International Letters of Natural Sciences Vol. 69

Abstract: A pot experiment was carried out at the Laboratory of Department of Agronomy, Hajee Mohamad Danesh Science and Technology University (HSTU), Bangladesh during 2016 to evaluate the response of maize varieties at germination and seedling growth stages under salt stress. The seeds of the BARI (Bangladesh Agricultural Research Institute) developed four maize varieties viz. Barnali, Khoi Vutta, Mohor and BARI Maize 5 were placed in plastic pots (each of 25 cm length and 12 cm width) on sand bed irrigated with tap water (control), 100 and 200 mM NaCl salt solutions. It was replicated in thrice with completely randomized design (CRD). Salinity stress significantly affected the germination characters and seedling growth parameters of maize varieties. The germination percentages (GP) and germination rate (GR) reduced significantly with increasing salinity, and the variety Khoi Vutta showed the highest GP and GR followed by Barnali and Mohor showed the lowest GP and GR followed by BARI maize 5. Under high salinity level, seedling growths characteristics like shoot and root lengths, fresh and dry weight of shoot and roots reduced remarkably in the variety Mohor indicating salt susceptible while the minimum reduction of the aforementioned traits was observed in the variety Khoi Vutta demonstrating high salt tolerant variety. The studied varieties can be ranked on the basis of salt tolerance as Khoi Vutta > Barnali > BARI Maize 5 > Mohor from the experiment.

Abstract: Air pollution in Pakistan is causing damage to health, environment and quality of life. Air pollution in Pakistan is not effectively monitored due to heavy cost involved in setting up ground stations. However, Satellite remote sensing can effectively monitor the air pollution in terms of Aerosol Optical Depth (AOD) at regional as well as global level. However, algorithms used to derive AOD from different sensors have some inherited differences which can pose challenges in monitoring regional AOD at high temporal resolution using more than one sensor. Therefore, this study focuses on comparison of four major satellite based AOD products namely Moderate Resolution Imaging SpectroRadiometer (MODIS), Multi-angle Imaging SpectroRadiometer (MISR), Ozone Monitoring Instrument multiwavelength (OMI) aerosol product and Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) with the ground based AErosol RObotic NETwork (AERONET) AOD which is only available from Lahore and Karachi in Pakistan. The correlation of various AOD products with AERONET AOD is estimated statistically through coefficient of determination (R²), Root Mean Square Error (RMSE), slope and intercept. It is noticed that MODIS is relatively accurate and reliable for monitoring air quality on operational bases over the land cover area of Lahore (R² = 0.78; RMSE = 0.18 ), whereas MISR over the coastal areas of Karachi (R² = 0.82; RMSE = 0.20 ). The results of the study will help the stakeholders in planning additional ground stations for operational monitoring of air quality at regional level.

Abstract: The authors carried out in the fieldwork with a new variety of amaranth «Lipetsky». In order to identify qualitative and quantitative laws of manifestation of the total antioxidant activity of amaranth the leaves were collected in different phases of plant vegetation, dehydrated in mild conditions of air-shadow drying and subsequently dried under harsh conditions 105º C to a constant mass of samples. Testing of plant samples was carried out using a coulometric method of titration (author's method) of free bromine radicals generated in the aquatic environment by plant titrant (water extract dried in the shade at a temperature of 22º±3°C of leaves). It was examined the combined samples of 10 samples of plant leaves of different tiers and of different ages with field plot of 10 ha. Biometric averages of plants during the growing season: growth, the weight of plants, number of leaves, the weight of leaves, stem and inflorescence of the plant are given. This shows the dynamics of total antioxidant activity of leaves of amaranth during the growing season. The thermal stability of the total antioxidant activity (TAA) for combined extracts of 10 samples of leaves of different ages and from different parts of plants when they are drying at 105°C was tested. The dynamics of change, TAA aqueous extracts of the dried amaranth samples with different stages of the growing season corresponds to the previously identified trends in the availability of high quantitative values in the phase of mass budding beginning of flowering and minima in the initial growth phases (3-8 leaves) and ripening of seed for different varieties of amaranth. There were revealed the increase in antioxidant activity upon drying amaranth samples at 105°C, revealed a new type of qualitative dynamics of TAA, while vegetation with a characteristic quantitative changes by more than 50% for the beginning of the growth phase (the first phase of 3-8 leaves) and the final phase of seed maturation.

Abstract: Brinjal (Solanum melongena L.) suffers from the attack of various pests throughout its cropping season. Different insecticides are used to control these pest infestations. The application of these insecticides on brinjal plants may have an effect on its quality and nutritional parameters of fruit samples. In the present study effect of three different insecticides viz. Triazophos 40% E.C Carbaryl 50% W.D.P, Cypermethrin 10% E.C, and Azadiractin 10000 ppm formulation belonging to different groups namely Organophosphate, Carbamate, Synthetic pyrethroids and Botanical insecticide on brinjal fruit quality, nutritional parameters and Total antioxidant capacity (TAC) were assessed in field conditions. The results showed that different insecticide at field application dose showed minute insignificant variation in fruit nutritional and total antioxidant activity parameters in comparison to the control samples. The fruit quality parameters also showed minute variation in comparison to the control except in the case of Triazophos treated samples which showed significant variation (p<0.05) in titrable acidity, total soluble sugar content and crude protein.