scholarly journals Lethal concentration (CL50) of un-ionized ammonia for pejerrey larvae in acute exposure

2006 ◽  
Vol 63 (2) ◽  
pp. 184-186 ◽  
Author(s):  
Sérgio Renato Noguez Piedras ◽  
Juvêncio Luís Osório Fernandes Pouey ◽  
Paulo Roberto Rocha Moraes ◽  
Daniela Fençon Cardoso

Ammonia results from decomposition of effluents organic matter, e.g. feed wastes and fish faeces. Its un-ionized form can be toxic because diffuses easily through fish respiratory membranes, damaging gill epithelium and impairing gas exchanges. The objective of this work was determining the 96-hour CL50 of un-ionized ammonia for newly hatched pejerrey Odontesthes bonariensis larvae. Trials were set up completely randomized design, with three different concentration of un-ionized ammonia (0.57, 0.94, and 1.45 mg L-1 NH3-N) and a control treatment (n = 3). Experimental units were 20-L, aerated aquaria stocked with 20 larvae (average weight 3.9 mg). Pejerrey larvae exposed to un-ionized ammonia during 96 hours present 50% mortality at 0.71 mg L-1 NH3-N.

Agrologia ◽  
2015 ◽  
Vol 4 (1) ◽  
Author(s):  
Evawani Tomayahu

Pest is one of the biological limiting factors that led to low production of potatoes. The use of pesticides is a solution in controlling pests. The objective of this study was to determine the diversity and evenness of insect; and potato yield losses due to insecticide applications methods. The treatment was controlled and intensive insecticide application which were compared with no insecticide application.  The experiment was set up in completely randomized design with five replications. The results showed that the insects are dominated by Empoasca sp, Liriomyza sp and Miridae. The highest insect population was Empoasca sp. i.e 80.83 Empoasca sp. which was found in control treatment. Controlled and intensive  application of insecticides decreased insect  population up to 56.50 and 26.17. Evenness index of insect and economic value of lost results unaffected by differences in pesticide application methods


2020 ◽  
Vol 4 (2) ◽  
pp. 48-53
Author(s):  
Muhammad Nur Hidayat ◽  
Amina Hajah Thaha ◽  
Reny Mayanti

This study aims to determine the effect of noni leaf (Morinda citrifolia lignosae) extract as a natural disinfectant on the percentage of hatchability and the hatchability weight of quail (Coturnix-coturnix japonica). This study used 1,500 quail hatch eggs with a male and female parent ratio of 1: 4. This study used a Completely Randomized Design (CRD) method, with five treatments and three replications each repetition consisting of 100 quail eggs with 10-gram weight. The treatments used were: T0 (control treatment), T1 (commercial disinfectant), T2 (noni leaf extract 10%), T3 (noni leaf extract 20%) and T4 (noni leaf extract 30%). The results of variance showed the average percentage of hatchability produced during the study, namely T0 (85%), T1 (83%), T2 (86%), T3 (84%), and T4 (93%). Furthermore, the average weight of hatchability produced, namely T0 (6.67 grams), T1 (6.76 grams, T2 (6.89 grams), T3 (6.84 grams) and T4 (6.89 grams). Overall administration of noni leaf extract had no significant effect (P> 0.05) on the percentage of hatchability and DOQ hatching weight of the quail.


The experiment was conducted in the agriculture field of the International University of Business Agricultural and Technology (IUBAT), Dhaka, from January to June 2017 to find out the effect of different Rhizobium inoculations on soybean production. The experiment was set up in a Completely Randomized Design (CRD) with four replications. Eight Rhizobium inoculations and one control treatment were used in the study to assess the effect of different biofertilizers on soybean production. The findings of the study showed that Strain Bacteria (SB) 316 inoculant performed better in all aspects of growing parameters and yield components like nodulation, vegetative growth, and yield. However, the control treatment performed lowest in every parameter. As a result of the experiment, it could be concluded that Rhizobium inoculation has a significant effect on vegetative growth, nodulation, and yield component of soybean. The SB 316 inoculant has been found as the most effective Rhizobium inoculation in soybean production.


2019 ◽  
Vol 97 (7) ◽  
pp. 3056-3070 ◽  
Author(s):  
Emily A Petzel ◽  
Evan C Titgemeyer ◽  
Alexander J Smart ◽  
Kristin E Hales ◽  
Andrew P Foote ◽  
...  

