Effect of Fertilizers on Proximate Composition and Nutritive Quality Potential of Lettuce (var. Eden), Sweet Pepper (var. Yellow Wonder), and Carrot (var. Bahia)

Background: Vegetables are diverse in their cultivated, semi-cultivated, and wild states. Generally, all over the world, vegetables are used either as a whole meal or as a complement to the main meal. In Ghana, vegetables constitute an important component of the diet of the people.

Purpose: A study was conducted on the effect of single-based fertilizers and compound fertilizers on the nutritive quality potential of lettuce (var. Eden), sweet pepper (var. Yellow wonder), and carrot (var. Bahia).

Research Methods: This was accomplished following a Completely Randomized Design (CRD) with four replications. Lettuce, sweet pepper, and carrot were fertilized using 71 kg, 100 kg, and 128 kg of ammonium sulphate (20.5 % N, 23.4 % S)/ha, 350 kg of NPK (15-15-15)/ha, and Control/No fertilizer application; 81 kg, 100 kg, and 138 kg of 6-24-12 NPK/ha, 225 kg of NPK (15-15-15)/ha, and Control; and on 43 kg, 71 kg, and 100 kg of 10-10-30 NPK/ha, 225 kg of NPK (15-15-15)/ha, and Control; respectively. Laboratory studies were conducted to ascertain the nutritive value of lettuce, sweet pepper, and carrot cultivated for the fresh market; as influenced either by a single-based fertilizer or a compound fertilizer. All data were analyzed using the Analysis of Variance (ANOVA) technique with the GENSTAT statistical program.

Findings: Compound fertilizer resulted in high Fe content in lettuce while Single 2 treatment was in favour of that in carrot and sweet pepper. Single 3 treatment resulted in high Ca content in lettuce and sweet pepper while Single 2 treatment was in favour of that in carrot. Compound fertilizer resulted in high Mg content in lettuce while Single 3 treatment was in favour of that in carrot and sweet pepper. The crude protein content of lettuce, carrot, and sweet pepper was significantly high in the single-based fertilizer treatments. Compound fertilizer treatments recorded high carbohydrate content for lettuce and sweet pepper. All treatments recorded high moisture and high-fat content.

Conclusion: The study concluded that changes in the mineral content of the different categories of vegetables studied in relation to their response to either single-based fertilizers or compound fertilizers did not show a similar pattern.

Limitations: No limitations.

Originality/Value: Proximate composition patterns were strikingly dissimilar in all test crops.