AGRONOMIC RESEARCH STATION
Bahawalpur, Pakistan.
Muhammad Aslam, Manzoor Hussian, Arshad Hussain, Muhammad Safdar, Muhammad Masood Akhtar, M. Akhtar, and Asghar Ali Malik.
Introduction. Wheat is the most important Rabi cereal crop of Pakistan. Wheat is grown on area of 80.109 x 10^6^ ha with an annual production of 16.6 x 10^6^ tons with an average yield of 2,053 kg/ha. The present study was designed to determine the appropriate seeding rate for obtaining maximum wheat yield under irrigated conditions of the Bahawalpur region. Singh and Uttam (1999) obtained higher yield using 125 seed/ha, whereas Ram et al. (1998) suggested 160 kg/ha to get maximum yields.
Materials and Methods. The study was conducted at six different farmer's field in the Sadiqabad, Uch Sharif, Duniapur, Burewala, Lodhran, and Jampur provinces. The four seeding rates (125, 150, 175, and 200 kg/ha) were studied with a plot size of one kanal/seeding level. Phosphorus, in the form of DAP, and potash, in the form SOP, was applied as a basal dose at sowing. The wheat cultivar Inqlab-91 was sown during study period on a well-prepared seed bed with a tractor drill. All agronomic practices were kept normal and uniform for all treatments in order to demonstrate the effect of seeding rate on different sites in the Bahawalpur region in farmer's fields.
Results and Discussion. Table 1 shows that grain yield was affected significantly by various seeding densities. Plots seeded at 150 and 175 kg/ha gave significantly higher grain yield (3,248 and 3,238 kg/ha, respectively). We concluded that a seeding rate of 150 kg/ha was the highest yielding, most economical on average, and large quantities of seed can be saved and must avoid to the unnecessary excessive seeding. Similar results were found by Ram et al. (1998), Singh (1999), and Zubair (1989).
| Site | Seeding rate (kg/ha) | |||
|---|---|---|---|---|
| 125 | 150 | 175 | 200 | |
| Sadiqabad Chak No.191/P | 4,066 | 3,933 | 3,900 | 3,730 |
| Uch Sharif | 3,800 | 4,000 | 3,800 | 3,800 |
| Duniapur Chak No.8/M | 2,200 | 3,100 | 3,100 | 2,500 |
| Burewala Chak No.331/Toppianwala | 1,900 | 2,900 | 2,800 | 2,300 |
| Lodhran | 2,090 | 2,700 | 2,830 | 2,533 |
| Jampur | 2,270 | 2,860 | 3,000 | 2,700 |
| Mean | 2,721 | 3,248 | 3,238 | 2,927 |
References.
Muhammad Aslam, Manzoor Hussian, Abdul Rashid, Muhammad Arshad Gill, Abdur Rashid, Ghulam Hussian, Asghar Ali Malik, M. Arshad, and L.H. Akhtar.
Introduction. Wheat is a major food grain of Pakistan and is the biggest volume crop grown in the country. The use of N-P fertilizers play an important role to obtian the highest grain yields. We began this project to determine the best N-P levels for obtaining reasonable yields. The studies are in the line with those of Pandey (1999), who concluded that increases in grain yield with N-P levels up to 150-75, and Rafique et al. (2000), who obtained the greatest yields with application of 150-100 N-P kg/ha.
Materials and Methods. This study was conducted at six different sites of the region of southern Punjab, Sadiqabad, Uch Sharif, Duniapur, Burewala, Lodhran, and Jampur, on farmers' fields under an 'Integration of Agricultural Research and Extension Activities' project for the year 2002-03. The wheat cultivar Inaqlab-91 was sown during the study period on a well-prepared seed bed with tractor drill. The four fertilizer levels were 80-58-60, 120-89-60, 160-115-60, and 200-146-60 (NPK) with a plot size of one kanal for each level. All agronomic practices were normal and uniform for all fertilizer levels.
Results and Discussion. A fertilizer level of 160-115-60 N-P-K kg/ha gave the highest average grain yield of 2,983 kg/ha (Table 2). The maximum wheat yield of 3,900 kg/ha was obtained at the 160-115-60 and at 200-146-160 levels, thus a 160-115-60 rate is the most economical for obtaining reasonable yields of wheat sown after cotton. Similar results also have been reported by Paddy (1999) and Rafique (2000).
| Site | Fertilizer level (N-P-K, kg/ha) | |||
|---|---|---|---|---|
| 80-58-60 | 120-89-60 | 160-115-60 | 200-146-60 | |
| Sadiqabad | 3,330 | 3,867 | 3,900 | 3,900 |
| Uch Sharif | 2,350 | 3,100 | 3,500 | 3,000 |
| Dunia Pur | 1,700 | 2,300 | 2,500 | 2,400 |
| Burewala | 1,300 | 1,500 | 2,000 | 1,900 |
| Lodhran | 2,270 | 2,830 | 3,130 | 2,930 |
| Jampur | 2,100 | 2,470 | 2,870 | 2,770 |
| Mean | 2,176 | 2,678 | 2,983 | 2,817 |
References.
