Land Preparation
Wheat crop requires a well pulverized but compact seed-bed for good and uniform seed germination. In irrigated areas, after the harvest of previous crop, the field should be ploughed with disc or mould board plough. Where tractor is available, one deep ploughing followed by two to three harrowings with disc or tines and 2 to 3 planking should be given to prepare a well pulverized seed-bed. But where bullocks are the source of power, deep ploughing followed by two to three harrowings or four to five intercross ploughing with local plough should be done. Planking should be done after each ploughing.
In rainfed areas, the field preparation should be done with care as conservation of moisture is dependent on it. Fields are usually prepared by giving one deep ploughing followed by two to three ploughing with local plough and then planking. In these areas, ploughing should be done in the evening and furrows should be kept open whole night to absorb dew moisture. Planking should be done early in the morning. A buffer zone of 10-30 m width should be kept to avoid contamination from the non-organic field.
Seeds and Sowing
The optimum sowing time of wheat varies widely over the growing areas. It depends upon (i) type of variety, (ii) weather conditions, (iii) soil temperature, (iv) irrigation facilities and (v) land preparation.
In general, the maximum productivity potential of promising wheat varieties under irrigated conditions is attained by sowing them between 10th and 25th November in all the climatic zones other than the peninsular zone. Rainfed wheat is generally sown during the second fortnight of October to early November. Under specific circumstances, wheat is sown in the month of December too. In late sown wheat, only short duration varieties should be used.
Seed Rate and Spacing
Seed rate varies with the variety used. It also depends upon seed size, germination percentage, tillering ability, time of sowing, moisture content in the soil and method of sowing. Usually, a seed rate of 40 kg per acre is sufficient for normal sowing. For varieties with bold grains like Sonalika under late sown conditions, seed rate should be increased to 50 kg per acre. In case wheat is to be sown by dibbler, a seed rate of 10 to 12 kg per acre is sufficient. For normal sown crop, a spacing of 20 to 22.5 cm between two rows is recommended. When sowing is delayed, a closer spacing of 15 to 18 cm should be adopted.
Methods of Sowing
Broadcasting:
The seeds are broadcast and then mixed in the soil using harrows. Generally, uniform seed distribution cannot be achieved leading to irregular plant stand and poor germination. When the broadcasted seeds are not covered properly, they are picked up by birds resulting in wastage of seeds. Hence, this method is generally discouraged. Behind Local Plough: The seeds are dibbled by hand into the furrows that are opened with the plough. This is called ‘kera’ (hand) method. When it is dropped through a Pora or Nai or Hazara, a special attachment with local plough, it is called ‘Pora’ method. The seeds are dropped at a depth of 5 to 6 cm. The germination is satisfactory under this method of sowing.
Drilling:
Before sowing the seeds by drilling, the seed-bed should be thoroughly prepared. It should be well leveled free from clods and weeds. The seeds are sown by seed drilling at uniform depth. It results in uniform germination and regular stand. Dibbling:
When there is limited seed availability, this method is used for sowing. Dibblers have a wooden or iron frame with pegs. The frame is pressed in the field and lifted and then one or two seeds are dropped by hand in each of the hole. It is a time consuming process.
Zero Tillage Technique:
This method is useful under “rice-wheat” cropping system. After harvesting of rice crop, field requires at least 6-8 tillage operations (ploughing and harrowing) to make field ready for sowing of wheat. A zero-till-seed drill machine is used for direct sowing of wheat in rice field without field preparation. This helps in advancing of the sowing of wheat. Under zero tillage, there should be proper moisture in the field at the time of sowing. The rice crop should be harvested close to the ground. The field should be free from weeds. Sowing depth of about 5 to 6 em should be maintained. Light plank may be used behind the machine.
Water Management
Adequate soil moisture is required for normal development of the wheat crop at all the stages of growth. In case of dwarf high yielding varieties, a pre-sowing irrigation should be given. At the crown root initiation stage (20-25 days after sowing), the first irrigation to the standing crop should be given to ensure good tillering, normal heads, sound root system and ultimately sufficient grain yield. The second irrigation should be given at tillering stage (within 40-45 days after owing). Irrigation is given at late jointing stage (within 70-75 days after sowing). Irrigation at flowering stage (within 90-95 days) is important to ensure more grain number and better grain size. At dough stage (within 110-115 days after sowing), another irrigation is required. Of course, the number of irrigations required depends on soil type, rainfall and amount of water applied per irrigation.
If only one irrigation is possible, it should be given at crown root initiation stage, i.e., 20-25 days after sowing. If two irrigations are available, first irrigation should be given at crown root initiation stage and second at flowering stage. If three irrigations are possible, first irrigation should be given at crown root initiation stage, second at jointing stage and third at milk stage.
Weeding
Critical crop weed competition period is 45 days.
Generally weeding is done 21 DAS when 1st irrigation will be given and after 6 weeks when 2nd irrigation will be applied.
Harvesting
Harvesting should be done when there is about 25-30% moisture in grains. It should be checked by biting one single grain, if it feels soft then it is the right time for harvesting.
Generally wheat crop is harvested by using a hand sickle.
Post Harvest Management
After harvesting, it is dried for 3-4 days on the threshing floor. Grains are separated by trampling bullocks or by using a paddle operated thresher. Weed seeds and chaffy grains are sorted out from the grains. Winnowing is done for separating the grains from husk. For safe storage grain should be cleaned and dried well in sun for a few days so that moisture content of the grain comes down to 10-12%. Clean and dry grains are kept in air tight poly bags.