02198naa a2200229 a 450000100080000000500110000800800410001910000200006024501110008026000090019152014900020065000110169065000200170165000130172165000210173465300110175565300220176665300220178865300140181070000160182477301280184014548202004-10-29       1985    bl uuuu     u00u1 u    #d1 aSILVA, P. R. F.  aEffect of rate and method of planting on light interception and on agronomic characteristics of sunflower.  c1985  aThe new interest for research on sunflower (Helianthus annus L.) in the Southernmost region of Brazil and the availability of new commercial hybrids have determined the establishment of cultural practices for this area in order to obtain optima grain and oil yields. With the objective of evaluating the effect of rate and pattern of planting on light interception and an agronomic characteristics of sunflower "Conti 711", a research was conducted in Guaiba, RS, Brazil, during the 1983/84 growing season. Populations of 25 and 50,000 plants/ha were tested in five methods of planting: two single row spacings, 100 and 70 cm apart; two double row systems spaced 150 and 200 cem apart; and one system with plants uniformily spaced within and between rows, 63 and 45 cm apart, respectively to 25,000 and 50,000 plants/ha. Grain and oil yields, light interception, plant height, and leaf area index were higher with 50,000 than with 25,000 plants/ha. On the other hand, grain weight, grain number per head, leaf area per plant, and biological yield were lower with the higher rate of planting. Generally, the method of planting had little or no effect on plant characters, except for light interception and plant height. In the systems with double rows, light interception between double rows was lower than in other methods of planting; however, within the rows, light interception was the highest. Platn height in the double row systems was higer than in the other methods of planting.  aBrazil  acrop management  aGirassol  aPratica Cultural  aBrasil  aCultural practice  aRio Grande do Sul  aSunflower1 aSCHMIDT, E.  tIn: CONFERENCIA INTERNACIONAL DE GIRASOL, 11., 1985, Mar del Plata. Actas. Mar del Plata: ASAGIR/ISA, 1985. t.1, p.295-299.