Leaf area estimation by linear regression modles for pigenonpea (Cajanus Cajan (L.) Millsp.)

Leaflet length (L) and breadth (B), fresh (LFwt) and dry weights (LDwt) of leaves of 50 samples (500 leaves, 10 in each sample) were used in the prediction model to estimate the leaf area (LA) in pigeonpea (Cajanus cajan cajan (L.) Millsp.). Two of the fifteen linear regression models, appeared more suitable for ease of measurement. These were LA = -17.784 + 6.823 L (Model-1) and LA = 0.5855 + 67.583 LFwt (Model-10). These regression models showed linear relationship when actual leaf area was plotted against predicted one in another 30 leaf samples (300 leaves, 10 in each sample). Moreover, models’ selection indices had high predictive ability represented by high R2 value with minimum error (low means square error and smaller percentage deviation). The selected models appeared unsophisticated but accurate, easy and rapid which can be used for estimation of leaf area of pigeonpea (Morphotype ‘Bogra’)

Drought and salinity affect leaf and root anatomical structures in three maize genotypes

Salt and drought stresses are being quite similar considered as two major constraints in maize production. To explore the anatomical bases of resistance to salt and drought stresses, 14 days old seedlings of three maize hybrid genotypes were subjected to salt (100 mM NaCl) and drought stress (equiosmotic PEG-6000) under hydroponic conditions. The experiment was laid out following a completely randomized design having four replicates. Root protoxylem and metaxylem thickness and root diameter were found to be unaffected in both of the drought resistant genotypes in response to salt and drought stresses whereas root protoxylem thickness increased (33.8 and 112.8% by salt and drought stress, respectively) in sensitive genotype (BARI hybrid maize-7). Bundle sheath thickness was found to increase in response to stresses (58.4 and 59.3% by salt and drought stress, respectively) in BARI hybrid maize-12. BARI hybrid maize-12 showed unaffected response in leaf epidermal thickness, phloem area, xylem area and total leaf thickness under both salt and drought stresse

Effect of defoliation on growth, reproductive characters and yield in mungbean [Vigna radiata (L.) Wilczek].

Loss of foliage in mungbean [Vigna radiata (L.) Wilczek] crop through leaf eating insects and diseases is common in tropical and sub-tropical countries where farmers do not protect their crops adequately. Experiments were carried out with eight levels of defoliations (0, 25, 50 and 75% either from top or from base of the canopy, and 100%) to investigate the growth, reproductive characters, and yield attributes in two high and two low yielding mungbean genotypes. Results revealed that degrees of defoliations parallely decreased leaf area and total dry matter (TDM) production irrespective of seasons and genotypes. Defoliation not only reduced source sizes but also decreased total sink (flower) production resulting in lower pod and seed yields. However, basal 25% defoliation did not significantly decrease TDM and seed yield plant-1 indicating the fact that the mungbean plant, in general, can tolerate 25% basal leaf loss of the canopy. Furthermore, the high yielding genotypes showed higher compensatory mechanism of source loss than the low yielders. Exceeding this threshold limit (> 25%) either from the base or from the top of the canopy defoliation significantly reduced TDM and seed yield. Reduction in yield was higher with top defoliation than basal defoliation. Implication of the results in relation to pest management is also discussed

Effects of flowering behavior and pod maturity synchrony on yield of mungbean [Vigna radiata (L.) Wilczek].

A number of experiments were set up to assess the flower production and flowering pattern in synchrony with pod maturity and seed yield in twelve mungbean genotypes. Synchrony of pod maturity was measured based on percentage of mature pods at first harvest, where; synchrony (>90% mature pods), partial synchrony (80-90% mature pods) and asynchrony (<80% mature pods). Results revealed that genotypes that produced maximal opened flowers within 10-15 days, and ceased flowering within 15-20 days after first flowering (DAF), have synchrony in pod maturity. Additionally, seed yield was strongly correlated with the number of opened flowers and number of produced mature pods. Four genotypes showed synchrony in pod maturity which accompanied with cessation of flower production at 10-15 DAF, but produced lower yields due to fewer opened flowers. In contrast, the remaining genotypes showed partial synchrony or asynchrony in pod maturity due to longer flowering durations, with higher number of opened flowers and seed yield. These results indicate that synchrony in pod maturity and seed yield in mungbean is inversely related

Comparative studies on germination and seedling growth of on-season and off-season produced jute seeds

To overcome the problems of crop loss and prolonged period of land engaged for jute seed production in on-season, the off-season production of jute seeds is being practiced but the seed quality of both these systems has not been thoroughly compared to get better seeds for higher yield in jute. Considering the above facts, the present research was carried out to perform a comparative study among different parameters, such as, germination and seedling growth of on-season and off-season produced seeds of Corchorus capsularis (Variety CVL-1) and Corchorus olitorius (Variety O-9897). In this study, significant influence of production period of seeds on germination percentage, seedling vigour index, germination coefficient, shoot length, root length, shoot and root dry weight, ratio of root dry weight and shoot dry weight was observed. The highest seed germination percentage, seed germination co-efficient, seedling vigour index, shoot and root length, shoot and root dry weight, ratio of root dry weight and shoot dry weight were found in off-season Deshi jute seeds followed by on-season Deshi and off-season Tossa jute seeds. The lowest value of each of these properties was found in case of on-season Tossa jute seeds and seedlings. Based on the findings of this study, it may be concluded that off-season produced jute seeds showed better performance than those of on-season jute seeds in both the species in terms of seed germination and other relevant characters. [Fundam Appl Agric 2019; 4(2.000): 777-784

