Purpose The purpose of this study is to investigate the natural convection characteristics of a reacting hybrid nanofluid in an open porous cavity bounded by vertical wavy walls subject to an inclined magnetic field. Design/methodology/approach The physical domain of the problem is constructed using coordinate transformations, and the equations are transformed accordingly. The resulting equations are then solved using finite difference method. Numerical results for the streamlines, isotherms and isoconcentration are illustrated with varying relevant parameters. Findings Whatever the values of parameters, streamlines have two counter-rotating cells, and their intensities are the highest near the open end. Moreover, the maximum temperature and the minimum concentration are obtained in close proximity to the open end. The strength of streamlines is increased with increasing Rayleigh number, Frank-Kamenetskii number and Darcy number, whereas it is decreased with the increment of volume fractions of nanoparticles. Research limitations/implications The limitations of this study are that the model is suitable for thermal equilibrium cases and constant thermo-physical properties, while the results can predict two-dimensional flow behaviors. Originality/value To the best of the authors’ knowledge, there is no study on the natural convection induced by a chemical reaction in an open cavity bounded by vertical wavy walls. The findings might be used to gather knowledge about the flow, energy and reactant distributions in an open space containing a chemical reaction.

The experiment was carried out to investigate the effects of different rooting media on rooting performance, plant growth and development of two varieties of Pitahaya (dragon fruit) cuttings at the Fruit Tree Improvement Project (FTIP), Germplasm Centre (GPC) of Bangladesh Agricultural University (BAU), Mymensingh during the period from May 2014 to August 2014. The two factors experiment consisted with of two different varieties of dragon fruit viz., BAU Dragon fruit-1 (V1) and BAU Dragon fruit-2 (V2) with 14 rooting media. viz. control (soil 100%) (T0), 50% cow dung + 50% soil (T1), Saw dust (100%) (T2), Compost (100%) (T3), 50% soil + 50% sand (T4), 50% soil + 50% saw dust (T5), Sand (100%) (T6), Indole-3 Acetic Acid (IAA) 500 ppm solution + soil (100%) (T7), 300 ppm solution + soil (100%) (T8), 200 ppm solution of IAA + soil (100%) (T9), 500 ppm solution of Indole-3 Butyric Acid (IBA) + soil (100%) (T10), 300 ppm solution IBA + soil (100%) (T11), 200 ppm solution IBA + soil (100%) (T12), (IBA+IAA) 200 ppm solution of each + soil (100%) (T13). All the parameter showed significant effect except number of branches per plant. In case of variety less time was needed for first root initiation (22.33 days) with the longest plant height (34.02 cm). The better result regarding number of roots per cutting (6.00) was found in case of BAU dragon fruit-2 (V2) where the highest root length (15.22 cm). In case of different treatment, the better result regarding number of roots per cutting (8.17) at 100 DAP was counted from the combination of (IAA+IBA) 200 ppm solution + soil (100%) (T13). The highest root length (25.38 cm) was observed in IAA 200 ppm solution + soil (100%) (T9). In case of combined effect, the minimum time was required for first root initiation (20.78 days) with IAA 300 ppm solution + soil (100%) (T8). The highest root length (25.87 cm) was observed in BAU Dragon fruit-1 with IAA 200 ppm solution + soil (100%) (V1T9). Number of roots per cutting was noticed (9.67) in BAU Dragon fruit-2 200 ppm solution of each IAA and IBA + soil (100%) (V2T13).Res. Agric., Livest. Fish.3(1): 67-77, April 2016

An experimental research was carried out to assess the potential of Pangasius pond sediment (PPS) on the performance of yield and yield quality attributes of vegetable crop (BARI's tomato variety) grown in bag gardening system on rooftop under integrated aquaculture-horticulture approach. For this purpose, PPS chemical analysis, recording of plant morphological parameters and biochemical analysis of yield were performed. The plants were grown in 100% PPS =T1; 50% PPS + 50% Virgin soil (VS) = T2; and 60% VS + 40% Cowdung + 50g TSP + 50g MoP = T3. To compare with PPS treated treatments, treatment T3 was considered as control because it is a standard and recommended fertilizing dose of BARI's tomato production. The PPS sediments were collected from different aged ponds ranging from 1to 5 years Pangasius culture. The old PPS was used in bag gardening for the determination of soil physico-chemical, plant morpho-physiological and production parameters. All PPS in bags were belonged to silt loam in texture. The total nitrogen level was higher in T1 where 100% PPS was used. The T1 had the plant height 77.98 cm, number of leaves per plant 184.33, leaf area 622.49 cm 2 , which were significantly (p<0.05) higher than T2 and T3. In the case of phenological development, onset of early flowering and fruiting was noticed in T1, which was almost 1.5 weeks earlier than T2 and 2 weeks than T3. The reproductive characters like flowers per plant (28.67), weight of fruit per plant (53.78g) and fruit yield per bag (1945.74g) and total biomass of plants after harvesting (119.47g) were also significantly (p< 0.05) higher in T1 followed by T2 and T3 (control). The numbers of branches per plant (29.54), number of clusters per plant (35.84) and fruits per cluster (5.10) were higher in T1 than T2 and T3. The vitamin C content of tomato (28.26 mg %) was also significantly (p< 0.05) higher in T1 followed by T2 (24.67 mg %) and T3 (21.28 mg %). The treatment T1 showed the best performance followed by T2 and T3 (control). The perceived aquaculture waste of PPS had the high potential to grow vegetables with better production without any manure and chemical fertilizers. Therefore, PPS could reduce use of chemical fertilizers, especially urea which is environment friendly and less costly for vegetable production in bag gardening system.

An experiment was conducted to investigate the effect of six pre-harvest treatments on yield, quality and shelf life of a particular Mango cv. Amropali under field condition. The experimental factors were Control, Decis and Savin @ 2 ml L . Boron treatment also extended the shelf life of mango as well. The maximum shelf life was found from large sized fruits. Similar performance on yield, quality and shelf life were obtained from Magic growth treatment @ 2 ml L -1 followed by pheromone trap treatment. Control treated fruits exhibited the minimum number of fruits per plant with lower quality but better TSS%. Smaller fruits were obtained from untreated control plants. Monira et al. Effect of pre-harvest treatments on AmropaliRes.

A study was conducted to investigate the effect of some postharvest treatments on shelf life and quality of mango. Experiment was conducted at the BAU Germplasm centre, Department of Horticulture, Bangladesh Agricultural University, Mymensingh during May to July, 2013. Two treatments viz. Aloe vera and Chitosan solution were used for this study. The experiment was laid out in Completely Randomized Design (CRD) to observe the post-harvest performance of mango with three replications. The fruits were divided into three grades eg. large, medium and small for the convenience of the experiment. In each group mango were treated with Aloe vera gel and Chitosan solution in three different concentrations of 0.5%, 1% and 1.5%. Amropali cultivar had the highest shelf life (7days) at 1.5% Aloe vera gel treatment to the large size mangoes at room temperature compare to other sizes and treatments. Nearly, similar effect was obtained from 1.5% Aloe vera gel to the medium size fruits than other treatments. 1.5% Chitosan showed the second best result in case of shelf life extension followed by 1% Chitosan solution.Res. Agric., Livest. Fish.3(2): 279-286, August 2016