20 research outputs found
Evaluation of Sustainable Agricultural Development in Golestan Province
Sustainable agriculture is a scientific activity, based on ecological principles that its main purpose is to create balance and sustainability in production systems. In order to assess the status of sustainable agricultural development in Golestan province, relative advantage assessment of support systems was used. For this purpose, five support systems are constructed, including agricultural resources, agricultural development, environment and ecosystems, rural societies and sciences, education and management based on 54 indicators. In final, status of sustainable agriculture developmant of 14 townships in Golestan province was calculated by sum of these support systems. Then, the status of sustainable agriculture were zoning in ArcMap media in 6 classes (high sustainable, moderate sustainable, weak sustainable, weak unsustainable, moderate unsustainable and high unsustainable). The results showed that Golestan province was weak in terms of sustainability in agriculture resources, agriculture development, environment and ecosystems and sciences, education and management, but it hadweak unsustainable in term of rural societies. In general, it can be stated that Gorgan and Gonbad-Kavous townships had the highest sustainability in some indexes. Also, Gomishan was identified as most unsustainable township in comparison with other townships in all studied indexes except rural societies and science, education and management. The results of sustainable agriculture development showed that Golestan province had unsustainable or weak sustainable status in development of sustainable agriculture, because only 5 townships from 14 townships had high and moderate sustainable and others townships were classfied in weak sustainability or un-sustainability classes
Physiological Fitness Associated to ACCase Target-Site Resistance Enhances Growth and Reproduction in Phalaris brachystachys
Short-spike canarygrass (Phalaris brachystachys (Link.)) from Iranian wheat fields has developed resistance to acetyl-coenzyme A carboxylase (ACCase) inhibitors due to a target-site mutation (Ile-1781-Thr). Target-site resistance mutations may confer pleiotropic effects in weeds. In this paper, the possible effect of the Ile-1781-Thr mutation on the ecological fitness during life cycles in P. brachystachys plants was investigated. ACCase genes of P. brachystachys populations resistant (R) and susceptible (S) to ACCase inhibitors were sequenced and the vegetative growth and reproductive characteristics of the plants were assessed. In the final growth stage (217 days after planting—DAP), R sub-population plants were 30 cm taller than the S plants. Additionally, the R sub-population produced up to 12 leaves and 2.8 tillers more per plant, and accumulated double the dry weight (2850 g m−2) compared to the S sub-population. The leaf area index (LAI) of the R sub-population was 1.1 times higher than that of the S sub-population. In addition, the net assimilation rate (NAR) and plant growth rate (PGR) between 114 and 182 DAP of the R sub-population were 0.11 and 13 g m−2 d−1 higher than the S sub-population, but the relative growth rate (RGR) was similar between R and S sub-populations. The number of spikes (6 vs. 3.8), the spike length (8.4 vs. 5.5), and number of seeds per plant (1276 vs. 751 seed plant−1) of the R sub-population were higher than the S ones, but the weight (3.25 g) and size (11.6 mm2) of 1000 seeds were similar between populations. The R sub-population of P. brachystachys exhibited higher plant growth and reproductive parameters than the S one, which may increase the frequency of resistance in the population in the absence of adequate weed-control methods
The First Case of Short-Spiked Canarygrass (Phalaris brachystachys) with Cross-Resistance to ACCase-Inhibiting Herbicides in Iran
The weed Phalaris brachystachys Link. severely affects winter cereal production. Acetyle-CoA Carboxylase (ACCase)-inhibiting herbicides are commonly used to control this weed in wheat fields. Thirty-six populations with suspected resistance to ACCase-inhibiting herbicides were collected from wheat fields in the Golestan Province in Iran. A rapid test performed in Petri dishes and whole-plant dose–response experiments were conducted to confirm and investigate the resistance level of P. brachystachys to ACCase-inhibiting herbicides. The seed bioassay results showed that 0.02 mg ai L−1 clodinafop-propargyl (CP) and 1.36 mg ai L−1 of the diclofop-methyl (DM) solution were the optimal amounts for reliably screening resistant