The aim of this study was to quantify the response of germination rate to temperature and to find cardinal temperatures and THERMAL time required for different germination percentiles in Cyperus difformis. We compared 4 non-linear regression models [dent-like, segmented and beta (4 and 5 parameter)] to describe the germination ratetemperature relationships of C. difformis over seven constant temperatures (ranging from 15 to 45oC, with 5oC intervals). Different statistical indices [Root Mean of Squares of Error (RMSE), Akaike Information Criterion (AICc)] were used to compare models performances. The dent-like model was found to be the best model to predict germination rate (RMSE=0.0009, AICc=-380.8). The base, the lower optimum, the upper optimum and the maximum temperatures for the germination of C. difformis were estimated to be 14.73, 34.34, 38.54 and 45.01oC, respectively. The THERMAL time required to reach 50 and 95% germination was 43.50 and 65.01 degree-days, respectively. The cardinal temperatures depended on the model used for their estimation. Overall, the dent-like model was better suited than the other models to estimate the cardinal temperatures for the germination of C. difformis.

To study the THERMAL REQUIREMENTs of grain corn hybrids, at different planting dates, a field experiment was carried out in the Agricultural Research Center of Isfahan, Iran in 2007 - 2008. It was conducted in split plot arrangement based on randomized complete block design with three replications. Planting dates (June, 5- June, 20 and July, 5) were assigned to main plots and hybrids (BC404، KSC320، OSSK552، KSC500، OSSK713 and KSC704) to sub plots. Results indicated that there was no significant difference for growing degree-days (GDD) REQUIREMENTs from planting to germination among hybrids and planting dates. However, KSC704 hybrid in the first planting date needed the highest GDD during its different growth stages. KSC 500 hybrid with 6.31 (t/ha) and OSSK 713 hybrid with 6.48 (t/ha) produced the highest grain yields. The highest number of grains per ear row belonged to KSC320 Hybrid (18.83). KSC704, OSSK713, OSSK 552, and BC404 possessed the highest kernels per ear row, 44.63, 44.59 and 44.74 kernels respectively. The highest thousand kernel weight (288.12 g) was also observed in BC 404 hybrids. The highest protein content was related to the third planting date. However, its percentages in all hybrids, except KSC 320 hybrid, were similar. KSC 500 hybrid had the highest phosphorous content (243 mg/100g). The highest plant disease incidences were observed in KSC 320 and KSC 404 hybrids. KSC 704 hybrid, in the mean time, showed the highest ear contamination percentage. The conclusion is that OSSK713 hybrid and the second planting date produced the highest seed yield in Isfahan, Iran.

Determination of cardinal temperatures during seed germination and emergence as well as the THERMAL time REQUIREMENT for each stage is essential in crop management and modeling of plant growth and development. Two experiments were conducted to predict cardinal temperatures and THERMAL time REQUIREMENT for germination and emergence of chickpea genotypes. In the first experiment, seed germination responses of six chickpea genotypes (MCC361, MCC951, MCC180, MCC873, MCC13 and MCC463) at seven temperature regimes (3, 5, 10, 15, 20, 25, 30 and 35oC) in a controlled condition were evaluated. The trial was carried out as split plot based on a completely randomized design with three replications using 10 seeds per Petri dish. Seed germination percentages and days to 50% germination (cumulative) were determined. Cardinal germination temperatures using non-linear regression between germination rate and temperature (R50 as y and T as x) were estimated. Temperature function, Dent like model was used to determine seed germination rate. In the second experiment, traits mentioned in first experiment were studied for emergence of chickpea genotypes, with nine planting dates considered as main plots. Therefore, the experiment conducted as split plot based on a complete block design with three replications in the soil. Based on the results, both base temperature for germination and emergence were stable traits and there were not significant differences among genotypes in this respect. Average base temperature of genotypes for germination and emergence were estimated 4.2oC and 6.1oC, respectively. Also, the average optimum temperatures of genotypes for germination differed from 20.4oC to 26.5oC, respectively and for emergence they were differed from 24.0oC to 26.8oC, respectively. There was no considerable genetic diversity for physiological days and THERMAL time required for germination and emergence of chickpea genotypes. There was a highly significant positive correlation between observed and predicted days to germination and emergence of chickpea using Dent like model. Therefore, this model can be used for simulating germination and emergence times of chickpea.

