ABSTRACT
Shade netting and fertilization strategies: Influence on yield and antioxidant levels in tomato

Antonio A. Pinto1, Susana Fischer2*, Richard M. Bastías2, Rosemarie Wilckens2, and Álvaro Urrea-Huilipang2
 
Shade netting is being increasingly employed to mitigate the impact of excessive solar radiation on crops. However, the influence of this technique on tomato (Solanum lycopersicum L.) remains relatively unexplored. This research assessed the effect of two types of shade nets on the yield and antioxidant content of tomato under two different fertilization regimes. A randomized complete block design with a split-plot arrangement was used. The main plot factor was shade netting (black nets and white nets), while the sub-plot factor was fertilization management (conventional and organic). Significant differences were observed in yield between shade and fertilization management practices. Total yield was significantly higher (86.76 t ha-1) under white nets compared to that obtained under black nets. Interestingly, the response of the antioxidants evaluated varied. Conventionally fertilized plants yielded substantially higher than those organically fertilized, reaching 78.96 and 67.81 t ha-1, respectively. A markedly higher concentration of lycopene (P < 0.05), with 6.19 mg 100 g-1 fresh weight, was recorded under white netting. Conversely, the concentration of polyphenols exhibited nonsignificant differences (P > 0.05) between shade netting and full sun conditions. In terms of fertilization, the greatest lycopene concentration (5.65 mg 100 g-1 fresh weight) was observed in tomatoes under conventional fertilization. On the other hand, the highest concentrations of polyphenols (21.38 mg gallic acid equivalent 100 g-1 fresh weight) and vitamin C (24.30 mg 100 g-1 fresh weight) were associated with organic fertilization (P < 0.05). In conclusion, this study underscores the substantial positive impact of both white netting and conventional fertilization as effective strategies to augment total crop yield and lycopene concentration, thereby enhancing overall tomato fruit quality.
Keywords: Lycopene, polyphenols, shade nets, Solanum lycopersicum, type of fertilization, vitamin C.
1Universidad de Concepcion, Facultad de Agronomia, Campus Concepcion, Concepcion, Chile.
2Universidad de Concepcion, Facultad de Agronomia, Chillan, Chile.
*Corresponding author (sfischer@udec.cl).