TY - JOUR JF - mdrsjrns JO - JAST VL - 6 IS - 1 PY - 2004 Y1 - 2004/1/01 TI - Summer Forage Sorghum Yield, Protein and Prussic Acid Contents as Affected by Plant Density and Nitrogen Topdressing TT - N2 - Two similar field experiments were carried out at Kushkak and Fars Agricultural Ex-perimental Staties to determine the effects of plant densities and nitrogen topdressing (NT) rates on forage yield, some agronomic traits, protein and prussic acid contents of forage sorghum (Sorghum bicolor L. Moench var. Sudenense). Both experiments were conducted as spilt plots arranged in randomized complete block design with four replica-tions. Plant density consisted of 25, 33 and 50 plants m-2 in the main plots and nitrogen topdressing rates were 0, 100, 200 and 300 kg N ha-1 as urea in the sub-plots. Increasing plant density increased main stem height (MSH), leaf area index (LAI), total tiller num-ber m-2 (TTN), total fresh forage (TFF), total dry matter (TDM), leaf dry matter (LDM), and stem dry matter (SDM) yields. However, it decreased crude protein percentages (CPP) and had no effects on leaf-stem ratio at both locations. Increasing nitrogen rates in-creased MSH, LAI, TTN, TFF, TDM, CPP, forage prussic acid percentage (FPAP) and decreased leaf-stem ratio. Optimum plant densities and NT rates for these experiments were 50 plants m-2 and 200 kg N ha-1, respectively at both locations. Nitrogen applications had more effects on the second than the first out. The reaction of forage yields and most agronomic traits to the treatments were extremely similar at both locations. SP - 73 EP - 83 AD - KW - Plant density KW - Crude protein KW - Dry forage KW - Fresh forage KW - Prussic acid KW - Total tillers number UR - http://jast.modares.ac.ir/article-23-7245-en.html ER -