Muhammad Aslam, Abdul Rashid, Ghulam Hussian Asghar, Ali Malik, Muhammad Rafiq, Arshad Hussain, Saeed Ahmad, and Lal Hussain Akhtar.
Introduction. Wheat is a staple food of Pakistan that provides approximately 72 % of the calories and proteins in the average diet. Pakistan is the 7th largest wheat producer, accounting for 2.73 % of the world's wheat production and the Punjab province is the main wheat producer in Pakistan (Anon 1997-98). Southern Punjab, although a cotton zone, contributes approximately 44 % to the wheat production of the province. Cotton has a long cultivation period in the field, so approximately 80 % of the wheat crop is being planted under late-sown conditions and planting time is the practice most affecting grain yield. Early sowing always produces a higher yield then later sowings. Ibrahim and Abdullah (2000) observed that delaying sowing by 1 month reduced grain yield by 27 %. Shah and Akmal (2002) found that early planted cultivars yielded the maximum of 282 spike-bearing tillers/m2, had a relatively higher seed weight/spike at 1,999, and 49 seeds/spike. Rachon (1997) concluded that late sowing reduced the number of reproductive tillers formed, the weight grain/spike, number of grain/plant, weight of grains/plant, and 1,000-kernel weight. Ahmed et al. (1997) found that late sowing resulted in reduced plant height, spike length, grain/spike, and low yield in all cultivars.
Materials and Methods. This study was done at six different sites in the southern Punjab region, Sadiqabad, Uch Sharif, Dunia Pur, Burewala, Lodhran, and Jampur, in farmers' fields under 'Integration of Agriculture Research and Extension Activities' for the year 2002-03. The wheat cultivar Inqlab-91 was sown on a well prepared seed bed with a tractor drill. Two plantings, 14 and 24 December with a plot size of 4 kanal for each planting time were studied. All agronomic practices were normal and uniform for all sowing times.
Results and Discussion. The data for wheat grain yield showed that the maximum average yield of 3,257 kg/ha was obtained when the crop was sown on 14 December (Table 3). When sowing delayed until 24 December, yield decreased at all six sites, ranging from 21-36 %. These results are in line with those of other researchers (Rachon 1997; Ahmed 1997; Ibrahim and Abdullah 2000; Shah and Ahmad 2002).
| Site | Sowing date | % decrease | |
|---|---|---|---|
| 14 December | 24 December | ||
| Sadiqabad | 3,640 | 2,800 | 27 |
| Uch Sharif | 3,400 | 2,700 | 21 |
| Donia Pur | 3,500 | 2,630 | 25 |
| Burewala | 2,300 | 1,600 | 36 |
| Lodhran | 3,300 | 2,550 | 23 |
| Jampur | 3,200 | 2,440 | 24 |
| Mean | 3,257 | 2,453 | 25 |
References.
Ghulam Hussian, Muhammad Aslam, Muhammad Arshad Gill, M. Hussian, Abdul Rashid, M. Arshad, and Lal Hussian Akhtar.
Introduction. Wheat is a major food grain of Pakistan and is the largest volume crop grown in the county. The aim of this project was to observe the performance of wheat cultivars at different six sites (Tehsil level) in the Bahawalpur region.
Materials and Methods. This study was conducted at six different sites in the Bahawalpur region, Sadiqabad, Uch Sharif, Donia Pur, Burewala, Lodhran, and Jam Pur, on farmers' fields as a demonstration of production technology under a 'Integration of Agriculture Research and Extension Activities Project' in 2002-03. Wheat cultivars were sown during the study period on a well prepared seed bed with a tractor drill. Five wheat cultivars, Drawar-97, BWP-2000, Iqbal-2000, and Inqlab-91, were sown with plot size a one kenal for each cultivar. All agronomic practices were normal and uniform for all cultivars.
Results and Discussion. The grain yield of two cultivars, Inqlab-91 and Manthar-3, were similar but significantly higher than other three cultivars at the six different locations (Table 4).
| Site | Drawar-97 | BWP-2000 | Manthar-3 | Iqbal-2000 | Inqlab-91 |
|---|---|---|---|---|---|
| Sadiqabad | 3,300 | 3,460 | 3,667 | 3,233 | 3,933 |
| Uch Sharif | 3,600 | 3,200 | 3,300 | 3,050 | 3,700 |
| Donia Pur | 3,400 | 2,800 | 3,200 | 2,800 | 2,900 |
| Burewala | 2,300 | 2,310 | 2,900 | 2,310 | 2,760 |
| Lodhran | 2,370 | 2,700 | 2,270 | 2,406 | 2,200 |
| Jampur | 2,320 | 2,600 | 2,100 | 2,516 | 2,000 |
| Mean | 2,872 | 2,845 | 2,906 | 2,719 | 2,910 |
Manzoor Hussain, M. Rafiq, G. Hussain, M. Zahid Aslam, A. Rashid, A.H. Tariq, and M. Arshad.
