The introduction and use of oat (avena sativa) cultivars in pakistan
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- 5. FORAGE OATS IN THE NORTHERN AREAS
- 6. INFORMATION ON FODDER OATS (MAINLY) FROM OTHER COUNTRIES 6.1. Characterization of a dual-purpose crop
- Figure 1. Classification of barley genotypes according to their dry matter-yield at the tillering stage and grain yield after clipping (after Yau and Mekni, 1985).
- 6.5 Factors affecting the response to date of sowing
- 6.6. Effect of nitrogen fertilization on dry matter yield
- 7. OAT RESEARCH AND INVESTIGATIONS IN PAKISTAN
- 7.1 Genotype x Environment Interaction and Screening Methods
- Table 1. Expected Variance of a Variety Means (Vx) for various assumed Numbers of Replicates and Locations per Test.
4. THE ROLE OF OATS Forage oats (Avena sativa L.) are grown throughout Pakistan in winter under a wide variety of soil and climatic conditions. Improved oats cultivars are now the main source of winter and spring forage in the plain irrigated / rain fed and high altitude (1000-2300 m asl), colder regions, especially in the Northern Areas. They are grown on more than 35 percent of the available arable land under forage crops throughout Pakistan. Grain yields vary from 2.4 to 3.2 tons/ha in the better environments, but less at higher altitudes (2,300 m). In Northern Areas at an altitude of 2,000-2,300 m, the highest recorded green fodder yield ranged from 80-120 tons /ha. It is an especially important crop in the plains during the cooler autumn, winter and spring months and in the mountains during autumn, spring and early summer. Reported green fodder and dry matter yields are generally higher in some parts of the North West Frontier Province (NWFP) and Balochistan provinces than in the lowlands and mid hills (up to three times higher through the use of locally bred or selected cultivars of western origin), due mainly to better inherent soil fertility combined with the widespread use of chemical fertilizers, farm yard manure and higher incoming radiation (less fog and cloud cover). In the Northern Areas, oats have proved to be invaluable for feeding milking animals especially the stall-fed cattle near or around villages and the bigger cities (such as Gilgit and Chilas, Skardu to meet domestic milk needs), and hence, not able to use traditional grazing lands. Temperate and cool sub-tropical conditions are congenial for the growth of oats. A well distributed rainfall of 400 mm and an optimum temperature range of 16-320 C from September to April are sufficient to meet its requirement as a fodder crop. Oats can provide green fodder after 60-70 days in an emergency to tide over the scarcity period, but in 90-100 days after germination, large quantities of fodder are produced. Oats are mostly fed green, but any surplus is made into hay. It is a favourite feed of all animals and the straw is soft and much superior to wheat and barley. It is high in total digestible nutrients (TDN), digestible crude protein, fat, vitamin B1 and minerals such as phosphorus and iron. The oat grain is a particularly valuable feed for horses, dairy cows, poultry and young breeding animals of all kinds. Improved oats have been especially successful for stall-feeding across a wide range of altitudes, climates and ecologies from 400 m to higher than 2,300 m. In the plains fodder oats are grown for dairy cows and buffaloes kept in and near big cities to meet the considerable milk demand; so much of the area under fodder oats is near large cities, and on military and private dairy farms. Forage (including crops other than oats) is transported daily to the cities and sold to feed milch cattle and horses kept for urban haulage. 5. FORAGE OATS IN THE NORTHERN AREAS New oat cultivars were first introduced to the Northern Areas by the fodder component of FAO Project PAK/86/027, Gilgit. They have proved to be valuable in the Northern Areas, since they grow much earlier and more vigorously than the traditional winter cereals. Green oats is cut in Gilgit and Chilas when no other green feed is available. Higher yields (up to three times) are produced in the 1,000 to 2,300 m band compared to lower altitude zones, possibly reflecting better agro-ecological adaptation. Many cultivars have been positively evaluated at different altitudes in winter in lowland areas through to high alpine areas around 2,300 m. Feeding of green oats to cows in winter increased milk yields from 1 to 4 litres per day. Not all milk is sold; additional production increases family dietary quality over traditional practices, especially important for the young and aged. (Milk and dairy products are valued constituents in Pakistani diets). Fodder oats, vetch, lucerne, shaftal, and berseem seed are produced for further cultivation, barter and sale to earn extra cash for household requirements. 6. INFORMATION ON FODDER OATS (MAINLY) FROM OTHER COUNTRIES 6.1. Characterization of a dual-purpose crop: Hadjichristodoulou (1983) described a dual-purpose crop as one suited to use as “grazing plus hay” or “grazing plus grain”, Yau and Mekni (1985) classified dual purpose barley cultivars (see Figure 1) as having high forage yield at grazing time and high grain yield after grazing. This was considered a “narrow-sense” definition; in the “broad sense”, dual purpose barley should perform well whether grazed or not. Therefore both forage and grain material should be used as resource material in breeding dual-purpose cultivars. In Cyprus, Hadjichristodoulou (1983) concluded that high-grain-yielding lines could be used as basic material for selecting dual-purpose varieties. By contrast, Yau and Mekni (1985) reported that improved high grain yielding barley genotypes generally did not perform well when subjected to grazing. Anderson (1985), however, found no clear differences between dual purpose and forage cultivars in their response to grazing over years as reflected in dry matter and grain yield.   grain type
