Room-and-pillar mining is commonly employed for the extraction of rock salt in underground mines. Pillar stress is a major concern in these mines as it is directly related to stability and mineral recovery. In this study a flat jack method was used to measure pillar stresses in three underground rock salt mines in Pakistan. The field work included determination of in-situ stress, in-situ elastic modulus, recording of field variables (pillar length and width, height and width of opening, opening width to height ratio, extraction ratio, and overburden height) and collection of salt block samples. The geomechanical properties of rock salt (uniaxial compressive strength, Young's modulus, Brazilian tensile strength, and density) were also determined to estimate overburden stress, pillar strength, and factor of safety (both estimated and actual). It was found that the measured pillar stresses are proportional to the overburden stress values, with their magnitude ranging from 6.05 MPa to 11.97 Mpa, and the pillars were found to be stable. Regression analysis was performed to develop statistical models for in-situ stress and in-situ elastic modulus. Finally a quick guideline chart was developed to determine the suitable length of pillar for a given span and required level of safety.

ABSTRACT The objective of the current work was to assess the effects of Tulsi plant powder on the health, growth and carcass characteristics of Japanese quail. In total, 300 quails (1-week old) were distributed into four treatment groups with five replicates each. The first group (T0) was a control group where a basal standard diet was offered to the birds. Groups T0.5, T1 and T1.5 were supplemented with Tulsi plant powder at a rate of 0.5%, 1%, 1.5%, respectively. Data were analyzed in SPSS software by applying one-way ANOVA and significant and notable means were analyzed through Duncan’s New Multiple Range Test. Dietary supplementation of T1.5 significantly (p≤0.05) increased the feed intake, body weight, gain in weight and presented a better feed conversion ratio. Significantly higher glucose, total cholesterol, HDL, WBCs, RBCs and HCT were observed in the quails from T1 than in the control group (p≤0.05). However, the quails from T1.5 had significantly (p≤0.05) higher hemoglobin, MCV, platelets and total protein contents. On the other hand, the T0 group was only higher in LDL contents. Non-significant (p>0.05) in MCH, MCHC, triglyceride, VLDL were noted among the experimental groups. It was concluded that the dietary supplementation of Tulsi plant powder at 1.5 % is beneficial for improving the growth performance and can be used in the diet of Japanese quail without compromising the health status and carcass traits.

RESUMO: O aumento da resistência das plantas daninhas aos herbicidas, a contaminação ambiental e as preocupações com a saúde devido ao uso excessivo de herbicidas são fatores que têm instigado os pesquisadores a se concentrarem em soluções para reduzir as doses de herbicidas aplicados no controle de plantas daninhas. Os adjuvantes são mais adequados para esse propósito, pois desempenham papel crucial na obtenção de um controle satisfatório das plantas daninhas, maximizando a atividade dos herbicidas. Uma pesquisa de campo de dois anos foi realizada no Departamento de Pesquisa Agronômica da Universidade de Agricultura de Faisalabad, no Paquistão, durante o inverno de 2014 e 2015, com o objetivo de otimizar a atividade de dois herbicidas de amplo espectro em dose reduzida (75% da dose recomendada pelo fabricante) para o controle de plantas daninhas no trigo. Foi registrada a densidade mínima da planta daninha, assim como seu peso seco e a captação de NPK, com dose reduzida de mesosulfuron-methyl + iodosulfuron-methyl-sodium a 10,60 g i.a. ha-1 combinada com etoxilato de álcool gordo a 200 mL ha-1. Em seguida, foram aplicadas doses reduzidas de sulfosulfuron a 18,75 g i.a. ha-1, combinadas com o mesmo adjuvante. Entre vários tratamentos com herbicidas, a aplicação da dose reduzida de mesosulfuron-methyl + iodosulfuron-methyl-sodium a 10,60 g i.a. ha-1 combinada com o etoxilato de álcool gordo a 200 mL ha-1 provou ser mais rentável e proporcionou o mais alto rendimento de trigo durante os dois anos de estudo.

ABSTRACT: Herbicide resistance development among weeds, environmental contamination and health concerns due to the overuse of herbicides have led researchers to focus on ways to reduce herbicides to be sprayed for weed management. Adjuvants are best suited for that purpose, as they accomplish a crucial role in achieving satisfactory control of weeds by maximizing herbicidal activity. A two-year field investigation was carried out at the Agronomic Research Area, in the University of Agriculture, in Faisalabad, Pakistan during the winter of 2014 and 2015, with the objective to optimize the activity of two broad-spectrum herbicides at reduced dose (75% of the label mentioned rate) for weed control in wheat. Minimum weed density, weed dry weight and NPK uptake were recorded with reduced dosed mesosulfuron methyl + iodosulfuron methyl sodium at 10.60 g a.i. ha-1 combined with fatty alcohol ethoxylate at 200 mL ha-1. This was followed by reduced dosed sulfosulfuron at 18.75 g a.i. ha-1 combined with the same adjuvant. Among various herbicidal treatments, application of reduced dosed mesosulfuron methyl + iodosulfuron methyl sodium at 10.60 g a.i. ha-1 combined with fatty alcohol ethoxylate at 200 mL ha-1 was proved to be most cost effective and resulted in maximum wheat yield during both years of study.

