Imperata cylindrica (Cogongrass) as an Adsorbent for Methylene Blue Dye Removal: Process Optimization

A novel sorbent, chitosan-immobilized pumice, has been prepared for the sorption of As(V) from waters prior to its determination by hydride generation atomic absorption spectrometry. The success of the immobilization has been checked with such characterization techniques as scanning electron microscopy, thermal gravimetric analysis, and elemental analysis. Points of zero charge of the sorbents were determined with potentiometric mass titration. Batch-type equilibration studies have shown that the novel sorbent can be employed at a wide pH range resulting in quantitative sorption (>90 %) at pH 3.0–7.0 and greater than 70 % sorption at pH >8.0. These results demonstrate the advantage of immobilizing chitosan onto pumice, because, under the same conditions, pumice displays <20 % sorption toward As(V), whereas chitosan gives approximately 90 % sorption only at pH 3.0. The validity of the method was verified through the analysis of ultrapure, bottled drinking, and tap water samples spiked with arsenate; the respective sorption percentages of 93.2 (±0.7), 89.0 (±1.0), and 80.9 (±1.3) were obtained by batch-type equilibration. Arsenic sorption was also examined in the presence of common interfering ions resulting in competing effects of PO₄ ^3? and NO₃ ^? on As(V) adsorption.     

GLUE algorithm capability in estimating the van Genuchten soil–water characteristic parameters and their uncertainties

Paddy and Water Environment - Uncertainty in the model’s structure, parameters, and input data can be viewed as the three primary sources of hydrological models failure; hence, doing an...     

Control of fruit-flies (Dacus spp.) by attractants of plant origin

Four dominating species of fruit-fliesDacus zonatus, D. cucurbitae, D. dorsalis andD. ciliatus are widely distributed throughout Pakistan. They cause heavy damage to ripe and semi-ripe fruits and vegetables annually in our country. A natural attractant of plant origin, i.e., from Tulsi (Ocimum sanctum L.) was isolated and extracted in PCSIR Laboratories Complex, Karachi, with a view to applying for the control of fruit-flies. Different extracts of roots, stems, flowers, seeds, bark, and leaves were prepared in chloroform, acetone, ethylene chloride, ethanol, and ethyl acetate; and were tested for trapping fruit-flies in specially designed traps under different field conditions. A cotton pad (0.3 mg) treated with 0.25 ml of leaves extract in ethyl acetate is found to be a potent attractant for luring and trapping the fruit-flies (Dacus spp.) from a distance of 0.8 km. Methyl eugenol used as a standard attractant also gave the same results.     

Laboratory and field evaluation of the pathogenicity of entomopathogenic nematodes to the red palm weevil, Rhynchophorus ferrugineus (Oliv.) (Col.: Curculionidae)

Ten Egyptian and imported entomopathogenic nematodes were evaluated for their pathogenicity to R. ferrugineus in both the laboratory and the field. In the laboratory, most nematodes were pathogenic to the pest larvae, pupae and adults. Larvae and adults were more susceptible to nematode infection (mostly 100?% mortality) than pupae enclosed in their cocoons. In the field however, the highest insect larval mortality was 66.67?% and most of nematodes failed in controlling the pest. Such failure could be due to hot weather, the tunnelling behaviour of the pest larvae and the too much sap in the infested sites in the trunks of palm trees.     

Selecting the ideotype of improved rice cultivars using multiple regression and multivariate models

ABSTRACT

Plant breeders require a classification of the limitations and the capabilities that exist in plants by appropriate statistical methods; this issue leads to the concept of the ideotype. Therefore, the aim of this research was to determine the ideotype of improved rice cultivars. The experiment was carried out based on a randomized complete blocks design with three replications and 13 improved rice cultivars in northern Iran in 2016 and 2017, the required data for determining ideotype was collected. The results demonstrated that the optimal values of six important traits which selected by the multiple regression model explained 64% of the paddy yield (PY). The determined ideotype would increase PY from 6,623 kg ha^?1 to 8764–9685 kg ha^?1. Selection of desirable phenological traits revealed the highest correlation with the first canonical variable, can cause of selection of superior cultivars with the best agronomic traits. The most genetic distance was observed between cv. ‘Kados’, ‘Shiroodi’ and ‘Dasht’ using mahalanobis method. It was concluded that the methods used in this study, owing to its concern with the genetic variations between cultivars, can be used in determining plant ideotypes in conjunction with other methods and it can guide plant breeders to move through ideotype crops.     

