No abstract

Lentil (Lens culinaris L.), a pulse crop, is grown in nutrient-poor soils in many developing countries, often with little or no fertilization. Knowledge on root traits of lentil and the assessment of their role in nutrient capture would help to sustain its production in these nutrient-poor soils. Root traits (root length, root hairs, root-induced acidification, and phosphatase enzymes) of 10 lentil genotypes (Barimasur-3, (2), L-107 × 87012, L-5 × 87272 and 8406-122) were investigated and then related to the plant uptake of phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), sulphur (S), iron (Fe), manganese (Mn), zinc (Zn), copper (Cu), boron (B), molybdenum (Mo), and cobalt (Co) in laboratory and pot experiments. There were significant (p < 0.05) differences in root length (RL) and root-hair density (number mm −1 root) among the genotypes. The genotypes did not differ to induce rhizosphere acidification and acid phosphatase activity (aptase). Uptake of most nutrients differed significantly (p < 0.05) among the genotypes, but root length (RL) was, in general, weakly correlated to the uptake of the most nutrients in the shoot dry matter (DM). The genotypes with prolific root-hair formation (Barimasur-4 and Barimasur-3) were particularly superior in uptake of those nutrients (K, P, Fe, Mn, Cu, Zn, Mo) whose availability in soils is usually low and whose transport 643 Downloaded by [University of Connecticut] at 15:23 07 October 2014 644 T. S. Gahoonia et al.to the roots is diffusion limited. The results of this investigation, though based on a small sample of lentil accessions/cultivars, suggest that genetic variation in lentil root traits and nutrient uptake can be pronounced. Screening of a large number of local and exotic cultivars or lines of lentil should be conducted by including more root traits (N 2 fixation, organic acids, mycorrhizae) to find nutrient-efficient germplasm to promote lentil production.

Bangladesh is the abode for 21 ethnic communities (Khaleque 1995). Among them, the Chakma tribe is the largest and the most dominant one. Total population of Chakma is about 253,000 (Tripura 1994) of which more than 90 percent live in Rangamati and Khagrachari districts. Even in the recent past, the Chakma people living in Bangladesh used to meet their daily needs mostly from natural forest products. For the primary health care, still most of them depend upon surrounding plants and plant products. The knowledge of such health care system is passed from generation to generation in verbal form by traditional medicine men, local headmen and elderly persons in their community. However, currently the indigenous healthcare knowledge of Chakma tribe is in great risk because of various threats. If the present trend of eroding situation prevails, the valuable knowledge possessed by the Chakma people on indigenous medicinal plants is going to be lost forever without being properly recorded and documented.Studies on medico-botanical information of ethnic communities in Bangladesh are at initial stage. Some of the articles published in this field include Mia and Huq (1988), Alam (1992), Alam et al. (1996), Khisa, B. (1996) (2004, 2006). None of these articles cover the entire medico-botanical documentation of the Chakma people of Bangladesh. In order to address this issue, the present article attempts to present some new medico-botanical information of Chakma people in the Chittagong Hill Tracts of Bangladesh.Rangamati and Khagrachari districts (latitude 21º91′-23º75′ N and longitude 91º75′-92º42′ E) were selected for the study as the majority of the Chakma community live there. Six field trips were conducted in the study area in the years 2004 and 2006. Information on the medicinal plants was gathered by interviewing Chakma traditional medicine men, local headmen and elderly persons in the community. Local names of each medicinal plant with plant part(s) used and the names of diseases or symptoms treated were recorded. This information was confirmed by asking two or more persons of the same community. The collected botanical specimens were identified at the

