HORTSCIENCE 48(6):768–772. 2013. and minerals (Schippers, 2000). Long Bean is popular in Asian countries, and its pods are similar to that of snap beans but are pencil Hydrolyzed Organic Fish Fertilizer thin and are harvested when immature before seed fill. Long beans have adequate levels of and Poultry Litter Influence Total vitamin C, provitamin A, folate, and protein (Mosha et al., 1995). Phenolics and Antioxidants Content Animal manures such as PL and hydro- lyzed fish fertilizers are relatively less expen- sive than conventional inorganic fertilizers but Not Yield of Amaranth, Celosia, and readily available (especially PL). Manures are relatively good sources of plant nutrients Gboma, and Long Bean and organic matter (Kpomblekou et al., 2002; 1,3 Toor et al., 2006) and not only improve soil Loutrina Staley physical and chemical properties, but also Department of Natural Resource and Environmental Sciences, Alabama enhance plant growth (Boyhan et al., 2010; A&M University, 4900 Meridian Street, Huntsville, AL 35810 Russo, 2010). For example, an incubation study 2 2 evaluating nitrogen (N) availability from liquid D.G. Mortley and C.K. Bonsi fish protein-based organic fertilizers, Hartz George Washington Carver Agricultural Experiment Station, Tuskegee (2010) showed that 79% to 83% of total N University, 1200 West Montgomery Road, Tuskegee, AL 36088 was available after 1 week and 83% to 99% after 4 weeks. In addition, PL and hydrolyzed A. Bovell-Benjamin2 and P. Gichuhi2 fish fertilizers when used as organic amend- Department of Food and Nutritional Sciences, Tuskegee University, 1200 ments also increase disease and insect resis- West Montgomery Road, Tuskegee, AL 36088 tance, extended the shelf life of produce, and enhanced microbial activity (Davis and Additional index words. organic liquid fertilizer, fish fertilizer, chicken manure, leafy Riordan, 2004). vegetables, sustainability Russo (2010) evaluated the effects of the frequency of applied PL compared with an Abstract. Dietary intake of a variety of vegetables is very important for disease prevention annual application of NPK on the production and may help in the treatment of certain maladies. Experiments were conducted to of bell peppers (Capsicum annuum), sweet evaluate yield and the content of antioxidants and phenolics of vegetable Amaranth corn (Zea mays), and cucumbers (Cucumis (Amaranthus hybridus), Celosia (Celosia argentea), Gboma (Solanum macrocarpon), and sativus). He found that an annual treatment Long Bean (Vigna unguiculata) in response to poultry litter (PL) and a hydrolyzed fish with PL produced higher marketable yields fertilizer [Megabloom (MB)]. The experiments were conducted as a randomized complete of bell pepper and sweet corn compared with blockdesignwithafour3 three factorial treatment and four replications. The treatments application in alternate years, whereas the wereappliedbasedonsoiltestrecommendationsinasingleband15to20cmawayfromthe opposite was true for cucumber. plants 1 week after transplanting. Plants were harvested sequentially during the season Boyhan et al. (2010) reported that PL as foliage and fruits became physiologically mature and once over at the end of the season. applications increased total yield of short- Species were analyzed for vitamin C content, total phenolics, and b-carotene content as well day onions but reduced that of medium bulbs. as antioxidant capacity. Organic amendments did not significantly influence biomass AdeOluwa and Cofie (2011) reported that production, whereas species impacted fresh and dry biomass. Amaranth, Celosia, and Long vegetable Amaranth plants had a positive Bean produced greater fresh and dry biomass than did Gboma. Vitamin C content was response to organic compost but the response highest among Amaranth and Celosia plants receiving nitrogen–phosphorus–potassium varied with time and environmental condi- (NPK) compared with the other two treatments, whereas that of Gboma was higher among tions, whereas Jaipaul et al. (2010) reported plants receiving MB. that organic manures