http://localhost:80/xmlui/handle/123456789/570 2026-04-28T12:37:57Z 2026-04-28T12:37:57Z Ahmed, Khalil http://localhost:80/xmlui/handle/123456789/1512 2019-11-19T04:34:32Z 2011-01-01T00:00:00Z

Title: SALINITY AND BORON INTERACTION IN MAIZE Authors: Ahmed, Khalil Abstract: Soil salinity is a major problem that threatens the sustainability of agriculture in the world including Pakistan. Boron toxicity is also an important problem as it decreases plant growth and crop yields in different regions of the world. Boron is usually present at high concentration in saline soil and removed slowly during the process of leaching, therefore it may be present at toxic level after reclamation of soil. A series of experiments were carried out to study the growth of maize (Zea mays L.) under salinity and boron toxicity. For screening against salt stress initially six maize genotypes (EV-20, EV-78, KS-64, R-2303, R-2310, and R-2315) were allowed to grow in 1⁄2 strength Hoaglands solution. The required salinity level of 75 mM NaCl was developed by adding NaCl, whereas no salt was added in control. After 30 days plants were harvested manually and ranking of genotypes was done to identify salt tolerant and salt sensitive genotypes. EV- 78 and R-2303 were ranked as salt tolerant and moderately tolerant where as KS-64 and R-2315 were recognized as salt sensitive and moderately salt sensitive maize genotypes. In a set of experiments these selected genotypes were grown in solution culture under different treatments of NaCl and boron to monitor the growth, physiological and biochemical characteristics. Salinity level of 75 mM NaCl was developed with NaCl while in control no salt was added and boron levels of 2.5 mM and 5 mM were developed with supply of boron as H 3 BO 3 . The studied parameters showed that reduction in growth traits was more in salt sensitive genotypes (KS-64, R-2315) than the salt tolerant genotypes (EV-78 and R-2303) particularly under 5.0 mM B in saline conditions. EV-78 and R-2303 accumulated less Na + and boron, and more K + as compared to KS-64 and R- 2315. The decreasing trend was observed in relative water contents and membrane stability index in sensitive and tolerant genotypes with increasing level of boron in saline conditions, but this reduction was less in salt tolerant genotypes. The physiological traits like photosynthetic rate, stomatal conductance and transpiration rate were also decreased with the toxic boron concentration under both saline and non saline conditions. The resistant genotype EV-78 produced better growth and yield under the combined salinity and boron toxicity as compared to the sensitive genotype KS-64 also by better management of oxidative stress

2011-01-01T00:00:00Z HASHMI, MUHAMMAD RAFI QAMAR http://localhost:80/xmlui/handle/123456789/1511 2019-11-19T04:34:13Z 2013-01-01T00:00:00Z

