Introduction:
Medicinal plants have curative capabilities due to the existence of many complex chemical compounds of varying compositions, which are found as secondary plant metabolites in one or more portions of these plants.
These plant metabolites, according to their composition, are categorised as alkaloids, glycosides, corticosteroids, essential oils, etc.
Concentration of these constituents can be affected by many things, as our body needs good food and environment to grow similarly these medicinal plants needs certain factors for optimum concentration of these secondary active metabolites,
It involves attainment of numerous pharmacological and environmental elements such rainfall, irrigation, fertilisers, pests, humidity, light and temperature. When all these parameters are precisely controlled to produce plants with optimum active ingredients, the technique is called Cultivation.
Advantages
Production of better medicinal plants with better quality and potency.
Good yield and more therapeutic activity.
Regular supply is possible.
Leads to industrialization.
Permits application of modern and scientific technology. Example- Mutation and Hybridization. (May have mixed impacts good as well as bad)
Disadvantages
Higher cost of maintenance
Ecological imbalances may cause loss.
The plants from wild sources are difficult for cultivation.
FACTORS AFFECTING CULTIVATION:
Cultivation of medicinal plants offers a lot of advantages over the plants from wild sources.
There are few factors that have to be considered, which have a genuine effect on plant growth and development, nature and quantity of secondary metabolites. The factors influencing cultivation are altitude, temperature, rainfall, length of day, daylight, soil and soil fertility, fertilisers and pests.
The effects of these factors have been studied by cultivating particular plants in different environmental conditions and observing variations.
Nutrients have the ability to enhance the production of secondary metabolites, at the same time they may reduce the metabolites as well.
Important Factors:
Altitude
Temperature
Rainfall
Day Length and Daylight
Soil
Pests and Pests Control
Microbes
Insects
Non insect pests
Weeds
Fertilisers and Manures
Chemical fertilisers
Biofertilizers
Manures
Other Factors.
Herbicides.
Air Pollution.
Altitude:
Altitude is a very significant factor in cultivation of medicinal plants.
Tea, cinchona and eucalyptus are cultivated favour-ably at an altitude of 1,000–2,000 metres.
Cinnamon and cardamom are planted at a height of 500–1000 metres, while senna can be cultivated at sea level.
e.g
2. Temperature:
Temperature is a significant element affecting the development, metabolism and thereby the yield of secondary metabolites of plants.
Even if each species has been adjusted to its own natural environment, they are able to exist in a considerable variety of temperatures.
Many plants will grow better in temperate climates throughout summer, but they lack the ability to survive snowing in winter.
e.g.
3. Rainfall:
For the correct development of plants, rainfall is essential in proper measurements.
Xerophytic plants like aloes do not require watering or rainfall.
The impacts of rainfall on plants must be considered in relation to the annual rainfall throughout the year with the water holding qualities of the soil.
Different results have been reported for the formation of components under different conditions of rainfall.
Excessive rainfall could induce a decline in the secondary metabolites due to leaching of water-soluble compounds from the plants.
4. Day Length and Daylight:
It has been demonstrated that even the length of the day influences the formation of metabolites.
Plants grown in long-day conditions may contain more or fewer elements than plants grown in short-day conditions.
In long day conditions, peppermint generated menthone, menthol, and traces of menthofuran, but just menthofuran in short day settings.
Plant development differs greatly in terms of the amount and intensity of light required.
Plants produced in the wild would meet the required conditions and grow, but during cultivation, we must meet the plant's requirements.
Daylight was discovered to enhance the amount of alkaloids in belladonna, stramonium, cinchona, and other plants.
The type of UV radiation also has an impact on plant development and metabolites.
5. Type of Soil:
Each plant species has unique soil and nutrient requirements.
Physical, chemical, and microbiological aspects are the three most essential basic characteristics of soils.
Soil offers mechanical support, water, and critical nutrients for plant growth.
Soil is made up of air, water, minerals, and organic materials. Different soils originate from particle size variations, which include clay, sand, and gravel.
The water retention capacity of soil is influenced by particle size.
The type and quantity of minerals are critical in plant cultivation.
Plants can choose their own soil pH range for growth; microorganisms that grow well in certain pH levels should be considered.
Nitrogen-rich soil has a strong influence on the formation of alkaloids in some plants. The soil is given the following titles based on the size of the mineral content.
6. Pests and Pests Control:
Microbes:
They include fungi, bacteria and viruses.
These parasites affect the crop and ultimately the yield.
e.g.
A fungus Clavicepus purpurea commonly called as Ergot affects Rye plants and was notorious as causing millions of deaths in the past.
