Emergence and vegetative development of melon in function of the soil salinity

Abstract

Soil salinity is one of the main factors limiting the development and global agricultural productivity. Melon (Cucumis melo L.) is mainly produced in arid and semi-arid regions around the world, favoring the accumulation of soluble salts in the soil. Therefore, this study aimed to evaluate the emergence and vegetative development of melon genotype under different levels of soil salinity. The assessments were performed based on the exchangeable sodium percentage (ESP) at 0, 20, 25, 30 and 35%. The emergence was affected around 30 percentage points, by comparing the control and the highest dose (35%). The emergence speed and the emergence speed index parameters were also affected in a similar way, as well as the length and dry matter of the shoot. The growth of the plants was also affected by the saline stress, being superior in the control (0%) in relation to the treatments with NaCl. The leaf area increased between weeks 4 and 7 after the planting and was slightly superior in the control in relation to the plants submitted to saline stress (20, 25, 30 and 35% of exchangeable sodium). The melon is more sensible to the saline stress in the seedling emergence than in the vegetative development over time. The development of melon seedlings is mainly affected in exchangeable sodium values superior to 20%. The analyzed hybrid is sensible to the saline stress even in 20% of exchangeable sodium.