جستجوی مقالات مرتبط با کلیدواژه « خردل وحشی » در نشریات گروه « زراعت »

Knowledge on germination ecology of weeds in response to salinity and drought stresses can help to predict weeds population dynamics in the future. Among the family of weeds, the weeds of Brassicaceae family include many important species that contaminate crops and orchards. In addition to the presence of weeds, salinity and drought are also considered as limiting factors in agricultural production. Due to the increase in salinity and drought stresses in agricultural fields, it can be significant expansion and contamination of Brassicaceae weeds, because Physiological dormancy, abundant seed production and emergence at different time, leads to be persistent for long-term in soil. Therefore, the aim of this research was to compare the characteristics of seed germination of four weeds Brassicaceae family to salinity and drought stresses.

In order to investigate the effects of salinity (0, 50, 100, 150, 200, 250, 300, 350 and 400 Mm) and drought stress (0, -0.2, -0.4, -0.6, -0.8, -1 and -1.2 MPa) on seed germination four Brassicaceae family weeds (Rocket (Eruca sativa), Hoary Mustard (Hirschfeldia incana), Wild Mustard (Sinapis arvensis) and Treacle Mustard (Erysimum repandum), two experiments as factorial based on completely randomized design (CRD) were conducted at agricultural sciences and natural resources university of Khuzestan in 2019 with three replications. Optimum Temperature for germination were selected 25°C for Rocket, Hoary Mustard, Wild Mustard and 15°C for Treacle Mustard. Duration of test for two experiments was considered 15 days. Criterion for germination was length radicle 2-3 mm.

By increasing drought stress, germination, vigour index and germination rate were decreased and no germination was observed in drought stress of -1.2 MPa. 50% reduction for germination in four weeds Rocket, Hoary Mustard, Wild Mustard and Treacle Mustard were estimated in -1, -0.49, -0.76 and – 0.41 MPa of drought stress respectively. Drought stress required to reduce 50% of germination rate for Rocket, Hoary Mustard, Wild Mustard and Treacle Mustard were estimated -0.85, -0.35, -0.28 and 0.22 MPa respectively.The vigour index of Wild Mustard in conditions without drought stress treatment was more than other weeds. Rocket and Hoary Mustard were introduced as resistant and Wild Mustard was introduced as sensitive to salinity. The salinity required to reduce 50% of germination for Rocket, Hoary Mustard, Wild Mustard and Treacle Mustard were predicted 267, 162, 39 and 46 mM, while 50% reduction for germination rate were 174, 142, 27, 44 Mm respectively. By increasing salinity and drought stresses, mean germination time was increased and maximum mean germination time belonged to Treacle Mustard and the reason for this increase was the lag phase of germination. Germination rate in four weeds was more affected by salinity and drought stresses than germination percentage. Generally the germination rate of Treacle Mustard was much less than other weeds. So that the maximum germination rate of Treacle Mustard was 5 seed/day in control treatment while in Rocket Hoary Mustard, Wild Mustard were more than 30 seed /day.

According to the results, in saline lands, the spread of two weeds Rocket and Hoary Mustard is more expected and in the conditions of drought stress and in rainfed agriculture, presence of Rocket is more evident than Wild Mustard.

For determination of economic damage threshold of four wheat (Triticum aestivum L.) cultivars in different densities of wild mustard (Sinapis arvensis L.)، experiments were conducted at Agricultural Research Station Gorgan during 2010-2012. The experimental design consisted of four randomized complete blocks in a factorial arrangement. The treatments comprised of factorial combination of wild mustard densities and wheat cultivars. Five different densities of wild mustard (zero، four، eight، 16 and 32 plants. m-2) and four wheat cultivars (‘Arta’، ‘Tajan’، ‘Mogan’ and ‘Morvarid’) were considered in all the replications. Cousens hyperbolic equation was used to describe the yield reduction due to wild mustard competition. The maximum yield reduction was associated with high densities of wild mustard and among the cultivars، ‘Arta’ and ‘Morvarid’ had the maximum and minimum yield reductions، respectively. Calculated competitive indexes indicated that ‘Morvarid’ cultivar in competition with wild mustard had a high capacity to prevent yield loss (high tolerance) and on the other hand، dry weight and seed amount of weed was also greatly reduced. Using extended Cousens hyperbolic model and Odonovan formula، economic damage threshold for wheat in two years determined in densities of 4. 11، 3. 68، 2. 33 and 2. 11 plant/m2 for ‘Morvarid’، ‘Moghan’، ‘Tajan’ and ‘Arta’ cultivars in climatic conditions of Gorgan.