Introduction. In the cotton zone of Pakistan, the wheat
crop is sown after cotton, i.e., in late November and month of
December, which is considered to be late planting. Grain formation
and filling generally is completed under high temperature during
the months of March and April. Because of high temperatures, most
genotypes have a lower grain weight, which is one of the main
causes of low yield in the region. Heat stress is one of the most
important factors affecting crop yield. Wheat is particularly
susceptible to yield losses as a result of heat stress (Wrigley
et al. 1994). Optimum temperature for growth and yield of wheat
is in the range of 18-24 C. Even a period as short as 5-6 days
of exposure to temperatures between 28-32 C result in 20 % or
greater decreases in yield (Stone and Nicolas 1994).
In southern Punjab in Pakistan, temperatures often fluctuate to
30 C and above during the grain-filling stage of the wheat crop.
The optimum temperature for photosynthetic activity of wheat from
anthesis to maturity is 20 C or lower (Al-khatib and Paulsen 1989).
Harding et al. (1990) determined that elevated temperatures accelerate
senescence, reduce the duration of viable leaf area, and diminish
photosynthetic activity. Hurkman and Tanaka (1987) studied the
effects of high temperature on thylakoid membranes, which lead
to a loss in the number of chloroplasts per cell. Heat stress
effects the quality of the harvested products, reducing bread-making
quality by affecting gliadin synthesis (Blumenthal et al. 1993)
and starch quality by affecting the ratio of A (large) to B (small)
starch granules (Stone and Nicolas 1995). Therefore, we initiated
a new project on heat tolerance at the Regional Agricultural Research
Institute, Bahawalpur.
Materials and Methods. A total of 330 lines from 26 crosses in the F3 generation was planted on 18 December at Regional Agricultural Research Institute, Bahawalpur. Late planting insured grain formation and filling under high temperature conditions in the field. Selections were made on the basis of 1,000-kernel weight. Inqulab 91 was sown as the check for comparison. Temperature at grain filling also was recorded.
Results and Discussion. The temperature during the grain-filling period (first 2 weeks of April) was 34-40 C, which is high (Table 5). For all 330 F3 lines, 1,000 grain weight were recorded and categorized as under. Only two crosses gave yields greater than 40 g. These crosses are (1) 94049//Inqlab-91/NR.8624/3/Inqlab-91 (BR 5050-1B-) and (2) Bulbul/Oasis//Skauz/3/BCN (BR5022-8B-).
| Strain number | 1,000-kernel weight (g) | No. of crosses | No. of lines |
|---|---|---|---|
| 1 | 40 + | Two | 7 |
| 2 | 35-40 | One | 10 |
| 3 | 30-35 | Seven | 25 |
| 4 | < 30 | Sixteen | 288 |
| Inqilab 91 (check) | 36 | --- | --- |
Seventeen entries were better than resistant to heat at grain filling among the 330 lines (Table 5). Most of the entries were affected by heat with a reduction in grain weight. A difference in grain weight from 40-30 grams indicates sensitivity of the genotypes to high temperature.
Conclusions. The selected lines will be retested under increased temperature during the next few years. High temperatures decrease grain weight, which is an important factor of grain yield. Clear differences in the 1,000-kernel weight of different genotypes shows that heat-tolerant cultivars can increase grain yield.
References.
M.Z. Aslam, M. Hussain, G. Hussain, M. Rafique, M. Aslam, M.
Arshad, and M. Rafi.
Seed has played a critical role in agricultural development since
prehistoric humans domesticated the first crops. In modern agriculture,
seed is the vehicle to deliver almost all agriculture-based technological
innovations to farmers so that they can exploit the genetic potential
of new cultivars. The availability, access, and use of seed of
adapted modern cultivars is, therefore, a determinant to the efficiency
and productivity of other inputs (irrigation, fertilizers, and
pesticides) for increasing crop production to enhance food security
and alleviate rural poverty in developing countries. For seed
to play this catalytic role, it should reach farmers in a high
quality state, i.e., genetically pure and high physical, physiological,
and health quality. In contrast to fertilizers and pesticides,
farmers select and save seed to plant the following year. Any
off-farm seed from other sources should be of high quality. Wheat
is a high-volume, low-profit seed crop and has been produced primarily
by heavily subsidized, government seed programs. The private sector,
however, may not focus on wheat seed because of its characteristics
(self pollinating, high-volume, and low-profit). Private seed
enterprises consider wheat seed to be of secondary importance.
