Effect of Planting Geometry on Growth, Water Productivity, and Fruit Quality of Tomatoes under Different Soil Moisture Regimes

The present study investigated the impact of planting spacing on tomato crop growth, water productivity, and fruit quality under different water regimes. Thus, a field experiment was conducted using a randomized complete block design in a factorial arrangement of treatments. The tomato plants were grown at three planting spacing patterns: 30 cm row-to-row planting spacing, 60 cm row-to-row planting spacing, and 90 cm row-to-row planting spacing, which were marked as (G(1)), (G(2)), and (G(3)), respectively. For each planting spacing pattern, irrigation regimes, namely (I-1), (I-2), and (I-3), were established by setting the soil moisture content to 50%, 100%, and 150% of the reference evapotranspiration. The I-3 x G(2) combination resulted in the maximum values of plant height (68.2 cm), stem diameter (12.1 mm), and yield (41,269.9 kg/hm(2)), providing the highest contents of protein (1.93 mg/kg), fat (0.81%), fiber (3.94%), and lycopene (4.00 mg/kg) of the fresh fruit. Conversely, the I-1 x G(1) led to the minimum values of plant height (37.3 cm), stem diameter (5.65 mm), and yield (7814.7 kg/hm(2)), providing the lowest contents of protein (1.15 mg/kg), fat (0.50%), fiber (2.39%), and lycopene (2.15 mg/kg) of the fresh fruit. The I-1 x G(1) had the highest water productivity (25.06 kg/m(3)) value, while the lowest WP (10.23 kg/m(3)) value was achieved by I-3 x G(3). While the I-1 x G(3) treatment minimized the uniformity coefficient and distribution uniformity, the I-3 x G(3) treatment maximized their values, indicating more uniform water distribution. Our findings indicate that the I-3 x G(2) combination can increase tomato productivity, growth, and fruit quality. However, the I-1 x G(1) performed better in terms of water productivity. The results of this study can positively contribute to improving tomato production systems' sustainability, productivity, and quality under the increasing problem of climate change.