جستجوی مقالات مرتبط با کلیدواژه « مدیریت تلفیقی » در نشریات گروه « زراعت »

To evaluate the effect of crop rotation and chemical management on weed seed bank in wheat fields, a three-year experiment was conducted in split-plot design with three replications in Khuzestan province. Main plots were crop rotation (wheat-wheat-wheat, wheat-rapeseed-wheat and wheat-sugar beet-wheat) and subplots were chemical management (Untreated Control (UTC), chemical rotation and no chemical rotation (farmer program)). The results showed the change in crop rotation reduced the frequency ratio of weeds seed bank population in both evaluated depths (0 to 10 and 10 to 20 cm). Also, the combination of chemical management along with crop rotation significantly reduced weeds seed bank population. In the absence of herbicide application in the three years of experiment, the frequency ratio of winter wild oat weed seed bank population on the soil surface decreased from 2.20 to 1.48 with rapeseed and from 2.73 to 0.63 with sugar beet planting, however, in the case of non-crop rotation, the frequency of wild oat seeds in the seed bank increased. This trend was also evident in the total weed seed bank population.

Backgrounds and Objectives:

Direct seeding is being developed in many Asian countries as a new technology that farmers are tending to use this technology in current years considering that it has appropriate economic efficiency, faster and easier cultivation, less labor force, more mechanization and shorter growth period than transplanting cultivation and due to discontinuous irrigation, less methane emission. But what makes it mainly obstacle are weeds.The use of seed priming can be one of methods that it can compensate the paucities of direct seeding and get promote seed quality. Seed priming also can active the initial germination mechanisms before planting and many benefits were mentioned for this treatment that the most significant of them is increasing the percentage and rate of germination. Indeed these plants expand their root system in shorter period of time compared untreated seeds. They are also reached to autotroph stage earlier by absorbing more water, nutrients and producing photosynthetic part. 

Materials and Methods:

The field experiment was conducted in Neka in 2018. The experiment was performed as a factorial in randomized complete block design in three replications. Experimental treatments include  seed priming in four levels 1- no priming, 2- hydropriming (priming with water), 3- priming with humic substances (10 g per 1.5 liters of water) 4- priming with auxin hormone (1.5 cc in 1.5 liters of water) and also, weed management at five levels 1- no weeding, 2- council active herbicide (15 g per 20 liters of water), 3- twice weeding (one month after planting + before the earing stage), 4- council active herbicide (15 g per 20 liters of water applied about one month after planting) + weeding (1.5 months after planting) and 5- complete weeding (weeding of all weeds during the growing season). 

Results:

Based on the results, by applying seed priming with humic acid, the maximum plant height, ear length and number of plants m-2 were obtained and complete weeding caused the maximum plant height, fertile tiller, total tiller and ear length. Also, seed priming with humic acid along with complete weeding caused the highest filled grain number (79.67 number) and total grain number (90 number), 1000-grain weight (23.47 g), grain yield (2327 kg ha-1), biological yield (11220 kg ha-1). Based on total weed density and biomass, in all three stages of sampling, the lowest amount of weed biomass and density was obtained with application of humic acid priming along with council active herbicide + weeding, which was not significantly different from application of humic acid priming and twice weeding and application of auxin with council active herbicide + weeding and twice weeding. Overall, the findings of this study indicate the effect of priming of rice seeds especially with humic acid and auxin along with council active herbicide + weeding and twice weeding, on reducing the weeds density and biomass as well as increasing the yield and yield components of rice in direct cultivation. 

Discussion:

According to results which were obtained this research and evaluation of yield and yield components are identified that application of herbicide cannot control the weed solitary. This research was showed that application of council active herbicide + weeding and twice weeding cause to reduce the weeds density and biomass as well as increasing the yield and yield components of rice in direct cultivation and also own to elimination of competing species, they improve the crop growth. Therefore, mechanical weeding, which is a non-chemical method of weed management, should be considered as a necessary part of sustainable agriculture.

