Browsing by Author "Gerochi, Dante D."
Comparison of the silo and broadcast methods of applying organic fertilizer in milkfish, Chanos chanos (Forsskal), ponds The efficacy of the silo and broadcast methods of applying organic fertilizers in ponds for the production of pond-floor, microbenthic biological complex, a natural food source known as lablab, was tested in 1-ha ponds, replicated thrice in time. Although there were no statistically significant differences (P > 0.05) in milkfish growth, survival and production between the two treatments tested, after 90 days production tended to be higher in ponds prepared with the silo method. Advantages of the silo method are that it is less laborious, cheaper, and less time consuming than the broadcast method and results in consistent lablab growth until the end of the culture period.
ArticleAT Triño, EC Bolivar & DD Gerochi -
International Journal of Tropical Agriculture, 1993 - Serials PublicationsThe effects of burning the varying amounts of dried rice straw on snails and soil properties in brackishwater ponds in the Philippines were evaluated. Cerithium tenellum, Telescopium telescopium and other unidentified snail species present in a drained brackishwater ponds were exposed to heat by burning 1.3, 2.7, and 4.0 kg dried rice straw piled 5, 10, and 15 cm thick in nine 1 m2-plot. While T. telescopium and the unidentified snail species were killed (100%) in all the treatments, C. telellum mortality ranged fro 83±3.75 percent in plots with 1.3 kg straw. The chemical properties of the soil after burning the straw revealed a decrease in the organic matter and available phosphorous and increase in the available iron and potassium. There was no effect of burning on soil pH. The acetate soluble sulfate decreased with 1.3 kg of straw and increased with the higher amounts of straw.
ArticleFF Catedral, DD Gerochi, AT Quibuyen & CM Casalmir -
SEAFDEC Aquaculture Department Quarterly Research Report, 1977 - Aquaculture Department, Southeast Asian Fisheries Development CenterP. monodon larvae were studied for the effects of temperature, ammonia, and nitrite on survival. Toxicity levels of nitrite were found to vary with larval stage. Larvae could tolerate ammonia up to about 10 ppm, with the effect more clearly shown by the zoea stage. Survival and growth were not significantly affected by temperature, although moulting was enhanced at temperatures higher than 29°C. Larvae of P. monodon have lower tolerance toward nitrite and ammonia compared to postlarvae. Although high survival was obtained at low levels of nitrite and ammonia, it is still necessary to know their effects on metabolism, in order to examine possible biochemical parameters for diagnosing sublethal toxicity or stress.
Conference paperI Bombeo-Tuburan & DD Gerochi - In JV Juario & LV Benitez (Eds.), Seminar on Aquaculture Development in Southeast Asia, 8-12 September 1987, Iloilo City, Philippines, 1988 - Aquaculture Department, Southeast Asian Fisheries Development CenterThis paper reviews the results of studies on the pond culture of milkfish Chanos chanos Forsskal at the SEAFDEC Leganes Brackishwater Station, Leganes, Iloilo since its establishment in 1973. Substantial contribution on the nursery system includes increased stocking density and survival through the use of nylon substrates, supplemental feeding with rice bran, the use of hatchery-reared and stunted fingerlings as alternative sources of stocks, and improvements in the acclimation process. Studies on monoculture and polyculture in grow-out ponds investigated the use of stunted fingerlings, kitchen or algal nursery ponds, stock manipulation techniques, increased stocking density using the plankton method, method frequency and quantity of fertilization, modular pond culture system, and initial findings on fish diseases. Constraints setting back increased production in the Philippines are discussed.