Fertilizing fish ponds: III. Growth of Mugil capito in Egypt by pond fertilization and feeding

The possibility of increasing the growth rate of M. capito fry by using supplemental artificial food and different fertilizers in seven ponds at Mex Experimental Station, Alexandria, is discussed. Growth was indicated by an increase in the length and weight of the fish.The experiment demonstrated different patterns of growth of M. capito. The best growth rates for the adolescent fish are achieved by using supplemental artificial food composed of powdered blood and flour. The next best results are obtained with the cheaper cotton seed cake and rice bran. The increase in the growth rate of the fish in the ponds fertilized with superphosphate and superphosphate plus nitrate, is lower for the 6–12-month-old fish, while it is highest from the fry stage until 6 months of age. Obviously there is a considerable difference between the treated and untreated ponds.     

Contributions to the biology of penaeid prawns in Lake Manzalah,Egypt. I. Growth studies and length-weight relationship

Some aspects of the biometrics of Metapenaeus stebbingi, M. monoceros and Penaeus trisulcatus in the brackishwater Lake Manzalah are studied.M. stebbingi dominated the catch all over the lake from December 1966 to June 1967 followed by M. monoceros. The lowest percentage was that of P. trisulcatus which dominated the catch in the northeastern and western parts of the lake in the period September–December. M. monoceros dominated the catch in the northwestern area in the same period. The relation of this distribution to the nature of the lake bottom, chemical composition of the sediment and salinity variations are discussed.Age and growth studies showed that P. trisulcatus has an average monthly growth of 10 mm, and that the fishery is supported by the 0-year class. For M. monoceros an approximate growth of 5 mm/month was observed and it was concluded that the 2-year age group supported the fishery of this species.For M. stebbingi an approximate growth rate of 2–4 mm/month was observed and it was concluded that the I+ and II+ age groups constitute the catch.The growth studies show that P. trisulcatus and M. monoceros spawn during spring, while the peak of the spawning season for M. stebbingi is in the autumn. A close relationship was found between the seasonal variations in the rate of increase of prawn weight and the spawning season.The study included the distribution of the different species and length groups in the different parts of the lake.     

Relationships between biochemical attributes (non-structural carbohydrates and phenolics) and natural durability against fungi in dry teak wood (Tectona grandis L. f.)

• Introduction   

Non-structural carbohydrates and phenolic compounds are implicated in the natural durability of wood. In order to find the chemical traits of natural durability in teak wood, the radial distribution of phenolics compounds and non-structural carbohydrates were studied in trees ranked by contrasting natural durability class against Antrodia sp.     

Effect of fermentation on sorghum protein fractions and in vitro protein digestibility

Changes in pH, titratable acidity, total soluble solids and proteins ofDabar sorghum (Sorghum bicolor (Linn) Moench.) during naturalfermentation at 37 ^°C for up to 36 h were monitored. The pH ofthe fermenting material decreased sharply with a concomitant increase in the titratable acidity. Total soluble solids increased with progressivefermentation time. The crude protein and non-protein nitrogen slightlyincreased during the last stages of fermentation. The in vitroprotein digestibility markedly increased as a result of fermentation.The globulin plus albumin fractions increased significantly (p 0.05)during the first 8 h of fermentation. Kaffirin fraction decreasedduring the first 8 h of fermentation but increased sharply as fermentationprogressed. Cross-linked kaffirins fluctuated during the fermentationprocess. Glutelin like protein, which was the minor fraction, trueglutelins, the second most abundant fraction, together with non-extractableproteins fluctuated during the fermentation process.     

Growth and flowering of black iris (Iris nigricans Dinsm.) following treatment with plant growth regulators

The effects of application method and concentration of gibberellic acid (GA₃), paclobutrazol and chlormequat on black iris performance were assessed. Plants (10 cm high, 4 ± 1 leaves) were sprayed with 125, 250, 375 or 500 mg L⁻¹ or drenched with 0.25, 0.5, 1 or 2 mg L⁻¹ GA₃. In a second experiment, the plants were sprayed with 100, 250, 500 or 1000 mg L⁻¹ or drenched with 0.25, 0.5, 1 or 2 mg L⁻¹ paclobutrazol. Other plants were sprayed with 250, 500, 1000 or 1500 mg L⁻¹ or drenched with 100, 250, 375 or 550 mg L⁻¹ chlormequat. In each experiment, the control treatment consisted of untreated plants. Results indicated that the tallest plants (37.3 cm) in the GA₃ experiment were those sprayed with 250 mg L⁻¹. The most rapid flowering (160 days after planting) occurred when a 375 mg L⁻¹ GA₃ spray was used, whereas flowering was delayed to 200 days using 1 mg L⁻¹ GA₃ drench. Drenching with 1 mg L⁻¹ GA₃ increased height of the flower stalk by 7 cm compared to the control. Though relatively slow to flower, plants drenched with 1 mg L⁻¹ GA₃ had long and rigid stalks, which were suitable as cut flowers. Number and characteristics of the sprouts were not affected by GA₃. All paclobutrazol sprays resulted in leaf falcation. A 500 or 1000 mg L⁻¹ paclobutrazol spray resulted in severe and undesirable control of plant height, drastic reduction in stalk height and weight, and delayed flowering. Plants drenched with 0.25 or 1 mg L⁻¹ paclobutrazol were suitable as pot plants. Chlormequat reduced plant height only at the highest drench concentration, which also reduced flowering to 70%. No leaf falcation was observed with GA₃ or chlormequat. Chemical names: ( ± )-(R*,R*)-beta-((4-chlorophenyl)methyl)-alpha-(1,1,-dimethylethyl)-1H-1,2,4,-triazol-1-ethanol (paclobutrazol); (2-chloroethyl) trimethylammonium chloride (chlormequat).     

