed packets.
Why Raised Beds?
There are two reasons for the higher yields on the bed system – raised beds in particular. First, the ability to carry out weeding from the adjacent paths makes wide spacing between rows redundant. It has been established that optimum yields can, in fact, be obtained if closer spacing, based on grid patterns are employed.
Secondly, the raised bed is usually associated with a higher level of fertility as a result of the application of regular and substantial amounts of organic material and the excellent soil structure and soil life that is maintained. It should be noted, too, that the overall increase in yield will more than compensate for the loss of ground given over to the paths.
Spacing:
The spacing given to plants determines as much as any other factor how they develop. By varying spacing we have a better chance to obtain the kind of growth we want. For instance, closer spacing of lettuce gives more leaf and less heart; it also follows the golden rule of less space, smaller plants, though not necessarily lower yield. The overall yield can still be greater, because of the larger numbers of lettuces grown in a given space.
Indeed, unless you want to grow mammoth vegetables for show purposes – often good for no other – small individual vegetables may be more useful for the average family. The spacing you choose will reflect your needs and also the layout of your garden. To a considerable extent, you can pre-programme the vegetable sizes of your choice. And when you are working with beds, quite different considerations apply, since there is no need to leave access space between the rows.
Instead of the conventional rows, plants are located equidistant from each other ‘on the square’. Using this system, the actual ‘rows’ can be closer. For example, to achieve equidistant spacing of 6 in (15 cm), the distance between the rows will need to be only 5 in (12.5 cm) – see drawing. This will also ensure that all the plants benefit equally from the available moisture, light and nutrients.
Envisage a circle around each plant from which these essentials are drawn. Now translate this into a hexagon and see how the plants fit together most efficiently, as in a honeycomb. With the closer spacing, the vegetable foliage should just about touch, so that this pattern is also the best way to achieve weed suppression.
Rotation:
Rotating means growing specific groups of plants in a different place each season. This may not be feasible in a very small garden. Moreover, there are a number of reasons why rotation is undertaken and some of them, such as supply of nutrients, may be important with a compost-rich organic system. On the other hand, pest and disease prevention is an important consideration.
Division:
In garden/nursery, herbaceous perennial plants are divided for two reasons- one is that you would like a generous group (so much better for making an impact) instead of one lonely plant; the other is for the sake of the plant – may herbaceous plants quickly use up the foods in the surrounding soil, their roots from a close-knit mat and they deteriorate at the centre of the clump.
Arguments continue about whether autumn or spring is best for division. In most climates early autumn is an excellent time, thus allowing many weeks for the roots to settle in warm soil before winter sets in. By moving plants at this time, it is much easier to see for yourself their colour, height, leaf-shape and, much more difficult to gauge in spring when there is little of the plant above ground, their overall spread. But, if you suspect a plant is tender, leave it till spring; grasses in particular are likely to die if moved in autumn. Remember that plants divided in spring will need regular watering.
The general run of herbaceous plants, such as Phlox, Michaelmas daisies (Aster novi-belgii) and Campanula should be divided into quite small pieces- as a rule of thumb, the faster the plant grows, the smaller the piece; and the poorer the soil, the smaller the piece and the better you should prepare the planting hole. An important feature plant, like a Rodgersia, might be moved in a larger- section, to make more of an impact the following year.
When dividing some plants, such as Bergenia and Heuchera, particularly if the clump is long- established, you will find some pieces with a woody stem (20 cm/8 in long), and no roots; if you plant these stems firmly, up to the leaf rosette, they will soon make roots. When replanting the divisions, always fork in some well- rotted manure or compost, at a rate of roughly two bucketful per square metre, then sprinkle on bone meal, a general fertilizer, or both, and work this in with the fork.
Other Horticultural Practices:
Crop families can be vulnerable to specific soil-borne diseases. The alliums – onions, leeks, garlic – are susceptible to white rot, a disease which, once present, will remain in the soil for many years. Root crops share many disease problems. Rotation can avoid the build-up of such diseases by depriving them of their host plants.
Monoculture is one of the prime causes of pest build-up and, as with diseases, some pests are specific to plants of the same botanical family. They can proliferate rapidly where a plant group is cultivated year after year in the same place. Cleaning crops, such as potatoes, can help clear an area for their successor crop.
Even though organically rich soil can be relied on to make its abundant nutrients available, crops complement each other in their food needs. So it makes good sense to follow legumes, which take in nitrogen from the atmosphere and make is available through the soil, by other plants which will benefit. Likewise, plants seek out their food at different soil depths, a fact which can be taken into account when planning rotation of root crops.
This can also be worked into a rotation plan, to improve fertility and avoid leaching of nutrients by keeping the ground covered. There are many rotation patterns, varying from simple three-year plans to four-, five-, six- and even elaborate eight-year programmes, depending on what you want to grow, soil conditions, the terrain you want to grow, soil conditions, the terrain you have available, its sitting, and so on.
Too, you will need to take account of perennial crops such as asparagus, artichokes and herbs. The possibilities for intercropping, which may cut across the rotation plan, also need to be considered.
An understanding of the main principles involved, rather than following a rigid formula, is your best approach.
Cropping Systems in Horticultural Crops:
Cover Crops:
A cover crop is a crop planted primarily to manage soil erosion, soil fertility, soil quality, water, weeds, pests, diseases, biodiversity and wildlife in an agro-ecosystem, an ecological system managed and largely shaped by humans across a range of intensities to produce food, feed, or fiber.
Cover crops are plants seeded into agricultural fields, either within or outside of the regular growing season, with the primary purpose of improving or maintaining ecosystem quality.
Advantages of Cover Crops:
1. Enhance biodiversity
2. Increase soil infiltration, leading to less flooding, leaching, and runoff
3. Create wildlife habitat
4. Attract honey bees and beneficial insects
5. Reduce erosion, and
6. Improve soil quality, through increases in Porosity (reduced compaction), increase soil organic matter, water holding capacity, beneficial microbes, micro- and macro-invertebrates, retain nutrients that would otherwise be lost. Cover crops also add nitrogen through fixation (leguminous cover crops), combat weeds and break disease cycles.
Mulching:
Mulching is a system of soil management in which hay, straw, or cut grass is placed on the soil between the tree rows to conserve the soil moisture by checking surface evaporation. It is considered that cultivation and the maintenance of soil mulch are important as means of preventing the evaporation of moisture.
If seeds are removed without disturbing the surface of the soil, very little after is lost by evaporation. Mulching checks the germination of weeds. Mulching favours to fire out break and facilitates the hibernation of rodents and pests.