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Chlorpyrifos (CP) is a toxic and broad-spectrum pesticide. Owing to the extensive soil and crop application of CP to control insects/pests, its significant concentrations have been reported in different crop plants, fruits, vegetables and other food items locally and internationally. The strategies to immobilize pesticide residues in the soil are of great concern to restrict their offsite transport. A batch study was conducted to evaluate the potential of biochar and compost in enhancing CP sorption. Soil samples were supplemented with biochar and compost at two levels, i.e. 0.25% and 0.50% w/w basis. The sorption of CP was assessed at five applied concentrations viz. 5, 10, 50, 100 and 200 mg L-1. CP sorption exhibited linear trend and increased with increasing concentration upto 50 mg L-1 after that it decreased with its increasing levels. Freundlich model well fitted and explained the sorption behavior of CP in un-amended as well as amended soil as indicated by the correlation coefficient (R2) values (> 0.90). Both biochar and compost addition significantly increased the sorption potential of the soil. With both amendments sorption capacity increased with increasing level. However, biochar-amended soil showed significantly higher sorption capacities (Kf, 28.68 and 218.83 mg kg-1) for CP compared to compost-amended soils (15.95 and 111.85 mg kg-1) at 0.25 and 0.50%, respectively. Conclusively, above organic amendments have potential to effectively sorb CP and could be used to remediate CP polluted areas by immobilizing CP and ultimately decreasing its bioavailability. [ABSTRACT FROM AUTHOR]

Lemongrass [Cymbopogon citrates (DC) Stapf] is a cosmopolitan economically important grass with a natural potential to adapt to different climates. However, the mechanisms of cross-locational adaptability are not studied in this grass species. To explore some physiological basis of cross-locational adaptability potential of lemongrass, experiments were performed on one population each from Faisalabad and Quetta, Pakistan. Both the population were planted at both the locations in a reciprocal swap arrangement using randomized complete block design with three replicates. The data were recorded on monthly basis from June to December over two consecutive years (2015 and 2016). The swap reciprocated lemongrass populations from Quetta and Faisalabad exhibited differential growth patterns from their native counterparts thus showing flexibility among the populations. Enhanced tillering, root proliferation and increased dry shoot and root weight was observed in the Quetta population adapted in Faisalabad. However, Faisalabad population adapted in Quetta produced taller plants with longer roots, while tillering and number of leaves were greatly reduced in the Quetta adapted population as compared to its counterpart in Faisalabad. Tissue analysis for hydrogen peroxide (H2O2) and malondialdehyde (MDA) data revealed that both the native and adapted populations in Faisalabad accumulated greater H2O2 and MDA in summer months while Quetta population did so in the winter months, thus showing that summer months in Faisalabad and winter months in Quetta to be stressful for the populations in the respective locations. Both native and adapted populations in Quetta displayed dark green leaf color, which was accompanied by increased chlorophyll a and b contents in summer months in Quetta and winter months in Faisalabad, while carotenoids accumulation was greater in the season with high temperature in Faisalabad and chilling temperature in Quetta. Fitting regression equation and finding correlation between maximum and minimum temperatures and relative humidity (RH) revealed negative correlations of temperatures with growth, H2O2 and MDA at both the locations in native and adapted population, while positive correlation of chlorophylls and carotenoids at Quetta and negative ones at Faisalabad, while RH was regressed with none of these attributes (data not shown). This implied that temperature was a major determining factor in the adaptation of populations at either location based on flexibility in physiological adjustments at both the locations. [ABSTRACT FROM AUTHOR]

Potassium (K+) nutrition ensures growth and quality of crops both under normal and saline soils. In view of that a study was conducted to assess the impact of various doses of K+ on growth, bio-chemicals, protein and oil contents of four soybean (Glycine max L.) genotypes under saline condition. Soybean genotypes were grown in pots having treatment combination of salinity (control, 6 and 12 dS m-1) and K+ doses (control, 50 and 75 kg ha-1). The results showed that sufficient K+ nutrition enhanced plant growth, biomass production, protein and oil percentage of soybean genotypes both in normal and saline condition. Water relation in plant as well as chlorophyll contents and leaf area improved with the application of potassium under salinity stress. Across K+ application rates, all soybean genotypes significantly varied from each other. K+ accumulation was positively correlated with growth and other parameters of soybean genotypes, but these relationships were stronger in case of genotypes No.62 and No 13 as compared to Ajmeri and William-82 genotypes. Soybean genotypes No. 62 and No. 13 classified as potassium efficient genotypes while Ajmeri and William-82 categorized as potassium inefficient genotypes on the basis of growth and K uptake. [ABSTRACT FROM AUTHOR]

Studies were conducted to assess the role of mucilage in seed desiccation, germination, and its interaction with fungus in Rough lemon, Sachtion citrumelo and Yuma citrange rootstock seeds of citrus fruits. Water loss percentage was minimum (with or without mucilage) in Rough lemon seeds (20.28%) and (31.25%) at 25°C and 35°C respectively, with high germination percentage (3.33%) while maximum water loss (29.50%) was observed in Sachtion citrumelo at 25°C having low germination percentage (1.33%). However, Yuma citrange showed maximum water loss (34.39%) at 35°C with germination percentage (1.67%). The pathogenic fungus which infected the seeds was isolated, purified and identified as Aspergillus niger. Fungus growth on seeds of Rough lemon, Sachtion citrumelo and Yuma citrange was 14.08 mm, 10.65 mm and 9.36 mm, respectively on 6th day of inoculation. It is obvious from the results that mucilage played significant role in desiccation, germination as well as fungal habitation. [ABSTRACT FROM AUTHOR]

Current water scarcity is an emerging issue in semi-arid regions like Pakistan and cause of deterioration in productivity of crops to reduce crop yield all over the world. Silicon is known to be better against the deleterious effects of drought on plant growth and development. A pot study was conducted to evaluate the effect of Si nutrition (0, 50, 100 and 150 mg/kg) on the growth of a relatively drought tolerant (P-33H25) and sensitive (FH-810) maize hybrids. Two levels of soil water content were used viz. 100 and 60% of field capacity. Water deficit condition in soil significantly reduced morphological and physiological attributes of maize plants. Silicon application significantly improved the plant height, leaf area per plant, primary root length, dry matter of shoot and roots and plant dry matter, water relation and gas exchange characteristics of both maize cultivars under water deficit condition. Poor growth of drought stressed plants was significantly improved with Si application. The silicon fertilized (100 mg/kg) drought stressed plants of hybrid P-33H25 produced maximum (21.68% more) plant dry matter as compared to plants that were not provided with silicon nutrition. Nonetheless, silicon application (150 mg/kg) resulted in maximum increase (26.03%) in plant dry weight of hybrid FH-810 plants that were grown under limited moisture supply i.e., 60% FC. In conclusion silicon application to drought stressed maize plants was better to improve the growth and dry matter could be attributed to improved osmotic adjustment, photosynthetic rate and lowered transpiration. [ABSTRACT FROM AUTHOR]