Introduction: The rapid increase in the world population and the need to increase agricultural production, and on the other hand, the rapid change of climate conditions, are the significant challenges facing the world in the coming years. Wheat, the most important plant in the cereal family, plays a vital role in the world's food security now and in the future. Therefore, producing new cultivars with high yields and carefully selecting cultivars suitable for cultivation in different climatic zones are important future research priorities. Materials and methods: This study investigated the reaction of different bread wheat cultivars regarding yield and its components. It also aimed to study the growing degree days (GDD) and some physiological traits related to cold tolerance in different bread wheat cultivars. This study was conducted as two independent experiments during the 2013-14 cropping year at the research field, Campus of Agriculture and Natural Resources, Razi University, Kermanshah, Iran. The first experiment was a randomized complete block design with three replications. Treatments included 12 bread wheat cultivars (Norstar, Zarin, Kavir, Baz, Sivand, Alvand, Pishgam, Pishtaz, Orum, Shahryar, Bahar, and Parsi). The second experiment was a factorial experiment in a randomized complete block design with three replications. In this experiment, 12 bread wheat cultivars were evaluated as the first factor and sampling times as the second factor in three levels: early January, early February, early March. Results: The results of this study showed that Sivand and Parsi spring cultivars with the highest plant growth rate in different stages of development, with 5170 and 5100 kg/ha, respectively, and Norstar winter cultivar with the lowest plant growth rate in various stages of development, with 2230 kg/ha, had the lowest value of grain yield. The correlation between grain yield, growing degree days REQUIREMENT to flowering, and physiological maturity were negatively significant. Cultivars with lower grain yield had higher growing degree day’s REQUIREMENTs. Examination of the growing degree days REQUIREMENT of cultivars up to the flowering stage showed that, on average, spring cultivars had lower growing degree day REQUIREMENTs than winter cultivars. The accumulation of soluble sugars in the crown of winter and intermediate cultivars during winter was higher than spring cultivars. The accumulation of soluble sugars in the wheat crown was downward during the winter, so at the beginning of winter, the crown had a higher sugar content than in the middle and late winter. Winter and intermediate cultivars, on average, had higher leaf greenness and maximum photochemical efficiency of photosystem II than spring cultivars. Conclusion: According to the results obtained in the study area, on average, winter and intermediate cultivars were superior to spring cultivars in terms of physiological traits related to cold tolerance. But, due to the obtained seed yield. However, according to the grain yield obtained in this study, spring cultivars are more recommended among cultivated cultivars than the other two growth types in Kermanshah and similar climate zones.

Introduction Study the phenology of the medicinal plant is important to manage the timing of recurring plant primary and secondary material utilizations, seed collection, pest control, prevent harvested untimely and weed control. Based on the weather conditions each plant for completing its phenological stages needs certain amount of heat units. The use of special codes to describe Phenological stages of plants has a long tradition in agricultural science. 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. The principal growth stages are described using numbers from 0 to 9; each principal stage is divided into secondary stages through coding from 1 to 99. The objective of this study was to describe the Phenological growth stages of ‘ Roselle’ based on BBCH scale. Materials and Methods Phenological stages of ‘ Roselle’ were described and defined according to the extended BBCH scale. The experiment was carried out as strip plot layout based on a randomized complete block design with three replications at the Experimental Farm of the Faculty of Agriculture, Iranshahr Branch, Islamic Azad University, Iranshahr, Iran (Latitude 27o 12 ' N and longitude 60o 42' E; 591 m above sea level), during the growing season of 2013-2014. The experimental factors were: four rates of consumption of inputs and agricultural operations require in different cropping including Ecological system (No-tillage + Disk +Leveler +Furrower + 100% Manure), Conventional systems with low inputs (One-tillage + 0ne-Disk +Leveler +Furrower + 75% Manure + 25% NPK), Conventional systems with average inputs (One-tillage + Two-Disk +Leveler +Furrower + 50% Manure +50% NPK) and Conventional systems with high input (Two-tillage + Two-Disk +Leveler +Furrower + 100% NPK) and wheat straw application as residue mulch in four levels (6, 4, 2 t. ha-1 and control). In order to recognize the different stages of Roselle, three plants were appointed in each plot and monitored during growing season. All phenological stages of Roselle from germination to senescence were recorded based on BBCH. Results and Discussion The extended BBCH scale considers 10 principal growth stages, numbered from 0 to 9. Starting at Germination (stage 0) and ending at the beginning of the rest period (stage 9). Based on BBCH scale, nine phenological stages were recorded for Roselle that included: (0) Germination, (1) Leaf development, (2) Formation of side shoots, (3) Main stem elongation, (5) Inflorescence emergence, (6) Flowering, (7) Development of bolls, (8) ripening of sepals and (9) Seeds Senescence. Growing degree days to reach each stage were 153, 1051, 501, 506, 583, 730, 892, 349 & 246, respectively. Due to the high temperatures during the growing season of Roselle, the plant phenological stages were occurred more rapidly and the plant reaches its physiological maturity. Despite the interesting characteristics of this plant (Heat and drought tolerance), a detailed description of the phenological growth stages of Roselle has never been performed. A precise description of the different growth stages of this crop will provide a useful tool for agronomic and research activities. In this Study, the description of the phenological development of Roselle was proposed utilizing the expanded BBCH scale. Conclusion Roselle plant phenology is described here for the first time, according to the BBCH General scale. The use of extended BBCH scale for Roselle is important for successful implementation of farm management practices including disease and pest control. Based on our results it seems increasing wheat straw on the soil surface increased water holding capacity of the soil and reduced soil temperatures, which causes delay in the occurrence of Roselle phenological stages. Acknowledgements This research was supported by Ferdowsi University of Mashhad, Iran (code 31152).

