By Dr Muhammad Tahir and Muhammad Rashad Javeed
GIVEN the country`s rich natural resources, it is imperative to fully realise the biological potential of our major field crops, particularly wheat. In Punjab, more than 50 per cent of the total planted area every year is under wheat cultivation, showing the socio-economic importance of the crop for farmers and their contribution to its yield. The climate here is conducive to growth and production of wheat, having high-yielding varieties, ample resources, fertile land and hard working farmers. But the growers fail to achieve the optimum potential of wheat crop. There are many constraints in raising wheat.
Quality seed is a basic requirement to sustain any crop. Target yield of the crop depends on availability of quality seeds of improved varieties as effectiveness of agricultural inputs depends on seed potential.
The Punjab Seed Corporation provides only 10 per cent certified seed to the farming community. The shortage of quality seed can be met by encouraging more private companies having good repute, strengthening the private-public relationship, increasing capacity of the Punjab Seed Corporation and provision of technical assistance for production of quality seeds.
A crop sown in time ensures better yield than the delayed one, because late sown crop fails to complete its physiological processes, remains under stress and fails to demonstrate its full potential.
Noteworthy point is that only Â± 20 per cent crop is planted before November 15, the optimum planting time, and 80 per cent is planted late every year. There is a considerable decrease in yield because of delayed sowing (One per cent per day i.e. 10-15 kg per day per hectare).
Normally delayed planting of wheat takes place in cotton belts (44.9 per cent) and rice track (21.3 per cent) which can be overcome by zero-tillage drill, turbo-seeder, late sowing varieties of wheat, early sowing varieties of cotton, sowing of wheat in standing sticks of cotton crop and using less time for land preparation. These practices enable farmers to save time, but still are not very effective in increasing yield.
Plant population per unit area is never considered to be an issue in wheat fields although it directly has a role in total productivity. Poor quality seed results in poor germination and less number of plant population per unit area. Plant population can be optimised by sowing recommended seed at a proper depth in line with a drill before November 15.
Water is involved in all chemical activities within the plant body, transporting raw materials and minerals from soil to the chemical reaction site. Experiments show that critical growth stages of wheat towards irrigation are crown growth initiation, tillering, booting and grain filling (milking) stages.
Shortage of water during these critical stages disturb the physiological, chemical and enzymatic function within the crop which cannot be overcome later, even giving ample water supply to wheat plant.
Sprinkler irrigation, sowing of wheat on beds, mulching, lining of water courses, leveling of land by laser, de-silting of canal and water courses, application of water in critical stages and introduction of drought resistant varieties are helpful in coping with this problem of poor yield.
Due to growing of continuous and exhaustive crops, the nutrients uptake is more than natural replenishment of the soil up to the required nutrient level, which seriously needs an artificial/synthetic addition to sustain wheat crop yield. In our country, consumption is more than production, which causes a severe hindrance in yield improvement programme.
The government should provide all inputs especially good quality seed and fertilisers at farmers door step before the wheat season starts. The government can manage and overcome these problems by controlling hoarding, enhancing capacity of already working fertiliser units, importing fertilisers in case of deficiency, increasing soil testing laboratories up to union council level, controlling price at the recommended level, preventing adulteration of seed and fertilisers and giving technical assistance to farmers on fertiliser management practices, to increase fertiliser use efficiency and increase yield.
Weeds reduce crop yield and are more beneficiaries of resources than the crop plants. Weeds reduce yield by 12-35 per cent by competing with crop for nutrients, space, and sunlight.
The problem can be overcome by crop rotation, use of clean seed, sprinkler irrigation, planting of wheat on beds, clean cultivation, optimum planting geometry and controlling of weeds on field bunds and water courses.
No doubt, we have enough natural resources and hardworking farmers, but there is lack of planning and management on both government and farmers sides. The government should promote co-operative farming, strengthen co-ordination among the three vital pillars of agriculture departments i.e. research, extension and farmers, and educate the farmers with new agricultural technologies to increase wheat yield.