Planting Geometry and Herbicides for Weed Control in Rice: Implications and Challenges

Weeds are one of the major biological threats to higher rice productivity worldwide. Various cultural, biological, physical and chemical practices affect the composition and intensity of weeds in rice fields. Generally, weeds can be controlled through herbicides; nevertheless, chemical weed control is not a sustainable option on a long term. Various agronomic practices such as the use of tolerant cultivars, adjusting sowing time, tillage permutations and plant geometry may reduce the weed pressure in rice. Integrated approaches for weed management, emphasizing on the combination of management practices and scientific knowledge, may reduce the economic costs and improve weed control owing to the complexity of the weed community. The present chapter reveals the role of planting geometry and herbicides as weed management strategies in rice, and discusses the issue of herbicide resistance associated with chemical weed control. Moreover, the research and knowledge gaps in rice weed management through planting geometry and herbicides were also highlighted

Microsoft Word - J2 - 632 revised

A field experiment was conducted to evaluate the effect of different phosphorus levels viz. 0, 25, 50, 75 and 100 kg ha -1 and inoculation with Rhizobium japonicum. In all the phosphorus levels oil content (%) in soybean seed were found non significant. While in case of plant height and number of pod bearing branches per plant, the two higher phosphorus levels i.e. 75 and 100 kg ha -1 , gave significantly better results as compared to other doses of phosphorus. While in all other parameters i.e. number of pods per plant, pod length, number of seeds per pod, biological yield, harvest index and oil yield, 100 kg P 2 O 5 ha -1 gave significantly better results as compared to all other doses of phosphorus. Inoculation with Rhizobium japonicum improved soybean yield and yield components as compared to non-inoculated seed

Defect formation during dissimilar aluminium friction stir welded T-joints

AA8011 remains one of the largest used aluminium alloys due to excellent ductility, corrosion resistance and sufficient strength in H14 conditions. The 5754, due to high strength and corrosion resistance finds key applications in marine, process industry, automobile and nuclear applications. A T-joint combination of the two alloys (when stronger forming is stiffeners) results in significant weight savings. The T-joint between 8011 and 5754 (with the latter forming the stringer) is highly prone to defect formation due to the stronger material being placed away from the heat source. In this paper, friction stir welding of AA5754 and AA8011 aluminium alloys in T-lap configuration is performed. Effects of processing parameters namely tool transverse speed, rotational speed and shoulder diameter on the weld properties are studied with the help of micro-hardness, macrostructure and microstructure analysis. Analysis of defects such as tunnel and kissing bond, and mechanism of defect formation is also discussed. Tunnel defect is observed on advancing side in all the samples, which is attributed to high heat flux on advancing side, insufficient material flow in the vertical direction and asymmetric flow of plasticized material from advancing side to retreating side. The size of the defect is found to increase with increase in shoulder diameter keeping the rotational speed constant. Kissing bond defect was also observed in some samples owing to the presence of oxide layer between the joining surfaces

Chilling and Drought Stresses in Crop Plants: Implications, Cross Talk, and Potential Management Opportunities

Plants face a combination of different abiotic stresses under field conditions which are lethal to plant growth and production. Simultaneous occurrence of chilling and drought stresses in plants due to the drastic and rapid global climate changes, can alter the morphological, physiological and molecular responses. Both these stresses adversely affect the plant growth and yields due to physical damages, physiological and biochemical disruptions, and molecular changes. In general, the co-occurrence of chilling and drought combination is even worse for crop production rather than an individual stress condition. Plants attain various common and different physiological and molecular protective approaches for tolerance under chilling and drought stresses. Nevertheless, plant responses to a combination of chilling and drought stresses are unique from those to individual stress. In the present review, we summarized the recent evidence on plant responses to chilling and drought stresses on shared as well as unique basis and tried to find a common thread potentially underlying these responses. We addressed the possible cross talk between plant responses to these stresses and discussed the potential management strategies for regulating the mechanisms of plant tolerance to drought and/or chilling stresses. To date, various novel approaches have been tested in minimizing the negative effects of combine stresses. Despite of the main improvements there is still a big room for improvement in combination of drought and chilling tolerance. Thus, future researches particularly using biotechnological and molecular approaches should be carried out to develop genetically engineered plants with enhanced tolerance against these stress factors

Integration of organic sources with inorganic phosphorus increases hybrid maize performance and grain quality

