Wheat improvement in Pakistan (A chapter from The World Wheat Book - a history of wheat breeding - vol 2))

The chapter has been written by Dr. Muhammad Aqil Khan Country Coordinator,  CSISA, Pakistan.

Important links of brochures for Zero til cum Bed Planter and Bed planting in wheat

Zero Till Cum Bed Planter – English

http://www.knowledgebank.irri.org/csisa/images/FactsheetsAndReferences/references/bedplanter.doc (Document; Size: 3.4 MB)

Bed Planting in Wheat – English

http://www.knowledgebank.irri.org/csisa/index.php/en/pakistan-punjab-csisa-hub/item/40-bed-planting-in-wheat (PDF; Size: 3 MB)

Quality Wheat Seed Production and farmers’ misconception

Majority of the farmers are using self-saved seed which, in unsanitary crop production conditions, becomes infested with off type wheat/weed seeds and, overtime, accumulates admixture and seed borne diseases. The use of such seed results in poor crops. Farmers often equate this situation to the variety deterioration. This is only a misconception. Seed doesn’t loose yield potential, it is the accumulated problems which weaken the plants and reduce crop yield. If farmers can maintain their seed, the original yield of the variety is possible year after year. The yield potential of a variety is not lost. Down the road, its resistance to diseases and insects which reduces its usefulness and so gives way to a need for new variety.

 It is easy to maintain the seed. Farmers, large and small, can produce their own seed in separate fields using low seed rate and disease and weed control measures. The row spacing should be wide to facilitate sanitation operations. Doubtful and diseased plants should be rogued during crop growth and maturity. Zero-tolerance should be exercised for unwanted problems- off type and sick wheat plants, other crop plants and weeds. The resultant seed should be as good as any good seed available in the market if not better. Using this plan, a farmer can use his seed as long as he wants or until the variety is replaced. He can then apply this methodology to the new seed. In the present situation when the private and public sectors seed quality is deteriorating, self produced seed especially by progressive responsible farmers, might be the best bet.

Present seed situation is not very enviable. Only 15-20 % seed is produced in the country, the rest is farmers’ old seed. Available seed is often picked up by farmers in periurban areas or by large farmers leaving deep rural situation in misery. Seed is still a magic factor so the farmers in those areas harvest very poor yields. Self production of quality seed is a very practical and economic way to improve deep rural seed situation.

Following technology can be used to raise a seed crop:

Time of sowing: 1-15 November

Seed rate: 25-30 kg/acre

Row spacing: 30 cm apart

Seed: Seed for seed production should be of high quality obtained from a reliable source. Basic seed from a crop breeder can a good start. If, however, seed from breeder or other reliable source is not available farmers can improve/purify their own seed with tangible impact on yield. Seed, if required, should be sifted, graded and purified from weed/diseased seeds and treated with a fungicide against soil borne diseases before sowing. A start with basic seed from a breeder can ensure farmer its certification from seed certification agencies. A seed crop with an unknown seed source is not certified how-high it may be in all quality attributes.

Irrigation, fertilization: As for normal crop.

Weed control: Wheat crop is often heavily infested by a variety of weeds which, over time, have become serious production hazards. Since seed quality standards are stringent and barely allow for disease and weed seeds, a judicious program for weed control is necessary. Major weeds in wheat are Phalaris (Dumbi sitti), Wild oat (Jungli jai), Chenopodium (Bathu) and Convolvulus (Laili). Some other weeds are becoming localized problems; e.g. Jungli matar, Jungli palak etc. Fortunately, all these weeds can be controlled by one or the other herbicide so producing weed free seed shouldn’t be a serious problem.

Rouging: Quality seed production is not possible without crop sanitation which includes keeping diseases, insects and weeds in check and crop free of off-type wheat and other crops plants. Seed producers should be watchful of these menaces and eradicate them timely and properly. Off-type plants eradication require frequent crop visitations and rouging. These plants can be identified from leaf shape and orientation, head size, shape and color. So crop visits during vegetative and reproductive phases are necessary. In eliminating off type plants one should ensure that these plants are uprooted from the ground intact leaving no part in soil to grow again. If farmer is purifying his seed he has to go very much through the same exercise.