Background and Objectives The sugarcane stem borers, Sesamia cretica Lederer and S. nonagrioides Lefever are the most important pests of sugarcane in Iran causing heavy losses in cane and considerable reduction in sugar yield. The egg parasitoid wasp, Telenomus busseolae Gahan is the most remarkable natural enemy of Sesamia spp. in Khuzestan province, Iran that plays an important role in regulating the populations of sugarcane stem borers. Temperature is an effective abiotic factor that influences the development of natural enemies. The present study aimed to investigate the temperature-dependent development of T. busseolae on S. cretica. Material and Methods The development rates and THERMAL constant of the immature stages of T. busseolae on S. cretica eggs were studied at seven constant temperatures (15, 18, 20, 25, 30, 35, and 37ºC), a photoperiod of 16L:8L, and 65%±5% RH. Fresh egg masses of S. cretica were exposed to the newly mated female of T. busseolae for 6 h. Afterwards, the parasitized eggs were kept at different temperatures. The parasitized eggs were checked daily until adult emergence. Development rate was modeled as a function of temperature using two mathematical models, including common and Ikemoto and Takai linear models. The linear models were analyzed using the SAS software. Results The results of regression analysis showed that the immature developmental period of T. busseolae decreased with elevating temperature from 18ºC to 35ºC. In 15ºC and 37ºC, no development rate was found for T. busseolae. Immature development time declined from 45 to 11 days and 46 to 12 days in male and female parasitoids, respectively. The percent of adult emergence was not affected by temperature. However, two linear models provided a satisfactory relationship between immature development rate and temperature. Based on statistical criteria, Ikemoto and Takai linear model estimated THERMAL constant and temperature threshold more precisely. For male and female parasitoids, the THERMAL constant was 250 and 255 degree-days and the low-temperature threshold was 12.44ºC and 12.5ºC on S. cretica eggs, respectively. Conclusion In the current study, the THERMAL REQUIREMENT of T. busseolae on S, cretica was estimated for the first one. Information regarding the THERMAL REQUIREMENT of T. busseolae can be useful for the rearing and application of this parasitoid in the biological control of sugarcane stem borers. This finding could be used to predict the number of T. busseolae generations and the best time for parasitoid release in sugarcane fields.