increased plant height of pepper and garden pea. Masarirambi et al. (2012) evaluated the effects of poultry ma- MB and PL enhanced b-carotene in Am- amendments on biomass production was nure applied at 20, 40, and 60 t·ha–1 on lettuce aranth compared with NPK but that of Celosia marginal and that species exerted a greater production in South Africa and reported and Gboma was enhanced by MB and NPK influence. However, there appears to be an greater total and marketable yields at the fertilizer. Total phenolic content was higher enhancement of total phenolics and DPPH 60-t·ha–1 rate. among Amaranth plants receiving NPK, activity in response to organic amendments. Plant responses to hydrolyzed fish fertil- whereas those for Long Bean were greater Vegetable Amaranth (Amaranthus hybridus) izers appear to be species-dependent. Schupp among plants receiving MB or NPK fertil- (Mosha et al., 1995), Celosia (Celosia argentea) et al. (1993) reported that fish hydrolysate izer. 2,2-Diphenyl-1-picrylhydrazyl (DPPH) (Orhue, 2010), Gboma (Solanum macrocarpon) fertilizer reduced fruit set of ‘Delicious’ and activity was enhanced by MB, MB and NPK, (AVRDC, 2002), and Long Bean (Vigna ‘Golden Delicious’ apples. In contrast, Smagula or MB only among Amaranth, Celosia, Gboma, unguiculata) (Chitindingu, 2005; Mosha and Dunham (1995) showed that fish hy- and Long Bean plants, respectively. These et al., 1995; Palada et al., 2006), are highly drolysate fertilizer was as effective as 5N– results suggest that the impact of organic nutritious niche market specialty vegetables 10P–5K in raising leaf N, P, and K concen- being evaluated for growth, adaptability, and trations in prune and crop-year leaf samples production under Alabama conditions, includ- as well as stem length and yield of low bush Received for publication 9 Jan. 2013. Accepted for ing responses to different organic fertilizers. blueberry; fish hydrolysate is an acceptable publication 11 Apr. 2013. Amaranth and Celosia are leafy vegetables that alternative to soluble fertilizer for cranberries This research was supported by funds from USDA/ are good sources of antioxidants and pheno- (DeMoranville, 1990). NIFA Evans-Allen Grant No. ALX-FV. lics, are similar to spinach, and are commonly Fruits and vegetables are critical parts of a Contribution of the George Washington Carver Ag- ricultural Experiment Station, Tuskegee University. grown in parts of Africa and Asia (Chitindingu, healthy diet and are rich sources of many 1Former Graduate Student. Currently PhD Student. 2005). Gboma is widely grown in Africa and nutrients such as vitamins C and K, folate, 2Professor. Southeast Asia for its fruits as well as its thiamine, carotenes, several minerals, and 3To whom reprint requests should be addressed; leaves, which are similar to those of kale and dietary fiber (Palada et al., 2006). In addition, e-mail [email protected]. are good sources of protein, fiber, vitamins, antioxidants that occur naturally in these fruits,
768 HORTSCIENCE VOL. 48(6) JUNE 2013 vegetables, and whole grains are powerful Fertilizer treatments consisted of PL with absorbance measured at a wavelength weapons in combating inflammation and low- (20% N), hydrolyzed fish fertilizer (MB; of 765 nm. ering heart disease and cancer risk (Odukoya 2% N), and conventional NPK. Fertilizer treat- The antioxidant capacity of the vegetable et al., 2007). ments for each species were based on soil test samples was determined based on DPPH Studies on organically grown produce recommendations and were applied in a single following the methods of Chaires-Martinez have shown differences in micronutrient and band 15 to 20 cm away from the plants. et al. (2009) and Seal (2011). Samples (0.5 g) phytochemical content, sometimes as high as Because no laboratory analysis was done on were combined with 50 mL of 95% methanol, 30% in contrast to crops conventionally grown the PL, we used the average values of litter shaken for 50 min, and filtered to a final volume (Riordan and Davis, 2005). Weibel (2000) nutrients in similar waste