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ThesisItem Restricted Simulation of nitrogen balance in rice as influenced by irrigation, nitrogen and climate change scenario(Punjab Agricultural University, Ludhiana, 2017) Gurpreet Singh; Vashisht, B.B.Yield potential of rice depends on climatic factors including rainfall, solar radiation and temperature as well as irrigation regime, cultivar and fertilizer nitrogen level. The excessive fertilizer N is being applied by farmers in the quest for higher yields ignoring economic water and N productivities, and environmental pollution. Whole fertilizer N not utilized by rice plants, some portions of N fertilizer are easily lost through various processes, such as NH3 volatilization, leaching and uptake. With prime importance to quantify the nitrogen balance components in rice, field studies were conducted at two different locations at research farms of Department of Soil Science, Punjab Agricultural University, Ludhiana, Punjab, on sandy loam soils during kharif 2016. In the field study, effect of irrigation regimes (irrigation based on two days drainage period, and based on soil water suction (16 kPa)) and nitrogen levels (0, 60, 120 and 180 kg N ha-1) on growth, yield of rice and nitrogen uptake were evaluated. To assess the N balance components, DNDC (Denitrification-Decomposition) model was evaluated and simulations for yield and N balance components were made for past 30 years (1986-2016) and future 30 years (2021-2050) on different soil series of Ludhiana district of Punjab. Averaged over irrigation regimes, rice yield increased significantly with increasing nitrogen levels. Highest rice grain yield was recorded with application of 180 kg N ha-1 (52.9-59.6 q ha-1), which was significantly higher than control, 60 and 120 kg N ha-1 at location 1 but at par with application of 120 kg N ha-1 at location 2. N uptake was also found higher (46.3-56.4 kg ha-1) in the treatments with 180 kg N ha-1. However, treatments with 60 kg N ha-1 gave higher nitrogen use efficiency in terms of agronomic (20-25 kg kg-1) and recovery (54.8-59%) efficiency. Simulated rice yield, N uptake and volatilization would decrease with lower nitrogen levels, coarseness in soil texture and future time slices but leaching losses would increase with higher nitrogen levels, coarseness in soil texture and future time slices. However, percent reduction in yield would be more in end part of mid century (2041-2050). Percent yield reduction would be low at higher nitrogen levels (150-180 kg N ha-1) and in fine textured soils (silt loam). The study suggests that higher N levels could be good option to compensate yield reduction in future however higher nitrogen levels would lead to higher N leaching and volatilization.ThesisItem Restricted Effect of angle of attack on heat transfer and friction characteristics of inclined rib roughened solar air heater duct(Punjab Agricultural University, Ludhiana, 2017) Gurpreet Singh; Hans, V.S.Thermal performance of solar air heaters is very low due to formation of laminar sublayer over the heat transferring surface. By use of artificial roughness in the form of wires, thermal performance of solar air heaters can be increased considerably. This study represents an experimental investigation carried out to examine the effect of angle of attack on heat transfer and friction characteristics of inclined rib roughened solar air heater duct. The various parameters related to roughness geometry and flow were Reynolds number in the range of 2000 to 16000, relative roughness height (e/D) in the range of 0.02 to 0.043, relative roughness pitch (P/e) in the range to 6 to 14 and angle of attack (α) in the range of 45o to 75o: The results obtained from this experimental investigation suggested that ribs inclined at 67o, having relative roughness pitch and relative roughness height value of 10 and 0.043 respectively outperformed the other rib configuration in terms of thermal and thermo-hydraulic performance. Correlations for Nusselt number and friction factor in terms of roughness geometry parameters and flow parameters have also been developed from experimental data.ThesisItem Restricted ASSESSMENT OF MICROBIAL CONSORTIA FOR PADDY STRAW DEGRADATION(Punjab Agricultural University, Ludhiana, 2017) Gurpreet Singh; NeemishaAn experiment was conducted to assess the potential of cellulolytic microorganisms for paddy straw degradation. Twenty seven samples representing hot spots for cellulolytic microorganism were collected from eight different locations. A total of 653 microorganisms were isolated including bacteria (520), fungi (100) and actinomycetes (33). The cultures were screened for cellulolytic activity using both qualitative as well as quantitative assay. Among all the cultures tested, only 48 cultures (44 bacteria, 2 actinomycetes and 2 fungi) exhibited cellulase activity. The zone of hydrolysis varied from 0.3 to 3.2cm and largest zone of hydrolysis was obtained by CDM35 (3.2cm). Hemicellulase activity was exhibited by 24 cultures and largest zone of hydrolysis was produced by CDM 23 (2cm). Quantitative estimation of cellulase enzyme was done using DNS method in which highest cellulase activity of 0.29 IU/ml was shown by CDM 26 followed by 0.19 IU/ml by CDM35. All the cultures were characterized using cultural, morphological and biochemical characterization techniques. The genetic diversity of most efficient bacterial isolates was determined using BOX-PCR, ERIC-PCR and 16S rDNA amplification. The dendrogram obtained from pooled data of BOX and ERIC fingerprints resulted in the formation of two major groups at 15% similarity, subgroups at 23% similarity and the maximum similarity obtained was 57%. Functional characterization revealed IAA production by all the isolates however, only 8 cultures exhibited P solubilization capability. Majority of the microorganisms exhibited optimum growth at 30-45˚C. On the basis of all the qualitative assays, quantitative assays, optimum growth temperature and pH, most efficient microorganisms were selected for assessment of degradation potential under glasshouse and field conditions. Ten most efficient cultures consisting of seven bacteria (CDM5, CDM4, CDM7, CDM3, CDM35, CDM2, CDM23), two actinomycetes strains (CDM26 and CDM42) and one fungal strain (CDM45) were selected for experiment. Under glass house conditions treatments T13, T14. T17 & T20, and under field conditions, treatments T5, T6 & T9 performed efficiently in decreasing ADF and NDF.ThesisItem Restricted Prevalence and Management of Rice Root-knot Nematode (Meloidogyne graminicola) in rice(Punjab Agricultural University, Ludhiana, 2017) Gurpreet Singh; Dhillon, Narpinderjit KaurThe rice root-knot nematode (Meloidogyne graminicola) is one of the most economically important nematodes affecting rice. It has been reported to cause significant yield losses in many regions of rice production. Surveys were conducted in rice growing areas of Punjab of district Bathinda and Faridkot in order to study the prevalence and incidence of rice root-knot nematode-M. graminicola. A total number of 152 nurseries were surveyed out of which 58 nurseries were found infested in both the districts with overall percent incidence of 38.16 percent. During a survey of rice crop a total number of 63 fields were visited out of which only 14 fields were found infested with an overall percent incidence of 22.22 per cent in both the districts. The studies were conducted on build-up of rice root-knot nematode M. graminicola in four different soils viz; sandy, sandy loam, clayey and loamy sand in two cultivars viz; PUSA 1121 and PR 116. Present studies revealed that significantly higher nematode population densities were observed in sandy soil while build up of rice root-knot nematode was minimum in clay soil indicating that losses caused by M. graminicola to rice crop were observed to be higher in infested sandy soils as compared to infested clayey soils. Effect of three water regimes viz; alternate wet and dry, saturated and flooded on build-up of rice root-knot nematode M. graminicola on two basmati (PUSA1121,PUSA PB1509) and two non basmati (PR116, PR114) varieties was studied. Significantly higher nematode population densities were observed in alternate wet and dry conditions followed by saturated conditions while build up of nematode population was observed to be minimum in flooded conditions. Studies revealed that nematode population would increase under water stress condition and more losses were observed to be caused by M. graminicola under aerobic cultivation. Of the eighty three genotypes screened against rice root-knot nematode five genotypes were found to be moderately susceptible and twenty two genotypes showed susceptible reaction and fifty six genotypes had showed highly susceptible reactions. In studies on effectiveness of chemicals, bio-agents and amendments, significant reduction in rice root-knot nematode population was reported with all the treatments. Basamid @ 40 g/m2 was found to be most effective in reducing rice root-knot nematode population.ThesisItem Open Access EPIDEMIOLOGY AND MANAGEMENT OF ALTERNARIA BLIGHT ON SEED CROP OF CARROT (Daucus carota)(Punjab Agricultural University, Ludhiana, 2013) Gurpreet SinghSurveys conducted during 2011 and 2012 revealed that Alternaria blight of carrot was observed at all the locations on all the cultivars. The disease incidence and severity was the highest on Local varieties as compared to PAU recommended varieties. The highest disease severity was observed on local variety grown at village Bohan in district Hoshiarpur, while the lowest disease severity on Selection-21 grown at PAU Ludhiana. Alternaria radicina and Alternaria dauci were found to be associated with the disease. Alternaria radicina has highest frequency than Alternaria dauci on carrot plants. Maximum colony growth and sporulation of Alternaria radicina was observed on carrot leaf agar followed by unmbel extract