Response of sweet potato cultivars to acid soil infertility factors. I. Effects of solution pH on early growth

2000 ◽  
Vol 51 (1) ◽  
pp. 23 ◽  
Author(s):  
V. P. Ila'ava ◽  
C. J. Asher ◽  
F. P. C. Blamey

Sweet potato [Ipomoea batatas (L.) Lam.] is cultivated on soils varying widely in chemical properties, but relatively little is known about the effects of pH on the growth of this crop. In commercial and subsistence agriculture, sweet potato is propagated mostly from stem cuttings. This paper reports effects of a range of pH treatments (3.5–8.0) in flowing solution culture on early growth from cuttings of 15 sweet potato cultivars. Root growth was either greatly reduced or inhibited at pH 3.5. Increasing the pH to 4.0 markedly increased root development. Further increases in solution pH from 4.0 to 8.0 did not appear to affect root growth in most cultivars. Top growth in most cultivars showed a tendency to increase when pH was increased from 3.5 to 5.5 before declining with further increases in solution pH. The sweet potato cultivars studied differed widely in their tolerance to low pH, producing 16–48% of maximum top dry mass at pH 3.5. Tissue analysis from selected cultivars showed that K and Ca appeared to be limiting at pH 3.5, while P may have been deficient at pH 8.0. Results of this study indicate that low pH per se does not appear to be a major factor responsible for poor sweet potato yields in acid soils.

2008 ◽  
Vol 26 (1) ◽  
pp. 112-115 ◽  
Author(s):  
Marcos José de O Fonseca ◽  
Antonio G Soares ◽  
Murillo Freire Junior ◽  
Dejair L de Almeida ◽  
José Luiz R Ascheri

Sweet potato (Ipomoea batatas) is a food crop that supplies energy, minerals and vitamins C and B. Some cultivars are very rich in carotenoids (pro-vitamin A). In this study were evaluated and compared the total carotenoids content of two cultivars and the losses on the dehydrated extruded sweet potato flour. Samples from organic and conventional crops were analyzed, in the form of fresh and dehydrated extruded samples. Total carotenoids content of the fresh product, expressed on wet basis, was of 437 µg 100 g-1 for the cream cultivar and 10,12 µg 100 g-1 for the orange cultivar. After dehydration, losses of total carotenoids were of 41% and 38%, respectively. The fresh orange cultivar presented high total carotenoids content in comparison to the cream cultivar. The extruded orange sweet potato flour showed the lowest losses in total carotenoids. Therefore, the processed flour of orange sweet potato could be used to obtain pre-gelatinized extruded flour with high total carotenoids content.


1990 ◽  
Vol 41 (5) ◽  
pp. 933 ◽  
Author(s):  
MA Ewing ◽  
AD Robson

The study tested the hypothesis that annual medic species which nodulate well in acid soils in the field (M. murex Willd. and M. polymorpha L.) will nodulate better in acid solutions with low calcium concentrations than annual medics which nodulate poorly in acid soils (M, truncatula Gaertn.). Effects of pH (5.5 and 6.5) and calcium concentration (0.2, 0.5, 1 and 2 mM) on the early growth and nodulation of three annual medic species (M. truncatula, M. polymorpha and M. murex) were investigated. Increasing pH or calcium concentration did not increase plant growth for any of the species. However, nodulation was generally depressed by low pH for all species. Increasing calcium concentration in solution increased nodulation in all species. Effects of low pH and low calcium concentration in decreasing nodule number were much greater for M. truncatula than for M. polymorpha and M. murex. At pH 5.5, M. truncatula failed to nodulate at any calcium concentration, whereas a large proportion of M. murex plants nodulated at 1 mM calcium and some M. polymorpha plants nodulated at 2 mM calcium. At pH 6.5, M. polymorpha required 1 mM calcium in solution for maximum nodule number, and M. murex only 0.5 mM calcium, whereas nodule number for M. truncatula increased up to 2 mM calcium, the highest concentration used. The results provide the basis for a simple screening system to distinguish differences among annual medics in nodulation tolerance to acidity. The maintenance of ranking among species with respect to nodulation over a wide range of stresses induced by combinations of low pH and calcium concentration suggest that screening using a single stress combining these two components would be adequate. Nodulation differences between species can be simply and effectively assessed using a scoring system combining number size and location of nodules.