and susceptible P. brachystachys populations. In the whole plant bioassay, all populations were found to be resistant to CP, resistance ratios ranging from 2.7 to 11.6, and all of the CP-resistant populations exhibited resistance to DM. Fourteen populations showed low resistance to cycloxydim, and thirteen of these populations were also 2-fold resistant to pinoxaden. The results showed that DM resistance in some P. brachystachys populations is likely due to their enhanced herbicide metabolism, which involves Cytochrome P450 monooxygenases, as demonstrated by the indirect assay. This is the first report confirming the cross-resistance of ACCase-inhibiting herbicides in P. brachystachys in Iran
Non-destructive estimation of maize leaf area, fresh weight, and dry weight using leaf length and leaf width
Leaf area and leaf weight measurements are required to calculate several growth indices, which are leaf area index (LAI), net assimilation rate (NAR), specific leaf area (SLA), specific leaf weight (SLW), and leaf area duration (LAD). We developed three predictive equations to estimate leaf area, leaf fresh and dry weight in maize from leaf length and leaf width measurements. A total of 1,314 leaves from different parts of plants at different plant growth stages, different planting densities and different sowing dates were collected in 2008 at the Agricultural Research Center near Gorgan, Golestan, Iran. To evaluate the equations, some goodness of fit indicators used included mean absolute error, root mean square error and index of agreement. This study found strong relationships between leaf length and leaf width and LA, LFW and LDW (R2 > 0.85). Based on the results LA, LFW and LDW of individual maize leaves can be estimated non-destructively by leaf length and leaf width. These equations allow the research workers to make non-destructive or repeat measurements on the same leaves. The general equation to estimate LA, LFW, and LDW was: Ln (Y) = a + b Ln (L) + c Ln (W)
Evaluation of radiation use efficiency and its relationship with dry matter accumulation in three millet species
A factorial arrangement of three millets species (Panicum miliaceum, Pennisetum glaucum, and Setaria italica) and two sowing dates with three replications were used in a completely randomized design to evaluate the radiation use efficiency and its relationship with dry matter accumulation. Leaf area index was used in daily intervals to calculate daily intercepted radiation. Light extinction coefficient was calculated as the slope of regression line between log transformed fraction of intercepted radiation and leaf area index during growing season. Radiation use efficiency was calculated as the slope of linear regression between cumulative intercepted radiation and cumulative biomass during growing season. Results showed that light extinction coefficient and radiation use efficiency for proso, pearl and foxtail millets were 0.75, 0.66, 0.57 and 1.43, 1.83, 1.74 g/MJ in terms of total radiation, respectively. Differences in biomass production were not significant between proso and pearl millets. Proso millet had higher intercepted radiation, but lower radiation use efficiency in comparison with pearl millet. Foxtail millet had lower intercepted radiation than proso and pearl millets, but its radiation use efficiency was higher than pearl millet. Total biomass of foxtail millet was lower than other species. Results indicated that proso and pearl millets can produce more biomass than foxtail millet
No fitness cost associated with Asn-2041-Ile mutation in winter wild oat (Avena ludoviciana) seed germination under various environmental conditions
Abstract Knowledge about the fitness cost imposed by herbicide resistance in weeds is instrumental in devising integrated management methods. The present study investigated the germination response of ACCase-resistant (R) and susceptible (S) winter wild oat under different environmental conditions. The DNA of the plants was sequenced after being extracted and purified. The segregated F2 seeds were subjected to various temperatures, water potentials, NaCl concentrations, different pHs, darkness conditions, and burial depths. The results of the sequencing indicated that Ile-2041-Asn mutation is responsible for the evolution of resistance in the studied winter wild oat plants. The seeds were able to germinate over a wide range of temperatures, osmotic potentials, NaCl concentrations, and pHs. Germination percentage of R and S seeds under dark and light conditions was similar and ranged from 86.3 to 88.3%. The highest emergence percentage for both R and S plants was obtained in 0, 1, and 2 cm depths and ranged from 66.6 to 70.3%. In overall, no differences were observed in the germination response between the R and S winter wild oat plants under all studied conditions. No fitness cost at seed level indicates that control of R winter wild oats is more difficult, and it is essential to adopt crop and herbicide rotation to delay the further evolution of resistance
