ONION YIELDS UNDER 3 WATER REGIMES AND 5 SPACINGS

The objective of this study was to evaluate the effect of three irriga tion regimes and five crop spacings on onion crop yield. The experimen t was carried out under a randomized block design, in a split-plot sch eme with three replications. The irrigation regimes consisted of the m aintenance of the matric potential in the root zone with the following bands: regime 1, between -6.0 and -8.5 kPa; regime 2, between -7.0 an d -10.0 kPa; regime 3, between -10.0 and -28.0 kPa. The crop spacings which constituted the sub-plots were: 0.30 x 0.08 m; 0.20 x 0.08 m; 0. 10 x 0.08 m; 0.15 x 0.10 m; and, 0.10 x 0.10 m. The largest marketable productivity of large and medium-sized bulbs and the largest bulb mea n weight ocurred under regime 1. Spacing 0.20 x 0.08 m resulted in the highest productivity of commercial bulbs. Spacings of 0.20 x 0.08 and 0.30 x 0.08 m resulted in large and medium-bulbs and in largest avera ge bulb weight.