Because wheat is an entirely self-pollinating crop with a very
low percentage of cross-pollination (1-4 %; Doerfler 1976), the
risk of genetic contamination is very small. Appropriate isolation
is , however, required to minimize physical contamination. Minimum
isolation distances (in meters) used in some Middle Eastern and
North African countries are listed in Table 6.
| Country | Seed class | ||
|---|---|---|---|
| Prebasic | Basic | Certified | |
| Cyprus | -- | 2 | 2 |
| Egypt | 5 | 5 | 5 |
| Iran | 5 | 5 | 5 |
| Sudan | 4 | 4 | 4 |
| Syria | 2 | 2 | 2 |
| Tunisia | 1 | 1 | 1 |
Because wheat is self pollinated crop and the grain can be stored for later use, farmers tend to replant their own seed. About 80 % seed used by the farmers in Pakistan is from their own production. In Pakistan, the private sector is more active in the highly profitable cotton seed production. Wheat seed in Pakistan is produced by farmers with concern of the public and private sector under control of the Federal Seed Certification and Registration Department (FSC and R). Purity is maintained with constant inspections under strict rules. The entire seed-production system in Pakistan is discussed below.
Cultivar evolution. Wheat cultivars are developed by breeders working in the public sector. A strong cultivar approval system is present in the country. Cultivars are approved by a technical committee then the cultivar is taken to the provincial seed council where they are registered by the Federal Seed Certification Department in Islamabad.
DUS test. The DUS test in Pakistan is made by the Federal Seed Certification and Registration Department. This trial consists of advance strains from the National Uniform Wheat Yield trial. A DUS test is a descriptive assessment that establishes the identity of the new cultivar using morphological characters, uniformity, and stability. The test is a useful tool for seed production, certification, and plant cultivar protection. The DUS tests usually run for 2 years. The new cultivar is compared with existing cultivars to establish its distinctness, a cultivar description is prepared, and differences with other cultivars are noted. In some countries, the cultivar is tested in on-farm verification trials under farmers' management conditions during the last year. After the DUS test and other trials, a cultivar is released for use. Many developing countries give priority to agronomic (VCU) trials rather than descriptive (DUS) tests. Although both tests are important, the benefits of the two tests must be considered based on the immediate needs in the country to use available resources efficiently and economically.
Seed production.
Price of seed. Price of seed of different categories are fixed by the Provincial Governments.
References.
THE SINDH RURAL WOMEN'S UP-LIFT GROUP
157-C, Unit No. 2, Latifabad, Hyderabad, Sindh, Pakistan.
Farzana Panhwar.
Introduction. The province of Sindh, between 23 40 N and 28 30 N and 66 40 E and 71 10 E, can be compared with Egypt. For the past 1,000 years, the two countries have received the gift of alluvium deposited by the Indus and Nile Rivers. Flood plains of both countries attracted early Neolithic people to experiment and develop food and feed crops.
Local names for wheat are Kanak and Gandum. Other names are popatiyea, Khapli, ravva, godhumalus, and Samba. Wheat cultivation started during the Neolithic period, probably as early as 6,000 to 7,000 years ago. The wheat crop requires a well-pulverized but compact seedbed for good and uniform germination. Three ploughings in the summer, repeated harrowing in the rainy season, followed by three or four cultivations immediately before sowing produce a good firm seedbed for the dry crop on alluvial soil. Triticum aestivum occupies 85 % of total area under wheat. Triticum turgidum subsp. durum is the second most important occupying 14 % of wheat-growing area. Durum wheat is the most important species under rainfed conditions. Triticum turgidum subsp. dicoccum is grown on very restricted scale. In Pakistan, wheat covers an area of 8,306,600 ha. In Sindh, wheat covers an area of 1,120,300 ha. Wheat production in Pakistan was 18,237,600 tons (2,196 kg/ha) last year; production in the Sindh was 2,624,900 tons (2,343 kg/ha).
The yield of high-yielding varieties (HYV) of wheat was 2,553 yield kg/ha in 1999-2000. Other cultivars averaged 981 kg/ha. The total wheat yield 2,491 kg/ha. In 1999-2000, HYV covered an area of 8,129,300 ha, other wheat cultivars covered an area of 333,700 ha. The total area planted with HYV was 8,463,000 ha. For the year, wheat production of HYV was 20,751,300 tons; the production of other cultivars totaled 21,078,600 tons.
As of 1 December, 2004, overall wheat sown in Punjab and Sindh remained slightly below the monthly target of 60 %, 67.2 % of the area was sown in Sindh in November 2004. Overall, wheat sowing remained at 54.3 %. The provincial governments of Punjab and Sindh were given the target of 6.2 x 10^6^ ha and 0.8 x 10^6^ ha, respectively, and the concerned food departments were asked to ensure wheat sowing of 60 % of the area in November. The decision was taken to achieve a total production of 20.2 x 10^6^ tons of wheat so that the government would not have to import wheat in the next fiscal year.
Wheat covers 8.5 x 10^6^ hectare in Pakistan. Unlike previous years when 40 % of the targeted area was sown in November, the Punjab, with an area of 6.2 x 10^6^ ha and in other to increase the per hectare yield from 1,000 kg to 1,300 kg, had 4.16 x 10^6^ ha sown to wheat before 27 November. This number compares to a little over 4 x 10^6^ ha sown during the same period of the previous year. Similarly, in Sindh, the sown area remained at 0.332 x 10^6^ hectares before 23 November, compared to 0.25 x 10^6^ ha in the previous year. The targeted area sown to wheat in NWFP is 0.77 x 10^6^ ha, 0.34 x 10^6^ ha in Balochistan, and 0.1 x 10^6^ hectares in the Azad, Jammu, and Kashmir provinces. However, the Federal Ministry of Food and Agriculture has not yet received final figures from these areas.