RESUMO: A aplicação de herbicidas em tanque com adjuvante é necessária para o manejo eficaz de plantas daninhas e para a redução da carga de herbicidas em culturas agrícolas. Estudos de campo foram conduzidos para investigar o efeito de herbicidas em doses reduzidas com adjuvante em ansarinha-branca (Chenopodium album) e corriola (Convolvulus arvensis) e no rendimento de grãos de trigo durante duas estações de inverno consecutivas. Os tratamentos incluíram a aplicação foliar em pós-emergência de quatro herbicidas, a saber: fluroxypyr + tribenuron-methyl + clopyralid, mesosulfuron-methyl + iodosulfuron-methyl sodium, bromoxynil + MCPA e iodosulfuron-methyl sodium, com as doses recomendadas (244,5; 14,2; 444,6; e 10 g i.a. ha-1, respectivamente), e doses reduzidas em 25% com sal de sulfato de aquil éter at 400 mL ha-1 como adjuvante. Um grupo de plantas daninhas sem aplicação de herbicidas foi mantido como controle. Todos os tratamentos com herbicidas causaram redução significativa nas densidades (até 85% e 89,2%) de C. arvensis e C. album, respectivamente, bem como no peso seco total (12.4-56%), N (3,7-50%), P (25-63,6%) e K (1,4-56,6%) das amostras de controle das plantas daninhas. Foi obtido melhor controle das plantas daninhas com uma dose 25% mais baixa de todos os herbicidas juntamente com o adjuvante, em comparação com o registrado com as doses completas sem adjuvante. Todos os tratamentos com herbicidas aumentaram o rendimento de grãos do trigo, variando em 10,4 ± 56,1% em relação ao controle, nos anos 2013-14 e 2014-15. Os herbicidas com adjuvante tiveram rendimento de grãos do trigo significativamente maior do que o observado apenas com herbicidas. Entre todos os tratamentos com herbicidas, verificou-se que as doses de bromoxynil + MCPA e iodosulfuron-methyl sodium, juntamente com o adjuvante de éter etílico-sulfato, foram as melhores, uma vez que proporcionaram rendimentos de grãos de trigo significativamente maiores (4902,3 e 5159,0 kg ha-1 e 4566,5 e 4891,0 kg ha-1) nos anos 2013-14 e 2014-15, respectivamente.

ABSTRACT: Tank mixed application of herbicides with adjuvant is required for effective weed management and to reduce herbicide load on agricultural crops. Field studies were conducted to investigate the effect of herbicides at reduced rates with adjuvant on common goosefoot (Chenopodium album) and field bindweed (Convolvulus arvensis) and grain yield of wheat for two consecutive winter seasons. Treatments included post-emergence foliar application of four herbicides viz., fluroxypyr + tribenuron-methyl + clopyralid, mesosulfuron-methyl + iodosulfuron-methyl sodium, bromoxynil + MCPA, iodosulfuron-methyl sodium (pre mixed formulations) at their recommended rates 244.5, 14.2, 444.6, 10 g a.i. ha-1, respectively and 25% reduced rates with alkyl ether sulfate Na salt at 400 mL ha-1 as adjuvant. A weedy check was kept as control. All the herbicide treatments caused a significant reduction in densities (up to 85% and 89.2%) of C. arvensis and C. album, respectively and total dry weight (12.4-56%), N (3.7-50%), P (25-63.6%) and K (1.4-56.6%) uptakes from weedy check. Better weed control was achieved with 25% lower dose of all herbicides along with adjuvant in comparison with that recorded with their full doses without adjuvant. All herbicide treatments increased the grain yield of wheat ranging from 10.4 6-56.1% over control during both years. Herbicides with adjuvant produced significantly the higher grain yield of wheat than those observed with herbicides alone. Among all herbicide treatments, 75% doses of bromoxynil + MCPA and iodosulfuron-methyl sodium along with alkyl ether sulfate adjuvant were proved to be the best as they gave significantly the higher (4902.3 and 5159.0 kg ha-1 and 4566.5 and 4891.0 kgha-1) grain yields of wheat during years 2013-14 and 2014-15, respectively.