Direct seeding of rice is one of the most common farming methods in the world. Economic efficiency, faster and easier cultivation, reduction of growth period and earlier maturity (7-10 days), needing to less labour, higher water efficiency, more mechanization and reduction of rice vulnerability due to end-of-season drought are some benefit of direct rice cultivation; while, the most important problem in this planting system is weed control, and if weeds are controlled properly; the yield of rice in direct seeding will be almost equal to that of transplanting system. So, this study was conducted to evaluate the effect of weed management methods on different cultivars of rice in direct seeding system.

This research was performed as a factorial in randomized complete block design in three replications at Rice Research Institute, Amol in 2018. Treatments include three different rice cultivars of Tarom Hashemi, Shiroodi and Neda under six weed management methods (no weeding, twice weeding (40 days after emergence and in the earing stage), using rice husk mulch (0.5 kg m-2 after sowing), application of triafamone+ethoxysulfuron herbicide (30 g ai ha-1 in 5 days after emergence in two-leaf stage), application of triafamone+ethoxysulfuron herbicide (30 g ai ha-1 in 5 days after emergence in two-leaf stage) + weeding (40 days after emergence) and complete weeding (all weeds are removed during the growing season) were considered. The studied traits included: plant height, tiller number, panicle length, 1000-grain weight, filled grain number, empty grain number, panicle number per square meter, grain yield, biological yield and total weed density and dry weight.

The results showed the highest plant height (137.7 cm) and number of tillers (24.7) was obtained in Tarom Hashemi and Shiroodi cultivars under complete weeding, respectively. The results of mean comparison of the main effects of the experimental treatments indicate that the filled grain number in Tarom Hashemi, Neda and Shiroodi cultivars were 67.6, 69.3 and 90.1 per ear and 1000-seed weight in these cultivars, was 19.9, 18.6 and 21.1 g, respectively. When Shiroodi cultivar had more seeds per ear and 1000 seeds weight. Also, the maximum filled grain number (94.9) and the highest 1000-seed weight with 22.7 g was observed in the complete weed control treatment. The highest panicle number per square meter (316.7) was related to Shiroodi cultivar and complete weed control, which had no significant different with herbicide + weeding and twice weeding in the same cultivar, as well as complete weeding in Neda cultivar. The highest grain yield (8192.5 kg ha-1) was observed in Shiroodi cultivar + complete weeding, which had no significant different with Neda + complete weeding and Shiroodi + herbicide + weeding. Lack of weed control in Tarom Hashemi, Neda and Shiroodi cultivars reduced 38.2, 63.3 and 61.7% of grain yield compared to complete weed control, respectively. The results showed that at all three stages of sampling, the lowest weed density and dry weight in all three sampling stages was related to herbicide + weeding treatment in Shiroodi cultivar which had good control over weed and was able to reduce weed density and its dry weight.

In general, it can be concluded that although the yield of rice in the direct planting system was the highest in the absence of weed contamination; however, since the application of triafamone+ethoxysulfuron herbicide along with weeding caused reduction the density and dry weight of weeds, and also, improved the yield and yield components of all three rice cultivars, so this management method can be used to control weeds more effectively and achieve proper yield in this system.

In order to investigate the effects of chemical and integrated weed management on yield and yield components of grain maize and weed population, the study has been conducted as a randomized complete block design with three replications in 2018-19 in Shavar Research Center in Shavar region of Shousha city. Treatments include unweeded (control), hand weeding, 1.5 liters of atrazine, 1 liter of atrazine + straw mulch, 175 g of ultima, 150 g of ultima + straw mulch, 1.5 liter 2,4-D + MCPA, 1 liter 2,4-D + MCPA + straw mulch, 1.5 liters cruise, and 1 liter of cruise + straw mulch. Results show that the highest grain yield has been obtained in hand weeding treatment as well as 1 liter of cruise + straw mulch by 14.4 and 13.2 t ha-1, respectively. The highest biological yield is recorded in hand weeding treatment (31.5 t ha-1). In case of harvest index, 1.5 liters of cruise show the highest value (55.7%), followed by 1.5 liters of 2,4-D + MCPA and 1.5 liters of atrazine by 53.6% and 47.7%, respectively. In terms of weed population dynamics, hand weeding, and 1 liter of cruise + straw mulch cause the greatest decrease in weed population and dry weight which reduce crop competition and increase productivity. In general, based on the results, the adoption of integrated approaches (chemical + cultural + mechanical) can make a significant contribution to increasing corn yield and reducing environmental pollution.