Wheat is grown in subtropical areas at higher altitudes in the tropics to produce locally adapted cultivars. The optimum temperature for germination is 29 C. Under favorable conditions germination take place in 4-5 days. Seeding rate varies from 50-200 kg/ha. Time of maturity is 95-150 days depending upon cultivar. Seeds should be used 50-60 kg/ha. Seed beds are 1.5-2-in rows with a distance 6-8 in giving 80-10 plants/acre. In November sowing, 50 kg/acre are used; the December sowing rate is 60 kg/acre. Recommended sowing dates for some popular cultivars are given in Table 1.
| Cultivar | North | South |
|---|---|---|
| Sarsubz | 1-25 November | 10 November-15 December |
| Soghat 90 | 1-25 November | 1-25 November |
| Mehran 89 | 1-20 November | 7-30 November |
| Abadgar 93 | 1-20 November | 7-30 November |
| Anmol 91 | 21 November-15 December | 1-20 December |
| Tando Jam 83 | 21 November-15 December | 1-20 December |
| Marvi 2000 | 1-25 November | 1-15 December |
| Momel 2002 | 1-20 November | 1-20 November |
Cultivars of wheat in Sindh.
Cultivars for upper Sindh. Abadgar 93, Mehran 89, Sarsubz, Kirn
95, Sogat 90, T.J. 83, and Anmol 91. Time of sowing from 1-25
November and 1-30 December.
Cultivars for lower Sindh. Abdagar 93, Mehran 89, Sarsubz, Kiran 95, Sogat 90, T.J. 83, and Anmol 91. Time of sowing from 1-30 November and 130 December. Recommended sowing at a seed depth of 2 in and a between row distance of 9 in.
Cultivars for western Sindh. Pavon-7, ZA-77, Sindh 81, Sarsubz, Bluesilver, and Tando Jam 83.
Cultivars for eastern Sindh. Pavon, Sarsab, ZA-77, Sindh 81, Blue silver, Tando Jam-83, H-68, C-591, c-273, Drik, and Pak-70 (Anon 2000),
Cultivars for Sindh, Pakistan. Cultivars for Pakistan are PB-85, V-86369, WDK-85, FSD-85, V-8624, CHKL-86, V-85060-1, PAK-81, FSDD-83, K-Noor-83, V-88022, V-86371, C-217, C-250, and C-591 (Rizvi 1998); C.pH47, A.T. 38, Hsw III, C-591, C-518, H-68, I.P. 120, Mexi-Pak-65, Pak-70, Inia-66, Noori, Blue Silver, Yacora, T.J. 75, and Munshi-76 (Khoso 1977).
Soil. Wheat requires a deep loam or alluvial soil that is well drained and has a uniform and mellow texture that helps to produce a profuse root system. Dwarf cultivars give better results when grown at a depth of 1.5-2.0 in on level land (Khoso 1977). Well-drained loam and clay loam are considered good for wheat, but it also can grow in sandy soil.
Timing of sowing. Proper sowing depends upon the cultivar and climatic conditions. In the Kotri Barrage area and Hyderabad district, local cultivars H-68 and c-591 can be sown 15 days earlier. Sowing of dwarf cultivars should be completed in November, whereas late cultivars can be sown up to 10 December (Khoso 1977). Sowing depth varies between 1.5-2.5 in. The row-to-row distance should be 9 in.
Preparation of seed for sowing. Wheat has certain seedborne diseases such as Karnal or partical bunt, loose smut, and flag smut. The crop will benefit from Belaton (1 gm), Vitavax-200 (2 kg), Topsin-M (2 gm), Benlate (2 kg) mixed with the seed before sowing. Before planting, Aldrin 55 or BHO 10 % dust at the rate of 25 kg/ha is recommended..
Proper time and seeding rate. Wheat seed should be healthy, free from disease, unbroken, not mixed with weed seeds, and have a germination rate near 95 %. For storage, Datayafa Stakin (25-30 tablets/ft3) or Malathion (1:3 water spray) is recommended. Pollination is completed in 3-5 days. Seeding rates for some popular cultivars are given in Table 2.
| Cultivar | Sowing dates | Seeds/acre |
|---|---|---|
| Sindh 81 | 1-30 November | 50 kg |
| Sindh 81 | 10-30 November | 50 kg |
| ZA 77 | 1-20 November | 50 kg |
| ZA 77 | 7-30 November | 50 kg |
| Pavion | 1-20 November | 50 kg |
| Pavion | 7-20 November | 50 kg |
| Sursub Z | 1-15 December | 50 kg |
| Sursub Z | 10 November-15 December | 50 kg |
| Blue Silver | 21 November-15 December | 60 kg |
| Blue Silver | 1-24 December | 60 kg |
| Tandojam 83 | 21 November-15 December | 60 kg |
| Tandojam 83 | 1-21 December | 60 kg |
Climate. Wheat is grown in tropical and subtropical areas. Wheat needs rainfall 12 to 35 inches and a latitude of 300 to 600. Its growing season is 100 days . It can be grown up-to-the height of 10,000 feet.
