scholarly journals Humic Acid Promotion of Root Development on Euphorbia pulcherrima Cuttings

HortScience ◽  
1997 ◽  
Vol 32 (3) ◽  
pp. 477A-477
Author(s):  
James N. Smith ◽  
Michael R. Evans

Vegetative 6-cm Euphorbia pulcherrima `Freedom' cuttings were placed in black 200-ml bottles containing humic acid solutions, nutrient solutions, or deionized water. Humic acid solutions were prepared using Enersol SC (American Colloid, Arlington Heights, Ill.). Concentrations of 500, 750, and 1000 mg/L humic acid were compared to solutions containing mineral element concentrations equivalent to those contained in humic acid solutions. After 4 weeks, 88%, 75%, and 88% of cuttings had rooted in the 500, 750, and 1000 mg/L humic acid solutions, respectively. Cuttings placed in nutrient controls or deionized water failed to form roots after 4 weeks. Average root fresh mass was 175, 80, and 72 mg for cuttings placed in 500, 750, and 1000 mg/L humic acid solution, respectively. Average number of roots formed per cutting ranged from 21 in the 500-mg/L solution to 6 in the 1000-mg/L solution. Average lengths ranged from 26 mm in the 500-mg/L to 12 in the 1000-mg/L solution. As humic acid concentration increased, average root fresh mass, average number of roots, and the length of the longest root significantly decreased.

HortScience ◽  
1997 ◽  
Vol 32 (3) ◽  
pp. 438B-438
Author(s):  
Jack A. Hartwigsen ◽  
Michael R. Evans

Cucumis sativus (cucumber), Pelargonium × hortorum (geranium), Tagetes patula (marigold), and Cucurbita pepo (squash) seed were sown into plug cells (5 ml volume) filled with a germination substrate containing peat, vermiculite, and perlite. After the seed were sown, the substrate was saturated with solution containing 0 (deionized water) 2500, or 5000 mg/L humic acid (HA). Additional treatments included seed which were sown into the substrate and saturated with nutrient solutions corresponding to the nutrient concentration of each humic acid solution. Seed were placed in a growth chamber and maintained at 22°C and under a 12-h photoperiod with a PPF of 275 μmol·m–2·s–1. After 10 d for cucumber and squash and 14 d for marigold and geranium, plants were harvested and root and shoot fresh mass recorded. Shoot fresh mass was not significantly affected by treatment for any of the species tested. Except for squash, root fresh mass was significantly increased by humic acid treatments. For cucumber, root fresh mass ranged from 0.24 g in deionized water to 0.34 g in 2500 and 5000 mg/L HA. Geranium root fresh mass ranged from 0.03 g in deionized water and 5000 mg/L HA to 0.05 g in 2500 mg/L HA. Marigold root fresh mass ranged from 0.02 g in deionized water to 0.03 g in 2500 and 5000 mg/L HA. Root fresh mass for nutrient controls were similar to those for deionized water.


HortScience ◽  
1996 ◽  
Vol 31 (4) ◽  
pp. 632e-632
Author(s):  
Jack A. Hartwigsen ◽  
Michael R. Evans

Seed of Cucumis sativus and Pelargonium ×hortorum were imbibed for 24 hours in solutions containing 0 (deionized water), 2500, 5000, 10,000, and 20,000 ppm humic acid. Additional treatments included seed which were imbibed in nutrient solutions corresponding to the nutrient content of each humic acid solution as well as an untreated dry control. Percent germination was reduced for geranium seed imbibed in 20,000 ppm humic acid and for cucumber seed imbibed in either 20,000 ppm humic acid or the corresponding nutrient control. Root fresh weights for untreated and water imbibed geranium seed were 0.05 g. Humic acid treatment increased root fresh weights to a maximum of 0.14 g at 5000 and 10,000 ppm. Shoot fresh weights for geranium were 0.12 and 0.10 g for untreated and water imbibed seed, respectively. Humic acid treatment increased shoot fresh weight to a maximum of 0.18 at 2500 ppm. Root fresh weights for cucumber were 0.16 and 0.18 g for untreated and water imbibed seeds, respectively. Humic acid treatment increased root fresh weight to a maximum of 0.33 g at 10,000 ppm. Shoot fresh weights for cucumber were 0.31 and 0.38 g for untreated and water imbibed seed, respectively. Humic acid treatment increased shoot fresh weight to a maximum of 0.43 at 10,000 ppm.