Title: TILLAGE, NITROGEN AND RESIDUE MANAGEPMENT STRATEGIES IN WHEAT (Triticum aestivum L.) GROWN UNDER RICE BASED SYSTEM Authors: HASHMI, MUHAMMAD RAFI QAMAR Abstract: Wheat is a major staple food of Pakistan, which not only provides the food for human but also has an important role in livestock feeds. It provides the raw material to various agro- based industries. Average wheat yield of the country is 2.7 metric t ha -1 (Govt. of Pakistan, 2010-11). Conventional methods of planting, late planting, poor management practices and imbalanced nutrient management are the major constraints of low yield in wheat production at farmer’s field. Zero tillage technology is considered more convenient and efficient planting system as it saves irrigation water, cost of inputs and increased the net income. Pakistani soils pH is high and productive without any major problem for crop husbandry. It is medium in K 2 O and deficient in N, P 2 O 5 and organic matter. Research was conducted at University of Agriculture, Faisalabad, Pakistan, to evaluate the different tillage systems along with nitrogen levels and mulch materials regarding yield, growth, soil physical properties and grain quality. The aim of experiment was to determine the most favorable tillage system along with the best nitrogen level and mulch material. Two studies were carried out during 2009-10 and 2010-11. First study comprised of four tillage systems; conventional tillage, deep tillage, zero tillage sowing with zone disc tiller and zero tillage sowing with happy seeder along with four nitrogen levels i-e 75 kg ha -1 , 100 kg ha -1 , 125 kg ha -1 and 150 kg ha -1 along with control. The study-2 comprised of same tillage systems along with four mulch materials i-e rice straw, wheat straw, plastic sheet @ 4 t ha -1 , natural mulch along with no mulch. Split plot design with three replications having net plot size 8.0 m x 5.4 m. Wheat variety Sehar-2006 was sown 22.5 cm apart with seed rate of 125 kg ha -1 having 24 rows per plot. Data pertaining to growth, yield, soil physical properties and grain quality were noted by using standard procedures. Data collected from both experiments were statistically analyzed by MSTATC and the differences among the treatment means were compared for significance by using the Duncan’s New Multiple Range Test at 5% level of probability. The computer package MS-Excel was used to prepare the graphs. In 2010-11, the climatic conditions were favorable for crop growth, production and overall 24 % greater grain yield produced than 2009-10 in first experiment. Higher grain yield was produced in deep tillage and happy seeder as compared to other tillage systems while N 125 kg ha -1 generated higher grain yield than all nitrogen levels during both the years. In both the year’s deep tillage and N 125 kg ha -1 gave maximum LAI and TDM than other tillage systems and nitrogen levels. Higher root length was recorded at deep tillage and N 125 kg ha -1 in comparison to all tillage systems and nitrogen levels both the years of study. During both the years’ soil bulk density was 10-20 % lower in deep tillage than all tillage systems at flowering and harvesting stage at 0-5 and 5-10 cm soil depth. Nutrient use efficiency was 44 % higher in deep tillage compared to all tillage systems. During both the years higher water use efficiency 7 to 10 % was noted at deep tillage and happy seeder compared to all tillage systems while N 125 kg ha -1 led to 53 % higher WUE. Higher grain protein content was observed at deep tillage and 5-40 % at N 150 kg ha -1 than other tillage systems and nitrogen levels during both the years. All the tillage systems in both years gave maximum net rate of return and benefit cost ratio were noted at N 125 kg ha -1 . In 2009-10 maximum marginal rate of return 498 % and 577 % were noted in conventional tillage and deep tillage at N 75 kg ha -1 while 545 % and 508 % in zone disc tiller and happy seeder at N 100 kg ha -1 . Maximum marginal rate of return in all tillage systems were noted at N 100 kg ha -1 during second year. xxIn second study 14 % greater grain yield was attained in 2010-11 than 2009-10. In both the years of study deep and happy seeder gave higher grain yield than other tillage systems while plastic mulch @ 4 t ha -1 produced higher grain yield than other mulch materials. During both the years higher LAI and TDM were observed at happy seeder and M Plastic @ 4 t ha -1 . Soil bulk density at deep tillage was 10-15 % lower than other tillage systems while plastic mulch materials @ 4 t ha -1 at 0-5 cm gave 4-10 % lower bulk density during both the years of study. During both the growing seasons higher water use efficiency 2 to 7 % was noted at deep tillage compared to all tillage systems while plastic mulch @ 4 t ha -1 gave 2 to 24 % higher WUE. In 2009-10 and 2010-11, higher grain protein content was noted at deep tillage and M Plastic @ 4 t ha -1 compared to all tillage systems and mulch materials. Conventional tillage and deep tillage during first year gave maximum net rate of return and benefit cost ratio at M Rice @ 4 t ha -1 while zone disc tiller and happy seeder gave at M Natural (Heavy Planking). In second year all tillage systems gave maximum net rate of return and benefit cost ratio at M Rice @ 4 t ha -1 . All tillage systems gave higher marginal rate of return at M Natural in first year. During 2010-11, higher marginal rate of return was recorded in conventional tillage, deep tillage and zone disc tiller at M Natural while happy seeder gave higher marginal rate of return at M Rice @ 4 t ha -1 . In light of above results, it is recommended that in rice-wheat cropping system, happy seeder and deep tillage with N 125 kg ha -1 application gave higher grain yield. While in case of mulch materials, happy seeder and deep tillage produced maximum yield when natural mulch was applied. On the bases of marginal rate of returns, it is recommended that the resource poor farmers should grow wheat with happy seeder and deep tillage alongwith N 100 kg ha -1 , while the progressive farmers may fertilize wheat with N 125 kg ha -1 to obtain higher net field benefits. In case of mulch, it is recommended that the resource poor wheat growers should grow wheat with happy seeder and deep tillage at M Natural , while the progressive farmers may grow wheat with M Rice @ 4 t ha -1 to get higher net field benefits. The fertility status of Pakistani soil is low due to warm climate and extensive cropping systems. Currently, farmers do unwise wheat tillage operation. So, it is strongly recommended that farmers should adopt zero tillage technology alongwith above recommendation of nitrogen fertilizer and mulch. It would helps to reduce cost of production and and increase yield. Subsequently, it increases farmer’s profit, improves his livelihood and eventually helps to reduce poverty.

