Assaying the allelopathic effects of Eucalyptus camaldulensis in a nursery bed incorporated with leaf litter     

Romel Ahmed  Mohammad Shafioul Alam  Farid Uddin Ahmed  M.K.Hossain 《林业研究》2018,(3)

Allelopathic effects of Eucalyptus camaldulensis Dehnh. were confirmed in Petri dish and pot experiments in our previous studies. However, the degree to which such effects under controlled experiments exist in more complex ecological settings remains to be tested. Thus, the present study was carried out by incorporating different proportions of ground litter of E. camaldulensis in soil. The growth of three agricultural crops: falen(Vigna unguiculata(L.) Walp.), chickpea(Cicer arietinum L.), and arhor(Cajanus cajan(L.) Millsp.), and two tree species, kala koroi(Albizia procera(Roxb.) Benth.) and ipil ipil(Leucaena leucocephala(Lam.) de Wit) were tested. There were inhibitory effects of leaf litter on germination, shoot and root growth, leaf number, and collar diameter as well as a reduction of nodulation by legume crops(25–80%reduction). The extent of the effects was dependent on the proportion of leaf litter, the species and the type of traits. In contrast to shoot growth, the effect on root growth was more severe. No effect on germination was found with the agriculture crops while the two tree species showed reduced germination. The effect was greater in the presence of higher proportions of leaf litter mixed in soil while in some cases lower proportions stimulated growth. Not all species were suppressed; A. procera, C. cajan, V. unguiculata showed compatible growth while C. arietinum and L.leucocephala were found incompatible. This study provides evidence that E. camaldulensis has allelopathic potential under field conditions and a careful selection of associated crops in agroforestry systems is highly recommended.  相似文献   

Evaluation of a point‐of‐care electrochemical meter to detect subclinical ketosis and hypoglycaemia in lactating dairy cows          下载免费PDF全文

A Zakian  M Tehrani‐Sharif  MR Mokhber‐Dezfouli  M Nouri  PD Constable 《Australian veterinary journal》2017,95(4):123-128

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Prediction of tillage operation strategies for dryland wheat production in a degraded loess soil     

Muhammad Sharif  Safdar Ali  Muhammad Ansar  Asma Hassan 《Archives of Agronomy and Soil Science》2017,63(8):1137-1149

Conservation tillage systems are advocated worldwide for sustainable crop production; however, their favorable effects on soil properties are subject to the length of their use. The following study aimed at using the CENTURY agroecosystem model to simulate long-term changes in soil organic carbon (SOC) fractions and wheat (Triticum aestivum L.) production. Tillage systems include conventional tillage (CT, control), minimum tillage, chisel plow (CP) and zero tillage with (R⁺) and without residues (R^?) in fallow-wheat system. The model validation with 2-year field experiment showed that the simulated results were strongly correlated with observed results for total organic carbon (r² = 0.94), active soil carbon (r² = 0.91), slow soil carbon (r² = 0.84) and passive soil carbon (r² = 0.85). Similarly, model simulations for biomass and grain yields were, respectively, 81% and 76% correlated with observed results. The long-term simulations predicted that SOC stock and its fractions will gradually build up, crop biomass and grain yield will enhance with crop residue retention, especially under chisel plough in comparison of existing CT system. The study concludes that CP and retention of crop residues have potential to improve SOC contents and ultimately crop production.  相似文献   

Development of New Submergence Tolerant Rice Variety for Bangladesh Using Marker-Assisted Backcrossing     

Khandakar Md IFTEKHARUDDAULA  Helal Uddin AHMED  Sharmistha GHOSAL  Zakiah Rahman MONI  Al AMIN  Md Shamsher ALI 《水稻科学》2015,22(1):16-26

Submergence tolerant high yielding rice variety was developed using BR11 as a recipient parent applying foreground, phenotypic and background selection approaches. Recombinant selection was found essential to minimize linkage drag by BC2F2 generation. Without recombinant selection, the introgression size in the backcross recombinant lines(BRLs) was approximately 15 Mb on the carrier chromosome. The BRLs were found submergence tolerance compared to the check varieties under complete submergence for two weeks at Bangladesh Rice Research Institute, and produced higher yield compared to the isogenic Sub1-line under control ed submerged condition. The BRL IR85260-66-654-Gaz2 was released as BRRI dhan52 in 2010, which was the first high yielding submergence tolerant variety in Bangladesh. BRRI dhan52 produced grain yield ranging from 4.2 to 5.2 t/hm2 under different flash flood prone areas of Bangladesh in three consecutive seasons. The study demonstrated the efficiency of recombinant selection and better adaptability of the newly released submergence tolerant high yielding variety in flash flood prone different areas of the country with respect to submergence tolerance and yield potential.  相似文献   

