- Introduction: Crop Diseases, their Losses and control with special reference to potato pests and diseases.
- Traditional Pest and Disease Control Approaches and their drawback.
iii. Pesticide use and its impact with special reference to Pakistan.
- Integrated Pest Management (IPM).
- Brief History of IPM.
- Components of IPM.
vii. IPM implementation through TOF-FFS approach
viii. IPM Model in Pakistan and its Progress.
- Benefits of IPM.
- IPM in Potato through FFS approach in Northern Areas.
Potato ranks third among food crops after wheat and rice and fifth in total production in Pakistan. It produces high energy and nutritional value per unit area than wheat, rice and maize. Although potato production in Pakistan has increased many folds but it’s per acre yield is far less than in other parts of the world (Malik, 1995). Among the various factors responsible for its low per acre production, potato diseases are considered to be the most important. More than 18 potato diseases are reported in the country, of which 13 are of common occurrence. Their importance, however, varies considerably in different potato growing areas (Ahmad et al., 1991). Most commonly occurring potato diseases in Pakistan are early blight, powdery and common scab, black scurf, stem rot, soft rot, brown rot, wilts, potato cyst nematode and root knot nematode (Ahmad, 1998). Diseases with mycoplasma pathogens and soil borne disease of potato caused serious problems in major potato growing areas of Punjab.
The Potato crop in Pakistanis affected by many pests and diseases, and of theses potato viruses, powdery scab, potato cyst nematode, aphids and white grub are the most damaging ones. Surveys done by Pakistani workers have revealed that viruses, powdery scab and aphids are wide spread, white grub are serious problems in the northern hilly areas (Table 1-4).
Table 1: Diseases caused by fungi
|Black Scurf||Rhizoctonia solani|
|Earlry Blight||Alternaria solani|
|Fusarium dry rot||Fusarium sp|
|Fusarium rot||Fusarium spp|
|Late blight||Phytophthora infestans|
|Powdery scab||Spongospora subterranean|
|Wilt/Verticillium wilt||V. albo-atrum & V. dahliae|
Recommended Control Measures for Fungal Diseases
- Wet poorly drained areas should be avoided for potato cultivation.
- Use disease free seed combined with seed treatment with benomyl.
- Seed should be planted on raised beds and in well-drained soil to encourage fast growth of the seedlings.
- Harvest the crop as soon as the tubers are mature, which can reduce the number of sclerotia on tubers.
- Apply boric acid before storage.
- Destroy and burn the plant debris before sowing.
- Harvest carefully to avoid bruises and injuries to potato tubers.
Table 2: Diseases caused by Bacteria
|Bacterial wilt||Ralstonia (Pseudomonas) solanacearum|
|Black leg and soft rot||Erwinia carotovora spp. carotovora and carotovora spp. atroseptica|
|Common scab||Streptomyces scabies|
Recommended Control Measures for Bacterial Diseases
- Use of healthy seed tubers.
- Cultivation in un-infested fields.
- Destruction of diseased plant debris.
- Cultural practices to stop spread.
- Long rotation.
- Destruction of host plants etc.
- Disinfection of seed tubers.
Table 3: Diseases Caused by Viruses
|Potato leaf roll virus|
|Potato mop top virus|
|Potato virus A|
|Potato virus M|
|Potato virus S|
|Potato virus X|
|Potato virus Y|
Recommended Control Measures for Viral Diseases
- Use virus free, certified seed potato.
- Control the aphid vector.
- Use resistant varieties.
- Heat treatment of tubers.
- Modification of cropping procedure.
- Chemical control of vector (Insects, nematodes and fungi)
- Non-chemical control of vectors (barriers and reflective mulches, oil sprays, biological control by predators).
- Plant resistant to
- Assess the health of tuber stocks by serological tests through ELISA, after harvest
Table 4: Diseases Caused by Nematodes
|Potato cyst nematode|
|Root knot nematode (Meloidogyne spp.)|
Recommended Control Measures for Nematodes
- Nematodes cyst on root can be observed at flowering stage.
- Soil analysis for extraction of cyst also provides an excellent mean of diagnosis.
- Use of resistant and tolerant varieties (Saif et al., 2000).
- Traditional Pest and Disease Control Approaches and their Drawback
2.1 Chemical control.
Traditionally, chemical control was thought to be the easiest method because farmers could observe the immediate effect of chemicals on pathogens and crop. However, it should be realized that chemicals can not eliminate a pathogen but can only suppress it only upto a certain extent and the remaining pathogens are again in a position to build-up the required fungal population to cause losses.