2013-01-01T00:00:00Z Chishti, Zia http://localhost:80/xmlui/handle/123456789/1510 2019-11-19T04:34:00Z 2012-01-01T00:00:00Z

Title: OPTIMIZATION OF FACTORS AFFECTING BIODEGRADATION OF CHLORPYRIFOS IN SOIL AND WATER ENVIRONMENTS Authors: Chishti, Zia Abstract: Chlorpyrifos an insecticide, is extensively used in Pakistan and contaminating the soil and water environments at several sites. Exploration of efficient chlorpyrifos-degrading bacteria to clean-up this toxicant is of immense importance. This study reports the isolation, screening and identification of highly efficient chlorpyrifos degrading bacterial strains from different soils and water samples collected from different sites of Pakistan. Out of total 50 isolated bacterial strains, 32 were tested for their biodegradation capability in a culture medium containing chlorpyrifos as carbon and energy source. The bacterial isolates showed a great variation (25-92%) in their ability to degrade chlorpyrifos in broth condition. Out of these 32 strains, four bacterial strains (SWLC2, SWLH2, SGB2 and SWLC1) were the most promising in their growth and biodegradation activity and were identified and characterized by biochemical characteristics and 16S rRNA sequence analyses. Three strains (SGB2, SWLC1 and SWLC2) showed the greatest similarity to the members of Enterobacteriacea and one strain (SWLH2) to Rhizobiacea families. These selected strains (Enterobacter sp. SWLC1, Enterobacter sp. SGB2, Agrobacterium sp. SWLH2 and Enterobacter sp. SWLC2) exhibited biodegradation potential between 81 to 92% of the spiked amount of chlorpyrifos (100 mg l -1 ) within 18 days of incubation in broth culture. Biodegradation of chlorpyrifos continued gradually throughout the incubation period (18 days) as examined by the HPLC - UV system. Abiotic degradation contributed only up to 15% of the spiked amount. Maximum biodegradation by the four efficient bacterial strains was observed at an initial pH of 7 and an incubation temperature of 30 o C, under shaking conditions. Among these four strains, Enterobacter sp. SWLC2 was found most efficient in biodegradation of chlorpyrifos and was selected for further studies. This strain was then optimized in broth as well as in soil slurry under different conditions. Enterobacter sp. SWLC2 showed maximum biodegradation of chlorpyrifos at pH 7, 30 o C, under shaking conditions with inoculum size of 800 μl. Biodegradation of chlorpyrifos by Enterobacter sp. SWLC2 varied in different textured soils, being more rapid in course textured soils than in fine textured soil. Among these soils, loamy soil was selected for further studies in soil slurry experiments due to its medium textured nature as soils of Punjab are mostly loamy in texture. An initial inoculum size of 800 μl (OD= 0.80), incubation temperature of 30 o C, under shaking, initial pH 7 of soil slurry of loam soil were found optimal conditions for maximum biodegradation of chlorpyrifos byEnterobacter sp. SWLC2. Exogenous application of sugars, yeast extract, manitol, organic acids and amino acids had stimulator or inhibitory effects on biodegradation of chlorpyrifos by Enterobacter sp. SWLC2. Among these, glucose, yeast extract, succinic acid and citric acid had stimulatory effects on biodegradation of chlorpyrifos. Biodegradation of chlorpyrifos by Enterobacter sp. SWLC2 was also checked at different initial concentrations of chlorpyrifos from 10-250 mg l -1 . Rate of biodegradation increased with increase in concentration of chlorpyrifos from 100-150 mg l -1 and suggested first order rate kinetics. In all experiments, utilization of chlorpyrifos by the strains was accompanied by a parallel increase in optical densities of broth implying that removal of this pesticide from the growth medium was a growth linked biodegradation. These results highlighted the potential of this bacterium to be used in the detoxification strategies of chlorpyrifos contaminated water and soil environments.

