Romel Ahmed

Allelopathic effects of leaf litters of Eucalyptus camaldulensis on some forest and agricultural crops

Allelopathic effects of different doses of Eucalyptus camaldulensis leaf litters were investigated through an experiment in the green house of Institute of Forestry and Environmental Sciences, Chittagong, Bangladesh. Three popular agricultural crops: Falen (Vigna unguiculata), Chickpea (Cicer arietinum), Arhor (Cajanus cajan) and two widely used plantation trees: Sada koroi (Albizia procera) and Ipil ipil (Leucaena leucocephala) were selected as bioassay species. Experiment was set on tray at room temperature 27°C. The effects of different doses of leaf litter extracts were compared to the control. Results suggest that leaf litters of E. camaldulesis induced inhibitory effects. It was also found that the effect depend on concentration of extract and litterfall, type of receiver species. Higher concentration of the materials had the higher effect and vice versa. Though all the bioassay species were suppressed some of them showed better performance. Vigna unguiculata, Cicer arietinum are recommended in agroforestry based on this present Experiment output. In mixed plantation, Leucaena leucochephala is a better choice while compared to Albizia procera.

Allelopathic effects of Lantana camara on germination and growth behavior of some agricultural crops in Bangladesh.

An experiment was conducted to understand the growth inhibitory effects of aqueous extracts derived from Lantana camara L. (a globally recognized invasive alien weed) on six popular agricultural crops of Bangladesh. The test was conducted in sterilized petridishes with a photoperiod of 24 hours and an average temperature of 29°C. The effect of different concentrations of L. camara leaf extracts were recorded and compared with control (i.e., distil water). Result showed different concentrations of aqueous leaf extracts caused significant inhibitory effect on germination, root and shoot elongation and development of lateral roots of receptor crops. Bioassays also indicated that the inhibitory effect was proportional to the concentrations of the extracts and higher concentration had the stronger inhibitory effect whereas the lower concentration showed stimulatory effect in some cases. The inhibitory effect was much pronounced in root and lateral root development rather than shoot and germination.

Inhibitory effects of Albizia lebbeck leaf extracts on germination and growth behavior of some popular agricultural crops

An experiment was conducted to observe the inhibitory effects of the leaf extracts derived from Albizia lebbeck (L.) Benth. on germination and growth behavior of some popular agricultural crops (receptor) of Bangladesh. Experiments were set on sterilized petridishes with a photoperiod of 24 h at room temperature of 27–30°C. The effects of the different concentrations of aqueous extracts were compared to distil water (control.). The aqueous extracts of leaf caused significant inhibitory effect on germination, root and shoot elongation and development of lateral roots of receptor plants. Bioassays indicated that the inhibitory effect was proportional to the concentrations of the extracts and higher concentration (50%–100%) had the stronger inhibitory effect whereas the lower concentration (10%–25%) showed stimulatory effect in some cases. The study also revealed that, inhibitory effect was much pronounced in root and lateral root development rather than germination and shoot growth.

Allelopathic effects of Leucaena leucocephala leaf litter on some forest and agricultural crops grown in nursery

An experiment was conducted to assess the effect of leaf litter of Leucaena leucocephala on two forest crops Sada koroi (Albizia procera), Ipil ipil (L. leucocephala) and three agricultural crops Falen (Vigna unguiculata), Chickpea (Cicer arietinum) and Arhor (Cajanus cajan) in the nursery of the Institute of Forestry and Environmental Sciences, Chittagong University, Bangladesh, in a Randomized Block Design. Results suggested that leaf litters of L. leucocephala induced inhibitory effects on germination and growth of bioassay. It was also found that the effect depended on concentration of extract and litterfall, type of receptor species. Higher concentration of the materials had the higher effect and vice versa. Growth response of receptor crops varied with the variation of leaf litter application. The study revealed that application of low-dose leaf litter specially litter of 10 g·m−2 had stimulating effect on shoot growth of C. arietinum, V. unguiculata and A. procera. While in all other cases significant inhibitory effect was observed and it was significantly increased with the increase of leaf litter application. However, the trend of inhibition was uneven with treatments. Root growth was found to be more affected than shoot growth.