To evaluate the effect of false seedbed preparation on rye (Secale cereale L.) control, an experiment was conducted during 2013 in Shahrekord. Experimental factors were arranged in split plot factorial design with three replications. The main plots included seed bed preparation at three levels: 1. conventional dry cultivation of wheat, 2. seedbed preparation, irrigation, weed control (including rye) with paraquqt (20% SL) at 2 L ha-1 after one month, wheat cultivation, 3. seedbed preparation, irrigation, mechanical weed control (using harrow), wheat cultivation. Subplots 1. included cultivars at three levels (Alvand, Pishgam and Back Cross Roshan) and 2. planting densities at three levels (200, 250 and 300 kg ha-1). According to the mean comparison, density and biomass of rye in the treatment of irrigation application of herbicide decreased relative to dry cultivation by 67.7 and 74.9 percent, respectively, Pishgam cultivar decreased rye density and biomass by 36.9 and 18.7 percent, respectively. The seeding rate of 200 kg ha-1 of wheat reduced density and biomass of rye by 24.3% and 22.4%, respectively. The highest grain and biological yield of wheat was observed in irrigation and application of paraquat with 4206 and 8872.3 kg ha-1, respectively. Based on the results of this research, for weed control, especially rye, yield and yield components of winter wheat, the best method of seedbed preparation, is false seedbed preparation using chemical control of weeds. The best wheat cultivar, was Pishgam and best wheat seeding rate, was 200 kg ha-1.

Cultivation of winter cover crops such as wheat and barley is one of the practical approaches for weeds control in cereal-based rotations. In order to investigate the effect of cover crop species and nitrogen rates on weed control of rapeseed (Brassica napus L.), a field experiment was arranged in split-plot based on a RCBD with three replications during 2013-2014 growing season at Research Field of School of Agriculture, Shiraz University, Shiraz, Iran. Treatments included nitrogen levels (75 and 150 kg N ha-1) as the main factor and cover crops (no cover crop as control, 25% wheat, 50% wheat, 75% wheat, 25% barley, 50% barley and 75% barley) as sub factor. The results showed that there was significant difference between the presence and absence of cover crop and its interaction with nitrogen level in terms of an array of measured traits. The lowest density, dry weight and height of weeds were obtained from the using barley as a cover crop at the presence of both nitrogen rates, suggesting that barley cover crop is more potent to suppress the weeds compared to wheat cover crop. The highest grain yield (5290 kg ha-1) and oil yield (1760 kg ha-1) of rapeseed were obtained from 50% barley cover crop and the highest rapeseed protein percentage (43%) was obtained from using 25% wheat cover crop at 150 kg N ha-1. Overall, the highest grain and oil yields were achieved from application of 150 kg N ha-1 along with using 50% barley cover crop treatment, though the latter combination did not significantly differ from 75 kg N ha-1 at 50% wheat cover crop

In order to evaluate the infection rate of different sugar beet lines and cultivars to S. ocellatella, 24 sugar beet lines and cultivars were evaluated under natural infection in the field in Karaj, in 2013.Considering the presence of several generations of the pest, the infection rate treatments were evaluated during the growing season (eight stages, every 10days). After last sampling on 16 September, treatments were classified to four groups (low, medium, high, and very high infection) based on standard deviation distance from mean. The commercial varieties Paya, Marak, and 7K43 were placed in low infection group, whereas Rosire, Dorothea and the male line of Jolgeh in the very high infection group. Based on field observations, the first symptoms of the pest infection were emerged at 6-8-leaf stage early July; however, the infection percentage was low early July (less than 0.34-1.37%) and increased to more than 50% in August. In general, it is recommended that in sugar beet breeding programs, the resistance potential of the cultivars be used for damage control.