Aphid control: Lately aphids have become serious production problem. They multiply very rapidly and can destroy the crop in few days if left unattended. Aphids start from a point (hotspot) which is recognizable from distance due to deeper green color of infested area. Early on they can be easily controlled by non chemical means. A thorough water spray by power sprayer can eliminate the aphid threat in hotspots. But if they spread out chemicals are the only effective remedy.

Seed crop harvest, threshing, bagging and storage: Seed crop should be harvested when the crop is properly mature and grain moisture contents about 12 per cent. The seed crop should be harvested and threshed separately from other varieties. Care should be taken not to mix seed crop bundles with other crop bundles nor seed crop should be threshed using unclean threshers. Threshers should be thoroughly cleaned of any remnant seed of previous crop. Similarly bags should be clean and free of any previous crop and disease debris. It is advisable to use new bags for seed crop to ensure purity and sanitation. The crop should be stored in aerated, well protected store. Proper fumigation and periodic examination of the stored seed is necessary to avoid storage losses.

Quality standards:

Crop certification standards

Crop category	Off type plants	Other crop plants	Obj. Weeds	Disease plants
Prebasic	None	None	None	None
Basic	0.05	None	None	None
Certified	0.20	0.05	0.02	0.2

Seed certification standards

Seed Category	Other variety seeds	Other crop seeds	Inert matter	% germ.
Prebasic	None	None	0.01	85
Basic	0.05	None	2.00	85
Certified	0.20	0.05	2.00	85

Extensionists and Farmer Trainings by CSISA, Pakistan

Extensionists and farmer training on water saving techniques

CKB & HCP trainings by CSISA, Pakistan

Extensionists CKB & HCP training by CSISA, Pakistan

Agronomists CKB & HCP training by CSISA, Pakistan

Agronomists CKB & HCP training by CSISA, Pakistan

Zero-til planting in wheat

Zero-till planting is a method of crop planting without conventional field cultivation practices. In wheat it is employed for planting wheat in standing stubbles of previous rice crop. It thus avoids preparatory tillage and so reduces the cost of crop production. By eliminating field preparatory tillage it facilitates early wheat planting. Timely wheat planting is a critical factor in wheat yield maximization. Unfortunately, most of the wheat in Punjab is late planted and the yields are, therefore, low. Cotton, rice and sugarcane all delay wheat planting and with rising temperatures at maturity the crop growth period is being curtailed which further affect wheat productivity. So practices which enable timely wheat planting would be critical in future. Zero-til planting entails several other advantages. Rice crop residues incorporated/left in the field provide mulch, retain moisture and keep crop temperatures low, a way to fight changing climate. Residues help buildup of soil organic matter, improve soil fertility and make soil porous for water penetration/retention. Crop residues left in the field promote biodiversity – soil flora and fauna – which are necessary for reviving soil health and maintaining balance so important in successful crop production. Using previous crop remnant soil moisture the zero-til planting has water saving aspect also. Also a zero-til planted field has less weed infestation due to undisturbed weed seed bank deeper in the soil layers. Finally, by reducing fossil fuel use it plays a role in arresting atmospheric pollution and its consequent climate change effects. Carbon dioxide from fuels is the main cause of rising temperatures being experienced lately.

