Search
Search Results
-
Comparison of the technological background of aquaponic systems
47-52Views:773Aquaponics is the combined culture of fish and plants in recirculating aquaculture systems, an ecologically sustainable horticultural production technique with long traditions.
The objective of this study is to compare flood-and- drain, and the water crossflow system and examine the differences in the water quality, fish yield and plant growth parameters for Common carp (Cyprinus carpio) and basil (Ocimum basilicum). During the study, water quality parameters of two treatments were compared in temperatures, pH, EC and NO3¯N were significantly different (p <0.05). Leaf area of the basil plants grew to an average of 20.37 cm2 (± 9.02 cm2). The plants’ biomass production was significantly different (p< 0.05) in the two systems. The biomass production showed lower yield, 458.22 g (± 214.59 g) in the constant flow system that in the flood- and- drain system 692.9 g (± 175.82 g). Fish Growth parameters were better in constant flow system (FCR 5.48 g/g ± 0.19). However, the specific growth rate (SGR) demonstrated that fish grew faster in flood- and- drain system 1.38 %/day (± 0.29).
-
The effect of silver crucian carp (Carassius auratus gibelio Bloch) on the yields and the production value of common carp (Cyprius carpio) fingerlings
5-10Views:409During the last few years, the spread of the silver crucian carp has caused significant problems in pond fish culture. One of the main challenges of successful fish production in fishponds, is to rid ponds of the silver crucian carp. The nature of the damage caused by silver crucian carp is a complex question. To get into the ponds, the crucian carps occupy the territory before the common carp, and competes for food with common carp. The silver crucian carp has a less favorable food coefficient than the common carp, and it’s value is also lower. Therefore, the income of the fish farm decreases. In the course of the experiment, carp fry were stocked in 5 nursing ponds at the same stocking rate, with different (0,- 50-, 100-, 150-, 200%) stocking rates of silver crucian carp fry, respectively. At the end of the experiment, the yield/hectar and the production values were calculated. The experiment proved that the presence of the silver crucian carp in the fishponds causes lower yields and production values.
-
A morphological survey of Ustilago trichophora, a smut fungi and evaluation as bioherbicidal agent for barnyard grass (Echinochloa crus-galli)
91-93Views:325Ustilago trichophora (Link) Kunze is a widespread smut fungus in all over the world. This fungus is pathogenic on species of Echinochloa genus. The subject of present research was that smut fungi occurrence on barnyard grass (Echinochloa crus-galli). Numerous barnyard grass plants with symptoms of smut galls caused by Ustilago trichophora on stems were collected from two counties, víz. Hajdú-Bihar (East-Hungary) and Jász-Nagykun-Szolnok (Middle-Hungary). The infested plants were examined in laboratory, which included the observation of the symptoms and the morphological properties of the spores and the colonies developed from sporidia. The results suggested that this fungus could be effective against barnyard grass weed so the biological control of this weed plant (Echinochloa cruss-galli) can be managed by using Ustilago trichophora biopreparates. As Ustilago trichophora can produce abundant sporidia in liquid culture, a high effectiveness control should be apply by Ustilago trichophora smut fungus as a mycoherbicide in Echinochloa weed control.