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Paddy and Water Environment - This paper revealed the irrigation rate by groundwater, evapotranspiration (ET), total water balance and yield in the experimental rice and mung bean fields in a... 相似文献
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Ronald P. Phelps Ryan Hastey Alden Pendetar Laban Linley Nikolaos Papanikos Rex A. Dunham 《Aquaculture (Amsterdam, Netherlands)》2007,273(1):80-86
Hybrid catfish (channel catfish, Ictalurus punctatus, female × blue catfish, I. furcatus, male) can be obtained by induced spawning and artificial fertilization but with variable results. Temperature of the surrounding environment affects the rates of physiological processes in fish including time to ovulation following hormone injection and time post-ovulation when quality eggs can be obtained. Brood females were held at 24, 26, and 28 °C in 100 L aquaria and injected with LH-RHa at 20 μg/kg followed 12 h later with 100 μg/kg. Fish were monitored hourly recording the time of the first egg deposit. Some females were manually stripped soon after the first eggs were observed, and the remaining females were stripped 4-6 h after the first eggs were observed. Eggs were artificially fertilized with blue catfish sperm and incubated. The percent of females that ovulated were 52.9%, 82.4% and 95.5% at 24, 26, and 28 °C (P = 0.001) respectively. The majority of females that ovulated did so between 58 to 64 h at 24 °C, 48 to 52 h at 26 °C and 24 to 40 h at 28 °C for a degree hour response time of 1405 ± 117, 1141 ± 238 and 951 ± 261 respectively (P < 0.001). Differences in eggs/kg female, eggs/g of eggs, percent viable eggs, percent hatch and survival of sac fry to swimup resulted in an average of 384.4 ± 316.97 fry/kg female at 24 °C, 370 ± 219.2/kg at 26 °C and 1284 ± 1394.1/kg at 28 °C (P = 0.136). Egg quality varied with how soon eggs were stripped after the first egg was observed. For fish held at 26 and 28 °C. the combined effects of egg quality and fry survival resulted in an average 1081 ± 1483.9 fry/kg female for fish stripped within 2 h after the first eggs were released and 500 fry/kg female when stripped after 4 or more hours once the first eggs were released. 相似文献
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Laban C. Lindley 《Journal Of Applied Aquaculture》2013,25(2):96-109
Copepod nauplii are a nutritious food item for first-feeding marine fish larvae. Unfortunately, mass culture techniques for producing copepod nauplii are not well established. Copepod nauplii can be collected from wild zooplankton populations or specially prepared ponds and transferred to larval fish tanks for feeding. This study evaluated the use of two trapping methods for harvesting zooplankton, particularly copepod nauplii, from fertilized ponds and the impact on the zooplankton population. Nine, 0.11 ha brackish-water (～2-7 ppt salinity) ponds were filled and fertilized with organic and inorganic fertilizers. The change in zooplankton abundance, mainly rotifers, nauplii and adult copepods, was monitored in the ponds for 22 d following initial pond filling. Beginning on day 8, three ponds were trapped with a large plankton net (Trap I), three with a pump and bag trap method (Trap II), and three ponds were not trapped. The ponds were trapped with the corresponding method for 1 h per day, for 15 d. The two trapping methods were similar in their efficiency to harvest nauplii, averaging 8,383,400 ± 2,508,378/h and 6,695,822 ± 433,533/h for Traps I and II, respectively. The zooplankton harvested by Trap I was not correlated to the densities in the ponds. However, the number of rotifers and nauplii harvested by Trap II was correlated to the rotifer and nauplii densities in the ponds. Both trapping methods were similar in terms of labor requirements and ease of use. Both methods were effective in collecting zooplankton without negatively impacting pond abundance. 相似文献
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Guo-Liang Jiang Laban K. Rutto Shuxin Ren Ronald A. Bowen Haley Berry Kyle Epps 《Euphytica》2018,214(9):158