2.2 Cultural control.
Efforts to reduce reliance on synthetic chemicals have built on a number of traditional approaches-including cultural controls (such as altering planting dates or pattern), use of pest-resistant crop varieties and simple forms of biological control (such as addition of an organism to suppress the growth of pathogens). Cultural control, the most widespread of these approaches, try to “outsmart” pathogens by manipulating the physical environment. For example, flooding helps to reduce disease incidence of panama disease of banana caused by Fusarium oxysporum f. sp. cubense (Mehrotra, 1980). Intercropping is a popular cultural technique showing much future promise for reducing diseases damage, particularly in most traditional farming systems. Sometimes, one crop is used to attract pathogenic disease away from other more important or more susceptible crop. In Eritrea, for example, subsistence farmers got good yield which attracts some and protection against foliar diseases in sowing of wheat and barley together. It is due to the fact that a wheat rust pathogen does not infact barley and barley pathogens do not cause diseases on wheat (Yahyaoui, 2000). Intercropping can also make it harder for pests to locate their host plants and fosters proliferation of natural enemies (Risch, 1981). Intercropping may thus have a role to decrease the need for insecticides.
2.3 Use of resistant varieties
Developing resistant varieties is perhaps the most widely used traditional means of pest control. Use of resistant varieties is probably cheaper, safest and environmentally sound method of disease control. It is continuos process to breed resistant varieties because of adaptability to break the resistant barrier of plant.
2.4 Drawback of Traditional Approaches in Isolation
Since long time, man has learned by experience to use many cultural practices to control the pest losses. These practices are proper tillage, crop rotation, removal of affected plants and crop resistance, burning or burying crop residue and eliminating plants harboring pests. These measures could not produce desired results in isolation on large scale commercial cultivation of crops. In addition to this, “grow more” pressure rendered the traditional methods in sufficient to control the ever increasing pest problems. Scientific development in manufacturing of chemicals and their use by machinery on large scale, opened a new era of chemical control of pest. When the use of chemicals increased dramatically after 2nd world war, scientists and the public saw them as wonder chemicals that would rid the world of insect pests, weeds and insect transmitted diseases. Over the last two decades, however, their numerous drawbacks have become more and more apparent. The major drawbacks of pesticide fall into three categories.
n Environment contamination.
n Human health effects.
n Pest resistance.
Synthetic chemicals contaminate the environment in many ways. Widespread application of chemicals on mono-culture by airplane leads to drifting and contamination of land and waterways adjacent to target fields. Chemicals in the soil may eventually also contaminate ground water, which is considered a severe problem in many farming areas. Environmental contamination is the widespread killing of non-target organisms, including wildlife, cattle, birds, fish, bees and pest’s natural enemies.
Host resistance and crop selection has been considered key element in the evolution of modern agriculture. Use of resistant cultivars is considered most popular and economical approach as it may not require as many treatments or as high rates of chemicals application to achieve adequate pest control. Although, genetically resistant cultivar is known to be a reliable means of maintaining healthy plants and reducing crop losses but traditional local cultivars (Germplasm) have less yield. On the other hand, developing of resistant variety is a continuous phenomenon as the organism has the ability to develop new races to overcome the resistance of the variety. It is also fact that complete resistant variety can not be developed against all biotic and biotic factors.
It is concluded from the above discussion that although, cultural practices, application of chemicals and use of resistant varieties provide control against pest but these techniques could not produce impact on pest control in their individual application. In the 20th century, agricultural experts developed strategies of integrated management approach to adopt the balance and appropriate use of these practices. This modern approach is called integrated pest management (IPM).
- Pesticide use and its impact with special reference to Pakistan.
3.1 History and Use of Pesticides in Pakistan.
Pesticides have played an important in enhancing crop yields through insect pest control. However, their improper and excessive use has been the cause of serious health hazards Pesticide use began in Pakistan in the 1950s for locust control. In 1954, the government imported formulated pesticides amounting to 254 tones (Habib, 1996). This was the beginning of the pesticide business in the country. Until 1980, the Plant Protection Department was responsible for pesticide imports and their distribution in the country through the national agricultural extension network. Most of the pesticide imports were used for aerial spraying to control locust, pests of sugarcane, cotton, rice, tobacco and fruit crops. The cost of pesticides was subsidized and aerial spraying was free of charge.
Pesticides were privatized in 1980 and since then there has been a steady increase in pesticides import and consumption. As a result, consumption of pesticides in Pakistan has increased from 665 tones in 1980 to 14,773 tunes in 1990 and 61,229 tones in 2000 worth about 7.7 billion rupees (Ahmad et al, 2002, fig 1). Highest pesticide use is in Punjab, followed by Sindh, NWFP and Baluchistan (fig 2). Crop wise, largest use is in cotton followed by rice and vegetables that includes potato (fig 3). Unfortunately, the widespread use of pesticides has resulted in complicating pests’ problems. Excessive and inappropriate pesticide use has disturbed the agro-ecosystem and killed non-target and environment-friendly organisms, including environment-friendly organisms, including birds. Besides this, the excessive inappropriate use has induced pest resistance and resurgence. Studies show that the populations of natural enemies in cotton growing areas have declined as much as 90 percent during the last decade (Husnain, 1999).
