Muhammad Nafees

Paclobutrazol Soil Drenching Suppresses Vegetative Growth, Reduces Malformation, and Increases Production in Mango

Emergence of unproductive vegetative shoots/flushes is considered to be a main cause of low yield, irregular bearing, and malformation of inflorescences in mango. Selected mango trees of the cultivars ‘Chaunsa’, ‘Dushehare’, and ‘Anwar Ratool’ growing in the subtropical region of Khanewal (30°18′0N, 71°56′0E), a district of Pakistan, were characterized as having excessive vegetative growth, erratic flowering, and fruiting with declining productivity due to malformation of inflorescences. Paclobutrazol soil drenching was evaluated as a method to suppress excessive vegetative growth and to increase the number of reproductive shoots even during the ‘off’ season. Different rates of paclobutrazol was applied at rates of (0, 2, 4, 6, 8, 10, and 12 g a.i.) in September through soil drenching. Results showed that soil drenching with paclobutrazol at the highest rates (12, 10, and 8 g a.i.) was significantly effective in suppressing vegetative growth, reducing the increase in canopy volume, and flush length as compared to control trees in all treated cultivars of mango. Statistically significant differences were recorded in treated trees as compared to control regarding the emergence of reproductive shoots, fruit setting, panicle length, fruit drop, intensity of emergence of malformed panicles, and yield. Response of selected cultivars of mango to paclobutrazol was statistically different regarding various vegetative and reproductive growth characteristics. Paclobutrazol was more useful in ‘Seasonal Chaunsa’ as compared to ‘Dushehare’ and ‘Anwar Ratool’ for improving various vegetative and reproductive parameters studied in this research.

Drinking Water Quality Status and Contamination in Pakistan

Due to alarming increase in population and rapid industrialization, drinking water quality is being deteriorated day by day in Pakistan. This review sums up the outcomes of various research studies conducted for drinking water quality status of different areas of Pakistan by taking into account the physicochemical properties of drinking water as well as the presence of various pathogenic microorganisms. About 20% of the whole population of Pakistan has access to safe drinking water. The remaining 80% of population is forced to use unsafe drinking water due to the scarcity of safe and healthy drinking water sources. The primary source of contamination is sewerage (fecal) which is extensively discharged into drinking water system supplies. Secondary source of pollution is the disposal of toxic chemicals from industrial effluents, pesticides, and fertilizers from agriculture sources into the water bodies. Anthropogenic activities cause waterborne diseases that constitute about 80% of all diseases and are responsible for 33% of deaths. This review highlights the drinking water quality, contamination sources, sanitation situation, and effects of unsafe drinking water on humans. There is immediate need to take protective measures and treatment technologies to overcome unhygienic condition of drinking water supplies in different areas of Pakistan.

Nitrogen application improves gas exchange characteristics and chlorophyll fluorescence in maize hybrids under salinity conditions

The understanding of crop physiological responses to salinity stress is of paramount importance for selection of genotypes with improved tolerance to this stress. Maize (Zea mays L.) hybrids Pioneer 32B33 and Dekalb 979 were grown in pots and subjected to three levels of salinity under four nitrogen levels to determine the role of nitrogen under saline conditions. Salinity stress effects on gas exchange characteristics and chlorophyll fluorescence of maize hybrids were evaluated under semi-controlled conditions. Under salinity stress, the changes in the net photosynthetic rate (PN), stomatal conductance (gs), and transpiration rate (E) were similarly directed: all decreased and were lower than in control at the higher salinity level (10 dS/m). Water use efficiency was increased with increasing salinity since transpiration was stronger depressed by salt than photosynthesis. Plants subjected to the lower level of salinity did not differ from control in tested characteristics. Nitrogen application ameliorated the effects of salinity.