Edamame, a vegetable or specialty soybean (Glycine max) with high nutritional and market value, is relatively new to North America. Because of its health and nutritional benefits and globalized trade, the edamame market and acreage in the United States are steadily increasing. To facilitate edamame breeding and commercial production, we genetically analyzed edamame seed composition using 86 breeding lines and cultivars developed in the U.S. Significant genotypic differences based on a single year or 2-year joint analysis were observed for most traits investigated, including protein, oil, dietary fiber, starch, sucrose, stachyose and total sugar content. No significant genotypic difference was observed for ash content in both years and for raffinose content in year 2016. Yearly differences were also significant except for sucrose, stachyose and total sugar. Genotype-by-year interaction was significant for protein, sucrose, raffinose and total sugar, but insignificant for other traits. The heritability was high and relatively stable for protein and oil content, followed by stachyose content, but was low for ash and starch content. The heritability for sucrose, total sugar and dietary fiber content varied from 38 to 75%. Genotypic correlations were insignificant among most traits. However, protein content was negatively correlated with oil content and dietary fiber, but positively associated with stachyose. Oil content was negatively correlated with starch and individual sugars. Although positive phenotypic or Pearson’s correlation existed between total sugar content and individual sugars, and between sucrose and starch content, their genotypic correlations were insignificant. 相似文献
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A framework for planning development strategies for sustainable land use in developing countries is proposed based on the carrying capacity concept. The rehabilitation of degraded land includes a stabilization and a restoration phase, with corresponding measures to be taken and funding modalities to be explored. Restoration measures focus on the rehabilitation of ecosystem functions, but are effective only when preceded or accompanied by measures stabilizing exploitation levels. Short-term benefits are required to ensure local participation, but may be counterproductive when long-term ecological rehabilitation is the major objective. Incentives are important policy instruments to enhance participation by rural communities in rehabilitation activities. Long-term economic, ecological and social (humanitarian) arguments, at a scale surpassing the local level, should receive more attention in the process of justifying investments for land rehabilitation. Some criteria and conditions to be met both at a macro-scale and at the local level are discussed. 相似文献
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Guillaume Drillet Laban C. Lindley Alan Michels Jeffrey Wilcox & Nancy H. Marcus 《Aquaculture Research》2007,38(5):457-466
Developing methods to store copepod eggs is necessary to increase the availability of copepods as a live food for the aquaculture industry and aquarium trade, and also to allow the exchange of copepods between researchers. The present study, evaluated the effect of glucose and two antibiotics (kanamycin sulphate and oxytetracycline HCl) on extending the shelf life of cold-stored subitaneous Acartia tonsa eggs. Also, egg development effects on the survival of the eggs were tested. Glucose did not have any significant effects on the survival of the eggs. However, the addition of antibiotics to the storage vials resulted in an increase of the survival of the eggs. In the best case, the shelf life of the eggs was almost doubled. After 7 days, the kanamycin+glucose treatment led to a hatching success of 86±1% of the hatchable eggs, while the untreated eggs presented a hatching success of 47±6%. However, long exposure to high concentrations of antibiotics was lethal to the copepod eggs. After more than 30 days of exposure to 100 mg L−1 of oxytetracycline, the survival of the eggs was lower than in the untreated samples. After 45 days, oxytetracycline-treated eggs (100 mg L−1) presented a hatching success of 4–5% while the non-stored eggs still had a hatching success of 9%, and the eggs treated with a lower concentration of antibiotics (10 mg L−1) showed a hatching success up to 21–23%. The size of the nauplii in all trials tended to decrease as the period of cold storage at 1°C increased. We consider that the use of antibiotics at the right dosage to be a means to increase the storage capacity of the Gulf of Mexico strain of A. tonsa eggs, which do not show any capacity to be stored for long periods of time, compared with some other strains. In addition eggs that were between 5 and 7 h old survived longer when stored in the cold than eggs, which were freshly spawned or closer to hatching. 相似文献
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