Basic biosecurity manual for tilapia hatchery technicians in Bangladesh

With the onset of Tilapia Lake Virus (TiLV) outbreaks in several Asian countries, WorldFish, in collaboration with Bangladesh’s Department of Fisheries, has developed a program to improve biosecurity in the tilapia industry throughout the country. As the first step, a training program has been designed and conducted to train a group of specialists called Master Trainers on improving tilapia hatchery biosecurity. This manual is a result of that program. The Master Trainers will use this manual for training tilapia hatchery technicians countrywide on how to improve biosecurity in hatcheries

Comparison of relapse rates of depot and oral antipsychotics in patients with schizophrenia

Introduction: Antipsychotics are the mainstay of treatment in schizophrenia. First-generation and second-generation antipsychotics are available as oral and depot formulations. The aim of this study was to compare the relapse rate in patients with schizophrenia treated with depot and oral antipsychotics. Methods: All patients diagnosed with schizophrenia under the Top End Mental Health Service in Darwin, Australia during a period of five years were included. Their medications and history of relapses were retrieved from electronic records. Mean relapses-per-month was calculated and compared using the independent t-test and ANOVA. Results and discussion: The study sample contained 193 patients; 137 were males. The mean relapses-per-month for oral formulations was significantly higher than for depot formulations. Second-generation antipsychotic depot formulations had significantly reduced mean relapses-permonth compared to oral second-generation formulations. The mean relapses-per-month for firstgeneration antipsychotics depot was not significantly different from first-generation depot formulations. First-generation antipsychotics depot formulations were significantly more effective than oral second-generation. Zuclopenthixol appeared to be the best first-generation antipsychotics depot compared to flupenazine and flupenthixol. First-generation antipsychotics depot formulations were equally effective as Second-generation antipsychotics depot formulations. Conclusion: Depot formulations overcome some of the adherence problems with oral therapy, and the resultant continuous therapy is effective in reducing relapse rates

STUDY ON GROWTH PERFORMANCES OF VANILLA AS AFFECTED BY DIFFERENT CUTTING TYPES AND MEDIA (Vanilla fragrans)

Vanilla is an orchid spice originated in Mexico It is climbing, branching, andterrestrial orchid growing on trees and shrubs. There is good potential for thevanilla pods in Sri Lanka. At present, 1-2 m long mature Vainila cuttingswere used for propagation but demand cannot meet since it is used longcuttings (I-2m) as planting material. Therefore it is important to get morenumber of cuttings per unit length of the Vanila to meet the existing demand.In this regard, present study was conducted to investigate the effect of cuttinglength and growing media on growth performances of Vanila. In experiment01 (Pot experiment), four potting media (coir dust, sand: coir dust 1:1, sand:coir dust: top soil 1:1:1, sand: topsoil: organic matter 1:1:1) and four cuttinglengths (one nodded cuttings, two nodded cuttings, three nodded cuttings,four nodded cuttings) were used for the study in the nursery. Experimentaldesign was factorial CRD with 4 replicates. In experiment 02 (fieldexperiment), plants taken from the cuttings with two maturity stages (matureand immature) and three cutting lengths (one nodded cuttings, two noddedcuttings, three nodded cuttings) were used for the field establishment. Theexperimental design was RCBD with six replicates. Data (Number of leaves,Number of roots and Leaf area) were measured once in three weeks in thenursery and once in four weeks in the field. Data were statistically analyzedby using ANOVA and means were separated by DMRT. In experiment 01,sand: top soil: organic matter 1:1:1 potting media gives good growthperformances. Four nodded cuttings are more suitable than others. Maturityand cutting length are significantly affected on growth of Vanilla. Maturecuttings with two nodes shows higher growth performance followed bymature cuttings with three nodes, mature cuttings with one node, immaturecuttings with three nodes, immature cuttings with two nodes, and immaturecuttings with one node. Therefore potting media of sand: top soil: organicmatter 1:1:1 is suitable for filling the poly bags to grow vanilla cuttings innursery and mature cuttings with two nodes are shown better growthperformance in the field