2003 ◽  
Vol 51 (1) ◽  
pp. 65-74 ◽  
Author(s):  
Juan de Dios García López-Durán ◽  
Asmae Khaldoun ◽  
Mohamed Larbi Kerkeb ◽  
María del Mar Ramos-Tejada ◽  
Fernando González-Caballero

Coatings ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 405
Author(s):  
Marlon L. Mopon ◽  
Jayson S. Garcia ◽  
Dexter M. Manguerra ◽  
Cyril John C. Narisma

Sulfuric acid anodization is one of the common methods used to improve corrosion resistance of aluminum alloys. Organic acids can be added to the sulfuric acid electrolyte in order to improve the properties of the anodized aluminum produced. In this study, the use of gallic acid as an additive to the sulfuric acid anodization of AA1100 was explored. The effect of varying anodization current density and gallic acid concentration on the properties of anodized aluminum samples was observed using electrochemical impedance spectroscopy, linear polarization, and scanning electron microscopy. It was observed that the corrosion resistance of samples anodized in gallic-sulfuric acid solution at 10 mA·cm−2 is lower than samples anodized in sulfuric acid. It was also observed that higher anodization current density can lead to lower corrosion resistances for aluminum samples anodized in gallic-sulfuric acid solution. However, samples anodized at 5 mA·cm−2 and at a gallic acid concentration of 5 g·L−1 showed better corrosion performance than the samples anodized in sulfuric acid only. This suggests that the use of low amounts of gallic acid as an additive for sulfuric acid anodization can lead to better corrosion resistances for anodized aluminum.


2016 ◽  
Vol 680 ◽  
pp. 392-397
Author(s):  
Zhu Ding ◽  
Meng Xi Dai ◽  
Can Lu ◽  
Ming Jie Zhang ◽  
Peng Cui

Magnesium phosphate cements (MPC) had been used as repair materials for deteriorated Portland cement concrete structures. In this paper a new MPC was prepared and the basic properties including workability and compressive strength were tested. The acid attack resistance of MPC was investigated by immersing the MPC mortars in solutions at pH 3, 5, and 7, for 14d, 28d and 60d respectively. The compressive strength of MPC mortars after acid attack was tested and the microstructure of MPC were examined. The results showed that the compressive strength of MPC decreased after immersion in acid solution for 14d and 28d, however the strength of MPC with suitable materials mixture can recovered again after 60d immersion. The results indicated MPC has high acid attack resistance in static acid solution. The behavior of MPC in flowing acid solutions is need to be studied further.


1957 ◽  
Vol 35 (5) ◽  
pp. 428-436 ◽  
Author(s):  
T. J. Hardwick

Identical values of the bimolecular rate constant of the ferrous ion – hydrogen peroxide reaction were obtained from intercomparisons of the methods previously used in following this reaction. In perchloric acid the bimolecular rate constant is unaffected by acid concentration; in sulphuric acid it increases slightly in acid concentrations above 10−2N. The results agree with and explain the differences between those obtained by Baxendale and by Dainton, but are only in marginal agreement with those recently reported by Weiss.


2008 ◽  
Vol 58 (6) ◽  
pp. 1193-1198 ◽  
Author(s):  
S. Vinitnantharat ◽  
W. Chartthe ◽  
A. Pinisakul

Textile wastewater normally has a visible color although it has low concentration. This may affect the aquatic ecosystem. Two dyestuffs, Reactive Red 141 (RR141) and Basic Red14 (BR14) were used as compound models. RR 141 is an anionic dye which has a big molecule whereas BR 14 is a cationic dye and has a small molecule. The target organisms for toxicity test were green algae (Chlorella sp.) and waterfleas (Moina macrocopa). The effect of humic acid on the toxicity of dyestuffs to test organisms was also investigated. From the observation of cell counts, Chlorophyll a and dry weight of algae in the dye solutions for 4 days, it was found that all parameters increased as times increased. This revealed that algae could utilize dyestuffs as a carbon source. However, BR14 gave higher absorbance than RR141 at the wavelength of 430 nm which competed to the Chlorophyll a for algal photosynthesis. This resulted in the 96-h EC50 of BR14 and RR141 to Chlorella sp. were 10.88 and 95.55 mg/L, respectively. As for dye toxicity to waterfleas, the 48-h LC50 of BR14 and RR141 to waterfleas were 4.91 and 18.26 mg/L, respectively. The high toxicity of BR14 to waterfleas related to the small molecule of dye could pass into the cell and was absorbed by organelles of waterfleas. Toxicity of BR14 in humic acid solution to Chlorella sp. showed less toxic than RR141 in humic acid solution. This dues to the negative charge of humic acid could bound with a positive charge of BR14, resulted in low amount of BR14 remaining in the bulk solution. The toxicity of BR14 and RR141 in humic acid solution to waterfleas was increased as humic acid increased. Hence, the proper treatment of textile wastewater to yield low concentration of dyes in the effluent before discharging to the natural water is needed.


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