1. The study was carried out to find out the influence of adapted fertilization and insecticide application on reproductive potential and formation of dispersing morphs of mustard aphid, Lipaphis erysimi in mustard. 2. Two levels of nitrogen viz. 100, 120 kg/ha, and one level of potassium 60 kg/ha, with spraying of phosphamidon 100 EC (0.1%) at flower bud initiation, flowering, silique formation and development and silique maturity stages and no spraying were cross combined. One treatment with normal fertilizer dose accompanied by routine spray, and one with normal fertilizer dose without spray were considered to obtain 10 treatments and replicated three times in a RCBD. 3. The performance of aphids developing under different treatments was assessed in terms of formation of alatoid nymphs and alates, and reproductive features based on total and developed embryos and size of the largest embryo. 4. The study revealed that two sprayings, one at flowering and the other at silique formation, and development stages accompanied by K20(60) + N(100) or N(120) produced comparatively lower number of alatoid nymphs. 5. Rather than K, however, higher N reduced the formation of alates. 6. Variation in the number of total and well developed embryos, and in the size of the largest developed embryo was found during the crop season with a reduced value towards the end of the season.
Light intensity strongly regulates plant biomass production through the utilization of light energy for photosynthesis. To examine the characteristics of biomass productivity acclimated to light intensity in napiergrass, which is well known as being the plant with the highest biomass productivity among herbaceous plants, the responses of total dry matter weight (TDW), and leaf area (LA) to changes in light intensity were compared between napiergrass and maize plants. TDW in both plants decreased under the conditions of low light intensity but recovered at the same level as those in the control plants under the condition of full sunlight exposure after that. Dramatical changes in TDW to light intensity were observed in napiergrass plant. Leaf areas (LA) in both plants remained high over the examination period, and leaf area ratio (LAR) in the napiergrass plant also remained higher during shade treatment. By shading, the distribution ratio of dry matter to the leaves dramatically increased while it was decreased in the roots of the napiergrass plant. Higher allocation of dry matter to the leaves was associated with maintenance of high LA in the napiergrass plant during shade treatment. In contrast, the distribution ratio of dry matter to the roots increased and the difference in the composition of dry matter distribution between the control and shaded plants was not clearly observed in napiergrass plant at 12 days after shading. Substantial change in the ratio of dry matter distribution and maintenance of high LA would be associated with high acclimation to light intensity in the napiergrass plant.
Urea is the most dominant form of nitrogen fertilizer being used in Bangladesh. To avoid urea N losses, point placement of urea super granule (USG) has been developed and is being popularized in the country, particularly in rice production. The objective of the present experiment was to study the suitability of applying USG deep point placement in upland vegetable crops, such as potato. The experiment was set up in two agroecological zones in Bangladesh, those being: Old Brahmaputra Floodplain at Bangladesh Agricultural University (BAU) farm, and Madhupur Tract at Madhupur farmer's field. Treatments used in both the experiments were the same, viz. (1) Control (-N), (2) Urea broadcast (109 kg N ha-1), (3) USG point placed (73 kg N ha-1) and (4) USG point placed (109 kg N ha-1). Point placement of USG, particularly at the higher N rate, greatly increased the yield of potato tubers both at BAU farm and at farmer's field in Madhupur. The yield increases of the tubers with USG at higher N rate 109 kg N ha-1 at BAU farm were 131.63% over control and 37.89% over urea applied broadcast (at the same N rate of 109 kg N ha-1), while at Madhupur farmer's field the yield increases were 75.96% and 27.52%, respectively. Point placement of urea super granule (USG) appeared highly promising in increasing potato production.