IN· VITRO PROPAGATION OF BLACK PEPPER (Piper nigrum)

Black pepper (Piper nigrum) is an important spice crop among minor export crops. Inconventional vegetative propagation systems of black pepper, cuttings and seeds havebeen used. But these methods provide limited quantities of planting materials, and alsospread certain pests and diseases. These problems can be overcome by adopting apropagation method through tissue culture techniquesAll experiments were set up according to completely randomized design. The beststerilization was obtained in 0.1 % HgCb solution for 10 minutes immersion prior todissection of the final explants. Bud length was maximized (4.6 ±..0.84) after 8 weeks inWP medium supplemented with 2 mgll BA and I mgll Kn. The highest survival rate (78%) was observed, when surface sterilized in leaf sections of third leaf with 0.1 % HgCI2in 10 minutes followed by dipping in 90 % alcohol solution. MS medium supplementedwith 0 mgll Kn and I mgll 2,4- D was the most suitable medium for callus formation ofpepper leaf culture.According to the experiment results, 0.1 % HgCI2 with 10 minutes was best treatment forsurface sterilization of buds. For multiplication of pepper buds, 2 mgll BA and I mg/I Kncombination was superior to other treatments. When surface sterilized in leaf sections ofthird leaf with 0.1 %HgCI2 in 10 minutes and dipped in 90 %alcohol solution was bestfor pepper leaf culture and MS medium supplemented with 0 mg/I Kn and I mg/I 2,4- Dwas superior treatment for callus formation.

RELATIONSHIP BETWEEN STEM BIOMASS AND VOLUME OF Pinus caribaea IN THE YAGIRALA FOREST RESERVE

The biomass is an important measurement in commercial forestry maintained to producepulp, paper, chips, fuel wood products etc. The estimation of the biomass of the tree is notan easy task and few studies were carried out so far.The present study was conducted in the 25 years old Pinus caribaea plantation in YagiralaForest Reserve, which is in the low country wet zone. According to the geographicaldifferences in the plantation, i.e., valley, slopes and ridge, stratified random sampling wascarried out and two 0.05 ha circular plots were established in each stratum. Altogether 6plots were used for the data collection.The diameter at breast height (dbh), total height were measured for all the trees in theseplots and after dividing the tree stem into several sections, the length and end and middiameters of each section was measured using the Spiegel relaskop.The volume of the stem was estimated by calculating section volumes. Smalian's andNewton's formula were used to estimate the section volumes except for the final section atthe top, which was assumed as a cone. In order to save time, one plot was measured forNewton's formula and the rest was measured for Smalian's formula. Then a relationshipwas build to estimate Newton's volume (Ne) using Smalian's volume (Sm) as theexplanatory variable (equation I). The R2value was 99.9%.Ne = 0.976 * Sm (1)Biomass of the tree was estimated by extracting core samples at the breast height and midheight of the tree. The density of the core samples were estimated using oven dry weightand the green volume of the core samples. When tested, there was no significant differenceof the density along the stem. Therefore stem biomass was estimated using the density atthe breast height, and the total stem volume. Also there was no significant densitydifferences between three sites.The regression analysis was used with the pooled data to find out the relationship betweenthe stem biomass (W) and the volume (V). Using variable of stem volume and the biomassand its tranformations developed the several models. The best model was selected bychecking the R2 value, standard residual distribution, modelling efficiency and bias. Thebest rclationshin for the hiOI1l;]SS :l1lrl YOIIl"lr ,,·:1< lhr rnll:l1;nn ') whir]' h·w 02 .... 1.. " n