management sys- of 50 mL with 95% methanol and thoroughly harvested apples from five pairs of organic/ tems of Fulhage and Pfost (1994) based on mixed. After mixing, 3.9 mL of DPPH solution integrated fruit farms with similar micro- incorporation 7 d or greater after collection. and 100 mL of the extracts were pipetted into climate, soil conditions, and planting sys- Six inner plants from the middle row of cuvettes, allowed to sit in the dark for 30 min, tem and reported that contents of phenols each three-row plot were harvested periodi- and absorbance was measured at 515 nm using (mainly flavonols) were 19% higher in organ- cally throughout the growing season (as green a Shimadzu ultraviolet-2401 PC ultraviolet-VIS ically grown apples, In contrast, Toor et al. leafy foliage or pods). Succulent stems with Spectrophotometer (Shimadzu Corporation). (2006) reported that lycopene levels in tomato intact leaves of 15 cm length (Amaranth and Beta-carotene content was determined were reduced by the application of organic Celosia) or leaves (Gboma) were harvested using the method of Scott (2001) and sapon- amendments. Zhao et al. (2007) reported that every 2 weeks and the entire plant at the end of ification based on the method of Larsen and the levels of phenolic compounds in lettuce the growing season and fresh weights taken. Christensen (2005). One gram of sample was were consistently impacted by the nutrient Plant tissues were dried at 70 Cfor72hand added to 20 mL of 100% acetone and shaken source and suggested that this could have dry weights of component plant parts deter- for 20 min. The extractant was filtered and been related to general factors including the mined. Samples for antioxidant and phenolics 50 mL of diethyl ether/petroleum ether stock environment, season, and cultivar differences. analysis were dipped in tap water followed by (100 mL diethyl ether in 900 mL petroleum Additionally, peppers and garden peas fertil- three successive deionized water rinses, blot- ether) and deionized water were added and ized with organic manure have been previously dried on paper towels, and frozen at –10 C allowed to precipitate. The precipitate was shown to have higher vitamin C, total phe- for72h.Sampleswerefreeze-driedfor72hat discarded and 0.05 g of butylated hydroxyto- nolics, and anthocyanin content (Abu-Zahra, –40 C after which they were ground to a fine luene, 50 mL of KOH/methanol stock (100 g 2011; Jaipaul et al., 2010). Similarly, broc- powder using a mortar and pestle. KOH in 1 L of 95% methanol) was added. This coli treated with organic and bio-organic Samples were analyzed for vitamin C step was repeated three times using 300 mL fertilizers produced antioxidants with greater content by titration according to the methods ofdeionizedwater,afterwhich5gofsodium chelating power (El-Moniem et al., 2012). of the U.S. Pharmacopoeia (USP, 1980). One sulfate was added to reduce moisture. The con- Although improved yield responses and gram of sample was added to 50 mL of de- centration of carotenoids was measured at higher phenolic concentrations have been ionized water, filtered, and brought to a final 450 nm using a Shimadzu ultraviolet-1700, reported in organically grown crops, these re- volume of 100 mL with deionized water. A Pharmaspec Spectrophotometer. ports are generally inconsistent, because other 20-mL aliquot was pipetted into a 250-mL Data were combined by treatments and factors may be involved (Carbonaro et al., conical flask and 150 mL of deionized water tested by analysis of variance using the Gen- 2002; Lombardi-Boccia et al., 2004; Sousa was added along with 1 mL of the starch eral Linear Model procedure (SAS Institute, et al., 2005). For example, Young et al. (2005) solution (0.50 g of soluble starch in 50 mL of 2007) with mean separation by Fisher’s pro- suggested that organic systems may expose boiling deionized water). Samples were titrated tected least significant difference at 0.05. leafy vegetables to attack by insects result- with 0.005 mol·L–1 of iodine solution to blue at ing in higher