2024-03-29T09:32:26Z
https://jdesert.ut.ac.ir/?_action=export&rf=summon&issue=2776
Desert
2008-0875
2008-0875
2007
12
2
Effects of drought stress and defoliation on sunflower (Helianthus annuus) in controlled conditions
A.
Nezamia
Z.
Boroumand Rezazadehb
A.
Hosseini
Abstract In order to evaluate the effects of drought stress and defoliation on sunflower, a study was conducted under controlled conditions. Treatments were a combination of three levels of drought ((100, 60 and 30 percent of Field Capacity (FC)) and three levels of defoliation (control, removal of either 4 or 6 leaves from lower part of the plant) laid out, in a Completely Randomized Design with four replications. Drought stress was applied from 4-leaf- stage up to the end of plant growth period while leaf removal was conducted at the heading stage. Results indicated that drought stress affected most of the measured parameters. Plant height, plant dry matter, stem diameter, head size, seed number/head, 100-seed weight and seed weight/ head declined upon drought stress as compared to control. SPAD readings increased as drought stress increased. Defoliation caused an increase in SPAD and a decrease in seed number/head. Leaf number was not affected by either drought or defoliation. Keywords: Defoliation; Drought stress; Plant height; Seed weight; Sunflower
defoliation
Drought stress
Plant height
Seed weight
Sunflower
2007
12
01
99
104
https://jdesert.ut.ac.ir/article_27108_44e0ce85ead30656d568e0f8e72effa5.pdf
Desert
2008-0875
2008-0875
2007
12
2
An evaluation of yield in "intercropping of maize and potato"
K.
Jamshidi
D.
Mazaheri
J.
Saba
Abstract To find out how maize and potato can grow and develop in an intercropping system rather than each grown alone in a sole cropping system the following factorial experiment was performend in the frame-work of a randomized complete block three replications in the experimental farm of the faculty of agriculture, Zanjan University in year 2004. Different potato to maize ratios of (1:0), i.e. sole potato;(3:1) meaning 75% potato plus 25% maize; (1:1), that is half and half of each crop; 25 percent potato together with maize of 75% (1:3); and finally sole cropping of maize (0:1) were employed. Two plant population treatments of 3.8 and 5.3 plants/ m2 were assigned to each crop. There was an increase observed in the radiation absorption and in Leaf Area Index (LAI) with an increase in plant density from 3.8 to 5.3 plant per square meter. Maximum potato yield (20390 kg/ha) was obtained from 3:1 crop ratio and maximum yield of maize (8898 kg/ha) from the 1:1 ratio of intercropping system. In the case of potato the new cropping system (intercropping) there were significant (? = 0.05) observed in yield, mean number of branches per plant, as well as in mean weight of potato tubers. In maize, the cropping system revealed a significant effect on yield, mean number of ears per plant as well as on mean number of seeds per year. Land Equivalent Ratio (LER) was shown to be more than one for all the treatments indicating more profitability and superiority of intercropping to sole cropping system. The highest LER for either one of the crops in intercropping system was 1.58. This was obtained for potato in the 3:1 ratio treatment while for maize it was obtained for the treatment of 1:1 ratio. Key Words: Sole cropping; Intercropping; Land Equivalent Ratio (LER); Dominance; Substitution
Sole Cropping
intercropping
Land equivalent ratio (LER)
Dominance
Substitution
2007
12
01
105
111
https://jdesert.ut.ac.ir/article_27109_d1a3b9102d4aab83f0b6319166d7e6a4.pdf
Desert
2008-0875
2008-0875
2007
12
2
A study of the influential factors affecting the slopes of deposited sediments behind the porous check dams and model development for prediction
A.
Esmaeili Nameghi
A.
Hassanli
M.
Soufi
Abstract Spacing between check dams depends on the stream bed slope, effective height of check dams and slope of deposited sediments behind the check dams. The slope of deposited sediments is more important than the other two factors because of complications in the way of its occurrence and its measurement after several years of dam construction. This research presents the effective factors affecting the slope of deposited sediments behind 60 selected check dams among 2000 evaluated ones in the watershed of Doroudzan Dam. Such factors as stream bed slope, slope of deposited sediments behind dams, height of check dams, width of stream on the dam site, sand, silt, clay, granule, pebble, cobble and D50 of sediments were assessed. Based upon the collected data three models: linear-logarithmic, modified linear –logarithmic and simplified linear-logarithmic, for determining the slope of the deposited sediments as well as the space between check dams were developed and compared. The results showed the factors significantly affecting the slope of deposited sediments are: stream bed slope, height of check dams, stream width, sand, granule and D50 of sediments. Keywords: Check dams; Optimum spacing; Loose rock dams; Doroudzan watershed; Slope of deposited sediments
Check dams
Optimum spacing
Loose rock dams
Doroudzan watershed
Slope of deposited sediments
2007
12
01
113
119
https://jdesert.ut.ac.ir/article_27110_c48e4d15f3d321b0c2fa949eb5435422.pdf
Desert
2008-0875
2008-0875
2007
12
2
Effects of various super absorbent concentrations on runoff volume in slopes and various intensity of simulated rainfall in Shahrekord plain
M.
