-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. (244,5; 14,2; 444,6; e 10 g i.a. ha -1 , respectivamente) (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%) Keywords: adjuvant, grain yield, herbicides, wheat 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 + tribenuronmethyl + clopyralid, mesosulfuron-methyl + iodosulfuron-methyl sodium, bromoxynil + MCPA e iodosulfuron-methyl sodium, com as doses recomendadasTANVEER, A. et al. Alkyl ether sulfate improves efficacy of herbicides against common goosefoot and field bindweed in wheat 2

-The aim of this study was to examine the dormancy behavior of Euphorbia dracunculoides and Astragalus spp., weeds of arid chickpea. The dormancy breaking treatments were: Gibberalic acid (GA 3 ) and Thiourea each at 50, 100, 150, 200, 250, and 300 ppm and Potassium nitrate (KNO 3 ) at 5,000, 10,000, 15,000, 20,000, 25,000, and 30,000 ppm (24 h soaking). Germination (G) percentage and germination energy (GE) of E. dracunculoides was maximum (89 and 22, respectively) at 250 ppm concentration of GA 3 and 81.50 and 11.50 at 15000 ppm concentration of KNO 3 . Thiourea at 250 and 300 ppm resulted in maximum G percentage (51) and GE (25.50) of E. dracunculoides, whereas the G percentage and GE of Astragalus spp. were maximum (28 and 19, respectively) at the lowest concentration of GA 3 (50 ppm). On the other hand, 5000 ppm and 150 ppm concentration of KNO 3 and Thiourea showed maximum GE (19.5) and G percentage (28) of Astragalus spp., respectively. Overall, effective dormancy breaking chemical against E. dracunculoides was GA 3 (250 ppm) while in Astragalus spp. none of chemicals showed very impressive results. These results showed that both weeds' seeds have dormancy in their habit. Hot water treatment and the above mentioned chemicals (best concentrations) when used with 4, 8, and 12 hours soaking showed ineffective results.

The species Euphorbia dracunculoides and Astragalus are problematic weeds of arid chickpea in the chickpea mono-cropping system in Pakistan. The influence of various ecological factors on germination and seedling emergence characteristics of these weeds was determined under laboratory conditions. The results suggested that seed germination of both species was 50% at 15 oC under light conditions, and germination decreased when the temperature was increased. The increase in drought stress from 2.5 to 15% significantly decreased germination of E. dracunculoides and Astragalus spp. Both species failed to germinate at the osmotic potential of -3.02 MPa. The increase in field capacity from 25 to 100% increased emergence percentage and emergence index of both weeds. A pH range of 6 to 9 did not influence seed germination of both species and they were able to germinate at a wide range of pH conditions. Both weeds were very sensitive to salinity; however, a few seeds (10%) of Astragalusspp. germinated even at a 150 mM sodium chloride concentration. To check the effect of burial depth, seeds were placed in pots under seeding depths of 0 to 6 cm at an interval of 1 cm, respectively. Maximum emergence was attained at the soil surface and emergence declined with increasing depths. Seedling emergence of E. dracunculoides was higher than that of Astragalusspp. at all burial depths. Studies on germination ecology of these two weeds will offer insights into their behavior under different environmental conditions. Their germination responses and growth patterns under different ecological factors will help us to design an efficient management strategy to control these two troublesome weeds.

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Brown chickpea (Cicer arietinum L.) is one of the two chickpea types grown in Pakistan and other countries. The critical period for weed removal in a rainfed chickpea system is an important consideration in devising weed management strategies. Field experiments were conducted in the winter season of 2011 and 2012 to determine the extent of yield loss with different periods of weed crop competition. Seven weed crop competition periods (0, 45, 60, 75, 90, 105 and 160 days after sowing - DAS) were used to identify the critical period for weed removal in rainfed chickpea. Experimental plots were naturally infested with Euphorbia dracunculoides and Astragalus sp. in both years. Individual, composite density and dry weights of E. dracunculoides and Astragalussp. increased significantly with an increase in the competition period. However, yield and yield-contributing traits of chickpea significantly decreased with an increase in the competition period. Chickpea seed yield loss was 11-53% in different weed crop competition periods. Euphorbia dracunculoides and Astragalus sp. removed 39.9 and 36.9 kg ha-1 of N, 9.61 and 7.27 kg ha-1 of P and 38.3 and 36.9 kg ha-1 of K, respectively. Season long weed competition (160 days after sowing) resulted in 19.5% seed protein content compared with 24.5% seed protein content in weed-free chickpea. A Logistic equation was fitted to yield data in response to increasing periods of weed crop competition. The critical timing of weed removal at 5 and 10% acceptable yield losses were 26 and 39 DAS, respectively. The observed critical period suggests that in rainfed chickpea, a carefully timed weed removal could prevent grain yield losses.