The insect’s world is filled with many odors. Insects use these odors to cue them in a variety of complex social behaviors, including courtship, mating, and egg laying. Scientists and pest control specialists have known about these complex communication systems for decades. The main aim of this study was to visualize the availability, trends and differences in the sources of pheromone control in agricultural growth of Bangladesh. It also concerned on constrains and present use of pheromone and their possible recommendation on behalf of Bangladesh agriculture. It concentrated on the data during last three decades (1980-2010), comprising status of pheromone use in Bangladesh agriculture and its future. Review revealed that Bangladesh has been enormously successful in increasing pheromone use in agricultural production (especially for vegetables). Understanding of the nature of pheromones and their potential for pest control along with the future prospective of pheromone technique in agriculture were stated. Since the pheromone, technologies for control of major crop pests in Bangladesh are still limited. So that this review emphasized on more attention to the authority to increase the research works and project facilities related to develop and promote pheromone techniques. It is highly recommended to increase availability of pheromone in market, more investment in research and development, introduction of newly identified pheromone for specific pest, to assist government and nongovernment organizations to work with farmers to reduce harmful insecticide use and promote pheromone tactics as one part of integrated crop management (ICM).

The insect’s world is filled with many odors. Insects use these odors to cue them in a variety of complex social behaviors, including courtship, mating, and egg laying. Scientists and pest control specialists have known about these complex communication systems for decades. The main aim of this study was to visualize the availability, trends and differences in the sources of pheromone control in agricultural growth of Bangladesh. It also concerned on constrains and present use of pheromone and their possible recommendation on behalf of Bangladesh agriculture. It concentrated on the data during last three decades (1980-2010), comprising status of pheromone use in Bangladesh agriculture and its future. Review revealed that Bangladesh has been enormously successful in increasing pheromone use in agricultural production (especially for vegetables). Understanding of the nature of pheromones and their potential for pest control along with the future prospective of pheromone technique in agriculture were stated. Since the pheromone, technologies for control of major crop pests in Bangladesh are still limited. So that this review emphasized on more attention to the authority to increase the research works and project facilities related to develop and promote pheromone techniques. It is highly recommended to increase availability of pheromone in market, more investment in research and development, introduction of newly identified pheromone for specific pest, to assist government and nongovernment organizations to work with farmers to reduce harmful insecticide use and promote pheromone tactics as one part of integrated crop management (ICM).

Plankton is an important food item of fishes and indicator for the productivity of a water body. The present study was conducted to evaluate the effects of bottom soil textural conditions on abundance of plankton in aquaculture pond. The experiment was carried out using three treatments, i.e., ponds bottom with sandy loam (T1), with loam (T2) and with clay loam (T3). The ranges of water quality parameters analyzed were suitable for the growth of plankton during the experimental period. Similarly, chemical properties of soil were also within suitable ranges and every parameter showed higher ranges in T2. A total 20 genera of phytoplankton were recorded belonged to Chlorophyceae (7), Cyanophyceae (5), Bacillariophyceae (5), Euglenophyceae (2) and Dinophyceae (1). On the other hand, total 13 genera of zooplankton were recorded belonged to Crustacea (7) and Rotifera (6). The highest ranges of phytoplankton and zooplankton densities were found in T2 where low to mediumtype bloom was observed during the study period. Consequently, the mean abundance of plankton (phytoplankton and zooplankton) density was significantly highest in T2. The highest abundance of plankton in the T2 indicated that pond bottom with loamy soil is suitable for the growth and production of plankton in aquaculture ponds.

Declining crop yield due to weeds and their resistance to herbicides are major constraint for successful crop productions. Milk thistle (Silybum marianum) is common weed species in Australian cropping rotation. Allelopathic potentiality of milk thistle on different crops has been documented sporadically, but there is no literature on about ryegrass and canola. Therefore, a laboratory based allelopathic extracts bioassay was conducted. The hot water extracts was prepared from milk thistle plant parts added into water with ration of 1: 10 (plant sample: distilled water) where mixture was heated 10 minutes. After heat treatment samples was immediately sieved and centrifuged and the resulted solution was treated as 100% concentration. Separately, to get the fresh water extract plant sample was added into water (1:10) and kept 24 hours in room temperature. After 24 hours, the sample was sieved and centrifuged and collected samples result was treated 100% concentrations. To obtain 50% concentration, both hot and fresh samples were diluted with distilled water. Therefore the experiment was conducted with five different treatment concentrations (0, 50% hot water extracts, 50% fresh water extracts, 100% hot water extracts and 100% fresh water extracts). The experiment was comprised with RCBD design with three replications under control conditions. During experimental period the allelopathic effects of donor species on germination and seedling growth of ryegrass and canola was observed. Results shows, germination and seedling growth of both receiver species are inhibited by milk thistle extracts. Extracts from fresh water at 100% was more toxic to receiver species followed by 50% concentration of fresh and 100% from hot water extracts. This concentration reduced the root, shoot growth of ryegrass and canola 84.971%, 84.269% and 89.898%, 87.394%, respectively. The result also revealed that allelopathic pattern of hot water extracts was same however; it is less toxic to both receiver species.