SEED GERMINATION OF MASBEDDA (Gymnema sylvestre), A RARE MEDICINAL PLANT AS AFFECTED BY pH AND ORGANIC SOLVENTS

The use of plants in treating diseases can be traced to the remote past. However due tolack of organized and scientific cultivation, proper management and awareness of socialfactors, the number of these medicinal plants is decreasing at an alarming rate. Gymnemasylvestre is one of rare medicinal plant species, which has high demand in the market.Since, little information is available on germination dynamics of Gymnema seeds, thepresent investigation was carried out to study the effect of pH and organic solvents ongermination of Gymnema sylvestre seedsFresh seeds taken from the plant were used for the experiment. Five pH solutions (i.e.4,6,7,8 andlO) were used to moist the filter papers in petri dishes, which contained seeds.A separate experiment was carried out to study the effect of organic solvents (i.e.Ethanol, Ether, Xylene, and Acetone) on germination following same procedure withusing distilled water as a control. eRD was used in both experiments with 20 replicateseach containing lO seedsResults showed that significantly (p<0.05) higher germination of seeds (56% and 52%) atpH 4 and 6 respectively, whereas the lowest germination (36%) showed at pH 10. Thehighest germination (62%) was recorded from the seeds treated with distilled water,followed by Xylene (42%) and Ether (39%). A significantly (p<O.05) lower germinationwas showed in Acetone (10%) and Ethanol (6%). According to the findings of theexperiment it can be concluded that slightly acidic media would be the best pH for thegermination of Gymnema sylvestre seeds, whereas the organic solutions showed negativeeffects.

CONSTRUCTION OF A PRECISE GROWTH MODEL TO PREDICT THE NDIVIDUAL STEM VOLUME OF Alstonia macrophylla WALL. EX G. DON

In order to reduce the pressure on existing Natural Forests in Sri Lanka,Forest Department promoted growing timber species as plantations and inhome gardens. Among the suggested species Alstonia macrophylla(Hawarinuga) has recently become popular due to its fast growth rate, ease ofestablishment and timber value. There are about 1913 ha extent of Alstoniamacrophylla plantations at the end of the year 1998 maintained by the ForestDepartment of Sri Lanka. However, this figure must be higher than thatbecause many other private organizations are establishing Alstoniamacrophylla plantations in the wet zone in large scale. This species is alsogrown in home gardens, alleys and borders as non-blocks (non-plantations).However, at present there is no method at present for estimating the stemvolume of this species, which is considered as the most important variable incommercial forestry. Therefore a mathematical model was constructed in thisstudy to predict the individual stem volume of Alstonia macrophylla treesgrown in plantations.Since Alstonia macrophylla is widely found in wet zone of Sri Lanka, studysites were selected from Galle (two even-aged plantations from Pituwala andWattehena Beats) districts. The ages of these plantations were 19 and 16respectively. Ten 0.02 ha circular plots with slope correction were randomlylaid out for each plantation, in order to measure the necessary parametersfrom the individual trees. Diameter at breast height (dbh), total height andheight to the crown base of all the trees inside the plots were measured.Newton's formula was used in this research because it is the most accuratemethod. In order to calculate the volume using the Newton's formula, thestem of each tree was hypothetically divided into 4 -5 sections. Then thebottom, mid and top diameters and section lengths were measured usingSpeigal Relascope and Blume Leiss Altimeter respectively. The final sectionof the tree was assumed as a cone and only the bottom diameter and heightwere used in that particular section. The total volume of each section wasestimated by adding the section volumes calculated using Newton's formulato the volume of the final section.First a theoretical model structure was developed using the relationship ofform factor with volume, height and area at the base. Regression analysis wasused to fit the data into the model. Untransformed as well as transformedcombinations of all variables were tested. In this procedure the combinedvariable (basal area * tree height) was always kept as the first explanatoryvariable. After trying with many combinations of selected variables withvolume, final model was selected using its compatibility with the real world,R2 values, and residual distributions, model bias value and modelingefficiency. The selected models at the preliminary stage indicated very highperformance and insignificant bias. In order to select a final one, the abovemodels were validated with a new set of data. The final selected model in thisstudy to predict the individual stem volume with insignificant bias ofAlstonia macrophylla is; --.jv= 0.659 log BA *Ht + 0.00404 ...fer h