Planting systems influence growth dynamics and quality of fresh market spinach

The objective of this work was to determine the effect of within-row plant spacing and mulching on growth, quality, and yield of an experimental semi- savoy spinach (Spinacea oleracea L.) genotype 'Ark-310' to produce a high q uality fresh market product. Within-row spacings were 15 and 25 cm, and mul ching treatments were bare-soil and black polyethylene mulch. Plants were d estructively sampled weekly (1995-96) or biweekly (1997-98) for leaf area ( LA), leaf number, leaf dry weight (LDW) and root dry weight (RDW) measureme nts. Plants grown on plastic mulch at 25-cm spacing had greater LA, LDW, an d RDW than when grown at 15-cm spacing on mulch or bare-soil. Leaf number a nd specific leaf area (LA/LDW) were less affected by either spacing or mulc hing. The amount of soil on harvested leaves was lower on plants grown on p lastic mulch in both years. In one year, total yields (MT/ha(-1)) were 42% higher at 15 cm than at 25 cm plant spacing, while mulch increased yields b y 20%, independently of plant spacing. These effects were not evident in th e year with higher rainfall (1997-98).