Pajuohesh
H.
Refahi
GH.
Zehtabian
A.
Salehpour Jam
M.
Kianian
Abstract In order to study the effect of super absorbent on runoff volume in slopes and various intensity of rainfall research was accomplish according to split – factorial blocks method with main treatment and two accessory treatments in three replicate . the main treatment consist of three dominant slopes (10 , 20 , 30 percent ) and accessory treatments consist of five levels of substance super absorbent ( instance , 20 , 40 , 60 , 80 kg/ha ) and three levels of various rainfall intensity (25, 30,40 mm/hr). the rain simulator set was used and the rainfall duration intervals was 30 minutes. To establish hydraulic pressure complementary water volume added to reservoir tank in each 5 minutes. Then runoff was gathered to measure output runoff volume. Finally statistical analysis was done on the collected data. Results shows that substance super absorbent treatments of various rainfall intensity in comparison with control plate has significant effect in decrease of output runoff volume to 5 level percent. Keywords: Soil erosion;, Super absorbent; Rain simulation; Volume runoff; Slope
Soil erosion
, Super absorbent
Rain simulation
Volume runoff
Slope
2007
12
01
121
128
https://jdesert.ut.ac.ir/article_27111_b24e5458a9e4578f3d40269486e33955.pdf
Desert
2008-0875
2008-0875
2007
12
2
Water and radiation use efficiency in different developmental stages in four bread wheat cultivars under moisture stress conditions
M.
Ghodsi
M.
Jalal Kamali
D.
Mazaheri
M.
Chaichi
Abstract This research was conducted in Toroq Experimental field station, Mashhad, Iran, for two successive cropping seasons (2000-2002), using split plot experimental design based on complete randomized blocks with three replications. Moisture stress treatments (at seven levels) were assigned to main plots, including: D1 ( full irrigation), D2 (no irrigation from one-leaf to double ridge) stage, and in other treatments, no irrigation and preventing rainfall as: D3 (from one-leaf to floral initiation stage), D4 (from floral initiation to the commencement of stem elongation or Terminal spikelet), D5 ( from commencement of stem elongation to flag leaf emergence), D6 (from flag leaf emergence to anthesis) and D7 (from anthesis to the soft dough), and four wheat cultivars, namely: Roshan, Qods, Marvdasht and Chamran, were sown in sub plots. The results of combined analysis of variance showed that the effect of moisture stress was significant. Applying D5, D6 and D7 treatments reduced the grain yield in comparison with control (D1) by 36.7, 22.8 and 45.6, respectively. Severe moisture stress treatments (D5 and D7) caused a reduction in water use efficiency (WUE) and radiation use efficiency (RUE), due mainly to reduction of dry matter. Based on these results, grain filling (D7) and fast growing (D5) stages of wheat were more sensitive to moisture stress. Genotypic differences were also observed with respect to concerned characteristics. Chamran had a higher moisture tolerance, therefore, greater grain yield as compared with the other cultivars. Keywords: Moisture stress; Developmental Stages; Water Use Efficiency; Radiation Use Efficiency; Grain yield
Moisture stress
Developmental Stages
Water use efficiency
Radiation use efficiency
Grain yield
2007
12
01
129
137
https://jdesert.ut.ac.ir/article_27112_d9b8b1cabd2f77ee9227236e00cc42c2.pdf
Desert
2008-0875
2008-0875
2007
12
2
Assessment of land use changes using remote sensing and GIS and their implications on climatic variability for Balachaur watershed in Punjab, India
S.
Bazgeer
P.
Sharma
R.
Mahey
S.
Hundal
A.
