Nitrous oxide emissions from kharif and rabi legumes grown on an alluvial soil

Nitrous oxide (N₂O) emissions were monitored for a period of 60 days in a pot culture study, from two kharif (June-September) and two rabi (October-March) season legumes, which were grown on a Typic Ustochrept, alluvial sandy loam soil. Black gram (Vigna mungo L. Hepper), var. T-9, and soybean (Glycine max L. Merril), var. Punjab 1, were taken up in kharif season whereas lentil (Lens esculenta Moench), var. JLS-1, and Bengal gram (Cicer arietinum L.), var. BGD-86, were grown in rabi season. All the crops were grown with and without urea and one pot (containing soil but with no fertilizer or crop) was used as a control. Nitrous oxide emissions were significantly higher in unfertilized cropped soil than in the control, while the addition of urea to the crops further increased the emissions. Significant emissions occurred during third and seventh week after sowing for all the treatments in both kharif and rabi seasons. In kharif, soil cropped with soybean had higher total N₂O-N emission than soil sown with black gram both under fertilized and unfertilized conditions; while in rabi, lentil had a higher total N₂O-N emission than Bengal gram under both fertilized and unfertilized conditions. In kharif, total N₂O-N emissions ranged from 0.53 (control) to 3.84 kg ha^-1 (soybean+urea), while in rabi it ranged from 0.45 (control) to 3.06 kg ha^-1 (lentil+urea). Higher N₂O-N emissions in kharif than in rabi was probably due to the favorable effect of temperature on nitrification and denitrification in the former season. The results of the study indicated that legume crops may lead to an increase in N₂O formation and emission from soils, the extent of which varies from crop to crop.     

Effects of stocking density of freshwater prawn Macrobrachium rosenbergii and addition of different levels of tilapia Oreochromis niloticus on production in C/N controlled periphyton based system

An on-station trial was conducted to evaluate the effect of stocking density of freshwater prawn and addition of different levels of tilapia on production in carbon/nitrogen (C/N) controlled periphyton based system. The experiment had a 2 × 3 factorial design, in which two levels of prawn stocking density (2 and 3 juveniles m^? 2) were investigated in 40 m² earthen ponds with three levels of tilapia density (0, 0.5 and 1 juveniles m^? 2). A locally formulated and prepared feed containing 30% crude protein with C/N ratio close to 10 was applied considering the body weight of prawn only. Additionally, tapioca starch was applied to the water column in all ponds to increase C/N ratio from 10 (as in feed) to 20. Increasing stocking density of tilapia decreased the chlorophyll a concentration in water and total nitrogen in sediment, and increased the bottom dissolved oxygen. The concentrations of inorganic nitrogenous species (NH₃–N, NO₂–N and NO₃–N) were low due to maintaining a high C/N ratio (20) in all treatment ponds. Increasing prawn density decreased periphyton biomass (dry matter, ash free dry matter, chlorophyll a) by 3–6% whereas tilapia produced a much stronger effect. Increasing stocking density of freshwater prawn increased the total heterotrophic bacterial (THB) load of water and sediment whereas tilapia addition decreased the THB load of periphyton. Both increasing densities of prawn and tilapia increased the value of FCR. Increasing prawn density increased gross and net prawn production (independent of tilapia density). Adding 0.5 tilapia m^? 2 on average reduced prawn production by 12–13%, and tilapia addition at 1 individual m^? 2 produced a further 5% reduction (independent of prawn density). The net yield of tilapia was similar between 0.5 and 1 tilapia m^? 2 treatments and increased by 8.5% with increasing stocking density of prawn. The combined net yield increased significantly with increasing stocking density of prawn and tilapia addition. The significantly highest benefit cost ratio (BCR) was observed in 0.5 tilapia m^? 2 treatment but freshwater prawn density had no effect on it. Therefore, both stocking densities (2 and 3 juveniles m^? 2) of prawn with the addition of 0.5 tilapia m^? 2 resulted in higher fish production, good environmental condition and economic return and hence, polyculture of prawn and tilapia in C/N controlled periphyton based system is a promising options for ecological and sustainable aquaculture.     