dual-purpose type Mean
A successful dual-purpose crop should provide a substantial amount of forage and recover quickly from defoliation so that a good yield of grain can be obtained. From the literature, it would appear that such a crop for southern Australia should have the following features: - Semi-prostrate or prostrate growth habit - Long pre-jointing phase - Free-tillering habit - Leaf canopy of relatively prostrate foliage in the early, pre-jointing phase, becoming more erect as stem elongation occurs and new leaves are higher in the canopy. - Late flowering time i.e. long vegetative phase, flowering time controlled by a relatively strong response to vernalization. A photoperiod response may also be necessary with early sowing of even a strongly vernalizing type to ensure flowering after risk is passed.
Cattle can be maintained in good condition on oats at a time of the year when the supply of other feed is scare and costly. Many cultivars provide good forage if cut at flowering or soon after. Broad-leaved cultivars produce a higher forage yield, but narrow leaved ones are preferred by horses and cattle. The demand for meat and dairy products is increasing due to the rapid population growth in Pakistan, so improvement of livestock production is urgently needed and quality forage plays a pivotal role. Although 16-19 % of the total cropped area in Pakistan is planted to fodder, animals are generally underfed. To operate an efficient and economical livestock industry, high yielding, nutritious and multi-cut fodder oats are needed to feed more animals (Dost, 1997). Hussain et al., (1993) reported that ‘Fatua’ oats harvested at various intervals produced more fodder and less crude protein with plant age/advance in crop maturity. The crop should be harvested at a stage that provides an optimum compromise between forage yield and quality. Maximum green fodder and dry matter yields and crude protein contents were recorded when oats was harvested at 50 percent flowering. Hussain et al. (1994) also reported that the highest green and of course dry matter yields of five oat cultivars were at 50 percent heading. Dost et al. (1994) concluded that forage yield, dry matter yield, and crude fibre increased while seed yield and crude protein declined with advancing maturity. Harvest at 50 percent flowering resulted in superior forage and dry matter yields with inferior nutritive forage value as determined by lower crude protein and higher crude fibre contents, compared to harvesting at the vegetative stage at 70 and 85 days after planting. Minimum forage and dry matter yields with maximum forage quality resulted from harvesting at the mid vegetative stage at 70 and 85 days after planting.Young cereal plants provide excellent quality herbage which is highly nutritious for lactating ewes and young growing lambs. Their digestibility, crude protein content, carotene, mineral and vitamin contents have been reported to decline with plant age, whereas crude fibre and nitrogen free extract increase (Skorda, 1977; Eagles et al., 1979; McDonald and Wilson, 1980). However, yield per unit area of both crude protein and digestible dry matter increase with advancing maturity until the milky stage (Hadjichristodoulou, 1976a & b; Hughes and Haslemore, 1984; Droushiotis and Wilman, 1987). High quality feed, suitable for growth and lactation, should exceed values of about 67 percent in digestibility and 13 –15 percent in crude protein; less than 65 percent digestibility indicates feed suitable for maintenance only (Raymond, 1969; Hughes and Haslemore, 1984). Whilst Hughes and Haslemore (1984) concluded that if the digestibility of a forage is satisfactory (above 67.5 percent), the protein content will generally also be satisfactory (above 12-15 percent), Raymond (1969) and Eagles et al. (1979) found that decline in digestibility of forage crops (including cereals) led to a reduction in voluntary intake by animals. Several workers (Lassiter et al. 1958; Zogg et al. 1961) report comparisons of maize and oat silage for milking cows. Both concluded that maize silage was superior to oat silage for milk production. However, in each study the silages were not fed alone and a considerable portion of the dry matter intake was from hay. Mowat and Slumskie (1971) indicated that maize silage contained more digestible energy than barley silage when fed to finishing steers. The low digestible energy content of barley silage was also demonstrated by Fisher et al. (1972) in a study with dairy cows. Neither report assessed the suitability of the crops in terms of both field yields and feeding value. Under Tasmanian conditions, Abdul-Rahman et al. (1985) found that very early-sown (4 January) oats still had a digestibility of 60 percent and crude protein content of 14 percent in June, when the crop was close to flowering. It is noteworthy that under the long growing season of high rainfall areas, crops always produce high dry matter digestibility (75-85 percent) in winter (Dann et al., 1977; Eagles et al., 1979). The relationship between digestibility, radiation and temperature has not yet been shown experimentally, but sunny days followed by cool or cold nights should give high levels of soluble carbohydrates (Wheeler, 1981). Whilst lower digestibility values were reported in low rainfall areas, crude protein content at later stages of crop development, by contrast, was higher (Skorda, 1977; Droushiotis and Wilman, 1987). This was attributed to less leaching of soil nitrogen in low rainfall areas (Hadjichristodoulou, 1976). 