برآورد نیازهای حرارتی مراحل فنولوژیکی کلزای پاییزه (ارقام Okapi SLM046,) در شرایط اقلیمی سرد ایران (مطالعه موردی شهرکرد)

Introduction
In recent years, characteristics of Canola and its suitable amenity with all climates and weather conditions invarious points of country , had result in expanding implantation of this plant as a good source of meal oil. This is considered in the general perspectives. Continental amenity of this plant and time difference of its growth period and in its capacity for using agronomy frequency, are the positive points of this plant in Iran. Expanded implantation of this kind with other kinds of corps has started since 1997-98 with the surface of 2893 Hectares. According to the last reports, the implantation of this plant in Iran in 2005-06, was about 119321. The average performance of Canola in that period was about 2035 kilograms a hectare.

Materials and methods
The study on Okapi and SLM046 Canola has began since 2000 in research farm of Farokhshahr in the research centre of Chaharmahal Va Bakhtiari. For the possibility of expanding these results to farms, we have tried to set real farm situation for the experiment. These steps were done in 7 periods in 2000-2001 to 2006-2007 continuously. The implantation to cropping the products , has longed about 10 months.
Beside the research farm, there was a climatology station to measure weather parameters in standard conditions.
Details of observation of phonology is directed according to Canola association of Canada. Look at the following:
First stage - Germination: the soil was pulled aside from 4 directions of the farm and according to the amount of germination, the percentage of germination was measured until the end of this phase.
Second stage - Green: at first , we based 4 small 1*1 plot with the standard procedure and by appearing first 2 leave , we counted the leaves and we established the number in each plot. After formation of rows, in every parts, we chosen 10 plants and we continued our observation on them.
Third stage – Rosette. in this level , we have some real leaves. The rise of the leaves will continue until hibernation.
4th stage – Bud Returns: At this stage, the main flower can be observed at the center of rosette. Then , rising of the stem will continue and other stems will be formed.
5th stage - Flowering: The first flower will be opened ( about 10% of purses will be opened) and pods will rise and they will start to grain. At the end of this period , the flowering of the most of the plots will finish in this period.
6th stage - Reach: In this stage , pods will reach the maximum size and will begin to change brown. The number of plates in each plots was recorded each day.

Results and discussion
According to the number one result of this study , average needed heat for rising of Okapi and SlM 046 are 2340 and 2383 respectfully (degree day). we observed that in the beginning of spring. also , in comparison between these 2 kinds , the maximum difference was calculated about 13% in green and about 8% in rosettet. the mentioned plant , can adjust itself to every environment and climate and in suitable conditions , it can grow very well. The effective heat is calculated about 1548 and 1559 degree day.
From other results we can mention the suitable heat for 6 parts of autumn cycle of Canola.
Germination: 160.9, Green: 216.4, Rosette: 522.3,Bud Returns:279.7, Flowering: 402.1, Reach: 780.2.
Also , the heat per day for effective growth is calculated :
Germination: 117.5, Green: 151.4, Rosette: 309, Bud Returns: 136.4, Flowering: 258.7, Reach 580.2.

Conclusion
The live cycle of Canola is divided to 6 periods that are illustrated with 6 codes form 0 to 5. These periods are consisted of: Germination, Green, Rosette, Bud Returns, Flowering and Reach.
The goal of this study is to find the heat needs of Canola in the climate of ShahreKord. We want to recognize its needs and build a base for the agronomy calendar of Iran. Canola is a plant for cold climates. It reacts to the heat changes and its very sensitive to the temperature. Our studies show that different kinds of this plant have various kinds of reactions to their original climate.