Growth comparison of exotic species for green forage.
Growth of exotic fodder crops (grasses and clovers) were compared in pots at Agronomy Research Farm, Khyber Pakhtunkhuwa Agricultural University, Peshawar. Initially 20 seeds was planted on 22.10.2005 and thinned out after emergence by leaving 10 seedlings pot-1 (30×50 cm). Clover's seeds were soaked overnight (>14 h) before sowing. Compound fertilizer (100, 60, 30) and (30, 60, 30) kg ha-1 N, P, and K were applied to grasses and clovers, respectively after thinning. Pots were manually irrigated. Biomass of pots was periodically harvested for dry matter after taking measurements of green leaf area index (GLAI) and light interception. Crop growth rate (CGR) was derived as ratio of dry matter and time-taken as growing degree days (GDD°C). LAI was measured non-destructively using LI-2000, LI-COR, USA. Radiation use efficiency (RUE) was derived from weather data and measurements made during the crop growth. The highest dry matter (1685 g m-2) was observed for Lolium multiflorum, followed by Lolium perenne (791 g m-2) and Dactylis glomerata (631 g m-2). GLAI were also recorded the highest for the species Lolium multiflorum (4.07) and Lolium perenne (3.93) with non-significant difference from each other. The highest dry matter of the grasses was in agreement to higher CGR and RUE. Grass species Lolium multiflorum yielded the highest CGR (1.06 g DM°C GDD) and RUE (3.41 g DM MJ-1 PAR absorbed) with strong positive relationship (r2=0.95). Lolium perenne was next to yield 0.47 g DM GDD-1 (°C) and RUE 1.63 g DM MJ-1 PAR absorbed. Rests of the grass species were found un-comparable for any observed parameter. Among the clovers, Trifolium repense was higher in dry matter (510 g m-2) yielded 1.10 g DM GDD-1 and RUE 0.71 g DM MJ-1 PAR absorption. From the study, it can be concluded that ryegrasses has potential to plant as green fodder in mix cultivation with local clovers on irrigated rangelands. Moreover, slow growth of fodder on arable land in early winter months can be improved through selection of an appropriate exotic grass/clover to be sown in combination with local types for the area.