Effect of Ficus religiosa leaves extract on agromorphological and physicochemical features of tomato cultivated in rainy and dry seasons from far north region of Cameroon

Postharvest losses of tomatoes during production by insect pests constitute a call for researchers worldwide. To further manage tomato pests and diseases, Ficus religiosa leaves extract was used comparatively to synthetic insecticide in dry and rainy seasons, where growth parameters of tomato plants and physicochemical characterization of fruits were assessed. The experiment was conducted under field conditions at market garden site of Dowedou village with furrow irrigation during the offseason (29–45 °C) and in rainy season (20–37 °C). The solutions of chemical insecticide, aqueous leaves extract of Ficus religiosa and water were applied twice per day using a maintained pressure sprayer very early in the morning (5.30 a.m) and late in the evening (6.00 p.m) on each subplot of tomato planted. The results showed that Ficus religiosa leaves extract was rich of bioactive compounds such as flavonoids and tannins which differed significantly ( P < 0.05) according to solvent. The number of leaves, flowers and fruits was less in plant with applied Ficus religiosa extract like synthetic insecticide. In rainy season, Ficus religiosa extract recorded the highest yield (72 %) followed by synthetic insecticide (64 %). In rainy and dry seasons, the higher amount of carbohydrates (4.4 and 4.9 gEG/100 g) was shown by tomato plants treated with Ficus religiosa extract whereas, the less value of carbohydrates was revealed in fruits of untreated tomato plants (3.4 and 2.7 gEG/100 g, respectively). According to proteins content, the applied synthetic insecticide on tomato plants cultivated in both seasons have fruits with high level (4.8 and 5.8 gEBSA/100 g) than fruits of tomato plants treated with Ficus religiosa extract (4.2 and 5.3 gEBSA/100 g). Moreover, lycopene was the abundant carotenoid in tomato fruits produced without or applied treatment. Total polyphenols content of fruits produced in dry season varied from untreated tomato plants (55 mgGaE/100 g) to tomato plants with applied chemical substance (190 mgGaE/100 g) while in the rainy season, tomato plants treated with Ficus religiosa leaves extract have fruits with high level followed by chemical treatment (274 mgGaE/100 g). Generaly, Ficus religiosa extract produced fruits with low potential antioxidant activities evaluated by the DPPH (109 and 140 mgET/100 g) and FRAP (271 and 379 mgET/100 g) methods in both seasons. Ficus religiosa leaves extract is an alternative treatment to control tomato pests and diseases. Therefore, characterization of the individual bioactive compounds in the Ficus religiosa leaves extract need to perform in the future.