3.2 Pesticide Residues in Food and the Environment
Although monitoring of residues in domestically consumed food products is rather irregular the few available analyses provide a cause for concern.In one recent study (Ahad et al, 2001) samples were taken of four different vegetables: okra (Hibiscus esculentus), brinjal (Solanum melongena), gourd (Citrullus vulgaris) and bitter gourd (Momordica charantia) (table 5). Not surprisingly, pesticide residues were found in all vegetable samples. In 60% of the samples contamination exceeded the respective maximum residue limits (MRL).
Table 5: Pesticide Residues in Food Chain
|Type of Sample||% of samples contaminated||% of samples >MRL|
|Vegetables (Brinjal, okra,bitter gourd, gourd)||100||60|
|Cotton seed oil||100||65|
|Cotton seed cake||100||65|
|Shallow ground water||100||30|
Source: Ahad et al, 2001
3.3 Health Hazards of Pesticides
Pesticides enter the human body through three routes: the skin, lungs and the digestive system. Poisoning can be acute or chronic depending on the intensity and duration of exposure. The effects of chronic exposure include various forms of cancer, adverse reproductive outcomes, impaired immune functions neuropathies, neurobehavioral disorders and allergic sensitisation reactions, particularly of the skin (Repetto and Baliga, 1996). Chronic pesticide poisoning can be measured either by Cholinesterase levels in the blood or pesticide residues in blood, fatty tissues and mother’s milk. A recent study done on behalf of Government of Pakistan by UNDP and FAO in cotton growing areas shows how seriously the pesticide use is affecting the health of farm workers and laborers (table 6). About 63% of farm workers get sick every year with workdays lost per crop season per person range from 2-90 with treatment cost ranging from Rs. 100-3000 per year. The gender implications of health hazards associated with pesticide use are far from neutral. Woman farm workers are the largest group affected at the farm level. It is estimated that 87% of pickers experience sickness every year. Though labourers working in pesticide industry also share these hazards but the number is lower than farm workers. It is therefore high time that the use of pesticides be rationalized and alternative approaches promoted.
Table 6: Quantitative Evidence of Pesticide Health Hazards
|Exposure during application at farm level 1)||– Households affected per season– Work days lost per crop season
– Health treatment costs (Rs/year)
– Number of deaths
|Exposure during cotton harvest 2)||– Pickers experienced sickness– Average work days lost per crop season
– Treatment costs (Mill.Rs.)
– Value of Work lost (Mill.Rs.)
|Exposure at local pesticide refilling facilities 3)||– Labourers experiencing sickness– Work days lost (per year)
– Treatment cost (Mill.Rs.)
– Value of Work lost (Mill.Rs.)
1) Estimated for 217 million households of 9 major cotton districts in Punjab.
2) Estimated for 5127 thousand tons of cotton picked by 2.6 million women
3) Estimated for 1000 labourers working at 25 plants in Multan City
Source: UNDP 2001
- Integrated Pest Management (IPM).
A wide range of methods is available to manage agriculture pests that can be grouped into, i. regulatory. ii. Physical. iii. cultural. Iv. chemical. and v. biological. All of these have been used individually or in combination. The approach that addresses the overall health of crop by using all available methods has become to be known as Integrated Pest Management (IPM).
Many definitions have been coined to describe integrated pest management. According to FAO, IPM could be defined as “pest management system that, in the context of the associated environment and the pollution dynamics of the pest species, utilizes all suitable techniques and methods in as compatible manner as possible and maintains the pest population at levels below those causing economic injury (FAO, 1967). According to more recent definition “Integrated Pest Management (IPM) means the careful consideration of all available pest control techniques and subsequent integration of appropriate measures that discourage the development of pest populations and keep pesticides and other interventions to levels that are economically justified and reduce or minimize risks to human health and the environment”. IPM emphasizes the growth of a healthy crop with the least possible disruption to agro-ecosystems and encourages natural pest control mechanisms.
- History of the Concept of IPM
The IPM concept was developed by a group of entomologists in the late 1950’s at the University of California at Riverside led by V. Stern. The used the term Integrated Control to address the IPM concept that emphasized the selective use of chemicals so that natural enemies were conserved in the ecosystem. Later, the word “control” was replaced with “management” that includes avoiding the problem and does not aim at eradication but at maintaining pest populations at acceptable levels. As it has evolved, IPM is more or less synonym with Integrated Crop Management that includes all activities aimed at growing a healthy crop (e.g. soil preparation, irrigation, fertilization, etc.).