Effects of extrusion temperature and dwell time on aflatoxin levels in cottonseed

Cottonseed is an economical source of protein and is commonly used in balancing livestock rations; however, its use is typically limited by protein, fat, gossypol, and aflatoxin contents. Whole cottonseed was extruded to determine if the temperature and dwell time (multiple stages of processing) associated with the process affected aflatoxin levels. The extrusion temperature study showed that aflatoxin levels were reduced by an additional 33% when the cottonseed was extruded at 160 degrees C as compared to 104 degrees C. Furthermore, the multiple-pass extrusion study indicated that aflatoxin levels were reduced by an additional 55% when the cottonseed was extruded four times as compared to one time. To estimate the aflatoxin reductions due to extrusion temperature and dwell time, the least mean fits obtained for the individual studies were combined. Total estimated reductions of 55% (three stages of processing at 104 degrees C), 50% (two stages of processing at 132 degrees C), and 47% (one stage of processing at 160 degrees C) were obtained from the combined equations. If the extreme conditions (four stages of processing at 160 degrees C) of the evaluation studies are applied to the combined temperature and processing equation, the resulting aflatoxin reduction would be 76%.     

Aflatoxin and fumonisin contamination of commercial corn (Zea mays) hybrids in Mississippi

Resistance to mycotoxin contamination was compared in field samples harvested from 45 commercial corn (maize) hybrids and 5 single-cross aflatoxin-resistant germplasm lines in years with high and moderate heat stress. In high heat stress, mycotoxin levels were (4.34 +/- 0.32) x 10(3) microg/kg [(0.95-10.5 x 10(3) microg/kg] aflatoxins and 11.2 +/- 1.2 mg/kg (0-35 mg/kg) fumonisins in commercial hybrids and 370 +/- 88 microg/kg (140-609 microg/kg) aflatoxins and 4.0 +/- 1.3 mg/kg (1.7-7.8 mg/kg) fumonisins in aflatoxin-resistant germplasm lines. Deoxynivalenol was detected (one-fourth of the samples, 0-1.5 mg/kg), but not zearalenone. In moderate heat stress, mycotoxin levels were 6.2 +/- 1.6 microg/kg (0-30.4 microg/kg) aflatoxins and 2.5 +/- 0.2 mg/kg (0.5-4.8 mg/kg) fumonisins in commercial hybrids and 1.6 +/- 0.7 microg/kg (0-7 microg/kg) aflatoxins and 1.2 +/- 0.2 mg/kg (0.5-3.0 mg/kg) fumonisins in aflatoxin-resistant germplasm lines. The results are consistent with heat stress playing an important role in the susceptibility of corn to both aflatoxin and fumonisin contamination, with significant reductions of both aflatoxins and fumonisins in aflatoxin-resistant germplasm lines.     

Biocontrol of soil-borne fungal plant diseases by 2,4-diacetylphloroglucinol-producing fluorescent pseudomonads with different restriction profiles of amplified 16S rDNA

Fluorescent pseudomonads producing the antimicrobial compound 2,4-diacetylphloroglucinol (Phl) are being studied extensively for use as biocontrol agents of soil-borne fungal diseases. Some of them can produce pyoluteorin (Plt) in addition to Phl, whereas others synthesise only Phl. Here, a collection of seven Phl⁺ Plt^- pseudomonads, seven Phl⁺ Plt⁺ pseudomonads and seven Phl^- biocontrol pseudomonads were compared for protection of plant roots against fungal pathogens. The seven Phl⁺ Plt⁺ pseudomonads were identical by restriction analysis of amplified spacer ribosomal DNA (spacer ARDRA), whereas the Phl⁺ Plt^- pseudomonads and especially the Phl^- biocontrol pseudomonads were quite diverse by spacer ARDRA. Collectively, the Phl⁺ Plt^- pseudomonads proved superior to the Phl⁺ Plt⁺ pseudomonads and the Phl^- biocontrol pseudomonads for protection of tomato against Fusarium crown and root rot (in rockwool microcosms) or cucumber against Pythium damping-off (in non-sterile soil microcosms). There was no correlation between protection in vivo and inhibition of the corresponding fungal pathogen on plates. However, there was a significant correlation between the amount of Phl produced on plates and protection of tomato against Fusarium crown and root rot, but not with protection of cucumber against Pythium damping-off. Interestingly, the minority of strains unable to produce HCN, an extracellular protease, or both, were among those unable to protect plants in both pathosystems. A seedling assay was developed to compare pseudomonads for suppression of Fusarium crown and root rot in vitro, and a significant correlation was found between disease severity in vitro and in vivo. Overall, results suggest that promising biocontrol pseudomonads may be identified based on the ability to produce Phl and/or specific ARDRA-based fingerprints.