6.4 Maturity period: Although grazing and cutting contribute to delay in flowering, a late flowering characteristic is important in dual-purpose cereals, in many places in high rainfall areas, to avoid the risk of frost damage . Through the findings of many researchers, time from sowing to heading or maturity is a good indicator for the selection of dual-purpose crops. In the high rainfall areas of Punjab, the recommended dual-purpose oat cultivar S-81 was the earliest to mature after heavy grazing/cutting. It was, however, the latest when ungrazed and grown for grain (Dost, 1994). This trait of late maturity in a dual-purpose crop was confirmed by McLeod et al, (1985) with a cutting height in oats of 2 cm. Hadjichristodoulou (1983) and Yau et al., (1987) concluded that dual-purpose lines tended to be later heading than the usual grain types. Furthermore, the time to heading or maturity appeared to be the main factor affecting yields, while tiller number, head number and plant height were less important (Yau et al., 1987). But these authors warned that, although late lines had better recovery to produce high grain and straw yields after simulated grazing, they were not good dual-purpose types since they gave little at the time of defoliation. 6.5 Factors affecting the response to date of sowing: The response to early sowing is apparently a valuable criterion of a dual-purpose crop. This advantage in high rainfall areas in Australia may be associated with a response to vernalization (Anon, 1986; Dann et al., 1977; Davidson et al., 1985a), which gives flexibility in sowing time with stability in flowering time. Varieties responding to long days (Davidson et al., 1985b), may show a similar delay in flowering and hence escape damage by water logging and frost. Johnson and Dann (1984) suggested that further improvement for dual purpose use could come from breeding cultivars with a higher vernalization requirement, permitting flexibility in sowing dates from late summer to mid autumn without risk of frost damage.and it is very important in areas with prolonged freezing temperature especially in the high altitude regions. For many cereal growing areas, however, these cultivars should also be able to flower early in spring (little requirement for long photoperiod), so that grain is produced before the onset of early summer moisture stress. Stern and Kirby (1979) stated that vernalization, photoperiod and temperature are the most important environmental stimuli on phenological events as they influence tillering, spikelet initiation and development of cereals. It is difficult to separate the effect of these factors on phenological events in cereals. 6.6. Effect of nitrogen fertilization on dry matter yield: Many workers in Australia have found that nitrogen fertilization at various levels (ranging from 67 to 180 kg N/ha) increased the forage yield of oats and that this was a good method of overcoming winter feed shortages (Archer, 1969; Blunt and Fisher, 1976; Crofts, 1966a; Wheeler, 1968). A better response to nitrogen was achieved in spring when the temperature rose (Cook and Lovett, 1974). Leaf area index (L), total living dry weight, stem dry weight and number of tillers were all significantly increased by nitrogen fertilizing of defoliated and non-defoliated oats (Cook, 1971). Mehra et al. (1971) found that fodder yield was positively correlated with plant height, leaf length and leaf width, tiller number, and stem girth. The number of tillers at the end of stem elongation and the final number of tillers with ears in cereals were reported to be increased by the addition of nitrogen, especially when applied early, thereby increasing yield (Needham and Boyd, 1976; Graham et al., 1983; Garcia del Moral et al., 1984). A nitrogen deficit reduces tillering due to: - Retarded appearance of lateral buds (Hewitt, 1963, cited by Garcia del Moral et al., 1984). - Limited root growth (Briggs, 1978; Cook, 1971). - Small weak shoots whose leaves contain reduced levels of chlorophyll and carotenoids (Briggs, 1978). By contrast, however, some workers have demonstrated that nitrogen fertilizer neither increased dry matter yield significantly nor compensated for the deleterious effect of clipping on the grain yield of oats and barley. This might be due to one or both of the following reasons: - Available soil nitrogen was already high (Dann, 1971), where the site had previously been under leguminous pasture (Spurway, et al., 1976), or a heavily manured crop (Gardner and Wiggans, 1960) or fallow (Brown, 1975). - Nitrogen fertilizer was applied in early winter when the temperature was very low (Archer, 1969). Cook and Lovett (1974) suggested that the ambient temperature rather than nitrogen supply is the limiting factor in growth of oats during winter.