Modern concept of integrated pest management (IPM) has passed through many stages. Initially, experts of IPM concentrated on the development and introduction of spray thresholds but later on non-chemical control methods were integrated with minimum and selective use of pesticides. At this stage, packages of IPM were developed by the scientists at their research institutions and then disseminated to the farmers through extension workers. This system could not work well mainly due to the large variation at farmer field conditions. Consequently, this system could not maintain the involvement of farmers. In 1980, new concept was given to IPM that farmers should be educated on spot about the ecosystem of their own field. Now more than 50,000 farming communities have started implementation of IPM programme in a large number of countries in Asia, Africa and Latin America through the innovative approach called Farmer Field Schools (Kenmore, 1997).
- Farmer Led IPM
The Farmer led IPM approach from earlier one in the sense that it is participatory. This approach has been developed by the Food and Agricultural Organization of the United Nations (FAO) and validated based on non-formal education methods that could not assist the farmers to understand the ecosystem of their fields and to take crop management decisions based on their fields and to take crop management decisions based on their own insights but also assisted a group of Asian countries to establish large scale National IPM programmes based on this concept. It has a strong bottom up character and became known as participatory or community IPM. The corner stone of this approach is:
- Training of facilitators (ToF)
- Season-long Farmer Fields Schools (FFS)
Use of Training of Trainers/Facilitators (ToT/F) and Farmer Field Schools (FFS) has been demonstrated as an effective means of IPM dissemination. Under the TOT/FFS, 25 participants (mostly agricultural extension agents, but also representatives from research, NGOs, or others) are trained over a cropping season. The schedule is such a participatory one that all participants of the ToF work in the field with farmers. For first two days each week, the ToF participants observe a selected field and do the agro-ecosystem analysis (AESA) and then discuss what they observed in the field including the soil, the crop health, need for water, insect pests and their natural enemies, etc. This is done throughout the season of the crop. For next two days the ToF participants break into groups of five each to run 10 FFS and interact with two groups of 25 farmers each in 10 FFS (with 250 farmers). There too, the farmers do the same AESA, where they collect the insects, etc., draw their figures and present results, on the basis of which, further cultural practice and action is decided collectively. This way, the farmers become more organized, vigilant and realistic and if something is not clear, some short & very simple experiments are set up by them to resolve some unclear issues. Thus, the farmers become better organized, learn to work in community, make their own day to day decisions and become experts so that they do not depend on the chemical companies or extension staff for day to day crop production advice and become able to resolve conflicts by themselves.
The world experience over the years has shown that the best way for the translation of knowledge is through training of facilitators (TOF) and Farmer Field School (FFS) activities. One of the main reasons for the success of this approach is that the decisions are not preplanned and are not dictated from a central command but are based on the analysis of agro-ecosystem and site situation and are made by the farmers with the help of facilitators. Through learning framers become experts who are aware of the principles of the pest management and capable of making well-informed and independent decision suited to local conditions. Participatory IPM integrate local farmers’ indigenous knowledge with experience gained in other IPM programmes and research based IPM recommendations. Thus the participatory IPM rests itself on four basic principles:
6.1 Principles of Farmer Led IPM
- Grow a healthy crop
- Understand and conserve defenders
- Visit fields regularly
- Farmers become experts in crop management
6.1.1 Grow a healthy crop
Growing a healthy crop is a key step in farming. Healthy plants are stronger and thus better equipped to withstand attacks by pests and diseases. Many crop management practices have an effect on the health of the crop and can thus be used to manage pest problems. For example: good variety, healthy seeds and seedlings, land preparation, correct spacing, fertilizer management, water management, crop rotation etc.
6.1.2 Understand and conserve defenders
Biological control agents (parasites, predators, antagonists) are the defenders of the crop because they are natural enemies of the pests. IPM farmers know defenders and understand their role through regular observations of the agro-ecosystem. They will try to conserve them by avoiding pesticides and they will create field conditions that favor their development.
6.1.3 Visit fields regularly
Regular field visits by the farmer will keep him/her up-to-date on the condition of the crop. By knowing what is going on in the field, the farmer can take the correct decisions and take swift action when needed.
6.1.4 Farmers become experts in crop management
IPM farmers are experts in their own fields. They understand the agro-ecosystem and are capable of analyzing the field situation. They continue to improve their crop management by experimenting in their own field and share their knowledge with other farmers.