agar medium. Lowest colony growth and sporulation was observed on Czapek‟s Dox agar medium. Maximum colony growth and sporulation was observed at 25°C temperature followed by 30°C, whereas no colony growth was observed at 35°C. Most suitable range of temperature was found to be 25 to 30°C. Maximum colony growth of Alternaria radicina was observed at pH 6, whereas maximum sporulation was observed at pH 7. The disease severity increase with the increase in the age of plants and a positive correlation between plant age and disease severity was observed. Similarly disease severity increased with the increase in the leaf wetness period. A positive correlation was found between leaf wetness period and disease severity. A minimum 8 hr of leaf wetness was required to cause infection on carrot plants. All three non systemic fungicides proved less effective than systemic fungicides. Among systemic fungicides ED50 values for difenconazole and propiconazole was less than 1μg/ml, while for hexaconazole and azoxystrobin was 1.0 and 5.9 μg/ml respectively. Among non systemic fungicides ED50 value was 17 for chlorothalonil, whereas it was 44 μg/ml for mancozeb. Under field conditions all systemic fungicides proved highly effective in controlling the disease as compared to non systemic fungicides. Azoxystrobin + Difenconazole @ 0.1 per cent proved most effective in checking the disease than other tested fungicides.ThesisItem Restricted CHEMICAL POOLS AND DEPTHWISE DISTRIBUTION OF MICRONUTRIENTS IN SOILS UNDER DIFFERENT CROPPING SEQUENCES AND THEIR RELATIONSHIP WITH THE UPTAKE BY CROPS(Punjab Agricultural University, Ludhiana, 2011) Gurpreet SinghRice-wheat, maize-wheat and cotton-wheat are predominant cropping systems, being practised by majority of farmers in Punjab. The adoption of these three cropping systems depletes a huge amount of macronutrients (N, P and K) and micronutrients (Zn, Cu, Fe and Mn) causing deficiency of these nutrients mainly in light textured soils. So, to overcome the deficiency of Zn, Cu, Fe and Mn in such soils, alternative cropping systems like maize-potatao-mungbean, cotton-gobhi sarson, groundnut-toria+gobhi sarson etc., are required. Lot of research work has already been done on the predominant cropping systems without inclusion of short duration crops like mungbean, toria, gobhi sarson and onion crop. So, there is need to explore research on inclusion of short duration crops in the main cropping systems, which helps in mobilization of Zn, Cu, Fe and Mn. Therefore, the present research study has been conducted with a prime objective to investigate the transformation (chemical pools) and depthwise distribution of Zn, Cu, Fe and Mn under different cropping systems. Surface (0-15 cm) and profile (0-120 cm) soil samples were collected from an ongoing field experiment (in progress since 2000) with 10 cropping systems at research farm of Department of Agronomy, PAU, Ludhiana. The plant samples (grain and straw) from each cropping system were also collected both for Rabi and Kharif crops. These soil samples collected at different stages were analyzed for DTPA-extractable and total Zn, Cu, Fe, and Mn and their chemical fractions using atomic absorption spectrophotometer (Varion AAS-FS Model). The grain and straw samples were also analyzed for their Zn, Cu, Fe, and Mn concentration with Varion AAS-FS Model. The levels of DTPA-extractable Zn, Cu, Fe, and Mn were significantly higher in soil under all the 10 cropping systems as compared to their initial levels. Higher levels of DTPA-extractable Fe and Mn and Zn and Cu were observed in rice-wheat and cotton-wheat cropping systems, respectively. Among maize based cropping systems, maize-potato-mungbean cropping system reported significantly higher concentrations of DTPA-extractable Zn, Cu, Fe, and Mn. The DTPA-extractable Zn and Cu decreased and Fe and Mn increased in soil under maize-potato-mungbeen cropping system. The DTPA-extractable Zn, Cu and Fe decreased with increase in the soil depth. Among chemical fractions, higher levels of Fe and Mn (WSEX and SpAd) were reported in the rice-wheat cropping system. On the other hand higher fractions of Zn [WSEX, SpAd, MnOX and CFeOX] and Cu [WSEX and OM bound] were reported under maize-potato-mungbean and cotton-gobhi sarson cropping systems respectively. Higher uptake of Fe was reported in rice-wheat cropping system, whereas Zn, Cu and Mn reported their higher uptakes in groundnut-potato-bajra (fodder) cropping system. Our study further, investigated that inclusion of short duration crops like mungbean, toria, gobhi sarson and onion helps in mobilization of Zn, Cu, Fe and Mn to ameliorate their deficiencies. Among fractions, SpAd, held on organic sites, oxide bound and amorphous fractions of Zn, Cu, Fe and Mn contributed towards plant available (water soluble and exchangeable) fraction. However, WSEX, SpAd, oxide bound and organically bound fractions contributed towards uptake of Zn, Cu, Fe and Mn by plant grain and straw.