1965 ◽  
Vol 45 (2) ◽  
pp. 221-234 ◽  
Author(s):  
L. B. MacLeod ◽  
L. P. Jackson

Alfalfa, red clover, ladino clover, alsike clover, and birdsfoot trefoil were germinated in soil (pH 6.5) or in inert silica (8 mesh) and allowed to root in a [Formula: see text] Hoagland and Snyder's nutrient solution (pH 4.5) with 0, 0.5, 1, 2, 4, and 10 p.p.m. of added aluminum. Each species, germinated in silica, was also rooted in an unlimed acid soil (pH 4.6) and the same soil limed to a pH of 6.5.Concentration of aluminum ion remaining in solution was 0, 0.1, 0.2, 0.5, 1.0, and 2.0 p.p.m. Saturation extracts of the unlimed and limed soil contained 0.45 and 0.0 p.p.m respectively of aluminum ion in solution. The pH of the nutrient solutions with 0.5, 1, and 2 p.p.m. of added aluminum increased to 5.0 or higher in 24 hours while that with 4 and 10 p.p.m. of added aluminum remained relatively constant.Seedling weight and chemical composition of the tops and root portions varied significantly between species. Alfalfa and red clover showed the most vigorous rate of establishment, and yields were higher with 0.1 and 0.2 p.p.m. concentration of aluminum ion than with the zero treatment. Significant restriction of top and root growth of all species occurred with less than 1.0 p.p.m. of aluminum ion while 2.0 p.p.m. was toxic to root growth. Growth restrictions were more severe at 21 days after seeding than at the 28- or 32-day stages. Yield of tops and roots growing into unlimed acid soil were 73 and 71% respectively of those growing into limed soil. Aluminum taken up by the plant was concentrated in the roots and only with the concentration of aluminum at 2.0 p.p.m. was the content in the tops increased significantly. Phosphorus in the roots, which increased significantly with aluminum ion concentration, was apparently immobilized by aluminum. Percent Ca in the roots increased and in the tops decreased with increasing concentrations of aluminum. Content of K and Mg also varied with aluminum concentration.


2000 ◽  
Vol 51 (1) ◽  
pp. 29
Author(s):  
V. P. Ila'ava ◽  
C. J. Asher ◽  
F. P. C. Blamey

Good growth in acid soils suggests that sweet potato may be tolerant of acid soil infertility factors such as Al toxicity or Ca deficiency. In a conventional solution culture experiment, 4 cultivars responded positively when solution Ca concentration was increased from approximately 4 to 1300 □М. However, a subsequent flowing solution culture (FSC) experiment showed no significant (P > 0.05) differences in growth by most of the 15 cultivars studied when solution Ca concentration was increased from 45 to 400 □М. Hence, it was concluded that sweet potato could be fairly tolerant of low Ca supply. In contrast, soluble Al markedly decreased growth of the 15 sweet potato cultivars studied. The results of the present study indicate that Al rather than low Ca supply would be more important in limiting sweet potato growth in acid soils. Furthermore, tolerance to low Ca and soluble Al appears to be linked in sweet potato. These results highlight the importance of selecting sweet potato cultivars for specific soil conditions such as soil acidity.


1970 ◽  
pp. 01-05
Author(s):  
Ncube Netsai ◽  
Mutetwa Moses, Mtaita Tuarira

There is significant variation in yield of storage roots and vines of sweet potato (Ipomoea batatas) among farmers due to use of different cutting positions and pruning of vines at different levels. This study was carried out to establish the cutting position and the vine pruning level that give the best yield of both the storage roots and vines. The study was conducted in a 3x3 factorial arrangement in Randomized Complete Block Design (RCBD) with three replications. Treatments included cutting position at three levels (apical cutting, middle cutting and basal cutting) and pruning at three levels, 0%, 25% and 50% respectively. Pruning was done. 50 days after planting. And storage root harvesting was done 100 days after planting. The two measurements were summed up to give the total vine weight. Storage root length, diameter and weight were measured at 100 DAP. Storage root length indicated significant difference (P<0.05) only among cutting positions with highest mean length (16.20 cm) obtained from apical cutting and the lowest (11.98 cm) from basal cutting. Storage root diameter, storage root weight and vine weight indicated significant interaction (P<0.05) of cutting position and vine pruning level. Highest mean root diameter and root weight were obtained from middle cutting and 25% vine pruning level, with the lowest being obtained from basal cutting and 50% vine pruning level. Highest vine weight was recorded from middle cutting and 50% vine pruning level, with the lowest being recorded from basal cutting and 0% vine pruning level. Both middle and apical stem cuttings can be recommended for higher storage root and vine yield. Vine pruning at 25% can be adopted for higher storage root yield while pruning at 50% can be suggested for higher vine yield.