7. Status of IPM in Pakistan
In Pakistan, research and development on IPM was initiated in 1971 by PARC-IIBC station, Rawalpindi (now CABI Bioscience Regional Centre-Pakistan). A seven-year project on cotton bollworms, a three-year project on cotton whitefly, and an institutional three-year support project on IPM, funded by Asian Development Bank, were the first IPM projects. Similarly, other IPM activities like introduction of natural enemies of sugarcane Pyrilla in Sindh and NWFP, cultural control of Gurdaspur borer in sugarcane, pheromones (methyl eugenol) to control fruit fly and effective & environment friendly use of pesticides against cotton pests, were successfully carried out on large scale by various researchers. Coccinallids sp was used to control mango hopper and apple scales. Biological control based IPM technologies for cotton, sugarcane, maize, fruits and vegetables have also been developed recently. A project on “Cotton IPM Implementation through Training of Trainers (TOT) and Farmers Field Schools (FFS) was also undertaken in Punjab by CABI Bioscience Centre (Poswal & Williamson1998). At present the centre is running IPM projects on fruits and vegetables in Balochistan and NWFP provinces.
A number of plant protection related institutes in the National Agricultural Research System (NARS) are involved in developing IPM technologies for major crops. IPM technology comprising of cultural practices, resistant varieties, use of bio-control agents and selective use of pesticides has been developed for managing rice pests in Pakistan. The technology is being disseminated on farmers’ fields and pesticide application has considerably been reduced in IPM fields.
Many progressive farmers and Sugar Industries are successfully rearing and augmenting Trichogramma sp. and Chrysoperla sp. to control pests of cotton and sugarcane. Chrysoperla sp. has played an important role in the control of whitefly during the last two cotton seasons in the Punjab where chemical control measures had failed. Control of Helicoverpa sp. has been demonstrated on small scale with Trichogramma sp. on chickpea, sunflower and cotton. Pesticides of plant origin like “Triaimol”, “Nimboli” and “Nimbokil” have been locally developed and are being used to control important pests.
- National IPM Programme
Although, work on research and development, and IPM practice was initiated a long time ago in Pakistan and has gained momentum in the last decade through both national and international cooperation projects, IPM was not institutionalized as in other countries. It needed to be placed as a coherent programme including all components at the federal and provincial level. There is awareness and commitment at the highest level in the Government to rationalize the use of pesticides and to adopt the alternative approaches and strategies based on IPM rationale. To achieve this, it was necessary to translate the Governments strategy into action plan whereby the IPM moves from project approach to a viable and sustainable national programme.
IPM was identified as a key element of sustainable agricultural development in the Policy and Strategy for Agriculture developed by Government of Pakistan as part of its response to increasing misuse/overuse of pesticides and their negative impacts on the society in the Country. A consultative process among potential stakeholders was begun, which culminated in the launching of the National Integrated Pest Management Programme (Nat-IPM) in December 2000.
The National IPM Programme (Nat-IPM) is led by the National Focal Point for IPM as the overall Coordinator and assisted by five component coordinators, one each for policy analysis, education, information dissemination & public awareness, research & development and field implementation. The Nat-IPM works under the guidance of IPM Inter-Ministerial Advisory Committee (IPM-IMC) and is technically supported by the National Expert Committee (NIPMEC). It keeps close liaison with NIPMEC members, relevant federal and provincial research and extension departments, committees and IPM units. It encourages interaction between various institutions.
The overall goals of the Programme are established in the light of the policy statement given in the policy and strategy document, “Agricultural Strategies for the First Decade of New Millennium” issued in June 2000. The agreed IPM programme is being implemented by partner organizations and coordinated by Nat-IPM. The Programme operates from National Agricultural Research Centre Islamabad under the auspices of Pakistan Agricultural Research Council – an apex body of the Ministry of Food, Agriculture and Livestock. Various federal and provincial public sector research and development organizations, NGOs and international organizations are participating actively in the Nat-IPM activities. The National IPM Programme has following vision and objectives:
- Vision Statement:
Achieve environmentally sound and sustainable agricultural production ensuring food security, social equity, self-reliance and economic welfare of the producer.
Large scale and sustainable implementation of IPM in Pakistan, rationalizing the use of pesticide while maintaining production levels and increasing farmers’ profit.
The overall objective is to ensure better coordination and adoption of effective IPM approaches that are more responsive to the needs of practitioners and clients
- Specific Objectives
- Enhance communication and coordination and strengthen collaboration among IPM stakeholders.
- Promote the adoption of holistic, ecologically sound and issue oriented IPM approaches.
- Facilitate the formulation and execution of projects, ensuring optimum use of available resources and maximum impact of IPM efforts on productivity of cropping systems.
- Communicate the results of these efforts, the benefits of IPM and relevant policy decisions to the public widely.
- Establish International Linkages.