AbstractTwo experiments were conducted to measure rates of ruminal disappearance, and energy and nutrient availability and N balance among cows fed corn husks, leaves, or stalks. Ruminal disappearance was estimated after incubation of polyester bags containing husks, leaves or stalks in 2 separate ruminally cannulated cows in a completely randomized design. Organic matter (OM) that initially disappeared was greatest for stalks and least for husks and leaves (P < 0.01), but amounts of NDF that initially disappeared was greatest for husks, intermediate for stalks, and least for leaves (P < 0.01). Amounts of DM and OM that slowly disappeared were greatest in husks, intermediate in leaves, and least in stalks (P < 0.01). However, amounts of NDF that slowly disappeared were greatest in leaves, intermediate in husks, and least in stalks (P < 0.01). Rate of DM and OM disappearance was greater for leaves, intermediate for husks and least for stalks, but rate of NDF disappearance was greatest for stalks, intermediate for leaves, and least for husks (P < 0.01). Energy and nutrient availability in husks, leaves, or stalks were measured by feeding ruminally cannulated cows husk-, leaf-, or stalk-based diets in a replicated Latin square. Digestible energy lost as methane was less (P = 0.02) when cows were fed leaves in comparison to husks or stalks, and metabolizable energy (Mcal/kg DM) was greater (P = 0.03) when cows were fed husks and leaves compared with stalks. Heat production (Mcal/d) was not different (P = 0.74) between husks, leaves, or stalks; however, amounts of heat produced as a proportion of digestible energy intake were less (P = 0.05) among cows fed leaves in comparison to stalks or husks. Subsequently, there was a tendency (P = 0.06) for net energy available for maintenance from leaves (1.42 Mcal/kg DM) to be greater than stalks (0.91 Mcal/kg DM), and husks (1.30 Mcal/kg DM) were intermediate. Nitrogen balance was greater when cows were fed leaves, intermediate for husks, and least for stalks (P = 0.01). Total tract digestion of NDF was greater (P < 0.01) for husks and leaves compared with stalks. Husks had greater (P = 0.04) OM digestibility in comparison to stalks, and leaves were intermediate. Apparently, greater production of methane from husks in comparison to leaves limited amounts of energy available for maintenance from husks even though total-tract nutrient digestion was greatest when cows were fed husks or leaves.


2021 ◽  
Vol 19 (1) ◽  
pp. 155-163
Author(s):  
S Sapkota ◽  
D Kc ◽  
H Giri ◽  
M Saud ◽  
M Basnet ◽  
...  

The present research was conducted on two factor Completely Randomized Design (CRD) with eight treatments and three replications. A set of experiments were carried out to evaluate the effect of postharvest ethephon treatment and packaging on ripening of mango cv. Maldah. The treatments consisted of ripening agent i.e., ethephon and control treatment under different packaging condition i.e., fiber with hole, fiber without hole, plastic with hole and plastic without hole. The result revealed that different packaging condition and ripening agents influenced the ripening behavior of mango. The highest TSS (15.26), sugar-acid ratio (23.66) and juice content (126.05) were recorded with fiber (without hole) and the lowest TSS (12.60), sugar-acid ratio (9.01) and juice content (116.05) with plastic (without hole). The highest TA (1.44) was recorded with plastic (without hole) and the lowest (0.66) with fiber (without hole). Similarly, the highest BT (2.83) was recorded with fiber (with hole) and the lowest (1.66) with plastic (without hole). Firmness, sweetness, TSS and juice content were the highest with the interaction effect of fiber bag (without hole) and ethephon treatment. In conclusion, mango fruits with ethephon treatment packed in fiber bag (without hole) enhances quality and ripening of mango whereas under controlled condition and without hole plastic packaging mangoes had low quality performance in terms of physio-chemical properties. SAARC J. Agric., 19(1): 155-163 (2021)


2013 ◽  
Vol 42 (1) ◽  
pp. 35-39 ◽  
Author(s):  
AR Kanak ◽  
MJ Khan ◽  
MR Debi ◽  
ZH Khandakar ◽  
MK Pikar

The experiment was conducted to study the comparison on biomass production of fodder germplasm. Para (Brachiaria mutica Stapf.), German (Echinochloa crusgalli L.) and Dhal (Hymenachne pseudointerrupta C. Muell) grasses were cultivated in a completely randomized design (CRD). The whole area was divided into nine plots. The area of each unit plot was 6 m x 6 m. Number of cuttings were 16,000 /hectare where Plant to Plant distance was 16 cm and row and raw distance was 16 cm. Equal amount of organic and chemical fertilizer were applied in all cutting. The fodders were first harvested after 60 days of planting, second and third after successive 60 days of re-growth. The findings of the study showed that fresh biomass (p<0.01) and dry biomass yield (p<0.05) of three fodder germplasm differed significantly. Crude protein and organic matter yield were significant (p<0.01) only in the second cutting. German grass was showed significantly higher in CP and OM yield (p<0.01) at second cutting than other grasses. However, no significant effect on plant height was observed among three grasses. From the above findings it may be concluded that among the three fodder germplasm, German fodder showed best result in respect of biomass production. DOI: http://dx.doi.org/10.3329/bjas.v42i1.15772 Bang. J. Anim. Sci. 2013. 42 (1): 35-39


Author(s):  
Andressa C. Neves ◽  
Camila N. Bergamini ◽  
Rafaela de O. Leonardo ◽  
Manoel P. Gonçalves ◽  
Dilcemara C. Zenatti ◽  
...  

