Effect of organic and mineral fertilization on proximate composition of three leafy vegetables harvested at different periods

Abstract

Leafy vegetables are part of natural resources traditionally harvested from forests in Benin. Some of these wild plants foods have been introduced in the small scale production system. The low productivity and the increasing demand for such products urged to use fertilizers. However, the impact of such practices on the nutritional properties of these leaves was poorly documented. In this study Sesamum radiatum, Ceratotheca sesamoïdes and Justicia tenella were cultivated using NPK, cowpat and mixture of NPK plus cowpat. Leaves harvested at 6, 9, 10, 12 or 14 weeks after transplanting were analyzed for proximate composition. Protein content ranged from 17.2 to 33.8 g/100 g DW; ash from 7.7 to 20.4 g/100 g; fat from 1.2 to 7.3 g/100 g, fiber from 5.6 to 13.1 g/100 g and polyphenols content from 0.24 to 1.33 g GAE/100 g (DW). Significant effects of species, fertilizer and cutting time were evidenced. Whereas ash content increased by 1 to 25.8% ratio in fertilized S. radiatum leaves, it showed a downward trend (-1 to -22%) during the two first cutting times of C. sesamoides followed by an upward trend (12.7 to 14.3%) at the last cutting time, in comparison to the non fertilized leaves.

Fertilizer micro-dosing and harvesting time of indigenous leafy vegetables affect in vitro antioxidant activities

“…Antioxidant properties of leafy vegetables tracts, which is in agreement with reports relating polyphenolic profile in leafy vegetables subjected to some agronomic and environmental factors including nutrient supply and harvest time (Brasileiro et al, 2015;Sossa-Vihotogbé et al, 2013a;Stefanelli et al, 2011;Tavarini et al, 2015). Uses of urea micro-doses and/or cattle manure were beneficial for polyphenolic compounds synthesis, which is consistent with reports on the effect of organic fertilizer associated with moderate doses of mineral fertilizer in promoting synthesis and availability of polyphenols within leafy vegetables (Sossa-Vihotogbé et al, 2013a).…”

“…These leafy vegetables are grown in various ecological zones and are often harvested on staggered timing after maturity (Achigan-Dako et al, 2010). They are inexpensive and rich sources of nutrients such as minerals, vitamins, carotenoids and polyphenols (Vodouhe et al, 2012), although their nutrient profiles are affected by agronomic and environmental factors including soil type, water and nutrient supply, cultivation methods and harvest time (Brasileiro et al, 2015;Sossa-Vihotogbé et al, 2013a;Tavarini et al, 2015).…”

Ethno-ecological Variability in the Consumption of Leafy Green Plants in the Republic of Benin

“…Various reasons were mentioned to explain the consumption of the studied vegetables, including dietary habits, taste, need to diversify sauces, nutrients and therapeutic benefits. Traditional leafy vegetables were reported as highly nutritive foods containing vital components of balanced and healthy diets such as vitamins and their precursors, polyphenols, minerals, proteins and fibres [21,22,3,4]. Richness of Amaranth, African basil and African eggplant in vitamins were reported as well-known by Beninese who considered it a key selection criterion of these vegetables [6].…”

“…A diet rich in a diversity of plant resources has shown to enhance one's health and nutritional profile [1]. In Sub-Saharan Africa (SSA), the consumption of indigenous leafy vegetables plays an important role in the nutrition and health of rural poor because of general availability, richness in micronutrients, and for their medicinal virtues [2,3,4]. In the Republic of Benin, biodiversity inventories of traditional leafy vegetables reveal that more than 180 plant species are regularly cultivated, or semicultivated as wild plants, and play a significant…”

“…Baco; AJAEES, 36(4):1-15, 2019; Article no.Benin map showing the geographical location of the survey sites; Article no.AJAEES.52185Benin map showing the geographical location of the survey sites…”