Integrative use of organic and inorganic fertilizers not only fulfills the nutritional needs of crops, but also ensures sustainable production and environmental protection. Thus, this study was conducted to determine the influence of phosphorous application from integrated organic and inorganic fertilizers on maize. In this study poultry manure and press mud were integrated with single superphosphate (SSP) as the phosphorus source. Maximum amounts of time to 50% tasseling (47.75 and 47.63 days), 50% silking (53.07 and 53. 11 days) and maturity (106.47 and 106.49 days) were recorded where the recommended dose of phosphorus was applied from only inorganic sources. For application of phosphorus from integrated sources, the treatment containing 25% poultry manure + 75% SSP provided the highest number of grains per cob (459.60 and 460.70), 100-grain weight (26.85 and 27.82), stover yield (9.61 and 10.41 t ha-1), grain yield (7.14 and 7.82 t ha-1) and grain protein content (8.59 and 8.63%) during both years. However, all treatments had non-significant effects on grain oil and starch content. Moreover, in given years, the integrated use of 75% poultry manure and 25% SSP resulted in a maximum benefit-cost ratio of 2.97 and 3.11 USD, respectively, as compared to integrated use of 25% poultry manure and 75% SSP, which produced a benefit-cost ratio of 2.58 and 2.81 USD. In conclusion, integration of organic sources with inorganic phosphorus substantially improves the yield and economics of hybrid maize

Reasons for smoking among the teenagers of age 14–17 years in Vikarabad town: A cross-sectional study

Background: Despite widespread knowledge of the health consequences, tobacco use, especially smoking is common globally. Most of the youngsters become smokers annually and one-third of them are believed to die due to tobacco use. Aim: To assess the various reasons for smoking among teenagers of age 14–17 years. Materials and Methods: A descriptive cross-sectional survey was conducted on 384 teenagers to know their views regarding the reasons for smoking habit. A specially designed pretested questionnaire was used for the survey. Results: Majority of 76.4% of the study subjects agreed that smoking habit gives psychological pleasure, 77.5% agreed that smoking starts because of friends, and 65.7% felt that smoking starts as an inspiration for outlook and personality. Conclusion: Various psychological factors, personal factors, and social factors are attached with smoking habit

Effect of Mepiquat Chloride on Phenology, Yield and Quality of Cotton as a Function of Application Time Using Different Sowing Techniques

Mepiquat chloride (MC) is a plant growth regulator used to manage the rampant vegetative growth of cotton. A two-year field experiment was conducted at the Postgraduate Agricultural Research Station, University of Agriculture, Faisalabad, Pakistan, during 2017 and 2018 to investigate the influence of MC applied at different times on phenology, morphology, lint yield and quality of cotton cultivated using different sowing techniques. MC was applied 50 days after sowing (DAS), 60 DAS and 70 DAS to cotton planted in flat fields (flat sowing), ridges (ridge sowing) and beds (bed sowing). The interactive effect of MC application time and sowing technique did not influence crop phenology, morphology, and lint yield and quality. It was revealed that the crop planted on beds took fewer days to flower (10%) as compared to that on the flat field, and the bed-sown crop produced a higher number of opened bolls (60%) and was characterized by a higher boll weight (32%) and seed cotton yield (50%) in comparison to the flat-sown crop. A late application of MC (at 70 DAS) caused a significant reduction in the time to flowering (8%), with a simultaneous increase in the number of opened bolls (60%), boll weight (32%), ginning out turn (8%) and lint yield (27%) as compared to MC application at 50 DAS. In terms of lint quality, cotton planted on beds had better fiber uniformity (8%) compared to that on the flat field, while MC applied at 70 DAS produced better fiber fineness by 27% in comparison to MC applied earlier. Overall, cotton planting on beds and MC application at 70 DAS may help improve cotton yield and fiber quality and may help in the mechanical picking of cotton

Effect of Mepiquat Chloride on Phenology, Yield and Quality of Cotton as a Function of Application Time Using Different Sowing Techniques

Mepiquat chloride (MC) is a plant growth regulator used to manage the rampant vegetative growth of cotton. A two-year field experiment was conducted at the Postgraduate Agricultural Research Station, University of Agriculture, Faisalabad, Pakistan, during 2017 and 2018 to investigate the influence of MC applied at different times on phenology, morphology, lint yield and quality of cotton cultivated using different sowing techniques. MC was applied 50 days after sowing (DAS), 60 DAS and 70 DAS to cotton planted in flat fields (flat sowing), ridges (ridge sowing) and beds (bed sowing). The interactive effect of MC application time and sowing technique did not influence crop phenology, morphology, and lint yield and quality. It was revealed that the crop planted on beds took fewer days to flower (10%) as compared to that on the flat field, and the bed-sown crop produced a higher number of opened bolls (60%) and was characterized by a higher boll weight (32%) and seed cotton yield (50%) in comparison to the flat-sown crop. A late application of MC (at 70 DAS) caused a significant reduction in the time to flowering (8%), with a simultaneous increase in the number of opened bolls (60%), boll weight (32%), ginning out turn (8%) and lint yield (27%) as compared to MC application at 50 DAS. In terms of lint quality, cotton planted on beds had better fiber uniformity (8%) compared to that on the flat field, while MC applied at 70 DAS produced better fiber fineness by 27% in comparison to MC applied earlier. Overall, cotton planting on beds and MC application at 70 DAS may help improve cotton yield and fiber quality and may help in the mechanical picking of cotton