Sood
Abstract Decadal changes in land use/land cover for Balachaur watershed in Nawanshahar district, Punjab, India were studied using black and white aerial photographs for March 1984 on approximately 1:20,000 scale and multidate geocoded false colour composites (FCC) of IRS-1D LISS-III on 1:50,000 scale for March 2002, September 2002, and May 2003 and interpreted visually to prepare land use/land cover maps for the year 1984 and 2003. The results revealed that the area under crop land, moderately dense forest, degraded forest, degraded land in hills and piedmont plains, barren land along choes (seasonal streams) has decreased; whereas, the area under settlements, dense forest, plantations, industrial use, ponds, choes and brick kilns has increased over a span of 20 years. By virtue of afforestation and forest conservation, the density of vegetation in Siwalik hills and piedmont areas has increased. The area under moderately dense forest (1956.7 ha) and degraded forest (755.5 ha) got upgraded to dense forest while 755.5 ha of degraded forest changed to moderately dense forest. The impact of land use/land cover alterations on climatic variability at micro-level revealed that the linear trends computed for the 5-yearly moving average of maximum temperature showed an increasing trend from 1984 to 2003, whereas the minimum temperature, rainfall, and potential evapotranspiration showed a decreasing trend. Inspite of increasing forest cover in the study area, these trends in different meteorological parameters did not corroborate the findings of some earlier reports. Thus land use/ land cover changes over time may not be the only factor which causes variation in meteorological parameters. It implies that there might also be other factors such as CO2 concentration and its effect on green house gases, atmospheric pollution and spectral distribution of the incoming solar radiation, which affect climatic variability in a region. Keywords: Land use change; Climatic variability; Remote sensing; Potential evapotranspiration
land use change
climatic variability
remote sensing
Potential evapotranspiration
2007
12
01
139
147
https://jdesert.ut.ac.ir/article_27113_2a89b0c679aaf867132f00a508bb024d.pdf
Desert
2008-0875
2008-0875
2007
12
2
Decision support system (DSS) for site selection floodwater spreading schemes using remote sensing (RS) and geographical information systems (GIS)
M.
Kheirkhah Zarkesh
A.
Meijerink
M.
Goodarzi
Bandar Abbas
DSS
Fasa
Flood mitigation
GIS
Floodwater spreading
RS
2007
12
01
149
164
https://jdesert.ut.ac.ir/article_27114_edc9c82906c185528881e267cec0f4fc.pdf
Desert
2008-0875
2008-0875
2007
12
2
Introduction of new indices to identify relative drought tolerance and resistance in wheat genotypes
S.
Moosavi
B.
Yazdi Samadi
M.
Naghavi
A.
Zali
H.
Dashti
A.
Pourshahbazi
Drought stress indices
Relative tolerance
Relative resistance
Wheat
2007
12
01
165
178
https://jdesert.ut.ac.ir/article_27115_59258d86de813f8dd78ba966287861bd.pdf
Desert
2008-0875
2008-0875
2007
12
2
Effects of water deficit and salinity on germination properties of Aeluropus spp.
Abstract
Seed germination is an important phase of plant development during which soil water availability is crucial. Salinity can affect seed germination in two ways: 1) Change of osmotic potential of available water, 2) toxicity effects. In this experiment, interactive effects of salinity and water deficit on germination criteria of two species of A, littoralis and A. logopoides were studied in a factorial design with completely randomized arrangement and four replications. Treatments were combinations of four levels of water deficit (-0.3, -5, -10 and -15 bar), four electrical conductivity levels (0, 20, 25 and 30 dSm-1) and two species of Aeluropus. Water deficit and salinity were induced through PEG-6000 and sodium chloride respectively. After three weeks rate, as well as percentage of germination were determined. Results showed that by increasing salinity and water deficit both criteria of percent germination and germination rate were reduced and there was an interactive effect of these stresses on germination. In general effects of salinity were more pronounced than water shortage. These results were somehow similar for either one of the species.
Keywords: Aeluropus; Germination; Electrical conductivity; Water deficit
Aeluropus
germination
Electrical conductivity
Water deficit
2007
12
01
https://jdesert.ut.ac.ir/article_27116_2b4e06d1442e2e27d45affc760ca4bf2.pdf
Desert
2008-0875
2008-0875
2007
12
2
The effect of 1991-2001 droughts on ground water in Neishabour plain
H.
Mohammadi
M.
Karimpour Reihan
Abstract This research investigates the effect of drought on ground water table of Neishabour plain. The precipitation data of Nishabour synoptic station during 1990-2001, the Bar climatology station during 1964-2001 and the data of hydrometric stations of Kherv and Bar in 1996-2001 have been used as the base of analysis. The method of Herbest et all has been used to analyze the drought. Using the effective precipitation and effective flow, the date of start and end of drought for the study region has been specified and then the time and intensity of drought have been calculated. The analysis shows that the main reason for the fall of the underground waters table level is the irregular use for agricultural consumptions. The climatic drought has had a direct effect on running water and it has also had direct effect on underground water of the region with a time lag. It was appeared that alluvial fan areas of Neishabour plain have a less decrease compared with the central and southern areas in spite of much consumption of water by deep wells. Key words: Climatic drought; Effective precipitation; Depletion of water table; Hydrograph; Ground water
climatic drought
Divine Will attribute Imammieh Moatazeleh Ashaereh
Effective precipitation
Depletion of water table
Hydrograph
Ground water
2007
12
01
185
197
https://jdesert.ut.ac.ir/article_27117_47a2a3d93ae646525cc42f4311b2bc00.pdf