Review of Upflow Anaerobic Sludge Blanket Reactor Technology: Effect of Different Parameters and Developments for Domestic Wastewater Treatment

The upflow anaerobic sludge blanket (UASB) reactor has been recognized as an important wastewater treatment technology among anaerobic treatment methods. The objective of this study was to perform literature review on the treatment of domestic sewage using the UASB reactor as the core component and identifying future areas of research. The merits of anaerobic and aerobic bioreactors are highlighted and other sewage treatment technologies are compared with UASB on the basis of performance, resource recovery potential, and cost. The comparison supports UASB as a suitable option on the basis of performance, green energy generation, minimal space requirement, and low capital, operation, and maintenance costs. The main process parameters such as temperature, hydraulic retention time (HRT), organic loading rate (OLR), pH, granulation, and mixing and their effects on the performance of UASB reactor and hydrogen production are presented for achieving optimal results. Feasible posttreatment steps are also identified for effective discharge and/or reuse of treated water.

Role of Bioremediation Agents (Bacteria, Fungi, and Algae) in Alleviating Heavy Metal Toxicity

Heavy metals are environmental contaminants globally. They have polluted agricultural soils and caused detrimental effects on our ecosystem. Toxic effects of heavy metals have been reported in plants, animals, humans, and microorganisms. Heavy metal remediation is essential to preserve the health of agricultural soils and would lead to enhanced crop growth and yield. Various techniques and strategies have been used in recent years to remediate contaminated soils, but most of them were costly, environmentally unfriendly, and negatively affect soil properties. However, use of microbes to remediate heavy metals has been found to be cost effective and environmentally clean. Microbes enhance stability in agricultural soil health, which leads to sustained plant growth and development under stressful conditions. Particular agents used for bioremediation are bacteria, fungi, and algae. Bacterially-mediated processes have been used to alleviate heavy metal toxicity. Endophytic bacteria have greater potential to tolerate and remediate heavy metals stress. Bacterial strains showed potential to alleviate heavy metals from the rhizosphere of target plant species and improve their growth. Arbuscular mycorrhizal fungi alleviate heavy metal toxicity by inhibiting their uptake and translocation in plant parts. In addition, many morphological and physiological changes are induced by fungi. Macro- and micro-algae have been reported to alleviate heavy metal toxicity mostly in marine systems. Reports suggested that applications of the above bioremediation agents alleviate heavy metal stress, enhance phytoremediation capacity in combination with plant growth–promoting bacteria, and ultimately improve plant growth attributes.

Biochemical diversity in wild and cultivated pomegranate (Punica granatum L.) in Pakistan

ABSTRACT The present study was conducted to screen out elite pomegranates through determination of biochemical diversity in wild and cultivated genotypes for a breeding program and for fresh/processed use in industry. The results showed high morphological diversity in accessions of wild pomegranate fruits as compared to cultivated genotypes. The first six principal components covered 80.75 and 75.49% diversity in 53 wild and 62 cultivated pomegranate genotypes, respectively. High values of the coefficient of variance (10.78–18.62%), and a high range of minimum to maximum values of total soluble solids, titratable acidity, ascorbic acid content, total soluble sugars, and total phenolic content (0.10–1.25, 5.88–29.96, 9.69–19.85 and 175.05–595.42), respectively, were recorded in the studied genotypes. Ascorbic acid content had a strong correlation with antioxidant activity (0.952%), super dismutase oxides (0.94%), catalase (0.921%), and titratable acidity (0.91%). Peroxides had a strong correlation (0.88%) with catalase, and 0.81% each with super dismutase oxides and antioxidant activity. Wild and cultivated pomegranates were clustered successfully in separate groups, based on biochemical traits. A variety improvement program and selection of high-quality pomegranate genotypes could help to reduce pomegranate-related malnutrition issues in the human diet.

Integrated nutrient management for better quality and yield of Kinnow mandarin

ABSTRACT This study was carried out to determine the integrated effect of organic matter alone and in combination with chemical fertilizers in order to maintain the nutritional status in Kinnow fruit plants. Lahore Compost was used as a source of organic matter. Treatments were made by using compost alone and in combination with nitrogen, phosphorus, potassium (NPK), and well-rotten farm yard manure (FYM; cow dung). Treatments were applied before flowering and after fruit set. Effect of these treatments on different physicochemical characteristics of Kinnow fruit and nutritional status in tree leaves was determined. Among all treatments, minimum flower drop, maximum yield, and better fruit quality were recorded in plants where 40 kg compost + 1/2 recommended doses of NPK were applied before flowering and after fruit setting, while minimum fruit set was recorded from the plants where 30 kg compost alone was applied before flowering.