This research was conducted to study the relative fitness of wild mustard biotypes of Khoozestan, Golestan and Kermanshah provinces that are resistant to Acetolactate Synthase (ALS) Inhibitors. Green-house experiments were conducted in two parts. In the first part, plant dry matter, leaf area and plant height change of resistant and susceptible biotypes of each province were compared under no competition with wheat condition. In the second part, growth ability of resistant and susceptible biotypes of each province, growth ability and yield of wheat were studied under competition conditions. According to the results, resistant biotype Ker-2 had significantly higher than susceptible biotype Ker-1, but there was no significant difference between them on the point of final height and dry weight per plant. Resistant biotypes of Golestan and Khoozestan (Kh5 & G3) were lower than susceptible biotypes of these provinces (Kh3 & G9) on the point of mentioned three criteria, significantly under competition with wheat condition. Resistant biotypes of Ker-2 and susceptible biotypes of Ker-1 had no significant difference on the point of ability of competition with wheat. Relative interference index of the two biotypes of Kermanshah were not significantly, different. Finally, difference of growth and yield of wheat were not significant in competition with these two biotypes. According to the results of Golestan and Khoozestan, susceptible biotypes of them (Kh3 & G9) had significantly higher growth and interference index than resistant biotypes (Kh5 & G3) in competition with wheat. Also, wheat had higher grain growth and yield in competition with resistant biotypes rather than susceptible biotypes. Finaly, results showed that among the three resistant biotypes, only Ker-2 had the same competition and growth ability to susceptible biotypes. Therefor it, could disperse rapidly and make high interference due to its resistance to ALS inhibitors.

Allelopathic phenomenon is an interference method of weed on crops that can help to know crop-weed interaction. This experiment was conducted to evaluation of Sinapis arvensis and Cirsium arvense allelopathic effects on canola germination and nutrient uptake in 2007 at greenhouse of University of Mohaghegh Ardabili. Treatments were differential concentrates (0, 2.5, 5, 10, 20 and 40%) of fresh and dry residual extract of Sinapis arvensis and Cirsium arvense. The experiment was laid out as factorial in completely randomized design. Analyses shown that fresh and dry extract of two weeds reduced germination of canola in compared with control 1.5 to 2.5 times. Also fresh and dry extract of weeds reduced canola dry aboveground mass. Nitrogen and P uptake reduced under fresh extract, while dry extract of Sinapis arvensis increased p uptake in canola more than 4 times. Fresh and dry extract of Sinapis arvensis and Cirsium arvense increased canola K concentrate. The experiment results show that in addition to competing weeds, through release of chemicals can be also inhibit on growth and physiological processes of crop.

The aim of this study was to investigate and to quantify the effect of burial depth on seedling emergence of volunteer canola and wild mustard. Seeds were buried in 12 different depths (1، 2، 3، 4، 5، 6، 8، 10، 12، 15، 20، 30 cm) in 4 replications and seedling emergence was measured daily. Results indicated that emergence percentage of volunteer canola was around 98 % from 1 to 2. 9 cm of burial depth and deeper depths decreased emergence percentage with a slope of -0. 4 and reached to zero in burial depth of 10 cm. Seedling emergence percentage of wild mustard was described using an exponential model on the response to burial depth. According to the model، wild mustard seedling emergence decreased from 66 % in 1 cm depth to 0 % in 8 cm depth. Increasing burial depth leads to reduction of seedling emergence rate that it well quantified for both species. Seeds of these two species that buried in deeper soil layers from 10 cm for volunteer canola and 8 cm for wild mustard can expand soil seed bank and will not emerge. The results of this study may provide useful information in ecological weed management and prediction seedling emergence of weeds.

