Water Availabilities Associated with Natural Phosphate and Triple Superphosphate in Radish Cultivation

Abstract

Aims: The objective of this study was to evaluate the development of giant Crimson radish cultivated in a oxisol under phosphate fertilizer sources (natural phosphate, triple superphosphate, natural phosphate + triple superphosphate and control) associated with water availabilities (40, 80 and 120% of the field capacity).
 Study Design: The experimental design was completely randomized, in a 4x3 factorial scheme, with 4 replications (48 units).
 Place and Duration of Study: The research was conducted in a greenhouse belonging to the Federal University of Mato Grosso, in the municipality of Rondonópolis (MT).
 Methodology: The dystrophic Oxisol was used to fill the 1.5 dm3 pots. The irrigation management was in accordance with the methodology of the maximum water retention capacity, by the gravimetric method. Phosphate fertilization was applied before sowing using 265 mg dm-3 phosphorus, varying the source used, triple superphosphate and Bayovar Natural phosphate. After the emergence of the plants, the other nutrients were applied to the soil. The parameters related to vegetative development and after the harvest of radish were evaluated at 20 and 35 days after sowing.
 Results: The parameters fresh mass of the aerial part, dry mass of the tubercle, dry mass of the aerial part, fresh mass of tubercle and length of tubercle had the highest values with the use of triple superphosphate, and for the field capacities of 80 and 120%. The highest harvest index (1.51) was found for the use of Natural phosphate in the field capacity of 120%. The water consumption by the plants was higher with the use of triple superphosphate and field capacity of 120% (6,425.25 L). The efficiency of water use was better with the application of triple Superphosphate and 40% of the field capacity (0.0547 g mL-1).
 Conclusion: There was influence of both water availabilities and phosphate fertilization on the studied parameters. Triple superphosphate associated with 80% of the field capacity allowed the best productivity averages for radish.