Fig. Zero Til Planted Wheat Field

Zero-til planting is done with an especially designed planter that opens up a slit in the unworked soil and places the seed in the slit. The seed remains uncovered but is safe from scavenger birds due to its inaccessibility in the slit. A well moist soil condition ensures better germination. A combine harvested rice field with 15-25 cm stubbles is ideal. Zero-til planting without crop residues doesn’t give satisfactory results due to absence of benefits enumerated up. A field with straw piles, however, obstructs planter working. Straw piles lifts the planter and seed is dropped on the surface and remains ungerminated due to dry surface conditions. The fields, as a result, give patchy look and may not yield well due to low population. Most of the zero-til planters come with fertilizer attachments which deliver the fertilizer in the seed row. Ideally fertilizers should be placed 5-7cm to a side and 5-7cm below the seed row. A planter which delivers the fertilizer in the seed row, therefore, is not the best arrangement. It can be used to apply phosphatic fertilizers during planting. Nitrogenous fertilizers especially urea shouldn’t be applied through such drills as they affect germination when placed in close proximity with seed. Zero-til planters come with adjustable seed rate, fertilizer and row spacing arrangements. So a farmer should see that the planter is adjusted to his needs. Before planting season starts farmers should check their planters for breakage, dirt accumulation or any blockage in delivery system and clear them and oil/ grease the moving parts and makeup for the breakages.

 Fig. Zero Til cum Bed Planter

A zero-til planting can averagely save farmers Rs. 4000.00 incurred on land preparation for wheat planting. Besides, there would an average benefit of Rs. 2500.00 in terms of yield gains due to early planting. So zero-til planting besides healthy effects on soil and crop environment entails direct monetary benefits for farmers.

Planting time: The best planting for wheat is the end of October or first fortnight of November. After mid November the yield starts declining and later the crop is planted higher is the yield loss. The rate of yield decline is indicated below: 

Rate of yield reduction in delayed planted wheat crop

Planting (weeks) after 10th Nov.	% yield reduction
2	8
4	15
6	32
8	49

Timely planting not only maximizes yield it minimizes the frost, insect and disease damages also. So timely planting is the best bargain for farmer on his investment.

Seed rate:  40-50 kg/acre

Seed quality and CSISA role in seed production: Seed is still the magic factor in successful crop production and makes black and white differences. Seed should be vigorous, healthy and free of diseases and debris. Its germination should be above 95 per cent. Farmers can easily produce quality seed themselves and CSISA, Pakistan can provide the needed technical know-how to interested persons and encourages local seed leaders for quick diffusion of quality seed. Seed situation in deep rural areas is particularly precarious and can be addressed through local seed leaders. Lately many farmers have reported occurrence of Karnal bunt. Once in the soil it can survive year after year and become an endemic problem. Farmers and seed industry should particularly be watchful of this disease.

Fertilizers: Fertilizer use should be guided by inherent soil fertility, a broad based departmental recommendation includes 2bags each of DAP and urea. Rich soils may require less fertilizers. In selected areas potash and micronutrients have proved beneficial. In canal irrigated areas sufficient potash is available in irrigation water. Previous crop residues can immobilize nitrogen so a little extra nitrogen application (10-15 kg/acre) is advisable.

Weed control: Weeds can rob farmers upto 40 percent of their yield and need to be checked. Wild oats, Phalaris, Chenopodium (Bathu), Convolvulus (Laili) are main weeds. Most of the weeds are easily controllable with available herbicides. Phalaris population is low in zero-til planted fields. Farmers should note that proper control requires right herbicide used at right time and in right manner otherwise weed control measures would remain ineffective. If rice season weeds persist, it is adviseable to control them with preseeding herbicide.

Irrigation: Undisturbed soil inhibits deep water percolation so zero-til planting can save 15-20 percent water. Crop should be sown in well moist soil, a dryer soil reduces germination. 4-5 irrigations are sufficient for wheat crop; first irrigation should be applied 15-20 days after planting. Other irrigations should be preferably timed with critical crop stages: boot and early milk stages.

Contributed By:

 Dr. M. Aqil Khan, Rana Farman Ali, Abdul Hamid & Hafiz Naveed Ramzan.

    CSISA, Pakistan

    An IRRI-CIMMYT project

    Ph # +92 41 2650690
    Cell # +92 333 8360023

    Ayub Agri. Research Institute, Faisalabad, Pakistan.