In four separate experiments, competition of different densities of feral rye (Secale cereale) and wild mustard (Sinapis arvensis) with wheat (Sayson cv.), also interference of Canada thistle (Cirsium arvens) and wild mustard with canola (Okapi cv.) were evaluated in 2008-2009 growing season, in Bu-Ali Sina University of Hamedan. Rectangular hyperbolic model, yield reduction of both crops than weed density and dry weight described properly. Increased dry weight of each three weed species than density per unit area was linearly. In interference with wheat, initial slope of yield loss (I) and economic threshold (ET) of wild mustard competition than feral rye were more and less, respectively. Inhibiting effect of Cirsium arvens on canola was more than wild mustard and had less economic threshold. Increasing dry weight of wild mustard per unit area instead of per plant, in competition with canola was less than wheat. Also ET of this weed in wheat was obtained more than canola. Except for experiment of Cirsium arvens interference with canola, in other cases when weed dry weight as criterion of yield loss was used, higher coefficient of determination (R2) and less residual mean square (RMS) than weed density was obtained. These results showed that weed dry weight, in comparison with density, was often better indicator of competitive ability and negative effects of weeds on crops. Also wild mustard interference with wheat was more competitive than feral rye. But its interference with canola showed less competitive ability as compared with broad leaf weed of Cirsium arvens.

In order to study the effects of wild mustard density on grain yield and yield components of canola cv. Hyola 401 under different rates of nitrogen fertilizer، a field experiment was conducted in 2011-2012. The layout was split-plot in a completely randomized block design and three replications. Main-plots included four levels of nitrogen (0، 70، 140 and 210 kg ha-1) and sub-plots consisted of different wild mustard densities (0، 6، 12، 18 and 24 plants m-2). Results showed at densities of 6، 12، 18 and 24 wild mustard. m-2، grain yield losses were 15. 5%، 36. 7%، 47. 4% and 58. 6%، respectively. Grain yield loss was due to reduction in number of grains per plant and 1000-grain weight. Agronomic N use efficiency (ANUE) of canola decreased as the weed density increased. The highest ANUE was obtained in 70 kgNha-1، without weed interference. The lowest ANUE was in 210 kgNha-1 and 24 wild mustard plant. m-2 treatment. Generally، application of 140 kgNha-1 lead to higher competitiveness and lower grain yield loss in canola compared with 0 kgNha-1، whereas، in 210 kgNha-1، the negative impact of 12 wild mustard. m-2 and above on canola grain yield، was higher than other N treatments.

In this research, seed germination modeling of wild mustard was conducted satisfactory. Beta function was used to describe seed germination rate to temperature. Base temperature was -2.9 oC and it was increased with decreasing water potential to about 2 oC in -0.6 MPa. The R2 values were 0.86 in sub-optimal temperatures, and this value for supra-optimal temperatures was 0.94. The R2 values showed a good fitness of the hydrothermal time model under both sub- and supra-optimal temperatures. The hydrothermal values were 207 and 274 MPa oC for sub- and supra-optimal temperatures, respectively. The parameters and relationships estimated here can be used in soil seed bank dynamics models or can be use to establish a new model for the environment. The results of this study will also be useful for future studies of wild mustard biology and ecology.

In this study the effects of osmotic potential of water and drought stress on seed germination and seedling emergence of wild mustard (Sinapis arvensis) ecotypes were studied. The seeds were collected from four provinces including Fars, West Azarbaijan, Khoozestan and Mazandaran. Trials were carried out to study the effects of osmotic potential of PEG-6000 solutions at seven levels (0, -0.01, -0.05, -0.25, -0.1, -0.5, -1.5 MPa) on seed germination of four populations of wild mustard. In addition, the seedling emergence pattern of the populations was investigated in response to three soil moisture regimes (field capacity (FC),FC–1/3FC–FC, FC–1/6FC–FC) on percent weed emergence in a greenhouse. Results showed the highest germination occurred at 0 MPa osmotic potential. Germination gradually decreased by reducing the osmotic potential to -1.5 MPa. The trend was different among the ecotypes. The most number of germinated seeds was observed at high soil moisture (field capacity). The seeds of all ecotypes were sensitive to drought stress. Seed undr drough stress transformed to secondary dormancy and hence returning to field capacity did not induce germination.