Herbicides for wheat. Recommended herbicides include Dicuran, Areton, Dozanex, Tolken, Buctril-1, 2-4-D, Bakral M, Logran Exter, Green Star, Boroe site, Dicron M, Talkon, Earlian, Panther, Graminan, Stamp, Pomaspur, Proturex, Promaspur, Turbuneler D.P 70, Stamp, Bactral M, Bramenal, Talkan, Logran, Topick, and Pochung.
Fertilizer. Some recommended fertilizer regimes based on soil type are given in Table 3. Wheat benefits from nitrogen and phosphorus applied in the ratio of 2:1. All phosphorus is applied at sowing; high doses of nitrogen may split into two applications, at sowing time and with the second irrigation. (Khoso 1977). Nitrogen (55 kg), phosphorus (27 kg), two bags of DAP, and one bag urea at planting time or 2.5 bags phosphorus during planting and 1.5 bags of urea at the first and second irrigations. Three bags of urea/acre, twice, first at sowing and at the first irrigation time. Phosphorus (2 bags/acre), potassium (2 bags/acre) or nitrogen (80-120 kg/ha), phosphorus (40-60 kg/ha), potassium (40 kg/ha), and zinc (50 kg/ha). The N:P:K ratio should be 10:23:15 with three bags/acre. During March and April, wheat usually withers with heat. An application of 50 lb phosphorus + 40 lb nitrogen, 30 lb nitrogen (Bux 1964), or 2-3 tons of FYM/ha + organic matter. give good results.
| Soil type | At sowing | 1st irrigation | 2nd irrigation |
|---|---|---|---|
| Weak soil |
3 bags N:P:K (10:23:15); 2 bags DAP; or 1 bag Engrozorour + 1 bag MoP |
1 bag urea | 1 bag urea |
| Medium soil |
2 bags N:P:K (10:23:15); 1.5 bags DAP; or 1 bag Zorour + 1 bag MoP |
1 bag urea | 0.5 bag urea |
| Fertile land |
2 bags NPK (10:23:15); 1 bag DAP; or 1 bag Zorour + 1 bag MoP |
1 bag urea | 0.5 bag urea |
| At sowing | After sowing | ||
| Weak | 2 bags DAP | 1 bag urea with water, 0.75-1 bag afterward | |
| Medium | 1.5 bags DAP | 1 bag urea with 1st watering application 0.5-0.75 bag urea afterward | |
| Fertile land | 1 bag DAP + 0.33 bag urea | 1 bag of urea with 1st watering | |
Rotation. Normally rabi wheat is followed by kharif. Green manure crops such as sanai, moong, guar, lobia, or hubam clover are sown immediately after kharif to enrich the soil. Gram, linseed, barley, and mustard are included in rotations. Unirrigated wheat is rotated with jowar, bajara, or cotton in kharif in preceding year. Wheat grown mixed with barley, mustard, gram, lentil, and safflower are common.
Irrigation. Three irrigations are needed as follows:
Other irrigation recommendations are for three inches (Khoso 1977); 4-6 irrigations needed with the first at crown-root initiation stage about 20-25 days after sowing, the second at late tillering, followed by irrigations at late jointing, flowering, milk, and dough stages (Wadhwani 1987) as follows:
Tillage. Wheat is a freely tillering annual 0.3-0.8-m tall with a seminal root number of 3-6. Table 4 lists the effect of primary and secondary tillage on the grain yield of barani wheat in the 1982-83 Rabi season at National Agriculture Research Centre. Islamabad.
| Primary tillage method | Depth (cm) | Secondary tilling method | Mean | |||
|---|---|---|---|---|---|---|
| Mould | Cultivator | Subsoil | Disc | |||
| Mould board | 30 | 4.50 | 3.98 | 4.30 | 4.46 | 4.30 |
| Subsoil | 45 | 3.90 | 3.78 | 3.70 | 3.82 | 3.80 |
| Chisel | 25 | 3.92 | 3.18 | 3.60 | 3.48 | 3.54 |
| Cultivator | 10 | 3.70 | 3.78 | 3.90 | 3.50 | 3.27 |
| Mean | 25 | 4.00 | 3.68 | 3.78 | 3.82 | 3.84 |
Diseases of wheat crop. Leaf spot diseases include S. nodorum blotch, S. tritici blotch, and yellow spot (Loughman 1994). These diseased are caused by three different fungal pathogens but disease symptoms and biology are the same. Infected leaves show irregular or oval-shaped spots, which initially are small, then turn yellow. Moisture enables the pathogens to sporulate, disperse, and infect, reducing photosynthetic area and causing early leaf senescence. Severe disease in a young crop can reduce tillering and delay flowering. Late infection can hasten maturity and reduce the time available for grain filling resulting in shrivelled seed.