Considering environmental issues of herbicide applications, using of integrated weed management could reduce the amount of herbicide usage accompanied with keeping their efficacy. Farmers are always faces the weed contamination and the number of weeding labor, tillage and the amount of herbicide application shows how important they are (Eue, 1986). However introducing the new herbicides are an important progress in agriculture (Pike and et. Al.) but crop damaging and concerns about herbicides carry over to non-target areas, weed herbicide resistance, environmental consequences issues and human health, are the reasons to revise the chemical weed management (Blachshaw, 2006). A long successful weed management needs to change the simple weed control to the system which reduce weed germination and reproduction and decrease the ability of competitiveness of weed with the crop. The purpose of this experiment was to evaluate the possibility of clodinafop application reducing in combine with different wheat densities to control Avena loduviciana L.
Matterials and a field experiment was conducted at Hossein Abad Malek village located at 25 kilometer at east of Gorgan city. Field preparations were tillage and two vertical disc and making plots. Plots were two meter width and five meter length. A factorial filed experiment based on randomized complete block design was carried out. Treatments were recommended and 150 % of recommended density of wheat and four clodinafop doses including 0, 60, 80 and 100 % of recommended dose which every dose applied by two different application like split and single application approach. Fresh and dry weight of weeds were sampled after one month and wheat yield was obtained from three m2.
Results showed that split application of clodinafop shows more control efficacy percent of Avena ludoviciana compared with single application. Increasing the density of wheat up to 150 % of recommended density increased the efficacy control of single application whereas at split application without any increasing in the density of wheat always shows more efficacies in comparison with single application. There was no significant difference between wheat yield at split application of 80 and 100 % recommended dose of clodinafop at both density of wheat. Also with increasing clodinafop control efficiency, wheat yield was increased as well, and this yield increasing had straight relation with both simple and split application weed control efficiency.
Split application approach cause increasing weed control efficacy and reducing herbicide usage up to 20 %.

Integrated weed management approaches can help to decline costs weed control and improve its condition. Critical period of weed control (CPWC) is defined as the best time for weeding. If CPWC is recognized we can accurately use herbicides and prevent environmental pollutions. Beginning and duration of CPWC despond on some agents such as crop and weed traits, environment and agronomical factors. With respect to inexistence data about the effect crop rotation on the CPWC this study was done.
In order to determine effect two different crop rotations (wheat – canola and soybean-canola) on the critical period of weed control in rape seed, two experimental designs were performed for the first and second rotation in 2011 and 2012, respectively. These studies did in the suburban of Galugah region in randomize completely block format with three replications. Treatments included periods of weed management on the canola growth stages(five weeding and competition levels up emergence , two leaf stage , four leaf stage , eight leaf stage , flowering stage plus two control treatments).
Findings showed canarygrass dominated in both rotations. Species diversity in soybean-canola rotation by using Shannon index (H= 0.69) was higher than wheat-canola (H= 0.45) .Canola yield was 4060 and 2280 kg ha-1 in the wheat-canola and soybean-canola rotations, respectively. Further yield in the first rotation can be related to positive role of organic matter which was more in the soil and its influence on the most important yield component that was number pod in each plant. The CPWC for wheat- canola rotation was between 161 and 354 days after planting(DAP) (emergence to six-leaf stage) and between 65 to 920 DAP(planting up maturity stage), using 5 percent acceptable yield reduction.
CPWC in soybean-canola rotation relative to wheat-canola rotation begined sooner and its duration also was longer.

To evaluate the integrated management of weeds in red kidney bean, a split-plot experiment using randomized complete block design with three replications was conducted in 2013 in the Damavand County. In this experiment, the mechanical control treatments consisted of two levels (no cultivation and one cultivation) asseigned to main plots and controlling chemical treatments consisted of six levels (non-application of herbicides, pre-emergence herbicide application of Pursuit with full dose of 1 liter per hectare, pre-emergence herbicide application of Pursuit a dose decreased 0.5 liters per hectare, post-emergence herbicide application of Pursuit dose reduced to 0.3 liters per hectare 2 thousand citogate, post-emergence herbicide application of Pursuit with a reduced dose of 0.5 liters per hectare 2 thousand citogate, post-emergence herbicide application of Pursuit full dose of 1 liter per hectar 2 thousand citogate) to subplots. The results showed that the effects of interaction between herbicide application and cultivation for traits of carotenoids, chlorophyll a, chlorophyll b and total chlorophyll contents, density of weeds and their dry weights were significant at 1 %, and grain yield at the 5% probability levels. The highest bean seed yield with an average of 5461.6 kg.ha-1 and lowest weed dry weight with an average of 345.9 kg.ha-1 were related to pre-emergence herbicide and cultivation with a dose of 1 liter per hectare treatment. The difference between full and reduced doses of chemical weed control was non-significant. It could be concluded that integrated mechanical and chemical weed control not only may increase seed yield but also reduce, environmental hazards.

