Evaluation of different sweet potato varieties for growth, quality and yield traits under chemical fertilizer and organic amendments in sandy ferralitic soils

Abstract

Growth, quality and yield components of sweet potato ((Ipomoea batatas (L.) Lam. Var. Tib1, IRA1112 and Red tuber coat) were investigated under three fertilizer sources (inorganic-NPK (100 kg/ha), green manure (Eichhornia crassipes) or poultry manure at 12 t/ha, singly or in combination) with three replications. Application of E. crassipes and poultry manure fertilizers in combination significantly (P < 0.05) increased the shoot length, tuber yield, chlorophyll content and harvest index in all varieties. The highest plant dry weight (480.60 g/plant), shoot length (263.23 cm), number of leaves (75.33) and tuber yield (18.66 t/ha) harvested were found in Tib1 when plants were supplied with both E. crassipes and poultry manure; while the lowest plant dry weight (62.54 g/plant), shoot length (195.45 cm) and tuber yield (2.11 t/ha) were recorded in Red tuber coat when plants were enriched only with inorganic-NPK. Leaf protein content of sweet potato varieties was positively influenced by inorganic-NPK, E. crassipes and poultry manure, singly or in combined treatments compared to leaf lipid and carbohydrate contents. A combination of high-yielding sweet potato varieties (Tib1) and adequate use of E. crassipes and poultry manure, singly or in combination could enhance sweet potato growth performance in sandy ferralitic soils.

Enhancing growth and yield of crops with nutrient-enriched organic fertilizer at wet and dry seasons in ensuring climate-smart agriculture

“…The lack of tuber yield responses in their studies might be due to pest and diseases or the closeness of fertilized and non-fertilized plots as the length of roots can reach 5.5 m (O'Sullivan 2008). Organic manure can serve as an alternative practice to mineral fertilizers (Wong et al 1999;Naeem et al 2006) for improving soil structure (Dauda et al 2008) and microbial biomass (Suresh et al 2004). Therefore, the utilization of locally produced manures by vegetable production operations may increase crop yields with less use of chemical fertilizer.…”

Agronomic performance of sweet potato genotypes under management of liming and mineral fertilization

“…We also observed that all evaluated genotypes were responsiveness to the treatments of soil fertility management, except for the CL-6 genotype, which did not show shoot yield variations regarding the soil fertility management. Désiré et al (2017) found similar results when evaluating the shoot biomass production from different genotypes of sweet potato in function of the application of mineral and organic fertilizers in sandy soils. Several authors have demonstrated that mineral NPK fertilization promotes the increase in the vegetative growth in various plant species by enhancing the absorption of available nutrients such as nitrogen, phosphorus and potassium (Wang et al, 2015;Mahjourimajd et al, 2016;Drakopoulos et al, 2016).…”

“…Essilfie et al (2016) evaluated the influence of mineral and organic fertilization on sweet potato yield, and observed that the highest (4.58 t ha -1 ) was product of the application of 20, 40 and 40 kg ha -1 of N, P and K, respectively. In these scenarios, yield was significantly lower than the national mean (13.99 t ha -1 ) due to the following facts: i) low potassium content in the soil and absence of practices related to topdressing fertilization with potassium fertilizers (i.e., potassium chloride); ii) prolonged water stresses during the initial plants development; and iii) absence of soil organic matter management practices (Désiré et al 2017). Foloni et al (2013) conducted an experiment with N and K dosages of 100 and 120 kg ha -1 , respectively, and obtained yield of 24, 9 t ha -1 .…”

“…Cavalcante et al 2010, in an experiment evaluating different sweet potato genotypes in the State of Alagoas, point out that without applying lime and fertilization it is possible to produce a mean of 6.29 t ha -1 of commercial roots. Désiré et al (2017) report that mineral fertilization did not promote increases in the yield of sweet potato genotypes grown in Nigeria. However, it is not clear how these studies performed liming, as studies aimed at evaluating only its isolated effect are scarce and rare in conditions of semi-arid environments.…”

“…The plant is rustic, of wide adaptation, with high drought tolerance, easy to grow and can be used as both human and animal food in the form of tubers and branches, respectively. Industries such as food, fabric, paper, cosmetic, adhesive preparation and fuel alcohol can also use the sweet potato as a raw material (Désiré et al, 2017). Moreover, the tubers have a high nutritional value, considered as an excellent source of energy because it is rich in carbohydrates and has a high content of A and B-complex vitamins, and minerals such as calcium, iron and phosphorus (Silveira et al, 2011).…”