Performance of mono‐sex tilapia (Oreochromis niloticus) in rice field with different ditch size          下载免费PDF全文

Md. Akhtar Hossain  Md. Anisur Rahman Mridha  Abul Kalam Md. Azad Shah  Md. Nahiduzzaman  Md. Sharif Uddin 《Aquaculture Research》2015,46(8):1891-1901

The effects of ditch size on growth and production of mono‐sex tilapia, Oreochromis niloticus in rain fed concurrent rice–fish system were technically and economically evaluated for a period of 4 months. Three different ditch sizes were tried: 5%, 10% and 15% of the total cultivable rice field. The fish fingerlings stocking density (5000 ha^?1) and management practices were similar in all plots. The water temperature, dissolve oxygen, pH, Secchi disc visibility, ortho‐phosphate, ammonia nitrogen and alkalinity were found to be in the range of 31.5–31.9°C, 5.10–5.27 mg L^?1, 7.56–7.62, 34.81–35.41 cm, 0.88–0.96 mg L^?1, 0.014–0.021 mg L^?1 and 66.23–69.76 mg L^?1, respectively, and all the values were found suitable for tilapia fish farming. Sediment organic matter, available nitrogen and phosphorous were increased significantly (P < 0.05) in all plots after cultivating the fish. Larger ditch size (15% of the total land area) resulted in significantly (P < 0.05) higher specific growth rate, survival and fish production compared with the smaller (5%) and medium (10%) ditch sizes. However, significantly (P < 0.05) higher net income and benefit–cost ratio were obtained in medium ditch size with the values of 2.6% and 3.6% higher than the smaller and larger ditch sizes respectively. It is concluded that rice–fish farming in a rain fed ecosystem of Bangladesh with medium ditch size and stocking density of 5000 ha^?1 mono‐sex tilapia can achieve better economic return.  相似文献   

Pyrethroid insecticide resistance in Rhipicephalus bursa (Acari, Ixodidae)     

A.A. Enayati  F. Asgarian  M. Sharif  H. Boujhmehrani 《Pesticide biochemistry and physiology》2010,97(3):243-248

Rhipicephalus bursa is one of the most common hard tick species in Iran. It is a vector of animal and human diseases. Tick control strategies in Iran rely heavily on pyrethroid insecticide use. Hence, susceptibility status of multiple field collected populations to λ-cyhalothrin and cypermethrin was investigated using the FAO recommended larval packet test. Resistance ratios at the LC₉₉ of field populations of R. bursa compared to a susceptible strain ranged from 0.95 to 4.78 for λ-cyhalothrin and 1.43-8.6 for cypermethrin. They were 2- to 6.9-fold higher than the maximum dose recommended by the acaricide formulating companies. Biochemical assays on different field collected populations showed significant elevation in esterase and glutathione S-transferase activities and monooxygenase contents compared with the susceptible strain. Therefore, close monitoring and resistance management strategies should be employed to delay the operational loss of pyrethroids for tick control in Iran.  相似文献   

Immune responses against Marek's disease virus     

Parvizi P  Abdul-Careem MF  Haq K  Thanthrige-Don N  Schat KA  Sharif S 《Animal health research reviews / Conference of Research Workers in Animal Diseases》2010,11(2):123-134

It is more than a century since Marek's disease (MD) was first reported in chickens and since then there have been concerted efforts to better understand this disease, its causative agent and various approaches for control of this disease. Recently, there have been several outbreaks of the disease in various regions, due to the evolving nature of MD virus (MDV), which necessitates the implementation of improved prophylactic approaches. It is therefore essential to better understand the interactions between chickens and the virus. The chicken immune system is directly involved in controlling the entry and the spread of the virus. It employs two distinct but interrelated mechanisms to tackle viral invasion. Innate defense mechanisms comprise secretion of soluble factors as well as cells such as macrophages and natural killer cells as the first line of defense. These innate responses provide the adaptive arm of the immune system including antibody- and cell-mediated immune responses to be tailored more specifically against MDV. In addition to the immune system, genetic and epigenetic mechanisms contribute to the outcome of MDV infection in chickens. This review discusses our current understanding of immune responses elicited against MDV and genetic factors that contribute to the nature of the response.  相似文献   

Changes in concentrations of biochemical markers of osteoarthritis following surgical repair of ruptured cranial cruciate ligaments in dogs.     

