Introduction:
- Pest problems in fruit production has increased the cost of tree/plant protection and squeezed the profit of the fruit growers.
- In India, there are several existing or potential key pests for each fruit trees whose population densities must be kept at sub-economic levels to sustain higher per unit production at the farmers fields.
- During the second part of 20th century, the major emphasis was on pest control, which involved a set of actions to avoid, alternate or delay impact of pests on crops, which mainly involved pesticide application with the sole aim of eradication.
- Because horticultural crops like fruits are intensively cultivated that allow more inputs cost, thus the use of insecticides for the control of specific pests of a particular fruit crop has increased manifold during the last few decades. However, the toxic materials generated from chemical use in crop production has polluted the environment, because majority of these are not biologically degradable and harmed consumers’ and farmers’ health.
- Uses of broad-spectrum chemicals for pest control have a very negative impact on our efforts to conserve biodiversity. Because of their broad spectrum nature of effect, it not only kills enemy insects but also useful insects like honey bees.
- The pest control option based on pesticide applications virtually eliminates the bee keeping activity.
- Now, a more environment friendly and economical alternative for fruit cultivation has been adopted, namely ‘Integrated Pest Management (IPM)’.
- Due to considerable awareness about the harmful effects of pesticides on human health and the environment, recently there has been a renewed interest in IPM in almost all countries.
Definitions:
- Pest is any living organism, which competes with human beings for resources of its interest. A phytophagous insect assumes pest status when its population is alarming to inflict significant damage in yield or quality of any economic crop such as fruits.
- Integrated pest management can be defined as “a sustainable approach of management of pests by the combination of biological, cultural, mechanical and chemical tools in a way that minimize economic, health and environmental risks”.
- In other words, IPM is economically justified and sustainable system for the protection of crops that leads to maximum fruit productivity without having any adverse effect on environment. IPM is now used all over the world, which lay emphasis on the use of bio-pesticides and bio-agents with rarest and smallest use of safe chemical pesticides.
Aims of IPM:
- Reduce the use of synthetic organic pesticides
- Adopt environmentally sound tactics for pest control
- Pest minimal risk of human health
- Re-usable return on investment
- Provide consumable safe food
Principles of IPM:
- Identification of key pests and beneficial organisms
- Defining management unit, the Agro-ecosystem
- Establishment of Economic thresholds (loss & risks)
- Development of assessment techniques
- Evolving description of predictive pest models
Tools of IPM:
1. Monitoring insect pest and natural enemies:
- Keeping a track of phytophagous insects and their natural enemies is basic requirement of IPM for taking management decisions.
- This provides knowledge about the current pests and crop situation and is helpful in selecting the best possible combinations of pest management methods.
2. Pest resistant varieties/rootstocks:
- It involves the breeding of pest resistance varieties, followed by selection of variety for resistance against a particular pest prevalent in a region/ area.
- For example, use of Malling Merton series rootstocks in apple can prevent/or reduce the attack of woolly apple aphid (Eriosoma lanigerum).
3. Cultural pest control:
- It includes all crop production and management techniques which are utilized by the fruit growers to maximize their crop productivity and farm income.
- It includes decisions on varieties to be grown, crop production practices that make crop environment less susceptible to pests.
- Crop rotation as practiced in vegetable and field crops, cover crops, row and plant spacing, application of fertilizers, planting and harvesting dates, destruction of old crop debris/residues are a few examples.
- Cultural control is based on pest biology and development, a few examples of cultural pest control are:
- Spacing may influence the population and damage many insect pests by modifying the micro-environment of the fruit crop or affecting health, vigour and strength of the crop plants.
- The type and time of tillage can markedly influence the soil environment and affect the survival of insect pests or their natural enemies.
- Intercropping with suitable crop can either divert the population of insects from the main fruit crop or inhibit the incidence of insect attack.
- Use of organic manure release nitrogen in small quantities over a longer period and hence their application does not generally leads to pest outbreak in comparison to the use of inorganic fertilizers. Integrated nutrient management (INM) must, therefore, form an integral part of IPM programme.
4. Mechanical control:
- These are based on knowledge of pest behaviour.
- Hand picking, installation of bird perches, mulching, and installation of traps (Plate 12.1) are a few examples.
Plate 12.1: Insect trap Courtsey: Dr Mohinder Singh, Dept. EAP, UHF, Solan
5. Biological control:
- Pest control with pesticides is not only harmful for environment but also a capital intensive technology as financial resources are required to buy the spray machines, pesticide, labour and technical guidance.
- However when other means of pest control fails, pesticides are used to keep the pest population below economically damaged levels.
- It is applied only when pest’s damage capacity is nearing to the threshold. Furthermore, time of application of pesticide is very important.
- Pesticides should be applied at most susceptible stage of a particular insect.
- For example, it is important to apply insecticides for the control of anar butterfly at the early stage of insect development (initial instars) otherwise they bore into the fruit where they are difficult to control.
IPM Packages:
- IPM packages of some fruit crops are available.
- It is not possible to cover these here.
- These should be taught to the students as per recommendations for important fruit crops of the adjoining areas of Universities/Colleges.
Economics of IPM:
- To date, successful IPM programs have produced many benefits. These include
i) lower production costs (at farm level), ii) enormous savings for governments from reduced pesticide imports and subsidies for pesticide use, iii) reduced environmental pollution, particularly improved soil and water quality, iv) reduced farmer and consumer risks from pesticide poisoning and related hazards, and v) ecological sustainability by conserving natural enemy species, biodiversity, and genetic diversity.
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