Characterization of dhaincha accessions based on morphological descriptors and biomass production
Forty five accessions of dhaincha germplasms were collected from different parts of Bangladesh and characterized on the basis of morphological descriptors and biomass production ability. Thirty eight accessions were identified as Sesbania bispinosa, four as S. cannabina and two as unidentified Sesbania spp. One accession as S. rostrata was included for comparison. Both at seedling and maturity stages, wide and significant differences were observed among the accessions of different dhaincha germplasms for their biomass production capability and other morphological descriptors. At the seedling stage, total dry mass (TDM) production varied from 10.2 to 41.6g 30-plants–1. At the maturity stage, plant height, total number of branches and base diameter of dhaincha germplasms varied from 347.5–474.7cm, 10.4–23.7, and 1.9–4.9cm, respectively. The highest amount (4.10kg 10-plants–1) of above-ground TDM was produced in one accession of unidentified Sesbania sp. followed by S. rostrata and one accession of S. cannabina (3.85kg 10-plants–1), and the lowest TDM (0.9kg 10-plants–1) was measured in two accessions of S. bispinosa. It may be concluded that the biomass production capability of at least two accessions of local Sesbania germplasms were higher/comparable to that of exotic S. rostrata. It will be too early to make a conclusive remark based on only a few dhaincha germplasms. A detailed study with a large number of germplasms collected from whole Bangladesh is obviously needed to reach in a precise conclusion.
Variation of chemical characteristics and pulpability of dhaincha (Sesbania bispinosa) on location
Dhaincha ( Sesbania bispinosa ) is a crop generally cultivated for improving soil quality. Due to the lack of forest worldwide, alternative source of raw materials for cellulose industries is the main concern today. In this investigation dhaincha samples were collected from 21 accessions of different districts of the country in order to study variation of chemical characteristics and its pulpability. The lignin, pentosan and α –cellulose content were varied from 21 to 23%, from 16 to 18% and from 38 to 43%, respectively. The highest and lowest α –cellulose content were found in two location of Mymensngh district. There was no correlation was found among the district. Therefore, pulping of dhaincha from selected seven districts was carried out in kraft process at the conditions of 18% active alkali at 170 o C for 2 h. But the pulping properties did not show any mentionable distinction for place variation. Average pulp yield is 42.9% with kappa number 11. The highest brightness 85% ISO was reached with D 0 E p D 1 bleaching. The papermaking properties were very close to the conventional raw materials used in Bangladesh. Therefore, dhaincha can be used as a raw material for pulp production in Bangladesh.
The infection process, sporulation and survival of Alternaria helianthi on sunflower
SUMMARY 
 
Electron microscopy was used to study the infection of sunflower leaves by Alternaria helianthi. Conidia germinated by producing one to many germ tubes which grew across the leaf surface before forming appressoria. The fungus directly penetrated its host through the cuticle and epidermis. Entry into the host through wounds and stomates was also observed. Extracellular sheaths were found to be associated with germ tubes and intercellular hyphae of A. helianthi. Conidiophores developed through collapsed stomates, from leaf veins, trichomes and also from mycelium growing across the host leaf surface. Microcylic conidia were produced directly from parent conidia under certain conditions. Studies using a volumetric spore trap showed that the airborne spore concentration followed a distinct periodicity with peaks occurring between 0900 and 1100 h each day. Laboratory studies showed that safflower, noogoora burr and bathurst burr could serve as alternative hosts for A. helianthi. The pathogen was readily isolated from sunflower crop debris from a diseased crop that had been harvested 1 yr earlier.