An alternative eco-friendly approach for sustainable crop production with the use of indigenous inputs under old alluvial soil zone of Burdwan,West Bengal,India

Experiments were conducted on mustard (Brassica campestris cv.B₉) in an old alluvial soil zone of Crop Research and Seed Multiplication Farm, Burdwan University, Burdwan, West Bengal, India, during the winter seasons of 2011–2012 and 2012–2013. The aim was to evaluate the use of vermicompost prepared from municipality waste and Eichhornia mixture and its efficacy on crop growth and yield. Different combined doses of vermicompost, dried cow dung and chemical fertilizer along with Azotobacter and phosphate-solubilizing bacteria compared to full recommended dose of chemical NPK fertilizer (100:50:50) were used to develop an alternative farming technology for sustainable crop production and conservation of natural resources. The variety B₉ gave a significantly higher seed yield and oil content along with other growth and yield-contributing factors as well as being the most economically viable option against treatment T4 (i.e. 75% NPK + vermicompost at 2.5 tons per hectare) among all the treatments applied for the experiment and was found to be superior to other treatments in old alluvial soil of Burdwan, India. In both the experimental years, seed yield and oil content were found to be the best for the treatment T4 and was better than using chemical fertilizer.     

Growth Analysis Using Classical and Functional Techniques in Relation to Soil Moisture in Mustard

A Reid experiment was conducted to study the effect of soil moisture on growth of two mustard cultivars using classical and functional techniques of growth analysis. Two soil moisture levels were irrigated at 10-day intervals and a rainfed control was included. Total dry matter (TDM), leaf area index (LAI) and leaf area duration (LAD) were significantly increased by irrigation at most of stages of growth. Starting from a lower value, LAI and LAD reached a peak and then gradually declined. Among the growth attributes, crop growth rate (CGR), leaf area ratio (LAR) and leaf weight ratio (LWR) increased significantly under irrigation. Net assimilation rate (NAR) decreased more in the irrigated plants than the rainfed plants at the later stages of growth. LAR and LWR declined throughout with increasing time and plant weight. Seed yield of the irrigated plants was positively correlated with the pre-flowering LAI and the post-flowering CGR and NAR. In the rainfed plants, seed yield was positively correlated with LAI and CGR at the post-flowering stage and negatively with the post-flowering NAR and pre-flowering LAR.     

Genetic Variance Estimates in Heterogeneous Potato Populations Propagated from True Potato Seed(TPS)

Twenty nine cross populations developed according to line x tester mating design along with their twelve parents raised from true potato seeds, were used to study variability and correlation for seven characters. The range of variation for all the characters were found to be wide and pronounced which indicated that characters were quantitative in nature and were under polygenic control. For all the characters, greater portion of the total δ^2p was mostly contributed by the δ^2g. Among the seven characters, tuber weight per plant showed the highest δ^2g, PCV, GCV, H2b, GA and expected GA%.On the other hand, dry matter contents (%) showed the lowest H^2b. Phenotypic and genotypic correlation coefficients of plant height with no. of tubers per plant and tuber weight per plant; no. of branches per plant with no. of tubers per plant and tuber weight per plant were found to be significant and positive.     

