Growth and physiology of ornamental sunflower under salinity in function of paclobutrazol application methods

ABSTRACT The ornamental sunflower has great importance in the floriculture sector due to the color and vitality of its flowers. However, the production and quality of flowers decrease under salt stress, which can be mitigated with paclobutrazol application. The objective of the present study was to evaluate the effects of different application methods of paclobutrazol in ornamental sunflower ‘Sol Noturno’ irrigated with brackish waters. The experimental design was randomized blocks arranged in a 5 × 3 factorial scheme, corresponding to five electrical conductivities of irrigation water - ECw (0.4; 1.9; 3.4; 4.9, and 6.4 dS m-1) and three paclobutrazol application methods (foliar application, via soil and a control treatment - without paclobutrazol), with four replicates. The increase in salinity of irrigation water reduced gas exchange, photosystem II photochemical efficiency, SPAD index, plant height, and chapter diameter. The paclobutrazol application via soil or foliar increased stomatal conductance and transpiration by 21.09 and 17.80%, respectively, in comparison to plants without application, whereas photosynthesis and instantaneous carboxylation efficiency increased by 28.33 and 31.18% via soil and 14.40 and 16.12% via foliar, respectively. The paclobutrazol application, mainly via soil, favored ‘Sol Noturno’ sunflower plants under salt stress, increasing chlorophyll SPAD index and external chapter diameter, and keeping the number of the petals.

Identification of seawater intrusion in Gapura Sub-district, Sumenep Regency, East Java, Indonesia

Gapura sub-district is located in the Sumenep Regency, Madura Island, that also recognized as the center of salt production. Due to not availability of a clean water network from the municipal water network (PDAM), the daily water need of the community is provided by groundwater. Local people have reported several brackish waters in the wells since a few years ago. Therefore, the purpose of this research is to identify seawater intrusion potential in this area. The seawater intrusion is analyzed based on the value of electrical conductivity (EC) and groundwater hydrochemistry. From the analysis of EC values, it can be concluded that there are two out of thirty groundwater samples classified as moderately saline water, while in the study of groundwater ion values, both two samples have chloride values that are more than 240 mg/L. However, the Cl and HCO3 ratio show that the two samples will only have a small effect on seawater. Therefore, it can be concluded that the Gapura sub-district does not have seawater intrusion. High salinity in some wells is mostly coming from salt production in this area.

A Brief Overview of the Integrated Fish Farming of Three Commercially Popular Fish Species (Snakehead, Tilapia and Catfish) in Malaysia

Aquaculture industry in Malaysia involves culture of many fish species of either fresh or brackish water origin and among the important fish species are Snakehead, Tilapia and Catfish. There is a substantial culture of these fish in Malaysia nowadays, though there are not one hundred percent native fish species but their presence in Malaysia is getting closer to over several decades and for almost a decade now, these species had been among the highest finfish produced in either fresh or brackish waters. As the global aquaculture production continue growing in order to meet up with ever increasing fish demand, especially as fish from capture has levelled off and makes an increase in aquaculture production as the only hope to meet the demand for fish, one of suggested ways in culturing them is by venturing into integrated fish farming. Integrated fish farming of different species is a practice which links together two or more normally separate farming systems, whereby the fish from different species become subsystems of a whole farming system. Although integrated fish farming may not be huge globally based on the available official statistical data but it is becoming important industry in Malaysia and neighboring countries. This review discussed briefly about the integrated fish farming of three commercially popular species (Snakehead, Tilapia and Catfish) in Malaysia and neighboring countries.

PHYSIOLOGICAL RESPONSES OF PEANUT CROPS TO IRRIGATION WITH BRACKISH WATERS AND APPLICATION OF ORGANO-MINERAL FERTILIZERS

ABSTRACT The use of organo-mineral fertilizer is an alternative measure to mitigate salt stress in semiarid regions. Thus, the objective of this work was to evaluate the physiological indexes of peanut crops under irrigations with fresh and brackish waters and applications of organo-mineral fertilizers. The experiment was conducted from June to September, 2019, at the Universidade da Integração Internacional da Lusofonia Afro-Brasileira (UNILAB), in Redenção, state of Ceará, Brazil, using a completely randomized experimental design in a 5 × 2 factorial arrangement, with four replications. The treatments consisted of five soil fertilizers (F1= 100% NPK mineral fertilizer at the recommended rate; F2= 100% bovine manure-based biofertilizer; F3= 100% plant ash; F4= 50% mineral fertilizer and 50% bovine manure-based biofertilizer; and F5= 50% mineral fertilizer and 50% plant ash); and two salinity levels (electrical conductivities) of the irrigation water (1.0 and 5.0 dS m-1). Photosynthetic rate, transpiration, stomatal conductance, leaf temperature, internal CO2 concentration, water use efficiency, and chlorophyll index of the plants were evaluated at 40 and 54 days after sowing (DAS). Plants irrigated with fresh water presented higher stomatal conductance, photosynthetic rate, and transpiration, regardless of the fertilizer used. The use of 100% bovine manure-based biofertilizer resulted in decreases in salt stress and increases in water use efficiency at 40 DAS, and decreases in leaf temperature and increases in relative chlorophyll content at 54 DAS.

