2020

The study was undertaken to determine the pre-harvest interval (PHI) for dimethoate and quinalphos in cauliflower, eggplant and hyacinth bean depending on Maximum Residue Limit (MRL) set by European Union. Six supervised field trials were conducted and sprayed with the recommended dose (2 ml/L of water) of each pesticide. Samples were collected at 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 and 12 days after spray (DAS). The collected samples were analyzed using Gas Chromatography (GC) with Flame Thermionized Detector (FTD) for the determination of pesticide residue. The quantities of residue were above MRL up to 9 DAS for quinalphos in cauliflower, 7 DAS in hyacinth bean, 8 DAS in eggplant; 11 DAS for dimethoate in cauliflower, 10 DAS in hyacinth bean, and 9 DAS in eggplant. At 11 DAS, no residue was detected from any of the tested samples except dimethoate in cauliflower. The determined PHI for quinalphos was 10 DAS in cauliflower, 8 DAS in hyacinth bean and 9 DAS in eggplant. In case of dimethoate it was 12 DAS in cauliflower, 11 DAS in hyacinth bean and 10 DAS in eggplant.

The present study was conducted to evaluate the frozen semen quality in terms of different motility patterns and fertility of imported pure Holstein Friesian and Sahiwal breeding bulls maintained under farming condition of Bangladesh. 100% pure Holstein Friesian and Sahiwal breeding bulls were imported and thereafter reared in the American dairy limited (ADL). Semen samples were collected once a week, processed and frozen in the laboratory of ADL. On the day of collection, semen volume and sperm concentration measured immediately after collection. Different motility patterns of spermatozoa (progressive, fast, slow, local, immotile) were measured by Computer Assisted Semen Analyzer (CASA). Effect of breed was found significant (p<0.05) on semen volume and sperm concentration. The semen volume (ml/ejaculate) and sperm concentration (×10⁶) were found to be 6.13±0.28 and 1664.28±62.41 in Holstein Friesian breeding bulls whereas 5.26±0.17 and 2036.00±43.99 in Sahiwal bulls, respectively. The progressive motility, fast motility, slow motility and local motility were significantly (p<0.05) higher in Holstein Friesian bulls than that of Sahiwal bulls both before and after freezing. Different motility patterns such as progressive, fast, slow, local and immotile motility were found to be 89.22±0.45%, 75.97±0.67%, 9.10±0.36%, 4.25±0.15% and 10.05±0.41% in Holstein Friesian bulls whereas 84.98±0.89%, 65.99±0.92%, 11.88±0.37%, 5.65±0.19% and 15.69±0.54% in Sahiwal breeding bulls, respectively before freezing. On the other hand, after freezing, the progressive, fast, slow, local and immotile spermatozoa were found to be 68.19±0.46%, 53.39±2.01%, 9.21±0.46%, 8.47±0.72% and 26.76±2.01% in Holstein Friesian bulls whereas 56.54±0.25%, 42.52±0.67%, 11.11±0.55%, 13.04±1.24% and 30.45±1.58% in Sahiwal bulls, respectively. Non-return rate was found insignificant between the breeds and it was 64.19% in Holstein Friesian and 64.71% in Sahiwal bulls. In conclusion, frozen semen quality of Holstein Friesian pure breed is better than that of Sahiwal breeding bulls but fertility of both breeds are similar. Therefore, frozen semen of both breeds can be used in the field level for the genetic improvement of cattle.

Forty-two fresh fecal samples from the Bengal tigers (n=30) and African lions (n=12) were collected during March 2018 to July 2018 from Bangabandhu Sheikh Mujib Safari Park, Gazipur, Dhaka. The fecal samples were processed using formol-ether concentration technique. A total of six types of parasites (egg/ cyst) were observed viz.; one protozoan (Coccidia spp.), two cestodes (Hymenolepis spp., and Diphyllobothrium spp.) and three nematodes (Ascaris spp., Toxocara spp. and hookworms). No trematodes were found during the study. Occurrence of gastrointestinal (hereafter GI) parasites recorded in tigers was 90% (n=27/30) and lions was 100% (n=12/12). The highest prevalence was of Coccidia spp. (85.71%) followed by Diphyllobothrium spp. (42.86%), Hymenolepis spp. (28.57%), Ascaris spp. (21.43%), Toxocara spp. (14.29%) and hookworms (14.29%). The prevalence of protozoans (85.71%) was higher than that of helminths (78.57%) in the hosts. On the basis of intensity of parasites, male carnivores were more susceptible to infection than females. The intensity of infection was higher in young ones as compared to adults.

