Efficacy of different herbicides for controlling narrow leave weeds in wheat-crop at different locations under adaptive research zone Sheikhupura

Field experiment was conducted at three locations i.e. Adaptive Research Farm and two at farmers field during Rabi 2014-15 under ecological zone of Adaptive Research Farm Sheikhupura to study the efficacy of different post emergent herbicides against narrow leave weeds. The experiment was carried out in randomized complete block design (RCBD) with three repeats. Present study comprised of five treatments including control. The treatments comprised of Axial (penoxadin), Exit (clodinofop propargyl), Brake (fenoxaprop-p-ethyl), Proton (Isoproturon) and weedy check. The data were recorded on Plant height at maturity (cm), no. of grains per spike, spike length (cm), weed density m, 1000 grains weight (g), and grain yield (t ha). All treatments of herbicide significantly control the weeds causing significant reduction in weed mass and also improved the grain yield significantly in comparison with the check at three locations. Highest death of weeds (96.12, 97.09 and 98.95 %) and with maximum grain yield of 2846.7, 3320.0 and 3300.0 kg ha which is 19.6, 39.6 and 39.9 % higher than weedy check were recorded in the penoxadin treated plot at three locations respectively. In the weedy check the weed density was 51, 126 and 127 weeds m with grain yield 2380, 2376 and 2358 kg ha at three locations respectively.


Introduction
Wheat (Triticum aestivum L.) is a major player in world food security and for a sustainable food supply.It is the major staple food of Pakistan and meets the major nutrition requirements.It also meets the food requirement for livestock and poultry.Being an important cereal crop and is gaining popularity all over the world and especially in Pakistan.Due to increase in population and food prices, higher yield of the wheat can play a vital role in stabilizing the food prices directly or indirectly.Management of many factors can significantly contribute in increasing the grain yield of wheat in Pakistan.Among these factors, weed management is an important factor.In Pakistan wheat crop grown on an area of 9250 thousand hectare and it contributed in total production was 25478 thousand ton during 2014-15 [1].While in the Punjab province the area under wheat crop was 6979.48 thousand hectare and its production remained 19282.0thousand ton during 2014-15.The average yield of wheat in Pakistan is 2714 kg/ha, that is too low as compared to other highly developed wheat producing countries of the world.Weeds cause considerable losses to production of crops that are economically more essential than fungi, insects and other pest organisms in many situations [2, 3].It was reported that the main goal of managing weed population is to keep the weed population at a satisfactory level rather than to keep the crop completely free of weeds [4].Weed management enhances the cost of production of crops and thus it is very necessary to adopt such methods which could decrease not only the cost of production but also save labor and time.To manage weeds to an acceptable level, scientists adopt various methods among them the chemical control is one of the best methods to eliminate the weeds density, which is being given attention in recent agriculture [5].Follwing narrow leaved weeds like Avena fatua L. and Phalaris minor Retz are predominant and wide spread in their nature.It has been estimated that losses of crops due to weed competition as a whole throughout the world are greater than those resulting from the combined effect of insect pests and diseases.Weeds may support the development of plant diseases like bacterial and fungal, thus providing shelter for pests of all kinds and act as host plants for plant parasitic nematodes.Thus it is very needful by these several reasons for completely eliminating weeds community from the crop environment.It was reported that with the rising costs of power and labor, the use of herbicides will be the only suitable method to control weed density [6,7].In light of the crop losses due to weeds, the present studies were therefore planned and an experiment was conducted at different locations under Adaptive Research zone Sheikhupura with the objective to evaluate different herbicides for controlling narrow leave weeds in wheat.

Materials and methods
Field experiments were undertaken at three locations: Adaptive Research Farm, Sheikhupura and two at farmer's field during Rabi season 2014-15.The experiment comprised of five treatments replicated three times, using Randomized Complete Block Design (RCBD).A total plot area of 10890 sq.feet was maintained with net plot size of each treatment was 20 x 35ft 2 .The treatments included four herbicides (Pinoxaden @ 825ml ha -1 , Clodinofop propagyle 300g ha -1 , Fenoxaprop -P-ethyl @ 1235ml ha -1 , Isoproturon 2000g ha -1 ) and weedy check (Table 1).Recommended agronomic cultural practices were applied in all the treatments to raise the crop during the experiment.
The dose of herbicides applied with the aid of a knap sack sprayer at 55 days after the sowing of wheat crop when weed population was significantly present.All the precautionary procedures were adopted to avoid any herbicides injury while spraying the herbicides treatments.Data were recorded on plant height at maturity (cm), spike length (cm), weed density m -2 at pre and post application of herbicides , no. of grains spike -1, 1000 grain weight (g) and grain yield (kg ha -1 ).The data were subjected to analysis of variance and the means were compared by the least significant difference test (LSD) at 5% level of significance

Results and discussion
Weeds density m -2 It is an important and key factor in figuring out the effect of treatments on weed growth.The major narrow leaf weeds were Phalaris minor (Birds seed grass) and Avena fatua (wild oats) that infested the experiment at all locations.The analysis of data presented in Table 2 showed that weeds density m -2 was significantly affected by different treatments of herbicides.The data showed that weed density was significantly affected by the integration of Pinoxaden (Axial 50 % EC).
The smallest weed density m -2 was recorded at application of treatment T1 i.e.Pinoxaden at 55 days after sowing of wheat when significant weed population was present, the mean of weed density 2.0, 3.67 and 1.33 m

Grain yield (kg ha -1 )
Grain yield is the most important parameters to assess the weed control treatments that are applied in experiments.Location wise experimental data regarding grain yield (kg ha -1 ) is documented in Table 7 which revealed that the all the herbicides had a persuasive effect on the grain yield of wheat crop as compare to control (weedy check).Among the herbicides, the pinoxaden treated plots gave maximum grain yield 2846.7, 3320.0 and 3300.0 kg ha -1 which were 19.6 , 39.6 and 39.9 % higher than the weedy check (2380.0 , 2376.7 and 2358.3 kg -1 ) at three locations respectively.Our findings are in agreement with that of [17,18] who reported that in fact the application of herbicides greatly affect the grain yield of wheat.Similarly [19] also reported the parallel results.They also reported that different treatments of herbicides increased the grain yield significantly in wheat.

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. Weed density was calculated with the help of following equation: WCE = NWC -NWT X 100% NWC Where WCE = Weed Control Efficiency.NWC = Number of Weeds m -2 from Control plots (weedy check).NW T = Number Weeds m -2 in plots Treated with herbicides.

Table 7 . Effect of different herbicides on yield of wheat crop sown during Rabi season 2014-15 at three locations under adaptive research zone Sheikhupura
In the light of above discussion it is concluded that all the herbicides significantly control the narrow leave weeds in the wheat crop and also improved the grain yield significantly in comparison with the check.Among the herbicides the highest weed control efficiency (96.12, 97.09 & 98.95 %) and with maximum grain yield of 2846.7,3320.0 & 3300.0 kg ha -1 which is 19.6, 39.6 & 39.9 % higher than weedy check were recorded in the penoxadin treated plot at three locations respectively.
Authors' contributions Conceived and designed the experiments: MQ Waqar & G Nabi, Performed the experiments: M Shahbaz, M Sajjad & M Riaz, Analyzed the