In order to study the effect of various densities of wild mustard (Sinapis arvensis L.) on growth indices of Canola (Brassica napus L.) in climate of Molathani, Ahvaz, an experiment was conducted in the experimental field of Ramin Agricultural and Natural Resources University, in 2006-2007. The split-plot set of treatments was arranged within randomized complete block design with four replications. Treatments included of wild mustard at five levels (0, 7, 14, 21 and 35 plants m2) and Canola at three densities (60, 80 and 100 plants m2). The results showed that the increase in mustard density rates lead to decreasing total dry matter, leaf area index, crop growth rate, relative growth rate and mean pod dry matter in three canola densities (60, 80 and 100 plants m2). Somewhat the lowest growth indices was obtained in 35 plants mustard (that is the highest mustard density). In addition damage rate of mustard decreased canola seed yield for 7, 14, 21 and 35 plants mustard up to 61, 71, 76 and 91%, respectively.

In order to study the effect of pre-harvest application of paraquat on yield and seed quality of canola, an experiment was conducted in Lorestan and Mazandaran during 2006-2007. The experimental design was factorial randomized complete blocks with 3 replications and 10 treatments. Treatments included three doses of paraquat (1.5, 2 and 2.5 L/ha) and three dates of paraqat application (early, on time and late physiological maturity stages of canola), and check (no paraquat application). Results indicated that there was no difference among doses or dates of paraquat application in yield, extracted oil and rapeseed seed germination. There was no difference between the results of two locations of the experiment. Because the population of cruciferous weeds in Lorestan was low, no significant difference of erucic acid content of the extracted oil was observed among treatments. On the other hand, due to the high population of Sinapis arvensis in Mazandaran, the erucic acid content of the extracted oil in paraquat treated plots was lower than in the check plots.

In order to evaluate the effects of shoot aqueous extracts of chickpea, black cumin and their mixed aqueous extracts on seed germination and seedling morphological characteristics of wild oat and mustard as two common weed, an experiment was conducted with a factorial arrangement based on completely randomized design with three replications. The experimental treatments were aqueous extracts in five levels (0, 10, 20, 40 and 60 percentage), Weed species in two levels (wild oat and mustard) and extract concentration in five levels (0, 10, 20. 40 and 60 percentage). Result indicated that the highest and the lowest percentage and seed germination rate, length of radicle and hypocotyle, dry weight of radicle and hypocotyle and radicle / hypocotyle ratio (R/H), were obtained in control treatment and 60% concentration, respectively. Aqueous extract of black cumin and mixed extracts had the highest and the lowest effect on percentage and seed germination rate, length of radicle and hypocotyle, dry weight of radicle and hypocotyle and radicle / hypocotyle ratio, respectively. Between two weed species, wild oat had the lowest percentage of seed germination and length of radicle compared with mustard. Mustard had the lowest seed germination rate, dry weight of radicle and hypocotyle and length of hypocotyle compare with wild oat. Generally, it was concluded that chickpea and black cumin aqueous extracts have highly inhibitory in terms of weed control that can be useful for sustainable agriculture.

To investigate the possibility of biological control of wild mustard, a laboratory and greenhouse study was conducted in 2009-2010 at Azad University Research Station of Khorramabad. The results caused to introduce the Alternaria alternata isolates A7 from fungi Fusarium compactum, Fusarium reticulatum, F. lateritum, F.javanicum and A. alternata, A.giasen, A.radicina as a potential for biocontroling of this weed. Result of this study showed that isolates A7 could significantly reduced dry weight due to increased virulence of fungus in the 6 leaf growth stage were wild mustard.

Experiment was carried out to evolution the allopathic effects of sunflower aqueous extracts on germination and catalase enzyme activity in canola، wild mustard and mallow. The experimental arrangement was factorial included 4 level of aqueous extract concentration (0، 20، 40 and 60 volum percent) and 3 level of plants (canola، wild mustard and mallow) in 4 replications. Results showed Increasing the concentration of sunflower extracts، decreased seed germination percentage in canola and wild mustard but did not affect in mallow. Increasing sunflowe aqueous extracts of significantly decreased seedling weight، shoot and root length in canola and wild mustard but decreased catalase enzyme activity in musturd.

A field study was conducted in Fars at Agricultural Experimental Station of Firooz Abad Islamic Azad University in 2006 to evaluate wild mustard densities on wheat yield and yield component. Increasing wild mustard density decreased grain yield, wheat dry matter, spike per plant and seed per spike. Wild mustard had no effect on wheat height and wheat seed weight per 1000 seed. Reduced grain yield ranged from 3.1 to 29.9% at 1 to 16 wild mustard per m2, respectively. At 16 plant per m2 wild mustard reduced wheat spike per m2 by 16.2% and seed number per spike per m2 by 19.6%, when compared to weed free check. Results also showed that increase in wild mustard dry weight, due to increase in mustard density, had negative effect on wheat dry weight. Wild mustard must be controlled either before or shortly after wheat emergence if detrimental effects on wheat are to be minimized.