Hordeum spontaneum C.Koch. is known as a significant factor in decreasing wheat yield. Its control by stale seedbed is a step toward achieving sustainable agriculture in wheat. For this purpose, field experiments were performed during 2007-2008 and 2008-2009 in the experimental fields of the Iranian Institute of Plant Protection, Varamin, Iran. In order to contaminate the field with the weed, wheat was planted in association with H. spontaneum, during the first year. After harvesting wheat in the summer, an experiment was conducted with 9 treatments. Treatments included: 1) field plowing after wheat harvesting and corn (Cultivar SC704) planting, irrigating weekly up to corn harvesting, 2) field plowing no corn cultivation, but irriatted up to corn harvesting in treatment 1. Treatments 3, 4, 5, 6, 7, 8, and 9 were not plowed but irrigated only once, each at an indicated date (July 4th, July 19th, August 1st, August 18th, September 10th, September 23th, and October 8th). Results revealed that stale seedbed from the middle of August favored H. spontaneum emergence. Thus its density reduced in wheat up to two thirds and wheat grain yield increased two times. Field plowing after wheat harvesting increased H. spontaneum burial depth and reduced its density in corn and wheat.

To investigate the effect of seed biological treatment and fertilizer integration on yield and nutrients uptake of turnip (Brassica rapa L.), an experiment was conducted at research institute of rice during 2011 and 2012. The experiment was arranged base on randomized complete block design with three replications. Treatments were involved 9 levels: use of fertilizer and uninoculation, seed inoculation with Azotobacter chroococcum strain 41 and without nitrogen, seed inoculation with A. chroococcum strain 41 and full nitrogen, seed inoculation with Pseudomonas fluorescens strain 12 and without P fertilizer, seed inoculation with P. fluorescens strain 12 and full P fertilizer, seed co-inoculation (with P. fluorescens strain 12 and A. chroococcum strain 41) and without fertilizer, seed co-inoculation and %50 N.P. fertilizer, seed co-inoculation and %100 N. P. fertilizer and without inoculation and fertilizer (control). Investigated characteristics were including plant height, stem diameter, nutrients content (N, P) in plant tissue, dried weight of leaf and tuber and fresh and dried forage yield. The results showed significant effect of seed biological treatment on all of investigated characteristics. This present findings showed that, fertilizer integrated management has important role in enhancement of turnip yield, and it could be suggested that these bacteria have positive effect on forage yield of turnip, and therefore can be used as complementary fertilizer.

To investigate wheat and wild mustard growth and competition to N levels، an experiment was conducted in Ramin Agriculture and Natural Resources University of Khouzestan، located at 36 km North of Ahvaz. Treatments included planting wheat solely، wild mustard solely، and intercropping wheat and wild mustard in pots. These combinations were exposed to N levels including 0، 60، 120 and 180 kg. ha-1. The results showed that grain yield، dry matter and spike number of wheat increased by increased N levels in sole crop treatment. These traits decreased by N levels when competing against wild mustard. Wheat grain and total protein content increased up to 120 kg N. ha-1 by increased N levels، but decreased while competing against wild mustard. The highest N apparent recovery by wheat was obtained from sole cropping of this crop and 120 kg N. ha-1. The lowest rate of this parameter was observed in competition condition against wild mustard and the level of 180 kg N. ha-1. The results showed that wild mustard traits had positive response to increased N levels، regardless to competition against wheat.