The mealybug destroyer, Cryptoleamus montrouzieri Mulsant is the most important natural enemy of the mealybugs. Increasing knowledge regarding ecological compatibilities of the natural enemies lead to increase their efficacy for controlling the pests. In this study, the effect of temperature as the most effective environmental factor on development of the mealybug destroyer was studied. Developmental time of incubation period, all larval instars, pupal period, and overall immature stages of the mealybug destroyer were recorded in temperatures ranging 15-35° C, 50-60% RH, and a photoperiod of (L: D) 16: 8h. According to the ANOVA, temperature affected significantly developmental time of the mealybug destroyer at 1% probability level and increasing temperature lead to decreasing developmental time. Degree-Day and Ikemoto-Takai linear models were used to describe temperature-dependent development of the mealybug destroyer. While, both of the linear models had shown an acceptable fit to data, because of better statistical criteria, estimation of the Ikemoto-Takai linear model was considered for THERMAL indices. Estimated values for THERMAL REQUIREMENT of incubation period, 1 st nd, 2 rd, 3, and 4 th larval instars, total larval period, pupal period and overall immature stages of the C. montrouzieri were 45. 38, 43. 67, 53. 04, 113. 27, 256. 89, 143. 29 and 483. 59 degree-days, respectively. Moreover, the values of the lower temperature threshold for the mentioned developmental stages were 9. 79, 10. 74, 10. 28, 9. 67, 10. 06, 10. 07, 9. 18 and 9. 64° C, respectively, using Ikemoto and Takaei linear model. According to the results, clarifying some aspects of THERMAL characteristics of the mealybug destroyer, would increase our knowledge to improve biological control program of the mealybugs.

Olive fruit fly, Bactrocera oleae (Rossi) (Dip: Tephritidae), is one of the most important and main pests that attack olives around the world, especially in Mediterranean countries. The fly larvae seriously reduces olive production, and in some successful years due to the favorable weather conditions, they cause high economic damage to olives. This pest typically reduces the measurable quantity and superior quality of canned olives as well as olive oil after attacking olive fruits. In this study, the desired effect of specific temperatures was studied as the key environmental factor undoubtedly affecting the continuous growth of olive fruit flies. Development time of incubation period for egg, larva, pupal stage, as well as total immature stages of the olive fruit fly were recorded in temperatures ranging 10-30°C, 60-70% RH, and a photoperiod of 16: 8 h (L: D). Based on the ANOVA, the specific temperature along the growth period inevitably affected significantly developmental time of the olive fruit fly at 5% probability level and the increase in temperature allegedly followed a decrease in developmental time. Degree-Day and Ikemoto linear models were used to describe temperature-dependent development of the olive fruit fly. Based on the obtained results in Siahpoush, Qushchi and Kallaj regions, the heat REQUIREMENTs for embryonic development of eggs were obtained 63. 45, 71. 28 and 63. 68 days-degrees, for the egg+ larva stage were 209. 18, 215. 83 and 159. 68 days-degrees, pupae stage were obtained 159. 44, 183. 15 and 175. 55 days-degrees and the total immature stages were 348. 51, 396. 94 and 338. 40 days-degrees, respectively, using Ikemoto model. In addition, the low threshold temperature of growth which estimated using Ikemoto linear model for the points mentioned were as follow: for embryonic developmental stages of eggs were 6. 67, 6. 33 and 6. 71°C, for the egg + larva stage were 8. 04, 6. 96 and 9. 43°C, for pupa stage were 9. 72, 9. 35 and 9. 45°C and for the total immature stages were 9. 31, 8. 41 and 9. 39°C, respectively.

The recent research es indicate that irrigating with mean values of crop reference evapotranspiration (ETo) level will only provide about 50% of plant water demand. In such cases, irrigation level may not provide optimum water for plant and plant may face with water stress or water excess. With respect to the impact of ETo estimation methods, irrigation schedule period, and optimal probability level on plant water REQUIREMENT, accurate evaluation of each case seems necessary to be studied. Using climatologies (1977-2006) of daily meteorological data, the daily ETo is estimated by means of five commonly used evapotranspiration methods (Blaney-Criddle, Penman, Penman-FAO24, Penman-Montieth and Penman-Montieth FAO-56). To evaluate the influence of each ETo models on actual plant water REQUIREMENT, the daily evapotranspiration values were determined for wheat (ETc) during the period of study (1977-2006). The dates of starting and ending of maximum water REQUIREMENT (MWR) were determined by means of moving average approach. Using the extracted dates, mean daily ETo values were plotted for different periods from one day to 30-days of MWR and different probability levels. The results indicated that if we apply the mean daily ETc values in designing irrigation systems (7-day period), at 50% probability level and Blaney-Criddle, Penman-Montieth FAO-56, Penman, Penman-FAO24 and Penman-Montieth ET0 methods, the water capacity of irrigation system will respectively be 12%, 10%, 18%, 14%, and 15% less than the corresponding values of 75% probability level. The statistical analysis of daily (ETc) data also showed that by increasing the MWR period, the estimated mean daily evapotranspiration would decrease. In addition, for a specific period, using higher probability level causes more crop water REQUIREMENT values.