The Co-ordinated Fodder Research Programme NARC, Islamabad vigorously evaluated 400 introduced cultivars (1970s introductions) throughout Pakistan and selected 20 promising ones based on maximum forage yield, dry matter yield, maturity etc. The 20 selected cultivars were further evaluated in all four provinces in the autumn (rabi) season under a wide variety of soil and climatic conditions to select and recommend the most promising and suitable ones for different areas within diverse agro-ecological regions. The variation in environmental conditions in different agro-ecological regions is well known to plant breeders. Fluctuations in rainfall and temperature are neither consistent nor predictable from year to year or from place to place. Fertility status and soil types also vary throughout the country. Serious losses in forage yields due to drought, disease, and insects are common in many areas. Pakistan has a long history of selecting and using local oat landraces, and in modern times, especially the last twenty years, breeding and testing of improved cultivars incorporating material from western sources into local fodder programmes has been a continuous process. Year-round fodder production is the most important component in the farming systems and a great deal of research is being carried out in the four provinces of Pakistan as part of a national coordinated fodder research programme. The details are presented below. 7.1 Genotype x Environment Interaction and Screening Methods: Considerable genotype by environment interaction has been noted across latitude, altitude, seasonal sequence, with some cultivars producing significantly better forage yields than others in certain environments and management regimes. So far, this is poorly documented and has only been modestly exploited in Pakistan due to limited local resources. Effectiveness of varietal testing programme is influenced by several factors. These include experimental design, the number of locations, and the number of years used to average variety means. Information is required as to whether forage oat varieties respond differently when planted under diverse environment interactions, and if so, how important such genotype x environment interactions might be in an oat variety evaluation and selection programme. Horner and Frey (1957) report that dividing the Iowa State into 2, 3, 4 and 5 sub-areas would reduce variety x location interaction effects by 11, 21, 30 and 40 percent respectively and hence increase the efficiencies of the state wide oat performance trials. Liang et al. (1966) studied genotype x environment interaction in wheat, barley, and oats and recommended dividing Kansas into 3 and 4 areas, for barley and wheat testing, respectively. It was concluded that it was not necessary to divide the state into smaller areas for oat testing. Dost et. al. (1993) studied the optimum allocation of resources in varietal evaluation for 13 oat genotypes for forage yield at 4 locations for 4 years and suggested that the three provinces under study should be divided into sub-areas on the basis of variation in rainfall, temperature, soil type, and soil fertility in order to minimize genotype x environment interaction for an efficient forage oat evaluation programme (Table 1). Table 1. Expected Variance of a Variety Means (Vx) for various assumed Numbers of Replicates and Locations per Test.
Dost et al. (1993) To evaluate the importance of genotype x environment interactions, De Pauw et al. (1981) compared three cultivars of wheat, three of oats, and three of barley for four years at five locations in north-western Canada. They concluded that cultivars showed differential responses in specific environments, which can be used to determine areas of cultivar adaptation. In a study on genotype x environment interaction at twenty-seven locations for five years, in Alberta, Canada, Kibite et al. (1988) suggested the need to divide Alberta into six rainfed and two irrigated areas. Directory: agp -> agpc agpc -> Reporting Officer agp -> Submitted by: g V pollard, slac-slcm date: 21 February 2006 II. Visit to Download 0.77 Mb. Share with your friends:
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