Quinoa – A Functional Food Crop: Morphological Descriptors

Quinoa (Chenopodium quinoa Willd.), one of the oldest cultivated plants of Andes, has gained worldwide attention for its ability to grow in various stressful conditions and also due to its various health-promoting characteristics i.e., easily digestibility with high amounts of protein, vitamin B, omega-3 fatty acids, and others. To study (in detail) on morphological descriptors of four quinoa genotypes, an experiment was conducted at the Field and Laboratory of Plant Systematics, Department of Crop Botany, Bangladesh Agricultural University during Rabi season (November 2020 to March 2021) following a Randomized Complete Block Design with three replications. A spacing of 25 cm x 10 cm was used. Weeding and irrigation operations were done twice at 20 and 40 days after sowing. Quinoa plants are characterized by the angular stem, red-green, leaf rhomboidal, green, panicle shape intermediate showing both shapes – glomerulate and amarantiform, panicle green at the flowering and became pink at the physiological maturity stages. Plant height and stem diameter were ranged between 60.17-65.65 cm and 4.22-4.58 mm, respectively. The percentage of red and red-green coloured stem, number of teeth leaf–1 and leaf area were significantly influenced by genotypes and ranged between 20.00-46.58%, 53.31-80.00%, 5.60-9.10 and 4.84-6.01 cm2, respectively. Pollen grains are monads, medium in size, 42.99-51.30 µm, polypantoporate, scabrate (microechinate), and exine thickness 2.08-2.40 µm. Panicle length and width, 1000-seed weight and seed yield varied between 31.16-37.23 cm, 3.66-4.37 cm, 3.14-3.43 g and 2.66-3.86 g plant–1, respectively. Among the genotypes, G2 was most productive in the environmental conditions of Mymensingh region. Qualitative morphological traits can be used as markers in the description and characterization of quinoa genotypes. The variation existing among the quinoa genotypes could prove useful in the breeding programs. [J Bangladesh Agril Univ 2023; 21(1.000): 12-22

Phytofabricated Silver Nanoparticles (AgNPs) Applied in Vase Solution as a Novel Anti-Microbial Agent for Enhancing the Vase-life of Cut-Rose Flower

Plant extract has been exploited for biogenic synthesis of metallic nanoparticles. This is considered as the promising alternative routes of chemical and physical synthesis methods owing to their abundancy in nature and ecofriendly friendly synthesis protocol. Rose is the top-ranked and universally favorite cut flower. Poor post-harvest management deteriorates the quality and reduces the vase life. Microbial proliferation of the stem base in the vase solution is a concern for these cut flowers that shortens their vase-life. To overcome this problem, a smart solution i.e. phytofabricated silver nanoparticles have been shown to act as anti-microbial agent. In this study, leaf extracts of Camellia sinensis were exploited to fabricate biogenic silver nanoparticles which showing UV-peak absorption ranging from 412-500 nm. This biogenic silver nanoparticles were applied @ 0.01, 0.05 and 0.1mM and compared with a control (without AgNPs) and silver nitrate (AgNO3). Interestingly, AgNPs showed a strong antimicrobial activity in vase solution and cut roses extended their vase life up to 13 days compared to 8 days in control and 9 days in AgNO3. Statistical differences in flower opening, bacterial growth (CFUmL−1) in vase solutions, water uptake, relative fresh weight and vase life of cut roses were found among treatments. In vitro microbial analysis and microscopic investigation of vessels showed that the development of microorganisms was reduced by a high concentration of AgNPs (0.1mM) at the cut end of flower and improving water uptake that followed by extended flowers vase life. The unique phytofabricated AgNPs technology can serve as a promising preservative to increase the ornamental value of cut rose flowers. Taken all together, applied phytofabricated AgNPs in vase solution significantly enhance vase life of cut rose flowers over control. [J Bangladesh Agril Univ 2022; 20(2.000): 133-140

Evaluation of the Tolerance Ability of Wheat Genotypes to Drought Stress: Dissection through Culm-Reserves Contribution and Grain Filling Physiology

Drought stress is one of the limiting factors for grain filling and yield in wheat. The grain filling and determinants of individual grain weight depend on current assimilation and extent of remobilization of culm reserves to grains. A pot experiment was conducted with eight wheat cultivars at the Pot House to study the grain filling and the contributions of reserves in culm, including the sheath to grain yield under drought stress. Drought stress was enforced by restricting irrigation during the grain-filling period. The plants (tillers) were harvested at anthesis, milk-ripe, and maturity. The changes in dry weights of leaves, culm with sheath, spikes, and grains; and the contribution of culm reserves to grain yield were determined. Results revealed that drought stress considerably decreased the grain filling duration by 15�24 and grain yield by 1