By: Maryam Naseer
Agriculture, industry and commerce are pillars of the economy of every country and provide a strong base for development. If we talk about Pakistan, here, agriculture is the only pillar that can boost the dwindling economy and can play a vital role for its development. Many people are associated with agriculture as the main earning source of income and live hood.
Wheat is important crop of Pakistan in terms of earning major foreign exchange and food for people. Wheat is grown at about 8.41 million hectare in Pakistan, out of which 6.27 million hectare (74%) falls in Punjab province (MINFAL). Its yield as well as production experienced substantial fluctuations during some years due to climatic changes. Among others, natural population of predators and parasitoids fail to manage aphid population to acceptable limits. Since independence, pest management techniques other than pesticide spray, such as development of resistant varieties and dependence on natural enemies of pests were successfully utilized against various pests of wheat on sustainable basis. Up to 90’s there was a good natural equilibrium between aphid population and its natural enemies. However, during recent past, this natural balance seems to be disturbed by extensive and indiscriminate use of non -selective pesticides on various crops. The wheat aphid attack as compiled by DG Pest Warning reveals that initially it was seen only in 10 districts till 2002, which increased up to 35 districts from 2004 to onwards.Wheat aphid is also becoming a potential threat as it started feeding on milky grain stage of crop when it’s not advisable to spray non selective pesticides on a large scale as a sole agent for its management. Therefore, we need scientific research to resolve the issue on permanent basis.
If we look at history, the Cotton Leaf Curl Virus (CLCV) was recorded for the first time during 1967 in Multan. But we did not take it seriously till it started economic damage in 1988 and until now, we are not succeeded to control this virus, resultantly losing billions rupees bales annually. Similarly cotton mealy bug was recorded in Umar kot (Sindh) during 1980 but we did not try to study its lifecycle, weak links, parasites and predators till 2005 when it caused economic damage to our cotton crop. So far, we have not been able to find its proper control. So we need to adopt proactive approach and must be ready with control strategy before any organism poses serious threat to our agriculture. In fact, we need to remain ahead of pests rather than following them. We need to learn lesson from our past experience where we ignored proactive research approach against hidden potential threat.
Wheat aphid is such other emerging problem and few progressive farmers already started pesticides spray for its control and spray area is continuously increasing every year (agri. Extension workers). The situation will further deteriorate if some timely, effective and safe management strategy other than sole dependence on pesticide spray will not be developed for aphid control. Furthermore, as mentioned above, wheat is sown on a very large area and as such it is neither feasible nor economical to manage pests on it through spray. Therefore we need to develop a package of Best Agricultural Practices (BAP) including agronomic and bio control agents to tackle the problem on sustainable basis before it becomes epidemic.We also need to develop the loss of pesticides comparatively safe for bio agent and environment but effective against wheat aphid as a second defense to handle the situation if primary defense fails.
Luckily aphid species attacking Saron( Brassicanapus) are different from that attacking wheat crop, whereas natural enemies of both groups are the same. Furthermore, aphid appears on Brassica much earlier than on wheat crop. This phenomenon may be exploited fully by intercropping Brassica in wheat crop which will help to develop reservoir of natural enemies of wheat aphid before the appearance of aphid attack on wheat crop. Consequently, this reservoir may play an important role in aphid management on wheat crop. The preliminary data on intercropping of Brassica napus in wheat crop by Directorate Entomological Research Institute Ayub Agricultural Research Institute (AARI) Faisalabad, confirmed the aforementioned hypothesis to some extent.
Wheat aphid can damage crop by making the leave yellow, weak and affect the quality and production of crop. Aphid also spread various viral diseases, although not witnessed in Punjab but Peshawar has observed some viral diseases. Among all aphid types, four are prominent in Punjab province, including, Green Bug, Corn Leaf Aphid, Bird Cheery Oat aphid and English grain aphid whereas predators and parasitoids are environment friendly.
Wheat is an important crop and farmers should avoid spray of pesticides. In order to resolve this issue Centre for Applied Biosciences International (CABI) with the financial funding of Punjab Agricultural Research Board (PARB) started to work on a project “Integrated Pest Management of Aphid in wheat crop” since July 2009. The other collaborative institutes in the project were Adaptive Research Farm (Bhun, Sargodha, Gujranwala, Shekhpura and Vehari) and Wheat Research Institute Faisalabad. The project manager is Dr. Rana Muhammad Shafiq .
Development of Best Agricultural Practices (BAP) for management of Aphid attack on wheat has been completed. After analyzing results of studies the following BAP has been finalized for demonstration phase
· Timely sowing of wheat crop up to 20th November
· Apply balanced fertilizers i.e N:P:k @ 69:46:25
· Improved Brassica/canola intercropping in wheat by the following two methods
1. Three lines of Brassica intercropped after every 100ft (4 kanals) distance
2. A compact block of one kanal Brassica intercropped after every 400 ft (2 acres ) distance
If the aphid populations explode due to favorable environmental conditions, the insecticides, found to be safe for natural enemies, such as imidacloprid and pymetrozine can be used to control aphids effectively.
Selection of 10 sites for sowing of wheat to demonstrate BAP has been identified and completed in six districts of Punjab including, Attock, Faisalabad, Chiniot, Gujranwala, Khanewal and Bahawalpur. A total of 13 farmer’sday was arranged against a target of 10 in all districts of Punjab to create awareness among farmers and agriculture extension workers about BAP. Almost 50-60 farmers participate in the event. Besides this, 5000 brochures containing BAP information has been prepared and distributed among participants.
The project is just going to be finished with encouraging results for the safety of wheat crop. Research is only a single way to combat challenges and problems related to agriculture and other sectors. This project was a mutual work of a team of scientists, PARB’s monitoring and the support of Chief
Executive PARB Dr. Mubarik Ali. PARB has funded 53 output oriented research projects in crops, livestock, forestry and fisheries sector under the Chairmanship of Minister for Agriculture Punjab Malik Ahmed Ali Aulkah. These all projects will be helpful in boosting our agriculture sector and it is hoped that Punjab government will fund more project from PARB’s platform in future so that the emerging problems can get resolve on urgent basis.
Agriculture is our main sector to make us a developed nation and bring huge foreign exchange for Pakistan. But we have to pay attention to secure this sector by solving the problemsotherwise many cash crops will suffer from low productivity, viral diseases and other potential threats.
Maryam Naseer (Author)
Maryam Nasser Currently Work as Research Publication Officer at Punjab Agriculture Research Board (PARB), Contact: 042-37232744 ext. 616, Email: [email protected]