Effect of row spacing and speeding rate on Alfalfa (Hassawi) seed yield and two related traits

Abstract

A field experiment was conducted at King Faisal University Research and Experimental Station, Al-Hassa during 1984 to 1987 to study the effect of row spacing and seeding rate on the seed yield of Hassawi alfalfa. The experiment included six row spacings: 15,30,45,60,75 and 90 cm and four seeding rates: 5, 10,20 and 40 kg/ha. An early seed crop was taken in the summer of the first year (1985) and two seed crops (early and late) were obtained in the summer of each of the second and third years (1986 and 1987). In the early seed crop of 1985, the 60 and 75 cm row spcaings gave the highest seed yeilds, producing 426 and 436 kg/ha, respectively. For the overall means of early and late seed crops of 1986 and 1987, the 30 and 75 cm row spacings produced the highest seed yields, giving 364.5 and 372.5 kg/ha, respectively. Lowest seed yields were obtained from either 15 or 45 cm row spacings, being 295.5 and 318.5 kg/ha, respectively. With respect to seeding rate, the seed yields obtained in 1985,1986 and 1987 were not significantly affected by the seeding rate treatments, although the 20 kg/ha seding rate gave the highest seed yield. In the late seed crop of 1986, the 75 row spacing gave significantly the highest 1O00-seed weight. In the early seed crop of 1985, the 90 cm spacing produced a significantly higher number of seeds per pod than the 15 cm spacing and in the late seed crop, the 90 cm gave a significantly higher number of seeds per pod than the 30 cm spacing. In the late seed crop of 1987, the seeding rate of 40 kg/ha gave significantly higher 1000-seed weight than the other seeding rate treatments. The seeding rate of 5 kg/ha produced a significantly higher number of seeds per pod than 40 kg/ha seeding rate