1. A study was conducted at Bangabandhu Sheikh Mujibur Rahman Agricultural University Gazipur, Bangladesh from October 2002 to May 2003 to determine the diversity index and equitability of insect community with four different intercrops in brinjal (Solanum melongena). 2. Results revealed that intercropping generally produced greater diversity index of insect community. 3. Richness of taxonomic categories was lower in intercropping systems compared to the combination of their component sole crops. 4. A combination of pitfall trapping and sweep netting methods for capturing the insects over the whole crop growth period revealed a highly significant positive relationship between richness (x) and diversity index (y), but a negative relationship between richness (x) and equitability (y).
The utility of fatty acid methyl ester (FAME) profiles for characterization and differentiation of isolates of Fusarium spp. was investigated. The modified MIDI method were used and allowed a clear differentiation among isolates of F. oxysporum, F. solani and F. roseum. FAME profiles using the modified MIDI method gave the most consistent and reproducible analyzed fatty acid data. After evaluating the FAME profiles by cluster analysis, tested isolates were presented the close correlation of FAME profiles with variation in the species level. Results indicated that FAME profiles could be an additional tool useful for characterizing isolates and forma species of F. oxysporum.
A laboratory experiment was conducted to document the effect of organic and inorganic amendments on soil P fractions under submerged conditions and to gain understanding of the changes in different P pools under prolonged submergence. Initial soil samples were collected from cultivated rice fields in Sreepur (Aerie haplaquept), Bangladesh Rice Research Institute (BRRI) Farm, Gazipur (Vertic haplustept) and Satkhira (Vertic haplaquept) and were incubated (28° ± 2°C) under submerged conditions in plastic pots amending with cowdung, poultry manure @ 10 t ha-1 each and triple super phosphate (TSP) @ 25 kg P ha-1 individually. The Sui fractionation scheme [dividing soil P into six empirical fractions (solution-P, labile-P, inorganic-P, organic-P, acid-P and residual-P)], with some slight modification, was employed at two intervals, 60 and 120 days after submergence (DAS). The solution-P, labile-P and inorganic-P fractions were increased significantly due to the use of organic amendments but TSP did not increase those fractions significantly. The organic-P pool (NaOH-Po), although contributing the largest fraction of soil P, was not greatly affected by any of the amendments but it was noticeably reduced with the application of poultry manure. Acid-P (HC1 soluble-P) significantly increased due to the application of cowdung and poultry manure amendment and it jumped tremendously up to (140-1400%) at 120 DAS from that of 60 DAS. The relative change (%) in acid-P between two periods of measurement was found significantly higher in control than manure amendments. A slight increase in residual-P was observed due to the use of organic amendments. Three soils varied greatly in different P pools where Satkhira soil ranked at the top, followed by BRRI and Sreepur soil. Solution-P, labile-P and organic-P were larger at 60 DAS than at 120 DAS, while inorganic-P (NaOH-Pi) and acid-P were higher at 120 DAS than at 60 DAS due to the longer period of submergence. In addition, residual-P remained stable and these trends were very pronounced in the case of the poultry manure treated soils in most cases.
A study was undertaken to find out the effect of ethrel (2-chloroethane phosphoric acid) treatment on flower production and fruit yield of snakegourd (Trichosanthes anguina L.). Seedlings of the crop at 2-true leaf stage and 4- true leaf stage were sprayed with ethrel solution at 0, 25, 50 and 100 ppm. It was found that ethrel spray reduced the days to first female flowering, and increased the number of female flowers. On the contrary, the hormone increased the days to appearance of first male flower and increased the node number from the bottom bearing first male flower. Suppression in number of male flowers was observed at all concentrations as compared to control. The effect of ethrel on number and weight of fruit per plant and fruit dimension was not significant.