ABSTRACT This study aimed to evaluate the effect of applying increasing doses of biofertilizer obtained by the anaerobic digestion of cassava effluent on the development of crambe plants. The experiment was conducted in a protected environment at the Federal University of Paraná (UFPR), Palotina Sector, between April and August 2015. A completely randomized design was used, and five different treatments with the following doses were applied in five replicates: 0, 40, 80, 120, and 160 kg ha-1 of K2O. The following parameters related to plant development were evaluated: final height, stem diameter, number of branches, dry shoot and root biomass, mass of the grains, and oil content. The 160 kg K2O ha-1 dose was found to have the best influence on the plant development, because all the measured parameters reached their highest values at this dose, except for oil content, which attained the highest percentage in the case of the control treatment (0 kg ha-1 of K2O). This study proved that the biofertilizer obtained by anaerobic digestion of cassava effluent can be used as an alternative to regular fertilizers in cultivating crambe.


2020 ◽  
pp. 1236-1241
Author(s):  
Gustavo H. Sera ◽  
Filipe G. Carvalho ◽  
Inês C. de B. Fonseca ◽  
Luciana H. Shigueoka ◽  
Santino A. da Silva ◽  
...  

The aim of this study was to prove that Arabica coffee introgressed with C. liberica, have resistance to Meloidogyne paranaensis (Mp). Open pollinated fruits were harvested from mother plants of 29 Arabica coffee genotypes from the IAPAR germplasm bank. Seeds were collected from the fruits and were sown to obtain seedlings to test the resistance to Mp. The experiment was set up in a completely randomized design with 29 coffee genotypes, 8 replications, and one plant per plot. Cultivars Catuaí Vermelho IAC 99 and IPR 100 were used as susceptible and resistant checks, respectively. Seedlings with three to four pairs of leaves were inoculated with 1,400 eggs and juveniles J2 of Mp (IP). At 120 days after inoculation, seedlings were evaluated by counting the nematodes per gram of roots, and the final nematodes population was obtained (FP). The reproduction factor (RF) was calculated using the formula: RF = FP/IP. The reproduction factor reduction was used to classify the resistance levels of genotypes, which were classified as highly resistant (HR), resistant (R), moderately resistant (MR), moderately susceptible (MS), susceptible (S) an highly susceptible (HS). All genotypes differed from Catuaí in resistance factor (RF), five of which did not differ from IPR 100 for RF, and only the line IAPAR 15242 had RF < 1.0. Out of 28 Arabica genotypes introgressed with C. liberica, five HR, 11 R, 11 MR and one MS were identified. However, only IAPAR 15242 and IPR 100 were classified as HR and presented 100% of HR plants, but only the first showed an RF < 1.0. Results revealed that these Arabica coffee genotypes with introgression of C. liberica genes have great potential to be used in breeding programs and they are a new alternative as a source of resistance.


2020 ◽  
Vol 44 ◽  
Author(s):  
Neliane Galvão Porto ◽  
Felipe Barbosa Ribeiro ◽  
Jefferson Costa de Siqueira ◽  
Marcos Antonio Delmondes Bomfim ◽  
Rafael Silva Marchão ◽  
...  

ABSTRACT Methionine is an essential amino acid, and generally, the first limiting one in the diets of tambaqui, the main native fish produced in continental aquaculture in South America. However, there is a lack of information on their amino acid requirement, especially for maintenance and efficiency of utilization. The present study aimed to determine the requirement of [methionine plus cystine] for the maintenance and efficiency of utilization using tambaqui of different body weights. Two experiments were carried out using 250 tambaqui with weights of 100 and 300 g. They were distributed in a completely randomized design with four treatment groups (0.264, 0.396, 0.528, and 0.660% of digestible [Met + Cys]), five replications. The control treatment (CT) was performed with the addition of methionine at the first level (0.264%) until the second level was reached (0.396%). The maintenance requirement was determined by the regression analysis between the consumption of [Met + Cys] and protein retention equal to zero. The efficiency was determined using the value of the slope coefficient of the line obtained by the linear regression. The protein and methionine retention values of tambaqui weighing 100 to 300 g were compared by the parallelism test, and no difference was observed between the parameters of the equations indicating the need for only one equation to describe the responses to body weights. The requirement of digestible [Met + Cys] for the maintenance of tambaqui with weights from 100 to 300 g was 60.47 mg kg-0.7 day-1 and the efficiency of utilization of 42%.


Author(s):  
Rahmad Afdillah ◽  
Yuli Andriani ◽  
Zahidah Hasan ◽  
. Rosidah ◽  
. Iskandar

This research aims was to determine the effective pressure on fine bubbles technology on the growth of Siamese catfish fry in the aquaponic system. This study uses a completely randomized design with four treatments and three replications. Treatment A (Control), Treatment B (FBs at a pressure of 4,5 atm), Treatment C (FBs at a pressure of 5 atm and treatment D (FBs at a pressure of 5,5 atm). The parameters observed were Specific Growth Rate, Survival Rate and water quality (Temperature, pH, DO, Ammonia) Data were analyzed using variance with the F test at a 95% confidence level. The best treatment for catfish growth was treatment D (5,5 atm pressure), which gave the highest SGR value of 7,24% and the highest SR value of 100%. The value of water quality parameters were in good condition for the growth and survival of catfish.


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