2007 ◽  
Vol 50 (4) ◽  
pp. 597-604 ◽  
Author(s):  
Nerilde Favaretto ◽  
Antônio Carlos Vargas Motta ◽  
Cristina Barcik ◽  
Sebastião Brasil Campos Lustosa ◽  
Jucinei José Comin

To analyze the influence of boron fertilization on shoot and root growth of Trifolium vesiculosum (arrowleaf clover), an acid soil profile (60 cm depth with 67% Al saturation) was recreated in a column (three layers of 20 cm each). Lime and fertilizer (P and K) were incorporated into the top 20 cm. The treatments consisted of six boron rates where boric acid was mixed throughout the profile. Addition of boron to soil with low pH and high Al increased the root and shoot growth, independent of the rate applied. Boron inhibited Al toxicity, but no effect was observed in the root length when Al was not present in the soil. It was also observed that there was more root growth below the plow layer (0-20 cm,) suggesting better root distribution in the soil profile which could be important for the plant growth, especially under drought conditions.


2020 ◽  
pp. 28-38 ◽  
Author(s):  
N. S. Donaldben ◽  
O. O. Tanko ◽  
T. O. Hussaina

The research sought to investigate the functional properties of starches obtained from four Nigerian root and tubers, yam and sweet potato varieties, in order to facilitate their exploitation as substitute raw material for the local food and pharmaceutical manufacturing industry. The varieties, namely: white yam (Dioscorea rotundata), water yam (Dioscorea alorta), orange flesh sweet potato (Ipomoea batatas) and cream flesh sweet potato (Ipomoea batatas), their respective starches were obtained by wet separation techniques and were analyzed for their pasting properties, physic-chemical properties, starch yield on dry and wet basis, functional, starch purity, amylase and amylo-pectin were undertaken in order to determine their suitability for food and other uses. The peak time, pasting temperature, peak viscosity, holding strength, breakdown, set from peak and set back from through ranged from 7.3 – 8.3 mins, 65.4 – 71.3°C, 511.5 – 1001.2 BU, 860.8 – 871.3 BU, 300.1 – 306.9 BU, 240.8 – 248.1 BU and 400.4 – 510.9 BU respectively. There were significant differences (p<0.05) in the pasting properties. The crude protein, crude fat, crude fibre, ash, moisture and carbohydrate ranged from 1.55 – 1.85%, 0.09 – 0.12%, 0.12 – 0.22%, 1.32 – 2.05%, 10.72 – 11.09% and 85.59 – 86.20% respectively. There were significant differences (p<0.05) in the proximate composition of the starches. The starch yield on dry weight basis, starch weight on fresh weight basis, starch yield from tubers and percentage dry matter ranged from 56.84 – 85.88%, 22.75 – 36.07%, 18.02 – 26.00% and 40.02 – 44.01% respectively. There were significant differences (p<0.05) in the all the parameters. The bulk density, water absorption capacity, oil absorption capacity, gelatinization temperature, starch purity, amylase, amylo-pectin and pH ranged from 0.56 – 0.61g/cm3, 86.8 – 99.4%, 103.2 – 125.4%, 59.78 – 60.42°C, 95.28 – 96.55%, 27.25 – 29.37%, 70.63 – 72.63% and 6.82 – 6.91 respectively. There were significant differences (p<0.05) in all the parameters but no significant difference (p>0.05) in the pH. The starches from yam and sweet potato varieties starches can be exploited for diverse uses based on their different characteristics.


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