concentrations of phenolics as the end point. Results and Discussion plants produce them as a part of their defense Total phenolics were determined using mechanism. gallic acid according to the method of Slinkard Analysis of variance for growth responses Our objective was to evaluate the influ- et al. (1999). One-gram samples were placed of the four vegetables is summarized in Table 1. ence of a hydrolyzed organic fish fertilizer in opaque bottles and 25 mL of 95% methanol Organic amendments did not significantly in- and PL on biomass production, total pheno- was added, agitated for 30 min after which fluence biomass production; however, species lic, and antioxidant content and DPPH activ- another 25 mL of methanol was added to each impacted fresh and dry biomass. There was ity of Amaranth, Celosia, Gboma, and Long sample. Samples were filtered, brought up to no significant interaction between organic Bean. a 50-mL volume with 95% methanol and amendments and species; therefore, only the thoroughly mixed. Approximately 20 mLof main effects are presented. Materials and Methods each sample was pipetted into cuvettes, fol- The main effect of fertilizer amendments lowed by 1.58 mL of deionized water, 100 mL on growth responses is shown in Table 2. Experiments were conducted in a ran- of Folin Coulteau, and 300 mLofNaCO3 and Although the fertilizer amendments did not domized complete block design with four 3 allowed to sit in the dark for 2 h. Samples were influence biomass production, there were three factorial treatment arrangement and read using a Shimadzu ultraviolet-2401 PC trends toward greater fresh and dry biomass four replications. Each replication contained ultraviolet-VIS Spectrophotometer (Shimadzu yield among plants receiving NPK or PL three plots with 10 plants each, the middle Corporation, New District Suzhou, China) treatments. Overall, however, the two organic row of which was harvested. Seeds of all four species were sown in moist commercial Jiffy Mix (Jiffy Produces of America Inc., Batavia, Table 1. Statistical significance from analysis of variance of fertilizer amendments (ORAMD), species, IL) medium in TLC Pro-Trays transplant flats and ORAMD * species for growth responses of Amaranth, Celosia, Gboma, and Long Bean. (TLC Polyform, Inc., Plymouth, MN) and Fresh biomass Dry biomass covered with 0.6 cm of the medium. Flats Ediblex Inedible Total Edible Inedible Total were placed in a greenhouse watered as Source of Variation df (kg ha–1) needed and seeds germinated within 5 to 7 d. · ORAMDy 2 NS NS NS NS NS NS Seedlings were grown for 6 weeks after z Species 2 *** *** *** *** *** *** which they were transplanted into three-row ORAMD 3 species 4 NS NS NS NS NS NS plots of 1.2 m 3 6 m at the recommended zSignificant at P = 0.0001 (***); NS = nonsignificant. plant spacing (Harrison et al., 2004; Mortley yORAMD = organic amendments (poultry litter, Megabloom—fish protein-based). et al., 1992) for each species and moisture xEdible (leaves for Amaranth, Gboma, and Celosia and pods for Long Bean); Inedible (lignified stems and supplemented with drip irrigation. roots at final harvest).
HORTSCIENCE VOL. 48(6) JUNE 2013 769 amendments were equally as effective as NPK Table 2. Main effect of fertilizer amendments on growth responses of Amaranth, Celosia, Gboma, and in the trends toward higher production. The Long Bean.z main effect of species on growth responses of Fresh biomass Dry biomass fresh and dry biomass yield is shown in Table 3. Edibley Inedible Total Edible Inedible Total Amaranth, Celosia, and Long Bean produced ORAMD (kg·ha–1) greater fresh and dry biomass than Gboma. Megabloomx 565 a 796 a 1361 a 174 a 128 a 303 a However, Long Bean and Celosia produced NPK 702 a 1049 a 1751 a 158 a 136 a 294 a greater inedible dry biomass compared with Poultry litter 805 a 1095 a 1907 a 178 a 166 a 345 a Amaranth and Gboma. Total dry biomass zMean separation within columns followed by the same letter are not significantly different based on least was greatest for Long Bean but similar to significant difference (0.05%). that produced by Amaranth and Celosia. yEdible (leaves for Amaranth, Gboma, and Celosia and pods for Long Bean); Inedible (lignified stems and Because there was a significant interac- roots at final harvest). tion between organic amendment and species xORAMD = organic amendments (poultry litter, Megabloom—fish protein-based). for antioxidant content, the effect of the in- NPK = nitrogen–phosphorus–potassium. teraction and not the main effects of amend- ment and species are presented (Table 4). Vitamin C content was highest among Am- Table 3. Main effect of species on growth responses of main effect of species on growth responses of aranth and Celosia plants receiving NPK Amaranth, Celosia, Gboma, and Long Bean. compared with the other two treatments, Fresh biomass Dry biomass whereas that of Gboma was higher among Edible Inedible Total Edible Inedible Total plants receiving MB. Although b-carotene Species (kg·ha–1) content was similar among Amaranth plants Amaranth 887 a 1127 a 2015 a 193 a 164 b 357 ab receiving both MB and PL and substantially Celosia 814 a 1280 a 2094 a 264 a 192 a 455 a greater than plants receiving NPK (Table 4), Gboma 372 b 540 b 911 b 60 b 75 c 111 c that of Celosia and Gboma was enhanced by Longbean 1078 a 1177 a 2471 a 292 a 275 a 567 a MB and NPK fertilizer. zORAMD = organic amendments (poultry litter, Megabloom—fish protein-based). Total phenolic content was higher among yMean separation within columns followed by the same letter are not significant based on least significant Amaranth plants receiving NPK but was difference at the 5% level. enhanced among Celosia and Gboma plants xEdible (leaves for Amaranth, Gboma, and Celosia and pods for Long Bean); Inedible (lignified stems and receiving PL (Table 4). Among Long Bean roots at final harvest). plants, however, total phenolic content was *Significant at *P = 0.01, **P = 0.001, ***P = 0.0001; NS = nonsignificant. greater among plants receiving MB or NPK fertilizer. DPPH activity was enhanced by MB, MB and NPK, or MB only among Amaranth, Table 4. Effect of interaction between species and organic fertilizer amendments on antioxidant content and capacity of Amaranth, Celosia, Gboma, and Long Bean. Celosia, Gboma, and Long Bean plants, Vitamin C b-carotene Total phenolics Antioxidant capacityy respectively. z These results show that species exerted ORAMD (mg/100 g) (mmol AAE/g) a stronger influence on yield than organic Amaranth Megabloom 156 b 91.6 a 467 b 30.6 a amendments and among the leafy greens; NPK 188 a 77.9 b 542 a 25.3 b Amaranth and Celosia produced a 39% Poultry litter 133 b 93.5 a 362 c 24.5 b greater fresh and dry biomass yield than did Significance *x **** Gboma. Although organic amendments had no significant impact on biomass production, Celosia there were trends toward a positive response Megabloom 163 b 81.1 a 400 b 30.7 a by the plants. For example, plants receiving NPK 197 a 87.9 a 420 ab 31.8 a PL produced 10% and those receiving MB Poultry litter 185 ab 54.2 b 440 a 19.8 b a 23% greater fresh biomass yield than those Significance * * * * receiving NPK. Although not measured in Gboma this study, nutrients in organic fertilizer are Megabloom 160 a 189.4 ab 200 b 77.2 a released through mineralization by soil micro- NPK 102 b 200.2 a 304 ab 68.6 a organisms (Kelly and Boyhan, 2009). Depend- Poultry litter 102 b 157.8 b 453 a 57.2 b ing on soil conditions such as pH and moisture Significance * * * * content, mineralization rates can be impacted, and it is probable that the lack of response to Longbean organic amendments in this study could be Megabloom — — 556 a 47.1 a related in part to mineralization rates result- NPK — — 592 a 37.1 b Poultry litter — — 401 b 39.8 b ing in fewer nutrients available for plant Significance — — * * uptake (Boyhan and Kelly, 2010). Although zORAMD = organic amendments (poultry litter, Megabloom—fish protein-based). we concentrated on the N (P and K) in the y2,2-Diphenyl-1-picrylhydrazyl (DPPH) percent radical scavenging quenched. organic amendments, it is worthy of note that