Yield gap analysis of cumin in nine regions of Khorasan provinces using modelling approach
There are three hierarchical steps to fill the yield gaps in agricultural systems. These steps are determination of potential yield, yield gaps and system optimization to fill yield gaps. In this study a simple mechanistic model was developed and tested to determine potential yield and yield gaps of Cumin (Cuminum cyminum) in nine regions of Khorasan provinces (including Bojnourd, Qaeen, Mashhad, Neishabour, Sabzewar, Gonabad, Ferdous, Kashmar and Birjand). Collected data of related year from 228 fields were used to calculate yield gaps. Results indicated variable potential yields in different climatic conditions (the areas with cooler climate and higher radiation had higher potential yields). Also, yield gaps varied considerably between regions (from 2.42 ton.ha-1 in Bojnourd to 0.68 ton.ha-1 in Sabzewar). The highest value for potential yield belonged to Bojnourd (3.7 ton.ha-1). The collected data from studied fields and sensitivity analysis on sowing date (based on common sowing dates range) showed that inappropriate sowing dates was one of the most important yield reducing factors in all regions. Results revealed that if the yield gaps can be filled based on appropriate management option, yield can be increased by two to three folds in some regions
Assessment of land suitability and the possibility and performance of a canola (Brassica napus L.) – soybean (Glycine max L.) rotation in four basins of Golestan province, Iran
AbstractA Geographical Information System (GIS)-based plan was used to assess the possibility and performance of a canola (Brassica napus L.) – soybean (Glycine max L.) rotation in Golestan province, one of the most important agricultural production regions of Iran. For this purpose, all needed raster layers, including climatic (precipitation, temperature), topographic (aspects and slope) and soil-related (texture, pH, EC) layers, were provided by interpolation, surface analysis and other related techniques in GIS. Overlaid layers were used to judge the capacity of agricultural lands to rotate a canola–soybean system in the study area, which included four important basins. Based on defined scenarios and pre-determined ecological requirements of the two studied crops, five suitability classes were detected and mapped. Our results indicate that just 11.82% of total lands are very suitable to rotate soybean after canola while most agricultural lands in the study area fell into the moderate and low suitability classes. The consistency of results adopted from final overlaid maps with real statistics in the study region show that GIS as a systemic approach can play a vital role in saving time and reducing research costs. These results could help policy makers to design proper cropping patterns, particularly rotation systems
The effect of growth indices in competitive ability of some canola (Brasica napus) cultivars against wild mustard (Sinapis arvensis).
In order to evaluate the interference of wild mustard on growth indices of Canola cultivars an experiment was carried out in Agricultural and Natural Resources Research Institute of Gorgan during 2005-2006 growing season. The experiment was established as a randomized completely block design in a factorial arrangement of treatments with three replications. Canola cultivars, Zarfam, Sarigol, Talayh, R.G.S 003, Option 500, Hayola 401 and Hayola 330 were kept under weed free and weed infested conditions. The results indicated that, wild mustard resulted in reduction of canola dry matter, leaf area index, leaf area index duration and crop growth rate, significantly. The maximum dry matter, leaf area index and crop growth rate in control plots (weed free treatment) belonged to Hayola330 cultivar. The maximum and minimum reduction rate of dry matter and leaf area index of canola cultivars was obtained in control Option500 and Zarfam cultivars respectively. Results revealed, cultivars with higher leaf area index, relative leaf area expansion rate and better vertical leaf area distribution could be more competitive in weed-infested conditions, and can be used in breeding programs to enhance competitive ability of canola cultivars