Analayzing the phonological growth stages and required temperature rate of Gole Mohammadi

Phonology is the study of plant and animal life cycle phenomenon، composed of environmental changes (Meier et al، 2009). Most agricultural issues such as suitable date for implanting، irrigation، reaping، fight against pest vermin and the optimum production can be obtained through determining the stages of phonology in each area، the required temperature units in each stage and the overall period of plant growth (Mir Haji et al، 2010). Rose is one of the most important crops for floriculture industry. Rosa includes 200 species and more than 18. 000 types (Baydar et al، 2004). Gole Mohammadi flower، that is known as Rosa Damacsena Mill is of Rosaceae group and is one of the most renowned and ancient roses in the history of gardening. The products of this plant include rosewater، essence، petal and dry bud (Ahmadi et al، 2008). In this study the growth process of the rose is determined based on the following stages: germination، leaf production، side stem development، the main stem elongation، beginning of the end of vegetative development، inflorescence، flowering، fruit growth، ripeness and dormancy (sleep). Mattson and Lieth (2007) have considered the growth stages of two kinds of roses، Cardinal and Fire ‘Ice’، as germination، appearance of the first leaf pair production، bud production، last leaf production and reaping. According to Pasian and Lief (1994، 1996)، from germination to reaping، the speed rate of Karma rose increased linearly between 5-30 ◦C accumulated thermal unit; according to them، the thermal unit for hybrid Cara Mia، Royalty and Sonia roses are 510، 580 and 545 (GDD) from germination to reaping، respectively. In all calculations، the threshold temperature is considered as 5. 2. Mattson and Lieth (2007) considered the (GDD) of 5. 2 (GDD) for hybrid rose types: the Cardinal and the Fire ‘Ice’. Stings and et al (2002) considered، the required temperature from germination to inflorescence as 9. 5◦C and 479 (GDD) for Red Sunblaze with 8. 1◦C base temperature and 589 (GDD). In general، the leaf area، stem length and the stem diameter of Cardinal rose generally grew with a decrease in temperature، but the best stem growth was observed at 18◦C. Flower dry weight، however، increased from 0. 7 to 3. 0 (g) as temperature decreased from 30 to 15◦C (Shier et al، 2001). Kafi and Riazi (2001) are of the opinion that the 21◦C in day time and 15◦C at night with +5 -10◦C can be effective for the quality of essence. Provinces of Fars، Kerman، Isfahan and eastern Azarbayjane in Iran are the appropriate regions for Gole Mohammadi cultivation. Isfahan has the highest level of flower production among these four provinces (Nemat Allahi، 2006). Although the amount of rosewater produced in Iran is very high which contributes to national economy، there do not exist phonological studies in this field. Here the attempt is made to analyze the phonological conditions of Gole Mohammadi. The species of rose under investigation: The species of the rose under investigation is Gole Mohammadi. Gole Mohammadi that is known as Rosa Damacsena Mill is of the Rosaceae group. It is one of the most important rose shrubs in the history of gardening. Based on the botanical science، Gole Mohammadi is a shrub with many pressed wide fine hook- shaped thorns، and with aromatic pink half-filled petals that are sometimes red. It has 5-7 small oval shaped-arrow-tipped- fine toothed petals. The leaves are shiny green with a furry back. The site under investigation: The site under investigation is a one acre farm that is located in Barzok، a suburb of city of Kashan، Isfahan province at 33◦C 45′ N latitude and 51◦C 14′ E altitude، at 2226 MSL height. Fig. 1: the study site plan There are 450 Gole Mohammadi shrubs in 27 agricultural plots in the farm under investigation. The annual average temperature of the area is 12. 5◦C; the average temperature of the hottest month (July) (min. 20. 1◦C – max. 29. 7◦C) with 24. 9 ◦C average and in the coldest month (January) (min. -3. 7◦C – max. 3. 5◦C) with a -0. 1◦C. The annual precipitation average of the area (1980-2009) has been 213. 10 mm; with April with the highest precipitation of 34. 4 mm and July with 7. 8 mm at the lowest (Table 1). The categorization of climate is done through Demarter، Amberje and Karimi methods (1985). They categorized the area into semi-arid، dry and cold، semi-humid and moderate with cold winters. Table 1: Specification of the climatic elements in Barzok station Annual Mar Feb Jun Des Nov Oct Sep Agu Jul Jon Apr May parameters 16. 7 10. 6 5. 1 3. 5 5. 3 10. 9 22. 0 25. 9 29. 1 29. 7 25. 7 19. 7 13. 8 Max. temp average 9. 1 2. 1 -2. 5 -3. 7 -0. 5 5. 1 13. 5 16. 8 19. 8 20. 1 15. 9 10. 8 5. 4 Min. temp average 35 24. 0 15. 4 16. 0 16. 0 22. 0 32. 0 33. 0 35. 0 35. 0 32. 0 27. 4 25. 0 Max. absolute temp -20 -6. 0 -6. 0 -20 -2. 0 -4. 0 6. 0 30. 0 14. 2 12. 0 5. 5 3. 2 -4. 0 Min. absolute temp 213. 10 29. 8 30. 9 24. 0 22. 4 15. 7 4. 8 7. 8 2. 2 3. 2 7. 9 29. 91 34. 4 Rain (mm) Uneven surface and the soil of the region: Barzok is a mountainous area 1800- 2600 meter above MSL. The soil of the area is mostly of depository type. Three samples of soil from various depths of 0-30، 30-60 and 60-90 Cm are selected and analyzed in the soil mechanics laboratory. The findings of the analysis indicate that the structure of the soil from 0-30 depth is Loam، and from 30-60 and 60-90 depths is Sandy Loam. The PH of the soil is of the alkaline type. The capability of electric conductivity of the three samples under investigation is suitable and unlimited for Gole Mohammadi cultivation. Table 2: Analysis of the texture of the soil structure of the test farm Physical tests P a. v. m p. p. m K a. v. a p. p. m N % o. c % T. N V Gypsum % Ph SP % Description Depth (Cm) LAB NO. Text C Si S L 15 37 48 4. 46 384 0. 06 0. 54 26. 45 Not seen 8. 08 30. 98 0-30 1-2920 S. L 13 31 56 2. 27 160 0. 05 0. 51 32. 75 Not seen 8. 14 27. 9 30-60 2-2920 S. L 11 27 62 4. 32 108 0. 05 0. 49 30. 66 Not seen 8. 14 47. 09 60-90 3-2920