Performance of salt-tolerant Boro rice was investigated under the interaction effect of variety and different doses of potassium fertilizer, which is a part of the research for developing agriculture in coastal areas of Bangladesh. A field experiment was conducted at the research field of Agriculture department, Noakhali Science and Technology University (NSTU), Noakhali-3814. The experiment was carried out in a Randomized Complete Block Design (RCBD) with three replications where two varieties viz. BINA dhan-8, BRRI dhan-28 and three doses of potassium viz. 120 kg/ha, 84 kg/ha and 36kg/ha were used as treatments. Plant height (cm), tillers/hill, grain/panicle, 1000 grain weight (g), grain yield (t/ha), straw yield (t/ha) and harvest index (%) were compared among varieties and treatments. Results revealed that only variety and only potassium fertilizer had non-significant influence but the interaction of variety and potassium fertilizer had a significant effect on the performance of salt-tolerant Boro rice. Therefore, the present study suggests that salt-tolerant BINA dhan-8 variety may be cultivated with 120 kg potassium/ha for obtaining higher yield in the southern coastal area of Bangladesh.

Biological activity was studied of the different solvent extracts such as n-hexane, ethyl acetate, n-butanol, and methanol extracts of the rhizomes of Sensevieria hyacinthoides. The cytotoxic potential were examined by using brine shrimp lethality bioassay. Ethyl acetate extract exhibited quite potent activity in brine shrimp lethality bioassay with LC₅₀ 1.95 µg/mL, respectively. These result suggested that it might contain antitumor or cytotoxic agent. The ethyl acetate extract showed significant free radical scavenging activity with IC₅₀ 10.51 µg/mL and demonstrated excellent antibacterial activity.  The free radical scavenging activity of the solvent extracts (n-hexane, ethyl acetate and n-butanol) were assayed by using DPPH method. The IC₅₀ for Vit-c (Ascorbic acid) and ethyl acetate extract were found to be 3.91 and 10.51 µg/mL, respectively.

Dry direct seeding is an alternative rice production method that reduces 50-60% irrigation water required compared to the conventional method. The present study was undertaken with a view to optimize irrigation requirement for dry direct seeded rice. The experiment involved seven water management levels and two rice varieties in a split-plot design allocating water management levels in main plot and rice variety in subplot. The treatments were replicated thrice. The water management levels are (i) puddled transplanted rice with full irrigation (PTR-CI), (ii) puddled transplanted rice with alternate wetting and drying (AWD) irrigation (PTRAWD), (iii) dry direct seeded rice with no standing water at all, (iv) dry direct seeding with AWD irrigation (DDSR-AWD), (v) dry direct seeded rice with 3-5 cm standing water from panicle initiation to heading, (vi) dry direct seeded rice with 3-5 cm standing water from panicle initiation to grain filling, (vii) dry direct seeded rice with 3-5 cm standing water from heading to grain filling. Two rice varieties included in the experiments are BRRI dhan28 and BRRI dhan29. The frequency and amount of irrigation for different plots were recorded. Data on different crop characters, yield and related attributes were collected and were subjected to statistical analysis using a computer package program MSTAT-C. The results reveal that rice gave the highest grain yield in dry direct seeding system where the standing water was maintained from panicle initiation stage to flowering (T5) or grain filling stage (T6) at reproductive phase. The T5 treatment required 7-9 irrigations whereas T6 required 9-12 irrigations. The treatment T5 required 50% less irrigation water than PTR-CI method. Thus, it may be concluded that dry direct seeded rice should be practiced for rice and standing water should be maintained from panicle initiation to heading for obtaining higher grain yield with least irrigation input.

An experiment was conducted to detect fertilizer doses in cauliflower (Brassica oleracea var. botryitis, L. Family: Cruciferae) during rabi season of 2016-17. The location for the study was at the Multi location Testing (MLT) site, (medium highland under AEZ-03) Goneshpur of Shibganj upazilla under Bogura district. The experiment was laid out in randomized complete block design (RCBD) with eight dispersed replications. There were eight nutrient packages viz. T₁ = 100% NPKSZnB (STB), T₂ = T₁+ 25% N, T₃ = T₁+ 25% NP, T₄ = T₁+ 25% NK, T₅ = T₁+ 25% PK, T₆ = T₁+ 25% NPK T₇ = 75% of T₁ and T₈ = Control. The highest yield (42.11t ha^-1) was obtained from the treatment T₆ which was statistically similar with the rest treatments except T₇ (35.89 t ha^-1) and T₈ (18.36 t ha^-1). In case of gross margin, the highest value, (824607) was also obtained from the treatment T₆ followed by T₃, T₁ and T_4. The treatment T₆ (T₁+ 25% higher NPK), fertilizer management practices produced higher in terms of cauliflower yield, gross return, gross margin over the other treatments. Therefore, the result revealed that recommended fertilizer dose N_138.25 P₅₀ K_143.75 s _4.5 Zn _3.22 B _0.51 Kg ha^-1 was optimum for maximizing the yield as well as economically and environmentally viable for cauliflower cultivation in Bogura region.