The National IPM Programme is pursuing its goal and objectives through establishment of following components:
- Policy analysis
iii. Information dissemination and public awareness
- Research and development
- Field implementation (IPM Practice)
The Programme is undertaking following strategic steps and actions to ensure progress of IPM at the National level within the framework of above components:
- Facilitate review of plant protection and IPM policies.
- Introduce/ promote IPM philosophy in educational institutions by pursuing respective departments for inclusion of IPM policies and syllabi in schools, colleges and universities.
iii. Enhance public awareness and establish IPM information network (IPMIN) to provide updated science based information to the stakeholders.
- Promote and coordinate research and development in IPM including study of various agro-ecosystems and indigenous knowledge.
- Facilitate and coordinate IPM implementation by provincial extension departments and promote cooperation and collaboration between institutions and provinces.
8.1 Key Issues and Challenges to the National IPM Programme
The National IPM Programme in Pakistan faces following challenges:
- Make participatory IPM training available to a larger number of farmers. With in these training programmes special attention needs to be paid to enabling and encouraging farmer initiative to continue experimenting after their Farmer Field Schools (FFS’s) and spread IPM through their communities.
- Develop special programmes to ensure involvement of women in IPM activities at the grass root level.
iii. Improve the policy environment for IPM through reform of policies and practices that directly or indirectly provide irrational support to chemical pest control.
- Reform crop protection research and extension to be responsive to support farmer initiatives in IPM.
- Enhance coordination and cooperation among government, NGO’s, donors and international organizations to achieve a high degree of coherence among different projects and initiative to optimize the benefits.
- Integrate participatory IPM into policies on sustainable agriculture and link the FFS approach to other development fields such as natural resource conservation, and community development etc.
The Nat-IPM is developing task forces, led by individual research and development organizations, to organize a coherent response to key issues and challenges affecting IPM research and implementation in the country. Under the umbrella of National IPM, currently initiatives are being executed with international support in an integrated strategy to forge a unified sustainable IPM Programme:
- Benefits of IPM
IPM emphasizes preventative pest control methods that provide economical, long term solutions to pest problems. The three main strategies in IPM program are chemical, biological and cultural practices. An IPM program places emphasis on monitoring crops, encouraging natural biological control and only using chemical control when it is necessary to prevent imminent crop loss or damage.
IPM is a flexible, dynamic strategy, which needs updating periodically as information is received from management practice results.
The use of all three strategies (chemical, biological, cultural practices) in an integrated approach has a number of benefits including:
- Reduction in the use of chemicals and thus lower production costs.
- Prevention of excessive residue levels on produce.
- Less risk of pests developing resistance to chemicals.
- Better survival and effectiveness of natural enemies.
- Minimizing the possibility of pest resurgence
· Avoiding the development of minor pests into major pests. Fits well with regular
maintenance and sanitation routines.
9.1 Important Considerations of IPM
Some considerations with the use of IPM are:
- IPM requires a greater level of pest life cycle knowledge and may be more labour intensive and requires commitment from growers.
- Biological and cultural controls may not offer an immediate high level of control as chemical control.
- Pests previously under control in a managed spray system using broad insecticide chemicals may become damaging.
- Some temporary damage may occur in the change from chemical spray system to integrated system.
9.2 Key Features of IPM
There are a number of essential ingredients to achieve an effective IPM program.
- Accurate monitoring of pests.
- This requires correct insect identification and sampling techniques
- Use of action level.
- Requires application of a control treatment when economic damage is imminent and must take into consideration abundance of natural enemies
- Choice of appropriate control measures
- Correctly timed and applied control measures
- Potato IPM
Integrated Pest Management (IPM) is a systematic approach to pest management that considers all factors affecting crop health, including plant nutrition, horticultural practices, and all suitable means of pest suppression. IPM programs are based on information obtained by sampling and monitoring, and this information is used to make management decisions. Pest management tactics may include biological, chemical, mechanical, and cultural methods.
IPM Guidelines can be used in a number of ways:
- As a checklist for farmers to evaluate their on-farm pest management programs and identify areas where management can be improved
- To verify and document that IPM is practiced on the farm
- As an educational tool which describes the scope and complexity of IPM to farmers, government officials, community groups and the general public.
Soil Nutrient Management and Cultural Practices
Cultural practices are of value in management of nutrients, weeds, diseases, or insects. The goal is to supply adequate nutrients with optimum timing for maximum economical crop yield, while avoiding excesses that can degrade water quality or adversely affect crop or soil quality.
Crop rotation is practiced as follows:
- Potato field rotation for two years.
- Potato field rotation for one year.
- Evaluation of filed for appropriate soil test, nutrient status and pH.
- Testing of organic matter status of field.
- Application of fertilizer according to soil test results of filed.
- Use of nitrogen fertilizer by split application. Some apply through the planter at planting, and some at cultivation or as a side dress.