Septoria nodrum bloch is caused by two stages of fungus. The sexual stage, Leptosphaeria nodorum, occurs on infested stubble and produces conidiospores from perithecia. The disease is initiated by aerial spore dispersal. The asexual stage occurs on infested stubble produces pycinidispores from minute brown pycnidia that spread the disease to new crop foliage. This disease is most damaging in warm moist conditions. Most damage occurs on the leaves.
Septoria tritici blotch also is caused by two stages of same fungus. The sexual stage, Mycosphaeraerella graminicola, occurs on infested stubble and produces ascospores from perithecia that initiate the disease by aerial dispersal. Ascospores can be dispersed moderate distances in the air. Ascospores in large quantities result in the development of an earlier and more severe infection. The asexual stage occurs on stubble and diseased plants producing pycnidiospore from small black pycnidia that spread the disease on to new crop foliage. Pychnidiospores are spread by splash dispersal. Pycnidia are produced in the rows between the veins of infected leaves, which are visible to naked eye.
Yellow spot is caused by two stages of same fungus. The sexual stage, Pyrenophora tritici-repentis, occurs on infested stubble by the appearance of pseudoperithecia, which can be seen in the autumn and early winter as black, raised, oval bodies about the size of a pin head. The aerial release of spores initiates the disease. Ascospores of the yellow spot fungus are dispersed only a short distance. The asexual stage, Drechslera tritici-repentis, produces conidia on leaf tissue killed by the fungus and spreads the disease in to new crop foliage.
All three diseases occur together and severity of each varies with season and location. Other pathogens of the wheat crop in Pakistan are listed below.
Diseases of wheat according to Wadhani (1987)
| Disease | Pathogen |
|---|---|
| Black mold | Cladosporium herbarum |
| Glume blotch | Septoria nodorum |
| Leaf blotch | Septoria tritici |
| Pythium root rot | Phythium gromini colum |
| Selerotial disease | Pellicularia rotifii |
| Dilophosphorus leaf spot | Dilophosphjora rotfaii |
| Leaf blight | Atternaria triticina |
| Foot rot | Helminthosporium sativum |
| Hill bunt | Tilletia foetida and T. caries |
| Karnal bunt | Neovossia indica |
| Flag smut | Urocystis tritici |
| Loose smut | Ustilago tritici |
| Stem rust | Puccinia graminis |
| Stripe rust (yellow rust) | Puccinia graminis |
| Leaf rust (brown rust) | Puccinia recondita |
| Powdery mildew | Erysiphe graminis |
| Mosaic streak virus | |
| Ear cockle | Anguium tritici |
| Tandu (yellow rot) | Corynebacterium tritici and nematode Anguina tritici complex |
| Molya or cercal root rot worm | Heterodera avonae |
| Disease | Pathogen |
|---|---|
| Black rust | Puccinia graminis |
| Brown rust | Puccinia recondita |
| Yellow rust | Puccinia striiformis |
| Loose smut | Ustilago nuda |
| Flag smut | Urocystis agropyri |
| Hill bunt | Tilletia caries |
| Karnal bunt | Neovossia indica |
| Leaf blight | Alternaria triticina |
| Leaf blotch | Septoria tritici |
| Nematode disease molya | Heterodera avenae (treatment DBCP 60 % EC at the rate of 30 l/ha) |
Diseases of wheat and their pathogen according to Khoso (1977)
| Disease | Pathogen |
|---|---|
| Leaf spot | Alternaria tenuissima, A. alternata, A. tricola, Drechslera sorokiniama, D. catenaria, D. nodulosa, D. tetramera, Helminthosporium atypicum, Dilophospora alopecuri, Leptosphaerulina trifoli, Chaetomium dolichotrichum, and Pyricularia oryzae. |
| Glume blotch | Septoria nodorum, Poma sorghina |
| Powdery mildew | Erysiphe graminis, Sclerophthora macrospora |
| Root rot , foot rot, and seedling blight | Curvularia verruciformis, Drechslera sorokiniane, D. tetramera, D. halodes, D. bicolor, D. bicolor, D. nodulosa, Fusarium moniliforme, F. dimuerum, F. semitectum, F. avenaccum, F. graminerarum, F. culmorum, Gaeumannoyces graminis, Pythium graminocolum, Sclerorolfsil, and Rhizoctonia solani. |
| Sooty mold | Cladosporium herbarum |
| Seed borne | Alternaria alternata, A. triticina, Drechlera sorokiniana, D. tetramera, Cochliobolus tritici, Nigrospora spharica, Curvalria pallescens, C. geniculata, C. verruculosa, C. tritici, Sclerotium, Stemphyliunia and, Phiobolus. |
| Ear cockle | Anguina tritici |
| Tundu | Anguina tritici and Corynebacterium tritei. |
| Molya | Heterodera avenae |
| Virus | Chirke disease of cardaman (Mosaic streak of wheat). |
| Physiological diseases | Nitrogen deficiency, zinc deficency, and potash deficency. |
Seed infection. Seeds can become infected with S. nodorum or P. tritici-repentis if moisture occurs late in the season. Seed infected with P. tritici-repentis causes pink grain that effects crop marketability but does not carry disease to next crop if used as seed. Seed infected with S. nodorum will infect the next crop.