Swallow-wort (Cynanchum acutum) is a problematic weed which has recently infested many agricultural fields in Iran especially orchards. Therefore، a three-year experiment was conducted in a randomized complete blocks design with 3 replications in a pistachio orchard in Yazd. Treatments included post-emergence herbicides glyphosate (Roundup 41% SL) at 2، 4، and 6 L/ha+ammonium sulphate (8 kg/ha)، paraquqt (Gramaxon 20% SL) at 3 L/ha، garlon (Triclopyr 62% EC) at 2 L/ha، cutting of swallowort، and weed infested control. Results of the first year showed that the best treatment for the control of swallowort was 3 times spraying with glyphosate 6 L/ha. In the second year، the best treatment for the control of swallowort was 3 times spraying with glyphosate 6 L/ha or 3 times spraying with Triclopyr 2 L/ha. Based on the results of the third year، the best treatments for the control of swallowort were 3 times spraying with glyphosate 6 L/ha، 2 and 3 times spraying with triclopyr 2 L/ha or 2 times cutting + triclopyr 2 L/ha. Therefore، it seemed that the systemic herbicides glyphosate and triclopyr had more efficiency in the control of swallow wort، compared to the contact herbicide paraquat.

In order to study the impacts of mechanical (using cultivation), chemical (using herbicides) methods and their integration in controlling broadleaf weeds in sugar beet fields, this experiment was carried out as a randomized complete block design with 4 replications in Mahidasht-Kermanshah in 2006. In this experiment, 9 different treatments consisting a mixture of post-emergence herbicides phenmedipham + desmedipham + Ethofumesate and Triflusulfuron Methyl with Sittogate combined with cultivation and 2 check treatments with and without control of the weeds were investigated. The results indicated that cultivation treatment accompanied by Triflusulfuron Methyl reduced dry weight of weeds by 54.91% and showed 100% control of Amaranthus spp. In comparison with control treatment. Cultivation treatment combined with a mixture of phenmedipham+desmedipham+Ethofumesate and Triflusulfuron Methyl with Sittogate increased the sugar beet root dry weight by 159.89% and caused 100% control of the density of Conringia orientalis. Phenmedipham+desmedipham+Ethofumesate plus Triflusulfuron Methyl with sittogate treatment increased root yield by 121.86% compared to the check. In conclusion, the highest root yield was obtained in the cultivation treatment combined with phenmedipham + desmedipham+Ethofumesate, a mixture of phenmedipham + desmedipham + Ethofumesate and Triflusulfuron Methyl with Sittogate and cultivation treatments in sugar beet.

In order to investigate the possibility of integrated weed management in corn fields an experiment was conducted in a split-plot with randomized complete blocks design with four replications in Arak Islamic Azad University Research Center during 2008. Treatments were corn density at three levels 70, 80 and 90 thousand plants per hectare in main plots and weed management at five levels including weed free and weed infested controls, one time cultivation, one and two liters per hectare of Nicosolforon. Results indicated that, there was no significant difference between one and two lit/ha of nicosulfuron treatments in high corn density was treatments. Therefore, the best corn density for reducing the dose of nicosulfuron 90,000 plants per hectare. Based on the results obtained from present research, in organic agricultural system, herbicide could be omitted for controlling weeds in corn using on time cultivation at 4-6 leaf stage of weeds plus corn density at 90,000 plants per hectare.

As factorial experiment based on randomized complete block design with four replications was carried out to evaluate the effects of weed management on yield and components yield of corn silage in Miyaneh region in the summer of 2009. Treatments were cultivation (with and without), herbicides (Foramsulfuron, Nicosulfuron and 2,4-D〣) and without controlling weed as control treatment. The results indicated that application of herbicides significantly influenced weeds dry weight at 1% probability level. The highest and lowest percentage loss of weeds dry weight were related to Foramsulfuron and 2,4-D〣, respectively, which were significantly different from other herbicides (Nicosulfuron). Cultivation was significantly effective on weeds dry weight as compared with non cultivation treatment. The results, also, indicated that cultivation and herbicides significantly affected increasing the biological and grain yields compared to non weeds control treatment. The highest biological and grain yield increase were obtained by 59.1% and 57.2% due to cultivation treatment and by 51.8% and 58.2% due to Foramsulfuron herbicide application, respectively. The lowest biological and grain yield was obtained by application of Nicosulfuron herbicide which was statistically comparable to that of 2,4-D〣 herbicide treatment.