By Muhammad Nazar and Muhammad Waqas Yonas
Department of Agronomy, University of Agriculture Faisalabad, Pakistan
Introduction
Agriculture is the backbone of Pakistan and contributes 25% to the national economy, provides employment for over 50% of the labour force and is main source of income generation in rural areas.Use of labour is much greater in developing countries to perform agricultural operations therefore, less reliable productivity and growth but advanced countries are engaged with modern technologies to produce agricultural commodities. Inspite of Green Revolution, average production of major crops in Pakistan is still low as compared to advanced countries.
In Pakistan maize is third important cereal after wheat and rice; while it ranks third most grown crop in the world with an area of more than 365 million acres with an annual production of about 750 million metric tonnes.GM maize is a new hybrid of maize developed by different multinational companies around the world. The Philippines was the 1st country in Asia to commercially introduce the cultivation of GM maize.
Uses of maize
- Mostly grown for grains which are rich source of starch and protein.
- Can be grown for fodder to make silage.
- Edible oil extracted from maize seeds, biofuel like ethanol, biodiesel are being obtained from maize.
- Poultry feed is prepared from maize.
Issues in maize crop
- In Pakistan corn earworm and corn borers are the major insect problems in maize crop reducing yield upto 20 to 40%. On the other hand, weeds are also in the list of major factors responsible for low yield. Farmers use many types of pesticides to control them, making atmosphere polluted and hence creating climate issues.
- Residues get entrance into the edible parts of plants which are toxic for consumers.
- insect pests have developed resistance against these insecticides/herbicides due to their intense use, so becoming less effective to control pests.
- Use of traditional varities which are low yielding and not resistant to insect pests.
- Issues described above can be solved by adoption of genetically modified (GM) maize.
Genetically modified (GM) maize:
GM maize consists of two golden features to compensate with insect pest problem in maize.
Resistance against insects: It is genetically modified by inserting a gene, obtained from Bacillus thuringiensis (Bt) into the genetic makeup of the corn plant which makes the plant able to produce two toxic proteins Cry1A.105 and Cry2Ab2 having ability to control certain maize insects. These two proteins effectively bind to the midgut when ingested by insect pests and kill them to eliminate the problem.
Effective weed control (Glyphosate Tolerance)
An additional site of action helps plants withstand glyphosate to prevent weeds from competing with corn by robbing plants of crucial nutrients and water because it is also a Roundup Ready crop i.e. genetically modified to be resistant to the herbicide Roundup. Roundup is the brand name of a herbicide. Its active ingredient glyphosate was patented in the 1970s. Glyphosate, is consider the most important herbicide around the world. The first Roundup Ready crops were developed in 1996, with the introduction of genetically modified soybeans that are resistant to Roundup.
GM maize with herbicide tolerant gene has the inbuilt mechanism against the application of non selective herbicide (Glyphosate) so this herbicide can be used in the fields to eliminate unwanted foliage (weeds).
Advantages of GM maize
- Less use of pesticides in GM maize keeps environment safe and clean.
- High yield is obtained due to better genetic makeup.
- Insect pests do not get resistance against pesticides.
- Production cost is low due less number of pesticide applications.
- Due to borer control, GM maize contains on average less mycotoxins because Fusarium molds, enter maize plants primarily through holes produced by corn borers.
The global GM crop area is increasing, reflecting grower’s satisfiaction due to the significant and multiple benefits of GM crops.
Refuges
GM maize must be cultivated alongside so called “refuges” of traditional varieties to prevent the insects from becoming resistant to GM maize.
Recommendation
GM maize is a golden product with better genetic makeup, performing efficiently in the field than local hybrids of maize. To save an average outflow of foreign exchange on import of edible oil, food and energy security. There is an intense need to create awareness among farmer society about GM maize crop which will accelerate the cultivation of GM hybrids to meet edible oil and other food needs and balance our economy.