Insect pests. The major insects affecting wheat in storage are the Kapra beetle (Troqoderma granarium), grain borer (Rhyzoperths dominica), grain weevil (Sitophilus oryzae), and the red-color beetle (Tribolium castaneum). These insects cause approximately 2-4 % damage to stored grain (Rizvi 1998).
Chemical composition of wheat. The whole grain contains the following chemical percentages:
| Water | 13.0 % |
| Protein | 11.5 % |
| Fat | 2.0 % |
| Carbohydrate | 70.0 % |
| Fiber | 2.0 % |
| Ash | 1.5 % |
| Water | 12.4 % |
| Protein | 10.0 % |
| Fat | 1.0 % |
| Carbohydrate | 76.0 % |
| Fiber | 0.3 % |
| Ash | 0.3 % |
Storage. Storage life depends upon moisture content. Grain with less than 10 % moisture stores well.
Uses. Wheat also is used for the production of alcoholic beverages and industrial alcohol. Grain may be fed to livestock and the straw provides valuable fodder. The straw is used for wickerwork, baskets, hats, thatching, and packing.
Fumigant gases. Fumigants include carbon disulfide, carbon tetrachloride, chlorpierine, Dichlorovos, ethylene dichloride, hydrogen cyanide, methyl formate, sulfuryl fluoride, phosphine or methyl bromide phosphine. Methyl bromide is the preferred fumigant for ship fumigation because is has a shorter exposure time. The doses required for fumigation with phosphine is 1-2 g phosphine/m3 administered for a minimum of 5-7 days. Phosphine should not be used below 12 C. The most convenient method for application of hydrogen cyanide is by means of impregnated discs, which is affective for medical quarantine fumigation. The substantial harvest and postharvest losses greatly contribute the low yield of wheat (Rizvi 1998).
Types of fumigants. Fumigants divided in to three classes. solid-based fumigants, liquid fumigants, and low-boiling fumigants.
Solid-based fumigants. Aluminium phosphide or magnesium phosphide. Phosphine gas is released by a reaction with atmospheric moisture. Aluminum phosphide is available in pellet and tablet form.
AIP + 3H2O -----> Al(OH)3 + PH3
Mg3P2 + 6H2O ----> 3Mg(OH)2 +2PH3
Liquid fumigants. Liquid fumigants include carbon tetrachloride, ethylene dibromide, and ethylene dichloride. Liquid fumigants are conveniently applied.
Low boiling-point fumigants. Methyl bromide gas penetrates quickly and is dispersed readily at the end of treatment. Methyl bromide is a powerful organic solvent. Methyl bromide supplied with 2% chlorpicrin added. Harvested wheat is sprayed with Malathion (25:1).
Properties of methyl bromide (monobromomethane) include chemical formula, CH3Br; boiling point, 3.6 C; molecular weight, 99.94; specific gravity, 1.732 at 0 C; T.L.V, 15 ppm, and G/m3 to ppm (30 C), 260.
Harvesting. The wheat crop should be harvested immediately after maturity, when the grains harden and the straw becomes dry and brittle.
Improvement. The objectives of wheat breeding include the following:
New technique to generate genetically modified GM wheat. In a reverse genetic, nontransgenic approach to wheat crop improvement by TILLING, or targeting induced local lesions in genomes, Ann Slade and colleagues of Anawah Inc., Seattle, WA, introduced a technique that can identify new mutations in a polyploid plant, such as wheat, and uncover inherent variation within a genome and eliminate the need to introduce foreign DNA to get a new strain. With TILLING, DNA from multiple individuals is pooled, and PCR is used to amplify a targeted region of the genome. The PCR product from the pool is heated and reannealed, allowing DNA strands from mutants and wild types to base pair with each other. Individuals comprising the positive pools are sequenced to determine which individual carries the mutation and further tests may be undertaken to reveal the nature of the mutation. Unlike conventional mutation breeding, TILLING provides a direct measure of the mutations induced. Slade identified 246 alleles of the waxy gene of wheat and was able to produce a new strain yielding large amounts of amylopectin in its grains. This full waxy wheat can be useful to making breads and pastas, and enhance the strength and printing properties of paper produce (http://www.nature.com/cgi-taf/DynaPage.taf?file=nbt/journal/vaop/ncurrent/full/nbt1043.html).
Conclusion. Methods that help increase yield/acre include selection of land and its preparation, better cultivars and time of sowing, proper fertilizer, killing of weeds, healthy seed, proper cultivation, proper irrigation, and proper harvesting and storage. If we take care of above factors, better quality and higher yields will follow.
References.