Integrated Pest Management (IPM): Principle, Essentials, Plant resistances and Culture methods

  • Integrated Pest Control is defined as a pest management system that in the context of the associated environment and the population dynamics of the pest species, utilizes all suitable techniques and methods in a compatible manner as possible and maintains the pest populations at levels below those causing economic injury.
  • In its restricted sense, it refers to the management of single pest species on specific crops or in particular places.
  • It can be applied to the coordinated management of all pest populations in the agricultural or forest environment.
  • It is not simply the superimposition of two control techniques such as chemical and biological controls, but the integration of all suitable management techniques with the natural regulating and limiting elements of the environment.
  • The term ‘Integrated Control’ was first used to denote the blending of biological control agents with the intervention of chemical control by Bartlett in 1956.
  • But nowadays, covers a wider sense and Geier and Clark (1961) called pest control protective management of noxious species or pest management.
  • In short, all available techniques are evaluated and considered into a unified programme to manage the pest population.
  • Integrated Pest Control (IPC) has recently been introduced throughout the world as an evolutionary approach in the pest control strategy. It was founded first by Smith and Allen (1954) and Stern et. al. (1959) and proposed management of insect pest population by the integrated pest control, which is termed as the Integrated Pest Management (IPM).
  • The term IPM aims at combining all available methods or tools of insect pest control in a legal manner that minimizes insecticide use and disturbance to the ecosystem (environment).
  • The importance of integrated pest management arises from modern agriculture, which is based on extensive cropping programme with genetically uniform high yielding varieties evolved.
  • Without regard for its susceptibility to pests, combined with the use of high doses of fertilizers, irrigation and pesticides together with the rapid straightforward introduction in many countries avoiding requisite preliminaries, has created a serious situation by disrupting the natural balance.
  • Pest attacks have consequently become more frequent and serious.
  • Hence, the concept of IPM implies the agro-ecosystem should be so adjusted or manipulated that pests are maintained at a sub-economic level of the population so as not to cause any extensive injury.
  • Therefore, various methods of control are recommended to be adopted should be integrated and incorporated into a crop production system but care should be taken that a high level of yield is also maintained for the sustenance of the growing human population at the desirable level of nutrition.
  • Some of the methods of control based on natural phenomena namely host resistance and biological suppression of pests, while use of pesticides and cultural methods are inducted into the natural system.
  • All these four methods together with autocidal methods of pest control form the basis of integrated pest management.
  • Integrated Pest Management has been introduced with success in a number of crops namely cotton in the Canete Valley, Peru, Spotted alfalfa in California; apple and pear insects in Nova Scotia; glasshouse crops in the U.K; tobacco pest management in North Carolina, U.S.A.

Principle of IPM:

Integrated control derives its uniqueness of approach from its emphasis on the fullest practical utilization of the existing mortality and suppressive factors in the agro-ecosystem. To achieve this goal, crop production must be guided by the following two principles:
(i) Pest control should be developed and applied in the total environment. The pest populations are managed in such a manner that existing, limiting and regulatory factors are exploited to the fullest extent possible and without disturbance to the regulation of other pests. This principle defines the underlying philosophical approach to integrated control.
 
(ii) Additional mortality or regulatory factors are introduced into the environment at appropriate times to maintain the pest population at levels below those causing economic injury. These levels should be determined in terms both of the foreseeable crop less and of the economics of crop production and marketing. This principle defines the goal of the integrated control system.
Attempts to totally suppress pests by insecticides may lead to the following problems:
(a) Development of resistance to chemicals in pest populations.
(b) Outbreaks of secondary pests.
(c) Resurgence of treated populations.
(d) Unacceptable residues on food and forage products and associated legal complications.
(e) Destruction of beneficial predators, parasites and pollinators.
(f) Hazards to personnel involved in insecticide application, domestic animals and wildlife.
(g) Expense of pesticides, involving the cost of material and labour and maintenance of equipment.
In integrated pest management, the ecological factors are exploited and the control programmes are so designed that they are compatible with natural mortality factors in order to optimize control rather than maximize it.

Essentials of Pest Management:

Five major components can be identified in all pest control management programmes.
(a) Understanding agro-ecosystems.
(b) The determination of pest damage thresholds and of economic thresholds.
(c) Means of monitoring populations of pests and their natural enemies.
(d) A decision-making framework to determine the action to be taken.
(e) Methods of selectively manipulating pest populations.

Integrated Tactics:

  • The integrated control is managed by harmonizing various techniques/methods in an organised way by making the techniques compatible and by blending (mixing) them into a multifaceted, flexible system.
  • In short, utilization of all suitable techniques either to reduce pest population or maintain them at levels below causing economic injury or to manipulate the populations that they are prevented from causing injury.
  • By using the following tactics, one can programme balanced coordinated integrated pest control.

Plant Resistance:

  • The ability of plants to withstand the attack of insect enemies is derived from certain morphological and biochemical characteristics which exert deleterious effects on the insects.
  • This causes the insects to avoid such plants that tell upon the total well being of their livelihood. Normally, these characters represent the inherent genetic features of the plants.
The use of resistant plant varieties contributes helpfully to IPM in two ways:
(i) Reduces insecticidal quantum: It is observed that some amount of an insecticide spray brings about greater control of pests on resistant plants than on their susceptible counterparts, which mean that a lesser amount of insecticide will be needed in the case of resistant plant varieties.
 
(ii) Improves performance of natural agents: Even a low level of resistance in plants has a dramatic effect on the efficiency of the natural agents in killing their hosts, which in effect, reduces the need for insecticides.
  • Resistance or tolerance of plants to insect attack is due to a great variety of conditions either physical, chemical or physiological and in most, it is not clearly understood. For example, some varieties of corn and sorghums resist the attacks of chinch bugs.
  • Many varieties of apple resist root wooly apple aphids, cotton, soyabeans and red clover have a degree of immunity from attack of tiny leafhoppers.
  • Many citrus fruits kill the young maggots of the Mediterranean fly, Hessian fly does not attack wheat varieties and tobacco cultivars are resistant to six major fungal, bacterial, viral and nematode pests.

Cultural Methods:

Regular farm operations performed so as to destroy insects or prevent their injuries. Cultural control is carried out by the following farm practices:
(a) Crop rotations.
(b)  Tilling of the soil.
(c) Variations in the time or method of planting or harvesting.
(d) Destruction of crop residues, weeds, volunteer plants, trash.
(e) Pruning, thinning.
(f) Fertilizing and stimulating vigorous growth.
There are some examples of this method that minimize the pest populations.
(i)Strip harvesting of alfalfa hay fields which prevent migration of bugs, Lygus, Hesperus into adjacent cotton when alfalfa is mowed. Similarly, interplanting of alfalfa strips in the cotton field attract Lygus out of the cotton.
(ii) Destruction of stalks after harvesting of tobacco as diapausing pupae is present on tobacco foliage of stalks.