Wastewater Re-Use for Croton in Substrates Amended with Zeolitic Tuff

ABSTRACT

Treated wastewater was compared with tap water for irrigation of croton (Codiaeum variegatum Blume cv. ‘Petra’) in substrates consisting of 1 peat moss: 1 perlite (PP) or 1 soil: 1 sand (SS), alone or supplemented with zeolitic tuff at a ratio of 3:1 (PPZ and SSZ). Substrates were allowed to reach 80% of available water before the plants were irrigated with wastewater or tap water. Results indicated that neither water quality nor substrate affected plant width, leaf area, shoot fresh weight, or root length or weight. Wastewater increased stem diameter; node and leaf number; tissue nitrogen (N); sodium (Na); and chloride (Cl); substrate electrical conductivity (EC); phosphorus (P); Na, Cl, and leachate EC; and concentrations of Na, Cl, NO₃ ^?, and NH₄ ⁺. Root count, tissue Na, substrate potassium (K) and Na, and leachate pH were higher for zeolite-containing substrates. Shoot dry weight and tissue contents of N and P were the highest for wastewater-irrigated PP and PPZ. Wastewater-irrigated plants in PP and tap water-irrigated plants in PPZ exhibited the highest K content. The highest level of tissue Cl was recorded for SS. Tap water-irrigated PPZ had the highest pH and K concentration. Wastewater-irrigated PP, PPZ, and SS exhibited the highest contents of N, Na, and Cl, respectively. Based on the results, amendment of the substrate with zeolitic tuff is recommended to offset the adverse effect of salinity associated with wastewater.     

Extraction, characterization, and nematicidal activity of chitin and chitosan derived from shrimp shell wastes

Chitin has been chemically extracted from the Egyptian shrimp shell waste. The obtained chitin was transformed into the more soluble chitosan. Chitin and chitosan were characterized using Fourier-transform infrared spectroscopy and proton nuclear magnetic resonance spectrometry. These products were also characterized by their nematicidal potential against the root-knot nematode, Meloidogyne incognita, infecting tomato in a glasshouse. Chitin or chitosan was incorporated into the soil at the rate of 1, 3, 5, and 10 g/kg, and their nematicidal activity was compared with that of the synthetic nematicide oxamyl at the rate of 0.01 g a.i./kg. The effects of the treatments on the growth of tomato were also examined. The obtained results show that chitin and chitosan reduced tomato root galls and J₂ of M. incognita in the soil in a dose-dependent manner. Chitosan was more effective in the reduction of galls and J₂ in the soil than chitin. However, the efficacy of chitin and chitosan in reducing the number of J₂ in the soil was less than that of oxamyl. As compared to the untreated inoculated plants, the length of shoots and roots was significantly (p ≤ 0.05) increased in soil amended with either chitin or chitosan, whereas both treatments did not significantly (p > 0.05) differ with respect to the inoculated control on the effect on the dry weight of shoot and root systems. Furthermore, neither chitin nor chitosan treatments at the tested rates were phytotoxic to tomato plants.     

Anxiolytic-Like Effect of a Salmon Phospholipopeptidic Complex Composed of Polyunsaturated Fatty Acids and Bioactive Peptides

A phospholipopeptidic complex obtained by the enzymatic hydrolysis of salmon heads in green conditions; exert anxiolytic-like effects in a time and dose-dependent manner, with no affection of locomotor activity. This study focused on the physico-chemical properties of the lipidic and peptidic fractions from this natural product. The characterization of mineral composition, amino acid and fatty acids was carried out. Stability of nanoemulsions allowed us to realize a behavioral study conducted with four different tests on 80 mice. This work highlighted the dose dependent effects of the natural complex and its various fractions over a period of 14 days compared to a conventional anxiolytic. The intracellular redox status of neural cells was evaluated in order to determine the free radicals scavenging potential of these products in the central nervous system (CNS), after mice sacrifice. The complex peptidic fraction showed a strong scavenging property and similar results were found for the complex as well as its lipidic fraction. For the first time, the results of this study showed the anxiolytic-like and neuroprotective properties of a phospholipopeptidic complex extracted from salmon head. The applications on anxiety disorders might be relevant, depending on the doses, the fraction used and the chronicity of the supplementation.     

A review on South Asian wheat blast: The present status and future perspective

The outbreak of wheat blast (Pyricularia oryzae, syn. Magnaporthe oryzae) in Bangladesh and India in recent times is a cause of grave concern for future wheat production in South Asian countries. In this review, we focus on the origin and pathology of P. oryzae and its current status and impact on trade of wheat in South Asia. We also consider future directions for efficient detection, monitoring, forecasting, and managing this destructive disease. Proper detection and monitoring are essential for imposing disease management strategies. Cutting-edge tools such as geospatial modelling and remote sensing technologies based on field observation will be pivotal to efficiently contain and manage the disease. Strong quarantine regulations too are critical in preventing the pathogen movement and are also discussed within. Complementary approaches, such as the induction of systemic resistance by applying plant growth-promoting rhizobacteria or probiotic bacteria, are also considered here. This review provides a comprehensive summary on the status of wheat blast in South-East Asia and will provide an important resource for wheat blast research in the affected areas.