Pests and diseases can be controlled in a variety of methods. The most popular and commonly used techniques are biological and chemical, however there are considerable differences between them. The background and ideas underlying each method, as well as the distinctions between them, will be explained in this article.
Control using chemicals
To manage illnesses, pests, and weeds, chemical pesticides are frequently utilized. The most popular and commonly used techniques are biological and chemical, however there are considerable differences between them. Plant protection products are pesticides that are applied to plants to protect them from pests, diseases, and weed invasion. Of course, it’s vital that the plant being protected doesn’t become toxic as a result of the protective products.
Crop protection efforts date back centuries. To kill parasites, the Chinese utilized lime and wood ash approximately 1200 BC. Sulphur and bitumen, a crude oil-derived material, were utilized by the Romans. From the 16th century forward, substances such as nicotine from tobacco, as well as copper, lead, and mercury, were used. True chemical pesticides were first used after WWII, and today there are hundreds of chemical pesticides available for use in agriculture and horticulture and for pest control.
Pesticides are divided into five groups based on the reason for which they are typically used. Fungicides are the first group, and they work against fungi. Herbicides, on the other hand, are used to kill weeds. Herbicides are absorbed by the weed’s leaves or roots, causing it to die. There are insecticides, which, as the name implies, kill hazardous insects, and acaricides, which protect plants against mites. Finally, nematodes that harm plants can be controlled with nematicides.
Chemical pesticides: pros and downsides
Chemical pesticides are widely used due to their low cost, simplicity of application, and effectiveness, availability, and stability. Chemical insecticides are often quick-acting, which reduces crop harm.
Chemical pesticides have a number of significant disadvantages but people are able to pest control, although they continue to be widely sold and utilized. Here, we’ll look at four of the drawbacks of chemical pesticides. To begin with, chemical pesticides are frequently hazardous to organisms other than those for which they were designed. Non-selective and selective pesticides are the two types of chemical pesticides. Non-selective products are the most dangerous since they destroy all types of organisms, even those that are beneficial and harmless. Herbicides, for example, can kill both broad-leaf weeds and grasses. Because they kill practically all vegetation, they are non-selective.
Pesticides with a narrower spectrum of action are known as selective pesticides. They only kill the pest, illness, or weed in question; other organisms are unaffected. A weed killer that only kills broadleaf weeds is an example. Because it does not destroy grass, it might be used on lawns, for example. Because practically all allowed products are selective and hence only control a restricted range of pests, it is now common to employ a combination of products to manage multiple pests.
Chemical insecticides also have the problem of resistance. Pesticides are often only effective on a certain organism for a (short) period of time. Organisms can develop immune to a material, meaning it has no impact on them. These creatures evolve and become resistant as a result of their mutations. This means that more insecticides will have to be employed to keep them under control.
The growth of debt is a third disadvantage. Chemicals can be transferred up the food chain if sprayed plants are eaten by one organism, which is subsequently eaten by another. The accumulation of pesticides in the systems of animals at the top of the food chain, such as predators or humans, puts them at risk of poisoning. However, as pesticides are required to break down more quickly so that they do not accumulate, this impact is gradually becoming less relevant.
Biological management
Biological controls are made up of three parts:
- Macrobials
- Microbial
- Bio chemicals
All three of these will be briefly explained.
Natural predators or parasites are used in biological control (macrobials)
Biological control is not a passing trend. Ants were used as a natural adversary of pest insects in China in the fourth century B.C., and they are still used to control pests in orchards and food warehouses in South China today. Parasites were only recognized to be valuable much later. Most parasites are insects, such as parasitic wasps (Encarsia formosa), that reside in or on a host during their egg, larva, and pupa stages. Antonie van Leeuwenhoek was the first to describe the intricate life cycle of these insects in the early eighteenth century. It would take several years, however, before they were discovered to be beneficial in pest management. Erasmus Darwin, Charles Darwin’s father, authored an essay in 1800 about the role parasites and predators can play in battling pests and diseases.
Biological control assumes that pests can be suppressed by natural predators or parasites. As a result, natural enemies were initially imported to combat the pests. These natural predators were released in modest numbers at first, but once established, they proved to be effective over time. Inoculation is another name for this practice. Inundation occurs when a natural predator is introduced on a regular basis.
Predators and parasites are two types of beneficial macrobial creatures. Parasites are organisms that exist at the expense of another, such as parasitic wasp larvae that reside inside whitefly larvae and consume them from the inside.
Microorganisms for biological control (microbial)
A variety of beneficial microbes can be utilized to boost plant health and combat pests and illnesses. Bacteria, fungus, and other microbes can cause these consequences by competing for nutrients or space, producing antibiotics, or simply eating other hazardous microbes.
Microbial can also be employed to protect plants by making them healthier and stronger. Pests and diseases are less likely to attack or affect plants when this happens. This type of pest control is unseen.
The benefits and drawbacks of biological control
Biological control, like chemical control, offers both benefits and drawbacks. We’ll go over three significant benefits as well as a few drawbacks in this section. The first benefit is that the natural adversary can establish itself, resulting in long-term consequences. Pests cannot develop resistance to being eaten, therefore the risk of resistance is significantly reduced. Natural pest control is highly targeted, making it an excellent method of controlling specific pests.
The downsides of biological control include the possibility that natural adversaries will flee. This problem can be controlled in greenhouses, but not in open fields. It takes time to spread out over a broader plot. Second, pests are never totally eradicated since the natural opponent must survive, and as a result, they will never eradicate the entire population. Finally, they cannot be used before the pest has appeared, which implies that crops will suffer some damage.
