Relative elemental growth rates (REGR) and lengths of epidermal cells along the elongation zone of Lolium perenne L. leaves were determined at four developmental stages ranging from shortly after emergence of the leaf tip to shortly before cessation of leaf growth. Plants were grown at constant light and temperature. At all developmental stages the length of epidermal cells in the elongation zone of both the blade and sheath increased from 12 μm at the leaf base to about 550 μm at the distal end of the elongation zone, whereas the length of epidermal cells within the joint region only increased from 12 to 40 μm. Throughout the developmental stages elongation was confined to the basal 20 to 30 mm of the leaf with maximum REGR occurring near the center of the elongation zone. Leaf elongation rate (LER) and the spatial distributions of REGR and epidermal cell lengths were steady to a first approximation between emergence of the leaf tip and transition from blade to sheath growth. Elongation of epidermal cells in the sheath started immediately after the onset of elongation of the most proximal blade epidermal cells. During transition from blade to sheath growth the length of the blade and sheath portion of the elongation zone decreased and increased, respectively, with the total length of the elongation zone and the spatial distribution of REGR staying near constant, with exception of the joint region which elongated little during displacement through the elongation zone. Leaf elongation rate decreased rapidly during the phase when only the sheath was growing. This was associated with decreasing REGR and only a small decrease in the length of the elongation zone. Data on the spatial distributions of growth rates and of epidermal cell lengths during blade elongation were used to derive the temporal pattern of epidermal cell elongation. These data demonstrate that the elongation rate of an epidermal cell increased for days and that cessation of epidermal cell elongation was an abrupt event with cell elongation rate declining from maximum to zero within less than 10 h.

No abstract

The livestock industry in Korea is primarily carries out feeding through the utilization of concentrates and rice straw. The amount of imported concentrate is estimated to be more than two thirds (about 11 million metric tons (MT) per year) of the total concentrates required, specifically corn. Recently, about 600 000 MT of forage was recorded to be imported per year. The main feature of grassland agriculture, including forage production, is the dependence on perennial grasses, legumes and high quality annual forage crops, such as corn, sorghum, sudangrass, rye, oats, barley, Italian ryegrass and forage rape, among others. In addition, proper land use and increased animal profitability is maintained through grassland agriculture. The important fields for forage production are upland, paddy land, grassland and forest areas. Rice straw is also one of the most important roughages in Korea. The aim of forage production in the past was to fulfil the domestic need of herbivores, but forage production in 21st century is geared towards international competitiveness in animal husbandry. The most important factor is to enhance forage sufficiency related to environment‐friendly livestock in Korea. Fortunately, there are many possibilities in forage production. A no forage‐sufficiency, no food‐sufficiency; no forage, no cattle concept is emphasized.

Near infrared reflectance spectroscopy (NIRS) has become increasingly used as a rapid and accurate method of evaluating some chemical compositions in forages and feedstuff. This study was carried out to explore the accuracy of near infrared spectroscopy (NIRS) for the prediction of chemical parameters of fresh whole crop barley silages. A representative population of 284 fresh whole crop barley silages was used as a database for studying the possibilities of NIRS to predict chemical composition. Samples of silage were scanned at 1 nm intervals over the wavelength range 680~2,500 nm and the optical data were recorded as log 1/Reflectance (log 1/R) and were scanned in fresh condition. NIRS calibrations were developed by means of partial least-squares (PLS) regression. NIRS analysis of fresh whole crop barley silages provided accurate predictions of moisture, acid detergent fiber (ADF), neutral detergent fiber (NDF), crude protein (CP) and pH, as well as lactic acid content with correlation coefficients of cross-validation (R 2 cv) of 0.96, 0.81, 0.79, 0.84, 0.72 and 0.78, respectively, and standard error of cross-validation (SECV) of 1.26, 2.83, 2.18, 1.19, 0.13 and 0.32% DM, respectively. Results of this experiment showed the possibility of the NIRS method to predict the chemical parameters of fresh whole crop barley silages as a routine analysis method in feeding value evaluation and for farmer advice.

This experiment was carried out to investigate the effect of cultivar and seeding date on the winter survival rate, quality and DM yield of Italian ryegrass on paddy field for three years in Suwon. Seeding started from 30th Sep. 2003. at intervals of five days and finished 20th Oct. New varieties of Italian ryegrass used in this experiment were "Kospeed", "Kowinmaster" and "Hwasan 101". The winter survival average rate of 5th Oct. seeding plot was 89.8% and it decreased with delayed seeding date. The heading date of "Kospeed" was 7th~13rd May, "Kowinmaster" was 16th May, but "Hwasan 101 ho" didn't show heading until 17th May. Dry matter (DM) yields of 30th Sep. seeding plot were Kospeed 7,909kg/ha, Kowinmaster 6,398 kg/ha and Hwasan 101 ho 5,204 kg/ha. DM yield was decreased with delayed seeding date. Total digestible nutrient (TDN) yield was also decreased with delayed seeding date. Crude protein (CP) content was the highest in Kospeed. seeding plot as 18.3% and in vitro dry matter digestibility (IVDMD) was not showed significant difference among seeding dates.