xSignificant at *P = 0.05 and **P = 0.001. Mean separation within columns followed by the same letter are other essential nutrients are present. For exam- not significant based on least square means at the 5% level. ple, Fulhage and Pfost (2009) have reported the NPK = nitrogen–phosphorus–potassium. presence of other essential major and minor elements including sulfur, calcium, magnesium, manganese, copper, and zinc and estimated of slow mineralization rates, which proves the The antioxidant and total phenolics con- their availability ranged from 80% to 100% findings of researchers in Georgia and Florida tent as well as DPPH activity of the vegeta- during the growing season after application. that are suggesting an advantage of applying bles varied with species. For example, NPK In fact Whitmore (2007) reported that 40% 50% more organic fertilizer 14 to 20 d earlier enhanced vitamin C content and total pheno- of total N from composted PL was available than normal to compensate for these slow rates. lics in Amaranth but not b-carotene or DPPH during the first year and the remainder at the These results suggest that plant responses activity. These values for vitamin C content rate of 6% to 12% per year thereafter because would be more positive in subsequent years. exceeded the 80 to 00 mg/100 g of the
770 HORTSCIENCE VOL. 48(6) JUNE 2013 recommended daily values for an adult male Literature Cited Jaipaul, S., A. Dixit, and A. Sharma. 2010. Growth (Babalola et al., 2010). These results are in- and yield of capsicum (capsicum annum) and Abu-Zahra, T.R. 2011. Influence of agricultural consistent with those of Hornick (1989) with garden pea (pisum sativum) as influenced by practices on fruit quality of bell pepper. Pak. organic manures and biofertilizers. Indian Jour- kale and hibiscus (Muso and Ogaddiyo, J. Biol. Sci. 14:876–881. 2012) who reported lower vitamin C content nal of Agricultural Science 7:637–642. AdeOluwa, O. and O. Cofie. 2011. Urine as an Kefeli, V.L., M.V. Kalevitch, and B. Borsari. 2003. with increased N fertilization. The major alternative fertilizer in agriculture: Effects in Phenolic cycle in plants and the environment. pathway of vitamin C synthesis in plants is amaranth (Amaranthus caudatus) production. J. Cell Mol. Biol. 2:13–18. through L-galactose mediated by the enzyme Renewable Agriculture and Food Systems Kelly, W.T. and G. Boyhan. 2009. Cultural prac- L-galactose dehydrogenase (Wheeler et al., 1:1–8. tices and varieties. Commercial Pepper Pro- 1998). Therefore, the increase in vitamin C AVRDC. 2002. Vegetables are vital: Healthy diets, duction Handbook: Bulletin 1309. Cooperative content in this study could be attributable in productive farmers, strong economies. Asian Extension, The University of Georgia College Vegetable Development Center p. 29–30. of Agriculture and Environmental Sciences, part to a decrease in protein production and an Babalola, O.O, O.S. Tugbobo, and A.S. Daramola. increase in carbohydrate production (Muso Athens, GA. 2010. Effect of processing on the vitamin C Kpomblekou, A., R.O. Ankumah, and H.A. and Ogaddiyo, 2012). High vitamin C content content of seven Nigerian green leafy vegeta- Ajwa. 2002. Trace and nontrace elements in the leaves may make plants more tolerant bles. Advance Journal of Food Science and contents of broiler litter. Commun. Soil Sci. Technology 2:303–305. of stress because reducing vitamin C content Plant Anal. 33:1799–1811. Boyhan, G., R.J. Hicks, R.L. Torrance, C.M. Riner, increases susceptibility to stresses (Conklin, Larsen, E., and L. Christensen. 2005. Simple and C.R. Hill. 2010. Evaluation of poultry litter 2000). saponification method for the quantitative de- and organic fertilizer rate and source for pro- There were also species differences in termination of carotenoids in green vegetables. duction of organic short-day onions. HortTech- b-carotene content, although generally it J. Agr. Food Chem. 53:6598–6602. nology 20:304–307. Lombardi-Boccia, G., M. Lucarini, S. Lanzi, A. appears that all three amendments enhanced Carbonaro, M., M. Mattera, S. Nicoli, P. Bergano, Aguzzi, and M. Cappelloni. 