Dry Matter Allocation and Yield Response of Carrot (Daucus carota L.) to Fertilization with Moringa oleifera and Tithonia diversifolia Leaf Extracts

Abstract

This study evaluated the effects of various fertilizers—Moringa leaf extract, Tithonia leaf extract, a mixture of both (Mix), and a standard inorganic NPK+Urea fertilizer—on carrot (Daucus carota) growth, root development, and overall yield. Initial growth parameters, including leaf area index, plant height, and leaf count, showed no significant differences among treatments. However, significant variations emerged in biomass accumulation and root morphology as the carrots matured. The study established a significant effect of fertilizer type on several key metrics. Fresh shoot weight was significantly higher with the Moringa treatment (0.430 g) compared to the Mix (0.290 g) and NPK+Urea (0.390 g) treatments. In contrast, fresh root weight was highest with NPK+Urea (2.39 g), followed by Moringa (2.08 g), Tithonia (1.88 g), and the Mix (1.66 g). In terms of root dry weight, Moringa (0.0539 g) significantly outperformed the Mix (0.0422 g) and Tithonia (0.0426 g). Both Moringa and Tithonia also significantly increased leaf dry weight compared to the Mix and NPK+Urea treatments. For root morphology, root length was greatest with NPK+Urea (16.8 cm) and Moringa (16.7 cm), both outperforming the Mix and Tithonia treatments. Similarly, root diameter was highest with NPK+Urea (36.3 mm), followed by Moringa (34.3 mm). Total yield was significantly affected, with NPK+Urea leading (8.08 t/ha), while Moringa (6.39 t/ha) and Tithonia (6.49 t/ha) demonstrated similar yields, proving to be strong organic alternatives to the Mix (5.42 t/ha). In conclusion, although the inorganic NPK+Urea fertilizer resulted in the highest overall yield, the Moringa leaf extract demonstrated strong potential as a competitive organic alternative. It significantly enhanced fresh shoot weight and achieved root dry weight and root length comparable to the inorganic standard, highlighting its viability for sustainable carrot production systems.