- If the cover crop in field was legume or legume/grass mix, its nitrogen contribution can be calculated and also possible to adjust the fertilizer for present year crop appropriately.
Pesticides Application and Records
Only approved and registered pesticides should be used. Records of pesticide applications including date, field identification, targeted pest, pesticide name, formulation, rate and number of acres treated should be maintained. Pesticide drift is minimized. Re-entry and pre-harvest intervals are adhered to.
- Calibration of pesticide equipment should be calibrated at the start of the season.
- It is must to check the calibration at least once during the season and equipment can be recalibrated as needed.
- Records of pesticide applications should be maintained and organized.
- Records of planting dates and stage of crop of treated fields should be maintained.
- It is possible to use the water-sensitive spray cards for the test and coverage of leaf surfaces of potato crop.
- Certified virus-free seed should be planted.
- Sanitation is practiced by properly disposing of cull piles (burial or composting) and by removing volunteer potato plants.
- Fungicide application intervals for early blight and late blight are based on potential for disease severity due to weather conditions and crop physiological age, e.g. by using BLITECAST forecasting system. Fields are monitored for diseases including late blight.
It is possible to monitor the potato beetle densities weekly by scouting 25 to 50 plants per field.
Insecticide resistance managements are practiced as fallow:-
- Don’t apply the same synthetic insecticide more than once per season.
- Don’t apply the same synthetic insecticide to the same generation of
the potato beetle.
- Potato beetle egg masses can be flagged at the beginning of each potato beetle generation to determine egg hatch and proper timing of microbial insecticides.
- Foliar application (Provado) is limited to one generation potato beetle
(overwintered or summer adults) per season. Foliar application is not
made where systemic application is make.
- Soil application is made as a perimeter treatment to outer six rows or
20″ in non-rotated fields or adjacent to fields previously planted to potato.
- If soil perimeter application is used, foliar application is not made in
the same year.
- Apply microbial insecticides at least once per generation for control of potato beetle.
- Non-chemical potato beetle control methods can be employed, such as
propane flaming, delayed planting, or disruption of movement from
over wintering sites.
- Monitor the aphid densities weekly by examining 50 leaves per week. Aphid
species can be identified and insecticides application will be best control of the
- Potato leafhopper densities are monitored by examining 50 leaves per week.
Weed management includes one or more of the following points:
- Herbicide use is supplemented by at least one cultivation or hand weeding.
- Herbicide rates are reduced through banding of herbicides & cultivation.
- No herbicides are applied and weeds are controlled through cultivation. Herbicide rates are reduced by delaying application until, or after,
- Weeds in fields, alleys and roadways are prevented from going to seed.
- Scouting of fields in midseason for weeds. Location and species of uncontrolled
weeds are mapped and the information is used in planning for next year.
- Outbreaks of new or problem weed species are controlled, using chemical or
non-chemical means, to prevent spreading or seed production.
- Trial plot is maintained to test a different weed management technique.
- Plan for healthy crop of potato
Check List of Control Measures
In order to manage a potato crop in a state of optimal health, it is necessary to understand that constitute a healthy potato plant. The potato is a member of the plant family Solanaceous, which also include tomato, egg plant and tobacco as well as weed such as nightshade, groundcherry and buffalo bur. Unlike these other crop, however, potatoes are not produced from true seeds but rather are grown vegetatively from tubers “ seed pieces (Fig 4). It is convenient to divide the growth and development of the potato plant into five distinct life stages.
Fig 4: A potato plant developing from a seed piece cut from a tuber. Tubers develop from the enlarge tips of stolons (underground stem). Tubers have eyes (dormant buds), which can develop into shoots and lenticels (pores), through which air penetrate to interior tissues.
The Year Prior to Growing Potatoes
- Select cultivars appropriate for intended markets and production conditions. Identify reputable seed potato growers and visit forms to examine seed lots and certification records. Arrange for delivery of high quality certified seed potatoes.
- Establish an appropriate long-term crop rotation, with potatoes grown no more often than every third year. Use rotation that suppresses diseases and insects and nematodes pests, and implement rotation-wide weed control strategies. Destroy volunteer potatoes and weed that may harbor diseases or insect pests.
- Analyze the soil hardness, irrigation, diseases and weeds of potato. Fumigate the soil and spray some pesticides. Add some nutrients for the balance of soil pH and add some nutrients in soil.
- Collect and analyze soil samples for fertility, pH and other pertinent factors. Apply preplant fertilizers and soil amendments as indicated by the results of soil analysis. Establish permanent records of fertility, rotation, cultural management and pesticide use for each field.
- Perform tillage operations necessary to manage weeds and crop residues, minimize erosion, and provide tilth for planting. In irrigated production, establish sufficient soil moisture in the root zone to provide adequate available water until the potato plants are fully emergence.