The study was carried out to assess effect of gamma radiation on the acidity and vitamin C content of the Citrus macroptera (Satkora) and Citrus assamensis (Ginger lime). Irradiation with doses 0.5, 1.0, 2.0, 3.0 kGy were applied to assess the effect on the titrable acidity and vitamin C contents every one week interval for total five weeks. Both titrable acidity and vitamin C content of C. macroptera, and C. assamensis are sensitive to both gamma radiation and storage time; have decreased with increase of radiation does as well as storage time and this changes of vitamin C and titrable acidity content with gamma radiation and increasing storage period have found statistically significant.

This article describes a simple solvent extraction method for the extraction of colorants from the three morphotypes such as, (Morphotype-1 (M1), Morphotype-2 (M2), and Morphotype- 3 (M3) of Annatto (Bixa orellana L.) seeds, and their separation, vivid, and qualitative demonstration by thin-layer chromatography. Several solvent systems (hexane, chloroform, acetone, ethanol, and a mixed-solvent having composition of CHCl3/C2H5OH/CH3COOH (80:2:1)) were applied for extraction of colored components. It was observed that a large portion of colorants was extracted by chloroform. Its effluent was deep brick red in color and transparent. Furthermore, various carrier solvent systems (Benzene-Ethyl acetate) were used to separate the components from the extracts. Carrier solvent system with the ratio of 7:3 was found as superior solvent for chloroform extracts. Three colored-spots were observed for all morphotypes. Among them, the first one was yellow colored having very low polarity and the second and third spots were both redbrick colored having medium and higher polarity respectively. In addition, for M1 no colorless-spot was observed in low and medium polar systems, revealing that the amount of wax and gum were minimum in the extract and superior morphotype among the three.

A field study was conducted to screen out a number of Bangladeshi Tomato (Lycopersicon esculentum L.) varieties for salinity tolerance. Three levels of salinity were 2.0-4.0 dS m-1, 4.1-8.0 dS m-1 and 8.1-12.0 dS m-1. Significant varietal and or salinity treatment effects were registered on plant height, leaf area, plant growth, yield, dry matter plant-1, Na+ and Claccumulation in tomato tissues. Variety BARI Tomato 14, BARI Hybrid Tomato 5 and BARI Tomato 2 consistently showed superior biological activity at moderate salinity (4.1-8.0 dS m-1), based on dry matter biomass production thus displaying relatively greater adaptation to salinity. Under saline condition, all plant parameters of tomato varieties were reduced compared to the control except number of fruits of BARI Tomato 14, BARI Hybrid Tomato 5 and BARI Tomato 2. Thus, BARI Tomato 14, BARI Hybrid Tomato 5 and BARI Tomato 2 can be regarded as a breeding material for development of new tomato varieties for tolerance to salinity in saline areas of Bangladesh.

The study was performed for evaluating the growth and production performances of crossbred climbing perch (Anabas testudineus) during August to October 2009. The crossbred groups of fish were produced by crossing between native climbing perch and Thai climbing perch (A. testudineus). Growth and production performances was compared at grow out condition between crossbred groups in the two reciprocal crosses of treatments viz. T1: Native climbing perch (♀) × Thai climbing perch (♂) and T2: Thai climbing perch (♀)×Native climbing perch (♂. At the same time, they were compared also with their respective control F1 pure line groups i.e. T3: Native climbing perch (♀) × Native climbing perch (♂) and T4: Thai climbing perch (♀) × Thai climbing perch (♂). It was evident from the results that among the treatments in grow out system, the highest mean harvesting weight was 69.25±9.01 g found in T4 (Thai climbing perch), which was significantly different (P<0.05) from all other treatments. Whereas, T3 (native climbing perch) also showed the lowest mean harvesting weight 33.38±8.74 g and showed significant differences (P<0.05) among all the treatments. The mean harvesting weight of both the crossbred groups i.e. T1 and T2 were 50.83±6.65 and 59.94±7.83 g, respectively and these results were statistically insignificant (P>0.05) between them but significant among all other treatments. The highest (93.60%) and lowest (83.06%) survival rates were observed in Thai koi (T4) and native Koi (T3) parental stocks, respectively. Wider variations in terms of productions performances were observed among the treatments, where the gross production of T1, T2, T3 and T4 were 2,753±96.67, 3,401±73.26, 1,733±168.47 and 4,051±185 kg/ha, respectively. The productions obtained from crossbred groups were at intermediate compared to their control pure line groups. Higher FCR mean value was observed in native control line (T3), while, lower FCR mean value was observed in Thai control line (T4).