2004. Nutrients and b-carotene content. For example, b-carotene and M. Cappelloni. 2002. Modulation of anti- antioxidant molecules in yellow plums (Prunus levels were similar among Amaranth plants oxidant compounds in organic vs. conventional domestica L.) from conventional and organic receiving MB and PL, whereas it was enhanced fruit (peach, Prunus persica L. pear, Pyrus by MB and NPK in Celosia and Gboma. communis L.). J. Agr. Food Chem. 50:5458– productions: A comparative study. Journal of 5462. Agriculture Food Chem. 52:90–94. Research has shown that light enhances the Masarirambi, M., P. Dlamini, P. Wahome, and T. biosynthesis of phenolics in the chloroplasts Chaires-Martinez, L., E. Monroy-Reyes, A. Bautista- Bringas, and H.A. Jimenez-Avalos. 2009. De- Oseni. 2012. Effects of chicken manure on of the cells and thus tends to accumulate in growth and yield and quality of lettuce (lactuca high amounts in the vacuoles or deposits in termination of radical scavenging activity of hydroalcoholic and aqueous extracts from bauhi- sativa L.) ‘‘taina’’ under a lath house in a semi- secondary cell walls as lignin (Kefeli at al., nia divaricata and bougainvillea spectabilis us- arid tropical environment. American-Eurasian 2003). One of the more important findings of ing the DPPH assay. Pharm. Res. 5:238–244. Journal Agriculture and Environmental Science this study is the impact of MB on increasing Chitindingu, K. 2005. Phenolic compound content 12:399–406. antioxidant capacity of all four species and in profiles antioxidant activities of amaranth. Mortley, D.G., E.G. Rhoden, and V.A. Khan. all cases equaling or exceeding the standard Journal Food Biotechnology 31:206–216. 1992. Plant spacing influences yield of veg- values for leafy vegetables (Tarwadi and Agte, Conklin, P.L., S.A. Sarascco, and S.R. Norris. etable amaranth. Acta Hort. 318:217–223. Mosha, TC., RD. Pace, S. Adeyeye, K. Mtebe, and 2003). 2000. Identification of ascorbic acid deficient H. Laswai. 1995. Proximate composition and The analysis of DPPH ability showed Arabidopsis thatiana nutrients. Genetics 154: 847–856. mineral content of selected Tanzanian vegeta- that Gboma and Longbean had a relatively bles and the effect of traditional processing on high antioxidant potential as evidenced by Davis, D. and H. Riordan. 2004. Changes in USDA food composition data for 43 garden crops. the retention of ascorbic acid, riboflavin and the reduction of the DPPH, radicals manifested 1950–1999. J. Amer. College Nut. 23:669–682. thiamine. Plant Foods Hum. Nutr. 48:235–245. by the decrease in absorbance at 516 nm. When DeMoranville, C. 1990. Fish hydrolysate fertilizer: Muso, A. and E.O. Ogaddiyo. 2012. Effect of DPPH accepts an ion donated by an antiox- Its potential role in commercial production. nitrogen fertilizer on the levels of some nu- idant compound, the DPPH is decolorized, HortScience 25:626. trients, antinutrients and toxic substances in which can be quantitatively measured from El-Moniem, F., El-Baz, Z. Salama, and H. Ali. hibiscus sabdariffa. Asian J. Crop Sci. 4:103– the changes in absorbance. It has been de- 2012. Enhancement of phenolics, flavonoids 112. termined that the antioxidant effect of plant and glucosinolates of Broccoli (Brassica olar- Odukoya, O.A., S.I. Inya-Agha, F.I. Segun, M.O. acea, var. Italica) as antioxidants in response to Sofidiya, and O.O. Ilori. 2007. Antioxidant products is mainly the result of radical scav- activity of selected nigerian green leafy vege- enging activity of phenolic compounds such organic and bio-organic fertilizers. American Journal of the Saudi Society of Agricultural tables. American J. Food Technol. 2:169–175. as flavonoids, polyphenols, tannins, and phe- Sciences 11:135–142. Orhue, E. 2010. Uptake of lead by Celosia argentea nolic terpenes (Rahman and Moon, 2007). Ferreira, I, P. Baptista, M. Vilas-Boas, and L. Barros. in the United States. Res. J. Agr. Biol. Sci. Furthermore, the antioxidant activity of the 2005. Free radical scavenging capacity and 6:103–107. phenolic compounds is mainly the result of reducing power of wild edible mushrooms from Palada, M.C., T.J. Kalb, and T.A. Lumpkin. 