- Properly dispose of waste potatoes left from previous crop- never in cull piles.
- Clean and sanitize storage facilities and seed-handling equipment prior to receiving seed potatoes.
- Examine seed tubers for diseases and defects upon delivery. Handle and store seed properly to maintain tuber health. Do not hold seed in storage areas that have been treated with a sprout inhibitors and may still be contaminated.
Fig 5: Potato development.
- Manage seed-cutting and healing operations carefully to ensure healthy, uniform, properly sized pieces. Sanitize cutting equipment at least daily and before cutting each seed lot. Apply a seed piece fungicide treatment as needed. Provide conditions for cut seed to suberize properly, or plant immediately after cutting, when soil conditions permit.
- Delay planting until soil temperatures are above 50F. As much as possible, schedule planting operations to coincide with favorable soil conditions and weather. Operate the planter so that the seed pieces are planted at the intended spacing at a depth that will ensure rapid emergence. Apply fertilizers and pesticides as appropriate.
Growth Stage 1: Preemergence
- Perform operation for preeemergence weed control and any practice hat reduce soil crusting and promote rapid emergence.
- In irrigated production, do not water prior to emergence unless the soil becomes excessively dry at the depth of the seed pieces.
Growth Stage II: Vegetative Growth
- In irrigated production, provide uniform soil moisture and avoid especially wet of dry soil.
- Apply post emergence herbicide as appropriate. Complete hilling-cultivating operations well before row closure, and avoid root pruning during tillage. Apply fertilizer side-dressings prior to the last hilling.
- Being insect scouting and disease monitoring. Delay the first insecticide or fungicide application until the action threshold for the target pest or diseases has been reached (Fig 6).
Fig 6: Growth stage of potato.
Growth Stage III: Tuber Initiation
- Avoid especially wet or dry soil, to minimize the development of common scab and tuber disorders.
- Begin petiole analysis for nutritional management, if appropriate.
- Continue insect scouting and disease monitoring, and apply pesticides as needed.
Growth Stage IV: Tuber Bulking
- In irrigated production, maintain uniform adequate soil moisture. Avoid overwinterinbg, to minimize disease development and nitrate leaching. Apply nutrients through sprinklers, if appropriate.
- Continue insect scouting and disease monitoring, and apply pesticides as needed.
- If desired, apply sprout inhibitors to plants when most tubers are at least 2 inches in diameter.
Growth Stage V: Tuber Maturation
- Reduce irrigation to promote tuber skin set, minimize tuber disease, and manage late-season weed growth.
- Cease application of nitrogen in irrigation water 4-6 weeks before vine killing. Schedule vine-killing operation to allow complete desiccation of the vines before harvest. Continue foliar applications of fungicide and insecticide, if appropriate, until the vines are completely dead.
- Inspect, repair, and sanitize storage facilities and harvest equipment. Make necessary modification to harvest equipment to minimize bruising.
- Train personnel for a safe. Low-bruise harvest. Conduct all harvesting, transportation, and bin-loading operations with bruise management as a primary goal. Ensure that tubers are not dropped from height of more than 6 inches.
- Begin harvesting after the vines are completely dead, early enough in the season to avoid from damage. Coordinate harvest operation with current and expected weather conditions, so that tubers are dug when conditions are as close as possible to optimal (60-65% of available soil water and tuber pulp temperatures of 50-65F.)
- Remove as much soil and debris as possible from tubers during harvest.
- Trap loads in the field to protect harvested tubers from rain, direct sun, and adverse temperatures. Isolate damaged or diseased lots in separate bins for immediate grading and marketing.
- Manage the curing period carefully to provide appropriate conditions for wound healing (50-60F), relative 95-99%, and good air movement).
- Monitor air movement, humidity, and temperature throughout the pile, and maintain the environmental conditions appropriate for each stage of the storage and on tubers. Continually monitor the pile for any signs of decay, and take appropriate action if decay develops.
- If appropriate, have a chemical sprout inhibitor applied by a custom application after the curing process has been completed.
- Before removing tubers for marketing, warm the store age to raise pulp temperatures above 50F. Manage bin-unloading operations to minimize bruising, following the same principles applied at harvest.
- Ensure that washed or flumed potatoes are well dried before packing. Use ventilated bags.
- Dispose of waste potatoes properly-never in cull piles.
Integrated Management of Potato Crop
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By Iftikhar Ahmad, Deputy Director General, Institute of Plant and Environmental Protection (IPEP), National Agriculture Research Centre, Islamabad, Pakistan.
Shazia Iram, Assistant Professor, Department of Mycology and Plant Pathology, University of the Punjab, Lahore.