Lentil is a protein-rich pulse, grown mainly in developing countries as a rain-fed crop in nutrient-poor soils. Hence, the importance of root traits for efficient capture of soil nutrients and water can be crucial to its economical yield. Little is known about the lentil root system and even less about its relationship to grain yield. We compared the root system of two Bangladeshi lentil varieties, Barimasur-3 (BM-3) and Barimasur-4 (BM-4), in a pot experiment and related it to their multi-location grain yield in the fields. BM-4 maintained faster root development both at an early growth stage (20 days after sowing) and at flowering (60 days) compared to BM-3. The roots of BM-4 penetrated the 25 cm depth of the soil profile after 19 ± 1 days and while those of BM-3 took 24 ± 2 days to reach the same depth. The roots of BM-4 were covered with denser (26 ± 3 mm )1 ) and longer (0.48 ± 0.11) root hairs than BM-3 (density 17 ± 2 mm )1 , length 0.32 ± 0.09 mm). The differential presence of root hairs increased the effective length of root system of BM-4 by 12 times and that of BM-3 by five times. The lentil varieties did not differ in their ability to induce pH change and acid phosphatase activity in rhizosphere. In the pot experiment, the uptake of macro-nutrients (K, P, Ca, and Mg) as well as micro-nutrients (Fe, Mn, Zn, Cu, B and Mo) by BM-4 was significantly higher, compared to BM-3. The varieties produced the same amount of shoot biomass. At five of six agro-ecological distinct field locations in Bangladesh, BM-4 gave significantly higher (10-20%) grain yield than BM-3. Linked with the higher grain yield, the benefit-cost ratio (BCR) of BM-4 was 3.14 and that of BM-3 were 2.62, indicating that BM-4 provided better return per unit investment, compared to BM-3, supported by the better root morphology and higher nutrient uptake. This may be one of the reasons supporting the popularity and preferred adoption of BM-4 among the Bangladeshi farmers, who grow lentil mainly on nutrient-poor soils. The results indicate the benefits of selection and breeding for superior root traits for better agro-economics.

Successfully synthesized PVP stabilized Pt NPs from 1.4 to 4.8 nm. Two new bands at 2021 cm−1 and 1994 cm−1 were observed in the FTIR spectra of adsorbed 12CO on Pt NPs which are assigned to the edge and corner sites at Pt surface respectively.

Transplanting of rice seedlings in non-puddled soil under conservation agriculture systems is a new promising technology for which effective and economic weed control strategies have to develop. Therefore, a study was conducted in wet season rice during 2013 and 2014 with some commonly used pre-and post-emergence rice herbicides (pyrazosulfuron-ethyl, butachlor, orthosulfamuron, acetochlor + bensulfuron methyl, butachlor + propanil and 2,4-D amine) in strip tilled non-puddled field condition at Mymensingh, Bangladesh to evaluate their weed control efficacy singly or in sequences, their cost-effectiveness and residual effect on the succeeding crops like wheat and lentil. Sole application of herbicide was less effective to control all types of weed species than sequentially applied herbicides. Sequential application of pre-and late post-emergence, early post-and late post-emergence or pre-, early and late post-emergence herbicides controlled weeds by 46-98% and 43-95%, respectively in terms of weed density and biomass. Sequential application of pyrazosulfuron-ethyl followed by orthosulfamuron and butachlor + propanil provided the most effective and economic weed control under this new rice establishment practice. Moreover, the study suggested a range of effective herbicides for strip-tilled non-puddled wet season rice, but possible rotation of those herbicides in a sequential application is needed. Additionally, residue of those herbicides did not show any adverse effect on the succeeding crops of rice like wheat and lentil. However, further research is needed with various new molecules of herbicide and their residual effect on the subsequent crop as well as soil environment.

This paper presents the first reports on the natural and anthropogenic radionuclides in soil and sediment of Jessore, a south-western district of Bangladesh. Surface soil and freshwater sediment were collected from in and around some major water-bodies of this district. To assess the radiological hazard of the natural radioactivity, the radium equivalent activity, the absorbed dose rate, and the external and internal hazard indices were calculated. In the soil and sediment in general, the activity concentration of 232 Th was found to be higher than that of 226 Th in this area were found to be higher than the world average. There was no activity due to fallout ( 137 Cs) in this area. The radium equivalent activity and the absorbed dose rate due to the natural radionuclides were found to be respectively lower and higher than the world average. The external and internal hazard indices were found to be well below the hazard limit of unity. Our results compare fairly well with other published results.

Three known compounds were isolated from the n-hexane extract of the rihzomes of Sansevieria hyacinthoides, they were two steriods; β-sitosterol (1) and daucosterol (2), and a flavonoid; isokaemferide (3). The structures of the compounds were elucidated on the basis of NMR spectral analysis as well as comparison with available data in the literature. All extracts and the three pure compounds were evaluated for their antimicrobial activity. The compounds showed moderate activity against Bacillus subtilis, Stapylococcus aureus, Salmonella typhi and Candida albicans.