2012-01-01T00:00:00Z ASHFAQ, SIDRAH http://localhost:80/xmlui/handle/123456789/1509 2019-11-19T04:33:48Z 2015-01-01T00:00:00Z

Title: DESIGN, DEVELOPMENT AND MODELING OF A SOLAR ASSISTED PADDY DRYER FOR ON-FARM PROCESSING Authors: ASHFAQ, SIDRAH Abstract: Drying is an important process used all over the world for the preservation of agricultural produce. Different types of dryers are available for drying purpose; however batch type dryers are the most favorite equipment used for drying purpose at farm level. These dryers are simple in design and construction, cheaper and easy to operate and offers possibility to be used under different environmental and climatic conditions. Un-even air distribution is a major drawback of batch type dryers. Over and under dried zones developed when air is introduce in the drying chamber, and this heterogeneity of the drying air reduces the dryer efficiency by increasing the drying time and energy consumption. To overcome this problem, a new batch type dryer with central air distribution model (along the length of the drying chamber) has been developed and evaluated in the Workshop of Farm Machinery and Power, University of Agriculture, Faisalabad. The dryer consists of drying chamber, air distribution model, flat plat solar air collector and blower. The prediction of air distribution pattern with in the drying chamber has analyzed using ANSYS-Fluent software. The simulations showed that air uniformly distributed within the drying chamber. The simulation results have been validated using experimental trials performed on freshly harvested paddy. A good distribution of air was found both numerically and experimentally within the drying chamber and this was due to the distinct feature (central air distribution model) of this dryer. The quality parameters of dryer have also been evaluated. Response surface methodology was used to determine the effect of independent variables like air velocity, depth of grain and desired moisture content on the head rice yield, whiteness and drying time of the dried paddy. It was observed that head rice yield and whiteness of the dried paddy decreases when moisture content decreases from 14 to 9%. Results showed that maximum head rice yield of 51.2% and maximum whiteness of 38% were achieved at moisture content of 14%. Drying time was increased when depth of grain and desired moisture content increased and vice versa. Quality of paddy dried with solar assisted dryer was also compared with conventional sun drying method. Results showed that the head rice yield and whiteness of the dried paddy with solar assisted paddy dryer was 14 and 13 times higher respectively, as compared with the open sun drying method. Solar assisted paddy dryer also cuts the 50% drying time as compared with the conventional open sun drying method. 100 kg of paddy can be dried in 10 hours to reduce its moisture to 14 % using solar assisted paddy dryers compared with 26 xiv hours in case of open sun drying method. Results of performance evaluation showed that the mean drying rate of the solar assisted paddy dryer was 0.87 kg/hr per 100 kg, whereas 0.46 kg/hr was the sun drying rate comparatively. Economic analysis was also performed to check the suitability of the dryer for our local farmers. Cost of drying with solar assisted paddy dryer was found to be 1.2 Rs/kg, whereas, the cost of drying with open sun drying method ranges 2 to 3 Rs/kg. Therefore, it could be concluded that using solar assisted paddy dryer, a good quality paddy can be dried at lower costs.

2015-01-01T00:00:00Z