In order to study the response of canola to plant densities of mustard (Sinapis arvensis L.) with emphasis on agronomic control in Ahwaz condition, an experiment was conducted in 2006-2007 cropping season at Ramin Agricultural and Natural Resources University. The experimental design was split plot arrangements in a randomized complete block design with four replications. Mustard plant densities (0, 7, 14, 21 and 35 plants m-2) were assigned to main plots and canola plant densities (60, 80 and 100 plants m-2) were randomized in sub plots. The results indicated that grain yield, biologic yield, harvest index (HI), silique number sub-branch-1 and grain number silique-1 were significantly affected by interaction between canola and mustard plant densities. Silique number main branch-1, diameter of canopy and first sub-branch height were affected by mustard plant densities. Thousand grain weight, final plant height and sub-branch number plant-1 was not affected by treatments. Furthermore, highest yield loss of 91% was recorded in 35 plants m-2 of mustard in 80 plant m-2 densities of canola. Results also showed no significant difference between canola plant densities (except in pure stand) in any mustard plant densities for grain yield. Therefore, the lower canola plant density (60 plants.m-2) could be recommended to decrease seed consumption when mustard is competing with canola in field conditions.

In order to determine grain yield and its components of seven canola cultivars in competition with wild mustard, a field experiment was conducted at the Araqai Mohaleh agriculture research station in Golestan province, in 2005-2006 growing season. The experiment was established as factorial arrangement using a randomized complete blocks design with three replications. The seven canola cultivars (Hayola‏401, Hayola‏330, RGS‏003, Option500, Sarigol, Zarfam and Talayeh) were planted in weed-free and weed-‏infested (with 30 wild mustard plants per square meter) plots. Grain yield, harvest index, number of pods/plant, number of grains/pod and 1000-grain weight were measured. Result showed significant differences in grain yield among cultivars. Results also indicated significant differences in yield components in weed-free and weed-infested conditions. Mean comparisons among cultivars showed that Hayola330 produced the highest grain yield with average of 2836 kg/ha and Talayeh produced the lowest grain yield in weed-free condition with average of 1729 kg/ha. Under weed-infested condition Hayola330 produced the highest grain yield with average of 870 kg/ha and option500 had the lowest grain yield with average of 101 kg/ha. Although, Hayola330 produced the highest grain yield in weed-infested but it had higher yield loss than Zarfam cultivar. Therefore, the degree of tolerance in canola cultivars differed, in competition with wild mustard. To develop cultivars with high grain yield in both weed-free and weed-infested conditions are to be included as a strategy in canola breeding program.

In order to evaluate wild mustard competitive effect on winter wheat, an additive series experiment was conducted in 2000-2001 at Agricultural Research Station of Mashhad University.The experiment had 3 factor: wheat seed rate (175, 215 and 255 kg/ha), nitrogen rate (150 and 225 kg/ha), and a range of wild mustard densities. Hyperbolic functions was used to describe yield-weed density relationship. Increasing wild mustard density had a negative, asymptotic – type effect on wheat biomass and grain yield. By increasing wheat seed rate, in optimum nitrogen rate, maximum wheat biomas loss has reduced about 51 %. Maximum yield loss has increased from 42.1 % to 50.4 %, as nitrogen rate incrased from optimum to upper optimum rate of wheat. By increasing of wheat seed rate from 175 to 255 kg/ha, maximum tiller number reduction due to high densities of wild mustard, has decreased by 54 %. Reduction of fertile tiller number was mostly occurred at presence of high nitrogen level, thus, reduction of fertile tiller number compared to control in N1 was 18%, while in N2 has increased to 30%. Wild mustard competition has reduced wheat seed number per ear 30% in compare to weed free control. Results show that wheat 1000 seed weight was more affected by nitrogen rate than plant densities. Apparently, in competition with wheat, wild mustard was better able to utilize the added nitrogen and thus gained a competitive adventage over the wheat.