Selection of Suitable Parents in the Development of Potato Hybrids in Bangladesh

Potatoes(Solanum tuberosum L)are the thirdlargest food crop in Bangladesh following rice andwheat and make a major contribution to the total foodsupply of the country.Although in many westerncountries potato is the number one staple food,it is al-most entirely used as a vegetable in Bangladesh.Thepotato is a short duration crop that produces a largeamount of calories in a short period of time[1].Thepotato produces more protein and calories per unitarea per unit time than any other major food…     

Genetic diversity in groundnut (<Emphasis Type="Italic">Arachis hypogaea</Emphasis> L.) genotypes and detection of marker trait associations for plant habit and seed size using genomic and genic SSRs

Groundnut (Arachis hypogaea L.) an important oilseed crop in India is known to have narrow genetic base. Therefore, the assessment of genetic diversity and detection of marker-trait association are important objectives for the genetic improvement of groundnut. The present study involved the development of 192 SSR markers from Arachis genomic survey sequences. From these, seven polymorphic SSRs along with 15 other genomic SSRs, 19 genic SSRs, and three STS markers were used to detect genetic diversity among 44 groundnut genotypes. These polymorphic SSR markers amplified 155 bands (76 genomic and 79 genic), of these 128 bands (67 genomic and 61 genic) were polymorphic. The genomic SSR exhibited 88.1% and genic SSRs displayed 77.2% allelic polymorphism. The polymorphic information content (PIC) of the markers ranged from 0.04 to 0.95. The pair-wise genetic similarity ranged from 24.2 to 90.7% for genomic SSR and 32.9 to 97.9% for genic SSR markers. Cluster analysis based on the pooled data from both genomic and genic SSRs revealed a dendrogram which could distinguish all the genotypes. Further, the AMOVA analysis detected 16.7% genetic variation due to differences in seed size and 13.0% due to plant habit. Based on locus-by-locus AMOVA and Kruskal-Wallis ANOVA and further confirmation by discriminant analysis and general linear model, six markers were found to be associated with plant habit and four markers with seed size.     

Effect of sulphur on biochemical parameters of rapeseed (Brassica campestris L.) in grey terrace soil

An experiment was conducted to study the biochemical response of rapeseed (Brassica campestris L.) to sulphur (S) fertilization at grey terrace soil. There were five treatments: S₀ (control), S₁ (20 kg S ha^?1), S₂ (40 kg S ha^?1), S₃ (60 kg S ha^?1) and S₄ (80 kg S ha^?1). Chlorophyll content in the leaf was determined at 30, 40, 50 and 60 days after emergence (DAE). The biochemical properties were found responsive to S. The highest chlorophyll content of mustard leaves was found in 60 kg S ha^?1 at 50 DAE. The same treatment also showed the maximum N content in the leaves at 45 DAE. The highest oil content was recorded in 60 kg S ha^?1. Other chemical characters such as acid value, peroxide and saponification values were lowest in 60 kg S ha^?1 while iodine value was found highest in the same S level. Non-essential fatty acids such as palmitic, stearic and erucic acid were increased in the rapeseed with decrease in S level, whereas essential fatty acids were maximum in 60 kg S ha^?1. Therefore, 60 kg S ha^?1 can be recommended to produce quality rapeseed in grey terrace soil of Bangladesh.     

Effect of foliar application of urea on the growth and yield of tomato

To study the effect of foliar application of urea fertilizer on the growth and yield of tomato and to find out the optimum concentration of foliar application of urea for maximum growth and yield of tomato, an experiment was conducted with different concentrations of foliar application of urea fertilizer, namely, 2500, 5000, 7500, and 10000 ppm. The experiment was laid out by a randomized complete block design (RCBD) with four replications. Results showed that different yield components and yield of tomato were influenced by the foliar application of different concentrations of urea. The maximum plant height (132.6 cm), number of leaves (30.73), number of green leaves per plant at harvest (21.08), days to first flowering (28.94), number of flower clusters (11.89), number of flowers (75.18), fruit clusters (5.81), fruits per cluster (4.14), and fruits per plant (21.49); length (4.72 cm), diameter (6.58 cm), and weight of individual fruit (151.0 g) were significantly influenced by the 10000 ppm concentration of foliar application of urea fertilizer. The 10000 ppm application gave the highest yield (63.69 t/hm²) with the lowest (28.48 t/hm²) in the control treatment. The yield per plant as well as per hectare increased with increasing concentrations of foliar application of urea fertilizer.