J F Innes  M Sharif  A R Barr 《American journal of veterinary research》1999,60(9):1164-1168

OBJECTIVE: To investigate longitudinal changes in concentrations of the 1/20/5D4 epitope (5D4) of keratan sulfate and total sulfated glycosaminoglycans (S-GAG) in synovial fluid and serum of dogs with cranial cruciate ligament (CCL) rupture that was repaired via intra-articular surgery. ANIMALS: 58 dogs with a ruptured CCL and osteoarthritis of the affected (index) joint. PROCEDURE: Prior to surgical repair of the ruptured CCL, 5D4 concentration was measured in serum and synovial fluid samples by use of an inhibition ELISA, and total S-GAG concentration was measured in synovial fluid samples by use of a direct dye-binding assay. Ruptured CCL were repaired surgically, using an intra-articular fascial graft. Dogs were reexamined 1.5, 7, and 13 months after surgery, and 5D4 and S-GAG concentrations in synovial fluid and serum were measured again. RESULTS: Serum 5D4 concentrations did not change significantly during the study. Concentrations of 5D4 in synovial fluid (expressed as a ratio of S-GAG concentration) did change significantly with time. In the index joint, the 5D4:S-GAG decreased from 0.19 at the beginning of the study to 0.09 1.5 months after surgery, but 7 months after surgery, the ratio increased again to 0.20. CONCLUSIONS AND CLINICAL RELEVANCE: Results support the hypothesis that serum concentration of 5D4 is not a useful marker of osteoarthritis in dogs. Surgical intervention transiently reduced the concentration of 5D4 in synovial fluid but had no effect on S-GAG concentration.  相似文献   

Evaluation of Meat and Bone Meal as Replacement for Protein Concentrate in the Practical Diet for Sutchi Catfish,Pangasius hypophthalmus (Sauvage 1878), Reared under Pond Condition     

M. Abdul Kader  Mahbuba Bulbul  Saichiro Yokoyama  Manabu Ishikawa  Shunsuke Koshio  M. Sakhawat Hossain  Gias Uddin Ahmed  M. Arshad Hossain 《Journal of the World Aquaculture Society》2011,42(3):287-296

An 80‐d feeding trial was conducted to evaluate meat and bone meal (MBM) as replacement of protein concentrate (PC) in practical diets for sutchi catfish, Pangasius hypophthalmus. Triplicate groups of juvenile sutchi catfish (initial weight 4.80 g) were stocked at the rate of 20,000 fish/ha in 12 earthen ponds (30 m² each). Four isocaloric diets (4.12 kcal/g) were formulated by replacing 0 (Diet 1, control), 33 (Diet 2), 67 (Diet 3), and 100% (Diet 4) PC protein with MBM. The growth parameters [final weight, % weight gain, and specific growth rate (SGR)] of fish fed Diets 1, 2, and 3 were not significantly different (P > 0.05) from each other but were significantly (P < 0.05) higher than those in Diet 4. The protein content in fish fed Diet 4 was significantly (P < 0.05) lower than the others. The total production of fish in different treatments ranged between 1917 and 2648 kg/ha/80 d. A simple economic analysis determined that the highest net profit (Tk. 52,965/ha) was obtained with Diet 2 and the lowest (Tk. 27,127/ha) with Diet 4 having 100% PC protein replacement. From the results of the study it is concluded that MBM can substitute up to 67% PC protein in catfish diet without hampering the growth and feed utilization.  相似文献   

Preliminary studies on enzootic bovine leukosis in Saudi dairy farms     

S M Hafez  M Sharif  A Al-Sukayran  D Dela-Cruz 《DTW. Deutsche tier?rztliche Wochenschrift》1990,97(2):61-63

The occurrence of sporadic cases of enzootic bovine leukosis in commercial dairy farms in Saudi Arabia was recently confirmed and found to be associated with importation of breeding heifers. Immunodiffusion test was applied to screen the prevalence of infection with bovine leukemia virus among local traditional and dairy cattle. All the 102 examined local cattle were negative, while out of the 1329 tested dairy animals (originating from 23 farms), 268 (from 16 farms) showed precipitating activity. As an epizootiological model, all animals of an infected dairy farm were serologically examined. Out of the 560 originally imported cows and the 1849 animals born locally in the farm, 217 (39%) and 468 (25%) animals, respectively, were found positive. The correlation between the age of locally born animals and the occurrence of antibodies against bovine leukemia virus was discussed.  相似文献