In order to analyze the phonological conditions of Gole Mohammadi، a pair of maximum thermometer and a pair of wet and dry thermometer are installed in the screen box of the shelter house in the site. The maximum and minimum variables and wet and dry daily temperature rates are checked in addition to phonological observations 3 times a day at (6:05، 12:05، 18:05 Hrs.) and are recorded in observation cards. In order to check the errors in readings the thermometers of the site were controlled and calibrated through the synoptic station measuring devices in Kashan station. Based on the findings of the meteorological and phonological observations from bud swelling to dormancy (sleep)، the major phases of growth، the length of each phase and the required temperature of each phase are calculated. The calculated amount was specified based on (GDD). It should be mentioned that the irrigation program، once every 12 days، followed the irrigation program of the similar farms. Using specific codes in agriculture is a traditional method for describing the phonological growth stages of the plants (Zadoks et al.، 1974). These stages are coded from 0-9 according to BBCH. In this research، BBCH coding system is applied. This scale has a table of 100 sections from 0-99 designed for different phases of the plants’ growth. In this scale، the growth stages are divided into two principal and secondary stages from 01-99. The principal growth stages are described using numbers from 0 to 9; each principal stage is divided in to secondary stages through coding from 1 to 99. In the principal stage for red flowers، BBCH scale has more advantages than that of the Flecking scale for fruit products of Rosaceae group (Fleckinger، 1948). The Flecking scale has only 11 stages، describing the round bud visible bud process mostly، but do not describe the opening of the flower، fruit، germination، leaf production and stem growth stages in full (Meier et al.، 2009). Therefore، all phonological stages of Gole Mohammadi from germination to dormancy (sleep) are based on BBCH and are recorded in the observational cards.

In order to calculate the required temperature in phonological growth stages of the plant، two popular methods، the effective (GDD) and cardinal temperature are applied. In the effective (GDD) threshold the base biological temperature of the plant is used and in cardinal temperature threshold mostly 0◦C temperature is used as the base temperature. The effective (GDD) is determined through the equation 1، where Tb is the base temperature and Ti is the average daily temperature and n is the time space between the two growth stages per day. Equation (1): Most of the scientists used 5. 2 base temperature rates for Hybrid roses and because Gole Mohammadi is a kind of Hybrid rose، the same base temperature is considered 5. 2 in order to calculate the effective temperature. The (GDD) is determined through equation 2 because the cardinal temperature is considered above zero. In this equation Tb is zero (Khoshhal and Baratian، 2009). Equation (2) The required level of temperature unit for Red flowers is determined based on the sum of the effective and cardinal temperature rates. Based on the findings illustrated in table 4، the Gole Mohammadi shrub requires 866. 2 (GDD) based on effective temperature and 1337 (GDD) based on cardinal temperature to accomplish the biological activities until the end of inflorescence stage in the mentioned region. The rate of total (GDD) 5 stages based on effective temperature is 48. 5، 174. 7، 305. 6، 337. 4، 1218. 1، respectively; the cardinal temperature for the same stages is 134. 5، 299. 5، 446، 457، and 1644. 5، respectively. The maximum temperature unit for Gole Mohammadi inflorescence stage until reaping is 337. 4 (GDD) effective temperature and 457 cardinal temperature days; and the minimum temperature unit for germination stage is 48. 5 ◦C effective temperature and 134. 5 Cardinal temperature days. The sum of effective temperature rate from germination to three leaf pair unfolding stage (until the end of leaf growth) is 223. 2 (GDD).

In this research، the phonological growth stages of Gole Mohammadi are divided in to 5 main stages: germination، shoot production، bud visible، inflorescence and dormancy (sleep). According to table 2، the germination begins on 19 March and ends on 3May. The period of germination is 17 days in this area. This stage begins when the temperature reaches 6. 5◦C the average daily، minimum and maximum temperature rates are 2. 11 and 13. 7◦C، respectively. In the second stage (shoot production) the temperature rate is increased and the growth reached its peak. In this stage the average، minimum، and maximum temperature rates are 12. 4، 6. 25، 18. 7◦C، respectively. The daily minimum and maximum temperature rates belong to the germination and open flower stages which are 7. 91 and 19. 86◦C، respectively. Among the phonological growth phases of Gole Mohammadi، the bud visible is the longest stage and the germination is the shortest، that take 27 and 17 days، respectively. In general، for Gole Mohammadi، from bud swelling that occurs in the winter dormancy period to reap stage 91 days are required. In general، the growth of Gole Mohammadi begins in second week in March and ends in the fourth week of June. The required temperature unit is calculated through the sum of (GDD) and cardinal temperature methods. Based on the findings، that is illustrated in table 4، the shrub of Gole Mohammadi requires 866. 2 (GDD) based on effective temperature and 1337 temperature unit based on cardinal temperature in order to accomplish biological activities until the end of reaping.