Air-nanobubbles ineffective to reduce pathogenic bacteria in fresh and brackish waters

ABSTRACTNanobubble (NB) technology has been hailed as a novel way to disinfect water. Previous studies suggested that when NBs collapse, they create shock waves that result in OH- free radicals, which can damage cells, including bacteria. In this study, we investigated, through a series of 11 experiments, the potential use of air nanobubbles (128 ± 44 nm, mean ± SD) to reduce the concentration of various pathogenic bacteria including Aeromonas hydrophila, A. veronii, Vibrio parahaemolyticus, and Streptococcus agalactiae under controlled, tank-based laboratory conditions. Despite the high number of nanobubbles continuously added to a relatively small volume of water in experimental tanks (50-100 L), we did not observe a consistent or significant decrease in bacteria that would control disease outbreaks. Although most of the experiments were conducted in fresh water on A. hydrophila, results were consistent across fresh and brackish water experiments, Gram-negative and Gram-positive bacteria, and a range of nanobubble concentrations. This study suggests air nanobubbles on their own are inadequate to significantly reduce high levels of pathogenic bacteria in water. We propose to explore other gases for improving the disinfection properties of this technology.SIGNIFICANCE STATEMENTAir nanobubbles did not sufficiently reduce the level of bacteria in laboratory experiments.

Komunitas makrozoobentos dan kaitannya dengan kualitas air aliran sungai Senggarang, Kota Tanjungpinang

Senggarang is one of the coastal villages in Tanjungpinang City which has a river that flows from the upstream downstream into the sea. The flow of the Senggarang river has distinctive characteristics that are commonly found in small island waters, namely having a relatively short upstream to downstream distance, and the downstream part is influenced by tidal conditions. Various activities along the Senggarang river flow would cause changes in water quality which would impact the presence of macrozoobenthic. The objective of this study was to determine the relationship between the macrozoobenthic community and the water quality of the Senggarang river. Macrozoobenthic sampling, and environmental parameters were carried out using random sampling methods. The results of this study were obtained 27 species from 6 phylum, namely phylum Arthropoda 13 species, phylum Ciliophora 3 species, phylum Echinodermata 1 species, phylum Mollusca 4 species, phylum Nematoda 5 species, and phylum Tardigrada 1 species. The average macrozoobenthic density is 172 ind./ m3 for freshwater and 704 ind./ m3 for brackish waters. The average diversity value for freshwater is 1.29 and 2.16 waters with medium salinity, the average uniformity value of 0.85 freshwater and 0.94 of high in brackish waters, the average dominance value of 0.32 freshwater and 0.13 of low in brackish waters. The relationship of macrozoobenthos with the quality of freshwater based on PCA analyses related to temperature and dissolved oxygen, in brackish waters to temperature, dissolved oxygen, and current.Keywords: Macrozoobenthic community, PCA, River flow, Water quality

Scientists from Zoological Museum and Zoological Institute of RAS — researchers of biological diversity and biological resources of the Caspian Sea

The origins of the study of the Caspian Sea date back to the 18th century, when the St. Petersburg Academy of Sciences was founded. The first explorers of the Caspian were academicians P.S. Pallas and S.G. Gmelin. In the 19th century, the study of Caspian fish was continued by K.E. von Baer and O.A. Grimm. Karl von Baer from 1853 to 1857 made four scientific trips to the shores of the Caspian Sea. He pioneered the fundamentals of sustainable fisheries. The main result of the expedition of K.E. von Baer — N.Ya. Danilevsky was the Charter of the Caspian fish and seal fisheries, approved by the government in 1865. According to the results of O.A. Grimm expedition 1874–1876 many new species of worms and crustaceans were discovered and it was found that from 278 species of fish, 150 are found nowhere else. The study of the biodiversity of fish and their parasite fauna in the first half of the last century was continued by scientists of the Zoological Institute N.M. Knipovich, A.N. Svetovidov, A.L. Behning, V.A. Dogel and B.E. Bykhovsky. In 2004, sciemtists of ZIN RAS published the “Catalogue of Agnathans and Fishes of Fresh and Brackish Waters of Russia with comments on nomenclature and taxonomy”, which includes valid names of taxa of agnathans and fish ranging from type to subspecies inhabiting fresh and brackish waters (up to 13 g/l) of the Azov and Caspian Seas and the freshened estuaries of the rivers of the northern and Far Eastern seas (18 orders, 43 families, 175 genera and 486 species). At present, scientists of ZIN RAS continue to study the fish resources of the Caspian Sea.

LOW-COST CONTINUOUS MEASUREMENT SYSTEM TO DETERMINE THE RELATIONSHIP BETWEEN THE ELECTRICAL CONDUCTIVITY "EC" AND THE TEMPERATURE "T" IN BRACKISH WATERS

This article presents a low-cost experimental design proposal to understand and learn the relationship between the electrical conductivity CE of brackish water and its temperature T, in which an embedded system (Arduino Nano). This design has been made to be used as good practices in subjects of the University Degrees with competences in the area of production and water treatment, both for civil and industrial consumption, mainly in the School of Engineering. Industrial and Civil of the University of Las Palmas de Gran Canaria. Furthermore, this design is mainly characterized by its versatility, when considering different situations, and using free tools and open source; both regarding computer applications, as in the components and elements used. This last aspect turns out to be an important characteristic, as it will allow the design to be modified, economically, according to future needs, by the students or by the teachers. A series of tests have been implemented with different types of common salts in brackish waters, at different temperatures. Results obtained from the design are shown, following suitable methods to observe the variability of the electrical conductivity of the solutions with the temperature, and with the type of salt used. These experimental results demonstrate that the experimental design can be used to understand and learn the proposed objective, as well as to obtain the relationship between CE and T, in the form of a straight line fit. Keywords: Electrical conductivity, reverse osmosis, water quality