Management and economic value of Schumannianthus dichotoma in rural homesteads in the Sylhet region of Bangladesh

Schumannianthus dichotoma (Murta) is widely grown in wetland areas of Bangladesh, providing the raw material for prayer and bed mats and also minimizing flood risk and soil erosion. The study was carried out in two villages in Gowainghat Thana (subdistrict) in Sylhet district, to determine techniques for traditional management of Murta plantations and its role in the household economy. On average, about 13% of the total homestead area is used for Murta plantations. Propagation was from rhizomes and branch cuttings, and little intensive management was required. Harvesting was usually done annually, from mid-September to the end of March. Three-quarters of respondents were directly involved in Murta-based cottage enterprises, providing an average annual income of US

Water stress effects on growth of dipterocarpus turbinatus seedlings

216: 43% of total income. Net average profit per man-day from selling articles varies from US

Rattan husbandry and its potentiality for income generation in the village groves of floodplain area of Bangladesh

0.23 to 0.73. Middlemen make significant profits, due to lack of marketing knowledge and available market information and marketing facilities of the villagers. The cultivation and processing of Murta has great potential for the rural economy of such areas.

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

Selecting the right species for the right location is a challenge for the forestry industry in Bangladesh, given the increasing risk of extreme weather and geophysical events posed by climate change. The occurrence of prolonged drought in northern Bangladesh has highlighted the need for drought‐resistant plant varieties in this region. The present study reports growth and yield performance of Dipterocarpus turbinatus (Garjan) seedlings grown under two different soil water supply regimes: watered control (WC) and unwatered (UW) for over a period of 40 days. Seedlings were grown following assignment to WC or UW groups by a completely randomized block design. Growth was in black polythene tubes containing a 3:1 compost mixture of nursery soil and cow dung. The experiment was conducted in the nursery of Institute of Forestry and Environmental Sciences, University of Chittagong. Growth and yield of D. turbinatus declined in the water‐limited condition along with the reduction of shoot water content. A strong relationship between soil moisture content and shoot water content was evident. Total plant mass production also declined in the absence of water due to the significant reduction in stem elongation and leaf expansion, which eventually influenced root, stem and leaf mass production. UW seedlings displayed marked recovery in stem elongation and leaf expansion with simultaneous influence in total mass and root mass, within a few days of re‐watering. The results indicate the potential of D. turbinatus as a drought‐resistant tree species.

Allelopathic Effect of Different Concentration of Water Extracts of Acacia auriculiformis Leaf on Some Initial Growth Parameters of Five Common Agricultural Crops

This paper focuses on the husbandry of rattan, its processing, marketing and potentialities of raising the household income of the growers in the floodplain area of Bangladesh. The survey reveals that almost all the clumps (98%) are located in the pond and ditch site and around half of the clumps (48%) are found in the western site of the homesteads. Planting materials used for propagation are suckers and seeds, which are not bought from the market; rather, growers themselves supplied 72% from own source and the remaining 28% comes from neighbours and wildlings. All categorized growers, except the medium and large ones, tend the clumps where female and children were the majority (84%) of the labour force. All the growers, except the medium and large ones, are found to harvest rattan all the year round, while 82% of the growers maintain a three-year rotation. The contribution of rattan husbandry is on an average Tk. 1883 (about USD 32) per household per annum. It has been found that all of the landless and marginal growers (100%) market rattan by themselves, while all of the large category growers (100%) market rattan through middlemen.

Allelopathic Effects of Different Concentration of Water Extracts of Eupatorium odoratum Leaf on Germination and Growth Behavior of Six Agricultural Crops

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.