Studies on Gonadosomatic index (GSI), ova diameter and histology of the gonad were performed to understand reproductive biology of Feather back, Chital (Notopterus chitala) for a period of 6 months from January to June 2010. Thirty live chital fish were used in this study. The mean GSI values for female chital were found to range between 0.20±0.013 and 4.63±0.50. The highest GSI value was found in June. The smallest diameter of ovum was recorded 0.04 mm (January) and the largest was 4.00 mm (June). During the experimental period, the fecundity was ranged from 8,238 to 18,569 (mean 13,052±4607) in fish samples with body weight range from 1,296 to 2,360 (mean 1,742.50±474.44 g) while the relative fecundity was 5.65 to 14.33. Histological study revealed that the percentage of late perinucleolus (LPN) stage was highest in April and Cortical alveoli (CA) stage appeared from April and reached to maximum in May. Vitellogenic stage (VG) appeared in the month of May and chronologically increased through June. Vitellogenic stage (VG) of oocyte as well as highest ova diameter reached to the peak in June. The variations in the gonad weight and GSI of the female fish reached to the peak during June indicating maturity of ovary and definite spawning season.

This paper is aimed to study the Agricultural activities of the Malayali Tribal for Subsistence and Economic needs in the mid elevation forest of Pachamalai Hills, Eastern Ghats, Tamil nadu. About 8 percent of the Indian population belongs to a category listed as “Scheduled Tribes” enumerated in the Schedule to Article 342 of the Constitution of India. Tribal people has been seen to be strongly associated with the forests, hills and remote areas, practicing a unique life style, having a unique set of cultural and religious beliefs. For millennia, tribal communities have lived in forests and survived on hunting and gathering. However, with growing population and resource pressure, it is now witnessing that a rise in livelihoods based on settled farming. In the study area, cereals are the major crop cultivated for their edible grains. The tribal people living in the hills tops of the study area were cultivated 11 major agricultural crops. They are, Eleusine coracana, Panicum miliare, Oryza sativa (verity I) (Mara Nellu), Oryza sativa (verity II), Manihot esculenta, Macrotyloma uniflorum, Vigna mungo, Sesamum orientale, Paspalum sp, Pennisetum americanum and Setaria italica. Among them, Paspalum sp gives the maximum yield with 655 kg acre-1.

The study was carried out to examine the effect of training and visit system on professionalization of extension agents in Osun State Agricultural Development Programme of Nigeria. Seventy-five data were collected by interviewing extension agents constituted the sample size and were interviewed through the aid of using a well-structured questionnaire and information obtained were analyzed using frequency counts, percentages and person correlation coefficient was used for testing the research hypothesis. The findings revealed that 80% of the respondents were between the age group of 30 -50 years, spent between 10 – 30 years in service (84%) and are married (98.7%). A large proportion (56%) of the respondents holds higher national diploma in general agriculture, exhibited favorable attitude towards the farmers (93.3%), specials in general agriculture (34.7%) and required training in one or more areas of agriculture (69.3%). Analysis performed shows that all the characteristics had positive relationship with effect of training and visit on professionalization of extension agents except years of service, which had a negative relationship though all characters were statistically insignificant. Hence, the more the numbers of years spent on the job the more experience you would be. Which indicated that personal characteristics of the respondent influenced the professionalization of the extension agents through training and visit system?

In the present study, we conducted an experiment to evaluate the effects of duckweed (Lemna minor) as feed on fish production in polyculture. The experiment had 2 treatments where in treatment 1 (T1) ponds were supplied with duckweed as feed and in treatment 2 (T2) ponds were kept as control (without supply of duckweed). Average survival rates in T1 and T2 were 90 and 89%, respectively. The specific growth rates (SGR) were higher in T1. Calculated net production in T1 was 6.25 tons ha.-1 yr.-1 and in T2 was 2.84 tons ha.-1 yr.-1. The ranges of physico-chemical parameters analyzed were within the productive limit and more or less similar in all the ponds under both treatments during the experimental period. There were 24 genera of phytoplankton under 5 major groups and 10 genera of zooplankton under 3 major groups found in the experimental ponds. The net production in T1 was significantly higher than that of T2 indicated the use of duckweed as feed for fishes is economically sustainable in polyculture.