Galls typically form when plants are harmed during cultivation or trimming. Pierce's Disease is caused by the bacteria Xylella fastidiosa, in which leaves get somewhat yellow or red around the margins and eventually dry or die.
Tobacco mosaic virus, mosaic virus, cucumber mosaic virus, tobacco ringspot virus, yellow vein mosaic, and other viruses have been documented to induce necrosis of leaves, petioles, and stems.
Control:
Chemical fumigation of the soil, fungicide, bactericide, pruning, proper water and fertiliser management, good sanitation, heat treatment of planting stock, cutting and removing infected parts, and genetically manipulating the plants to produce plants resistant to fungi and bacteria are all practises used to prevent or minimise the effects of microbes.
Insects:
Ants are of different varieties, they spoil the soil by making nests and they feed honeydew secreted in plants.
Branch and Twig Borer (Melalgus confertus) burrow into the canes through the base of the bud or into the crotch formed by the shoot and spur.
When shoots reach a length of 10–12 inches, a strong wind can cause the infected parts to twist and break.
Control:
Tilling the soil affects ant nesting sites and helps to reduce ant populations, collection and destruction of eggs, larvae, pupae, and adults of insects, trapping the insects, insecticides, creating a situation where males compete for mating with females, cutworms can be prevented by natural enemies such as predaceous or parasitic insects, mammals, parasitic nematodes, pathogens, birds, and reptiles,
Non insect pests:
They are divided into vertebrates and invertebrates.
Ver-tebrates that disrupt the plants are monkeys, rats, birds, squirrels, etc.
Non vertebrates are, Web Spinning Spider Mites cause discoloration in leaves and yellow spots.
Nematodes produce giant cell formation, disturbs the uptake of nutrients and water, and interferes with plant growth.
crabs, snails are the other few invertebrates that cause trouble to the plant.
Control:
Construction of concrete warehouses, traps, biological methods, rodenticides, etc.
Weeds:
Weeds inhibit plant development and yield by competing for water, nutrients, and sunlight.
Weed control increases both the establishment of new plants and the growth and productivity of current plants.
To attain these goals, trained individuals are required; however, the strategies for employing tools differ from year to year and from location to location.
Soil characteristics are important to weed management.
Few common weeds are, Bermudagrass, It is a vigorous spring- and summer-growing perennial.
It grows from seed but its extensive system of rhizomes and stolons can also be spread during cultivation.
Control:
Use of low rates of herbicides:
If herbicides remain on the soil surface without incorporation, some will degrade rapidly from sunlight.
Frequent wetting of the soil promotes more rapid herbicide degradation in the soil. Herbicide degradation is generally faster in moist, warm soils than in dry, cold soils.
7. Fertilisers and Manures:
Plants also need food for their growth and development, many of which is obtained from the soil itself, while for getting good yield addition of additional food is desirable.
Chemical fertilisers:
Many chemical fertilisers are used as per the type of the plant as well as requirement.
However, studies found that these have environmental as well as health hazards, so cautious use is advised.
Biofertilizers:
Biofertilizers are the most appropriate forms to try. These are many types of microorganisms or lower creatures that fix atmospheric nitrogen in soil and can be used by plants on a daily basis.
As a result, they are symbiotic.
Biofertilizers include Rhizobium, Azotobactor, Azosperillium, Bijericcia, Blue-green algae, Azolla, and others.
Manures:
Manures include farm yard manure (FYM/compost), castor seed cake, chicken manures, neem and karanj seed cakes, vermin compost and so on.
They are easily accessible to plants. Organic fertilisers also include bone meal, fish meal, biogas slurry, blood meal, and press mud.
8. Other Factors:
Air Pollution:
It has been demonstrated that air pollutants can cause deaths and losses in growth of plants.
There are many chemicals released into the atmosphere due to industrialization, excessive use of fossil fuel anad many more reasons.
Pollution injury typically shows itself first as leaf damage. Spots between the veins, browning of the leaf margins, and tip burns are all prevalent.
These symptoms are also regulated by host sensitivity, which can be influenced by genetic and environmental variables.
Herbicide:
Herbicides should be handled with extreme caution; misapplication of herbicides can frequently harm non-target plants.
Some herbicides cause aberrant foliage development, such as cupping or twisting, while others cause foliage yellowing or browning, defoliation, or death.
Commonly Asked Question.
Write a note on cultivation of medicinal plants.
State use of fertilisers/ paste control during cultivation of medicinal plants.
Discuss various factors considered while cultivating the medicinal plants.