Two separate field experiments were carried out in two different agro-ecological zones in Bangladesh. The experimental sites selected were the Bangladesh Agricultural University (BAU) farm in Mymensingh and a farmers' field in Madhupur. The objective was to investigate the response of super granules of urea (USG), Urea-DAP and NPK on HYV rice crops. Soil types under investigation at both the BAU farm site and at the Madhupur farmers' field were silt-loam in texture and poor in nutrient status. The soil reaction was mildly acidic (pH 6.8) at the BAU farm, while it was strongly acidic at the Madhupur farmers' field (pH 5.5). Fertilizer treatments used in the experiments were (1) Control (without any fertilizer), (2) Urea (70 kg N ha-1 from urea), (3) USG (52 kg N ha-1 from USG super granule), (4) Urea-DAP SG (52 kg N and 20 kg P2O5 ha-1 from Urea-DAP super granule) and (5) NPK SG (52 kg N, 20 kg P2O5 and 20 kg K2O ha-1 from NPK super granule). In treatments 2-3, P, K, S and Zn fertilizers were applied as basal @ 40 kg P2O5, 40 kg K2O, 20 kg S and 3 kg Zn ha-1 respectively. In treatment 4, K was applied as basal @ 40 kg K2O ha-1 along with S and Zn as in treatments 2-3, while in the case of treatment 5, S and Zn were applied as basal as in treatments 2-3. USG, Urea-DAP, and NPK super granules were point placed after 7 days of transplanting at a depth of 7 centimeter between every fourth rice mound. Each treatment was replicated four times in a completely randomized block design. Test crops used were HYV rice, BR-30 at the BAU farm and BR-11 at the Madhupur farmers' field. The experiments were conducted during the wet season (July-November) of 2001. Point placement of USG, Urea-DAP and NPK super granules greatly increased the grain yields of rice. The highest increase in grain yield was recorded in NPK super granule followed by Urea-DAP and USG point placemen at both of the experiment site. The maximum grain yield at the BAU farm recorded was 6.23 t ha-1, while at the Madhupur farmers' field it was 5.73 t ha-1 using the NPK super granule point placement. The minimum yields of rice grain were obtained in the control treatment at both the BAU (3.41 t ha-1) and Madhupur farmers' field (3.22 t ha-1). Point placement of USG and multi-nutrient fertilizers in super granules both NP and NPK appeared to be highly promising for application on wetland rice.
Cocoa samples from hybrid criollo and forastero cocoa on Inang Sari Estate in West Sumatra was dried with three methods using sun dryer until the moisture content reach at 7%; mechanic (tunnel dryer), and the combination of both of sun dryer until the moisture content reach at 20% and tunnel dryer at 60°C which was continuously treated for 18 hours. The observations have been carried out to evaluate the effect variations in pH, total amino acid, total reduction of sugar content and characteristic flavor of Indonesian cocoa beans treated in comparison with those of Ghanaian beans. The result showed that the cotyledon from treated beans has reached the highest level of pH, total amino acid content, total reduction of sugar content, flavor characteristics in the use of the combination with drying methods of sun dryer and tunnel dryer.
Research entitled effect of the size of raw material on oleoresin content and quality of unripe fruits nutmeg fuli (Myristica fragrans HOUTT) has been conducted in laboratory of station for testing certification of product quality (BPSPB), trade department in air tawar padang, west sumatera since February until May 2005. The objective of this research was to study the effect of the size of raw material on oleoresin content and quality of unripe fruits nutmeg fuli. Completely randomized design (CRD) with 6 treatment and 3 replicates was employed in this research. Data collection was analyzed statistically using F-test and then continued using Duncan's New Multiple Range Test (DNMRT) at significant level 5%. The treatment were original material (A), 10-mesh sizing; material (B), 20-mesh sizing; material (C), 30-mesh sizing; material (D), 40-mesh sizing; material (E) and 50-mesh sizing; material (F), respectively. Parameter measurement was oleoresin content, volatile oil content, specific weight, bias index, and solvent residue. The result showed the size of raw material in influence to oleoresin content, volatile oil content, specific weight, bias index, and solvent residue. The best result was found from E treatment (40-mesh sizing material) with 39.88% oleoresin content, 35.24% volatile oil content, 1.004 specific weights, 1.49 bias indexes, and 3.56% solvent residue.