%0 Journal Article %T Determining Planting Dates for Spring Safflower by Temperature and Digital Elevation Model in Esfahan Province %J Physical Geography Research %I University of Tehran %Z 2008-630X %A Yasari, Talat %D 2014 %\ 10/23/2014 %V 46 %N 3 %P 389-405 %! Determining Planting Dates for Spring Safflower by Temperature and Digital Elevation Model in Esfahan Province %K Digital Elevation Model %K Kriging %K planting date %K spring safflower %K temperature %R 10.22059/jphgr.2014.52138 %X IntroductionPlanting date plays main role in crop performance. Planting date through correspondence withthe climatic elements affect vegetative and reproductive growth and ultimately affect the qualityand quantity of crops. Among the climatic elements, temperature and day length are moreimportant under irrigated condition. It is necessary to mention that the majority of cropscultivated in Iran are indifferent to day length. The temperature is the most important element incontrolling their growth period. By using long-term weather data and related software such asArc map we can determine the suitable planting dates for a wide area. Therefore, by eliminatingfield experiment and avoiding large amount of time and cost, much can be saved. The purposeof this study is to determine the best planting dates for spring safflower in different parts ofEsfahan province in order to gain the maximum performance in any climatic zone.MethodologyThe minimum, maximum and mean temperature of 51 synoptic and climatic stations of Esfahanprovince and other neighbouring provinces from 1961 to 2011 have been used to determine theappropriate planting dates of spring safflower in Esfahan province. Using the mean temperatureand Kriging method, Esfahan province is divided into three zones including zone 1 (warm),zone 2 (moderate) and zone 3 (cold). For determining the planting dates of spring safflower indifferent part of Esfahan province daily mean and minimum temperature from January toOctober as average of 15 days have been calculated and related maps were plotted in GISenvironment. Interpolation of temperature was done by Digital Elevation Model (DEM) and􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯∗E-mail: yasari85@yahoo.com Tel: +98 9133278087Physical Geography Research Quarterly, 46 (3), Fall 2014 19regression analysis between temperature and height in the GIS environment. Beginning ofplanting dates in warm, moderate and cold regions were considered to reach mean oftemperature to 7, 9 and 12°C, respectively. For determining the growth inhibitory of hightemperatures, average of the 15-days mean and maximum temperature calculated from June toSeptember and related maps were plotted in GIS environment. The daily mean temperature of30°C and the maximum temperature of 37°C are considered as high-temperature inhibition.Results and DiscussionDelay in spring planting of safflower accelerates the development stages, decrease vegetativegrowth and yield components, and ultimately cause safflower yield reduction. Early plantingdates due to production of higher seed yield are recommended. Thus, if the thermalrequirements of safflower provide the safflower cultivation, earlier and higher yield will beachieved.In the first thermal zone, information layers of the regions were combined that in themmean temperature is reached to 7°C and the minimum temperature to above 0°C. Therefore, inmid-January the eastern and northern half of the province is appropriate for safflowercultivation. In this zone, in east and north parts of the province the planting dates start atJanuary 19 and end in March 6. Khorobiabanak and Biazehbiabanak are stations that located inthis region. In the second thermal zone, information layers of the regions were combined that inthem mean temperature reached to 9°C and the minimum temperature reached above 0°C.Therefore, in mid-March the areas of south-eastern and central provinces were added to theprevious range. In this zone, on some parts in south of the province the planting dates start atMarch 7 and end at April 4. Esfahan, Kabootarabad, Palayeshgahe Esfahan, Najafabad, andBalan stations are located in this region. In the third thermal zone, information layers of theregions were combined that in them mean temperature reached to 12°C and minimumtemperature reached above 0°C. Therefore, in mid-April, additional narrow strip of the northwestto the south of the province was added to the previous range. In this zone, in the other partsof the province the planting dates start at April 5 and end at May 21. Golpaygan, Meymeh,Abyaneh, Daran, Singerd, Chadegan, Emam Gheys, Mehrgerd and Hamgin, Damaneh Freydan,Freydoon Shahr, Badijan, Hana and Khonsar stations are located in this zone. It is noteworthythat in the west and north western part of the province some regions with 2338 to 4405 m heightare not suitable for safflower planting due to low temperature.ConclusionBased on the results in the first, second and third thermal zones, planting dates in the province isgenerally started from January and continue to May.. By considering temperature requirementsof safflower the suitable planting date must be considered. Cultivation and planting shall notface to limited temperature and in every zone the first planting date is the best time for planting. %U https://jphgr.ut.ac.ir/article_52138_5f7442a7ef05009a1cabfba2394f23f3.pdf