The introduction and use of oat (avena sativa) cultivars in pakistan
Table 7. Green fodder and dry matter yields and crude protein of
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- 7.5 Oats as a dual-purpose crop
- 7.6 Fertilization of winter forages
- Table 9. Green fodder yield of oats cultivar Scot (tons/ha) under different fertilizer doses at various locations during 1999-2000
Table 7. Green fodder and dry matter yields and crude protein of oat and barely as affected by cutting at different stages
* Data for one year Hussain et al 1995 CS1= Repeated cutting at 4-leaf; CS2= Tillering; CS3= Jointing CS4= Booting stage; CS5= Harvest once at ear emergence; CS6= 50 percent flowering; CS7= 100 percent flowering; CS8= Early milk CS9= Early dough stage. Lawes and Jones (1970) investigated the ensiling characteristics of barley, wheat, and oats crops cut at two different dates and reported that dry matter yields increased until the end of July. Digestibility and crude protein content declined until mid July when values of 56-60 and 6-7 percent for the barley and wheat and 53-55 and 5-6 percent for the oats respectively were maintained. Crops of all varieties were suitable for ensiling at maximum yield. Brundage and Sweetman (1967) have recommended that oat/pea forage be harvested in the late milk stages of oat maturity to take advantage of higher yields of lower moisture silage. Bolsen et al. (1976) and Polan et al. (1968) recommended harvesting small grain forages at the dough stages of maturity. Comparing oat forage ensiled at the boot, early milk, and soft dough stages of maturity, Martz et al. (1959) recommended harvesting at the boot stage or soon thereafter. 7.5 Oats as a dual-purpose crop: Seed production is a major problem with the majority of forage crops as most of them are harvested and fed to livestock well before seed formation, unless intentionally kept for seed. Therefore, development and cultivation of dual purpose forage crops varieties could be one of the best options/solutions for seed production and availability. The most common cereal grown as a dual-purpose (harvesting/grazing plus grain) crop in Pakistan is oats. Dost et al. (1994) evaluated oat cultivar S-81 under different maturity/ harvesting treatments during 1991-92 at NARC, Islamabad (Table 8). It was reported that forage yield, dry matter yield, and crude fibre increased while seed yield and crude protein declined by harvesting the crop with advances in maturity. Maximum forage and dry matter yields with considerably inferior quality forage (as determined by lower crude protein and higher crude fibre values) were observed at 50 percent flowering stage. Minimum forage and dry matter yields with superior quality forage were recorded in the crop harvested at 70 and 85 days after planting. The results of this research also indicated that it is possible to have a satisfactory forage yield, forage quality and grain yield from oats crop that has already been harvested once for forage at 115 days after planting. Table 8. Average Plant Height (PH), Tillers/Plant (TL), Leaves/Tiller (LV), Green Fodder Yield (GY), Dry matter Yield (DY), Seed Yield (SY), Crude Protein Contents (CP), and Crude Fibre Contents of Oats cultivar S-81
Tilt (1965) reported that skilled grazing management of dual-purpose oats has a big effect on ultimate grain yield. Early sown oats can be grazed from the end of April through to August when they are either ploughed under or “shut up for grain”. The later the grazing continues, the more the grain yield is likely to be depressed. In 1964, a plant breeding programme to develop a dual-purpose variety adapted to Tasmanian conditions was initiated by the Department of Agriculture and resulted in the release of “Esk” in 1975 for all Tasmanian areas (Vertigan 1975). “Esk” is now the most common oat variety in Tasmania, and is normally sown between February and April. It is used for winter grazing by sheep and, depending on the farmer’s requirement for stored (conserved) feed, may be harvested for hay or grain. It is late maturing, resistant to most diseases and to grain shedding (Vertigan, 1975). Smith (1960) found that the analysis of oat forage indicated that the percentages of protein, fat, ash, P, Ca, K, and nitrate declined from early growth to maturity while the percentage of fibre increased until the heads were emerging from the boot, and then decreased. The yields per acre of dry matter and of protein, ash, P, and Ca, constituents important to animal nutrition, increased steadily to a stage of growth when the seeds were nearly ripe and then decreased. However, a high proportion of the total yield per acre of protein, ash, P, and Ca was produced at early dough, the stage of growth often indicated as the best stage to harvest for hay or silage. Forage stand losses resulting principally from lodging of oats and volunteer growths from shattered seed have promoted widespread interest in the harvesting of oats at immature stages of growth as pasture, silage, or hay. Chemical analyses (Berry 1920, Fagan and Watkin 1931, Keitt and Tarbox. 1912, Meyer et al. 1957, Nicholson 1957, Smith and Ross 1943, Sotola 1937, Thurman et al. 1957, Underwood and Moir 1944) and limited feeding trials (Meyer et al. 1957, Sotola 1937) have shown that oats at immature stages of growth can provide nutritious and high quality forage. The most complete studies of the changes in composition of oats from early to late stages of growth have been made by Berry (1920) in Scotland and by Sotola (1937) in the state of Washington, USA. However, many of the analytical studies have been made at only the more advanced stages of growth (Fagan and Watkin 1931, Keitt and Tarbox 1912, Nicholson 1957, Thurman et al. 1957, Underwood and Moir 1944) or have been made for only a few chemical constituents (Henderson and Davis 1955, Meyer et al. 1957, Smith and Ross 1943). Several investigations have shown that grazing or clipping of small grain stands can provide, in addition to grain, high quality forage and reduced lodging. However, clipping frequently decreased subsequent grain yields (Gardner and Wiggins, 1960, Crowder 1953, Cutler et al. 1949, Thakur and Shands 1954, Washko 1947, Welton and Morris 1931, Westrate and Grafius 1958). The effects obtained have varied with the soil and climatic conditions (Cutler et al. 1949, Sprague 1954), nitrogen fertilization (Morris and Gardner 1958), and with the date of clipping. In Saudi Arabia, Farnworth and Williams (1977) planted oats, barley, and wheat crops for two cuts for forage followed by grain. The first cut for forage was obtained at a stubble length above ground of 2.5 cm and 12.5 cm. Oats produced the highest forage yields but lowest grain yields while wheat produced highest grain yields. Similarly oats produced higher yields of straw. It was also found that oats had higher protein, fibre, and ash levels than barley or wheat but lower carbohydrate levels. Barley had the lowest protein level and wheat the lowest fibre and ash levels. 7.6 Fertilization of winter forages : Application of different doses of nitrogenous and phosphatic fertilizer produced substantially higher yields (at the five locations in Pakistan indicated in Table 9) than using no fertilizer or farm yard manure alone, especially on seriously depleted soils, which had been mono-cropped for many years with wheat/maize/ barley etc. Maximum forage yields were obtained through application of 150-75 N P kg/ha. at most of the locations under trial and was followed by 150-25 N P kg/ha (Table 9). However, increased usage of chemical fertilizer could not realistically be justified in many instances for economic and environmental reasons (Table 9). Table 9. Green fodder yield of oats cultivar Scot (tons/ha) under different fertilizer doses at various locations during 1999-2000
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