2006. their redox properties, which can play an northeast Portugal: Individual cap and stipe The role of AVRDC—The world vegetable important role in adsorbing and neutraliz- activity. Food Chemistry 100:1511–1516. center in enhancing and promoting vegetable ing free radicals and quenching the singlet Fulhage, C.D. and D.L. Pfost. 1994. Spreading production in the tropics. Horticulture Science and triplet oxygen (Hasan et al., 2009). Al- poultry litter without lab analysis but with soil 41:556–560. Rahman, M. and S. Moon. 2007. Antioxidant though the values for DPPH activity were tests. Dept. of Agr. Univ. of Missouri Ext. WQ222. Fulhage, C.D. and D.L. Pfost. 2009. Spreading polyphenol glycosides from the plant draba greater among plants receiving MB in partic- poultry litter with lab analysis but without soil nemorosa. Korean Chemical Society 28:827– ular, values for all species in general were tests. Dept. of Agr. Univ. of Missouri Ext. 831. consistent with the findings of others (Ferreira WQ223. Riordan, H. and D. Davis. 2005. Elevating antiox- et al., 2005). This suggests that these plants Harrison, G.W. and J.A. List. 2004. Field experi- idant levels in food through organic farming have the ability to scavenge significant quan- ments. J. Econ. Lit. XLII:1009–1055. and food processing. 2 Jan. 2011.
HORTSCIENCE VOL. 48(6) JUNE 2013 771 Schupp, J.R., H.A. Schupp and M.H. Bates. 1993. Smagula, J.M. and S. Dunham. 1995. Comparison Weibel, F. 2000. Are organically grown apples Effect of foliar applications of fish hydrolysate of fish hydrolysate and inorganic fertilizers for tastier and healthier? Acta Hort. 517:417–426. fertilizer or urea on apple yield and quality. lowbush blueberry. HortScience 30:187. Wheeler, G.L., M.A. Jones, and N. Smirnoff. 1998. HortScience 28:254. Sousa, C., P. Valentao, J. Rangel, G. Lopes, J.A. Pereira, The biosynthetic pathway of vitamin C in Scott, K. 2001. Detection and measurement of F. Ferreres, R.M. Seabra, and P.B. Andrade. 2005. higher plants. Nature 343:365–369. carotenoids by UV/VIS spectrophotometry. Influence of two fertilization regimens on the Whitmore, A. 2007. Determination of the miner- Current Pro. Food Anal. Chem. F2.2.1–F2.210. amounts of organic acids and phenolic com- alization of nitrogen from composted chicken Seal, T. 2011. Determination of nutritive value, pounds of tronchuda cabbage (Brassica oleracea manure as affected by temperature. Nutri Cyc. mineral contents and antioxidant activity of L. Var. DC). J. Agr. Food Chem. 53:9128–9132. in Agro. 77:225–232. Tarwadi, K. and V. Agte. 2003. Potential of com- some wild edible plants from Meghalaya State, Young, J.E., X. Zhao, E.E. Carey, R. Welti, S. monly consumed green leafy vegetables for their Yang, and W. Wang. 2005. Phytochemical India. Asian J. Applied Sci. 4:238–246. antioxidant capacity and its linkage with the Singleton, V. L., R. Orthofer, and R.M. Lamuela- micronutrient profile. International Journal of phenolics in organically grown vegetables. Raventos. 1999. Analysis of total phenols and Food Science and Nutrition 54:417–425. Molecular Nutrition Food Research 49:1136– other oxidation substrates and antioxidants by Toor, R.K., G.P. Savage, and A. Heeb. 2006. 1142. means of Folin-Ciocalteu reagent. Meth. Enz. Influence of different types of fertilizers on Zhao, X., E.E. Carey, J.E. Young, W. Wang, and 299:152–178. the major antioxidant components of tomatoes. T. Iwamoto. 2007. Influence of organic fertil- Slinkard, K. and V.L. Singleton. 1977. Total phenol Journal Food Composition Analysis 19:20–27. ization, high tunnel environment, and postharvest analysis: Automation and comparison with man- United States Pharmacopoeia. XX (Twentieth Re- storage on phenolic compounds in lettuce. ual methods. Amer. J. Enol. Viticult. 28:49–55. vision). 1980. Mack Co., Easton, PA. p. 55. Horticulture Science 42:71–76.
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