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The main objective of this study was to evaluate the process of parameters such as mean temperature; total precipitation on phenology and phenological stages of apple golden type in Razavi Khorasan. For this reason, long-term data of absolute minimum daily temperature, precipitation, humidity, as well as Digital Elevation Model (DEM) was used. After collecting data on phenology and Growing Degree Days (GDD) for golden apple, to pass each phenological stage at different growth stages, the start and end dates, phenological stages of the locations were identified. Then, regression equations with variable longitude, latitude and altitude on SPSS software at level of 50% and 95%, respectively were used, and finally phenological stages and spatial distribution maps of temperature and precipitation variables based on these equations were drawn in ARC GIS software. The analysis of the phenological stages showed that Torbate Heydarieh station has a decreasing trend which is significant at 1% in all stages of phenology and Ghoochan station does not show any significant increase or decrease trend at all stages of phenology.

Identifying any environment and efficient use of that needs studies in different fields. In environmental studies, in order to access to a confident model, the subject of systematic approach should be pursued. The possible environmental powers are not distributed equally in all places and each country has different capabilities due to weather conditions for farming and other activities [

The studied area is about 146,954 Km^{2} consist of Razavi Khorasan, Northern Khorasan, is located in the geographical range, between the latitude of 30˚N to 38˚N and longitude of 55˚E to 61˚E from Greenwich Meridian (

In this study for feasibility of apples daily average minimum and maximum temperatures of 12 synoptic stations has been used during the period of 25 years including: Mashhad, Sabzevar, Ghoochan, Golmakan, Neyshaboor, Sarakhs, Gonabad, Kashmar, Torbate jam, Torbate Heydarieh, Ferdous and Boshrooyeh. The absolute minimum daily temperature, precipitation, humidity, as well as Digital Elevation Model (DEM) were used to identify areas favorable and unfa-

vorable for apple cultivation. Since the base temperature that apple trees can tolerate is between −30 to 35 degrees Celsius, all areas of the province are considered favorable for apple cultivation. Each plant needs a certain number of heat units for germination, growth, stem elongation, maturity. This is called constant thermal units that defers from one plant to another. One of the most important issues in Climatology is checking the Degree Days (DD). Most physiological changes such as the growth of plants and hydrologic phenomena such as snow melting are function under the environmental thermal power. For this purpose, the heat index is used as an indicator of Growing Degree Days (GDD). Each process is activated at a certain temperature threshold, i.e. the threshold for melting snow is zero degrees Celsius and the threshold for apples growth is 7 degrees Celsius. So to estimate the degree-days for different periods of cultivation is one of the essential tasks. Since the beginning of active growth apple time begins the daily average temperature of 7 degrees Celsius exceeds the threshold value, so in this study to calculate the GDD, The base temperature of 7˚C was included. GDD calculation formula is as follows:

where, GDD is Growing Degree Days _{b} the base temperature is 7 degrees centigrade, a and b are the start and finish the phenology process [

Presence or absence of trend, time series analysis and proposed climate change are divided in two categories: parametric and nonparametric methods. Parametric methods are mainly based on the regression equation on time series data. Nonparametric methods of application compared to parametric methods are extensive and impressive. For a series that is not fitted on them and skewed distribution of specialty or high elongation using non-parametric methods are more appropriate. One of the most widely used non-parametric is Mann-Ken- dall test methods are used for time series trend analysis [

The calculation of the difference between each observation with each other and function symbols and parameter extraction the s parameter actions as follows:

where n is the number of observation, and

For independent random variables with uniform distribution and without group (Two or more data with the same numerical values in the series are ordered to follow). The mean and variance(s) are as follows:

where n is the number of observations data, if there is duplicate data observations, the variance are calculated as follows:

So that q is the number of repeated groups. For example, if in a given series, only two values are equal we will have a nut with the resistant of 2(t_{p}_{−1}).

If a data series is more than ten, s will follow a normal distribution and standard statistical criteria (z) will be as follows:

This test is a two-way, if

After collecting data on phenology and growing degree days required passing each phenological stage of Golden apple variety at different growth stages, start and ending dates of phenological stages of the stations were identified. Then, regression equations with variables of longitude, latitude and altitude with the probability of 95% were calculated in SPSS software, and finally the map of spatial distribution at different stages based on these equations were drawn in Arc GIS software and spatial distribution of the mean temperature and total precipitation maps were drawn. Analysis of the phenological stages, mean temperature and total precipitation were evaluated by Mann-Kendall test in

Given that one of the major limiting factors for raising the apple is not meeting the required GDD in a few cases from the stations, the needed growing degree days were used to identify the areas that were suitable and unsuitable for apple cultivation,. Therefore, after determining the required growing degree days for the period of 25 years in 12 synoptic stations in the study area, linear regression method based on digital elevation model (DEM) was used to generalize the results to a wide study area. The relationship between GDD with altitude, latitude is shown in Equation (7):

In the above equation Y represents a growing degree days, lat represents the

The name of phenological process | Description | The required heat units (degree days) | The cumulative thermal units (degree days) |
---|---|---|---|

First | Bud formation | 32.4 | 32.4 |

Second | Bud break | 80.4 | 112.8 |

Third | Flowering | 73.2 | 186 |

Fourth | Growing fruit | 1977 | 2163 |

Fifth | Fruit ripening | 623 | 2786 |

latitude, long reagents the longitude and E represents the altitude. Coefficients of determination and correlation equation respectively are 77 and 61 percent.

Shows the cultivation areas in regardless of stations that are not covered by required growing degree days. The relationship between the starting date of phenological stages with latitude, longitude and altitude at 95% is shown in

Figures 4-8 maps indicate the start date of phenological stages at the level of 95 percent. According to

The process of phenology | Relations between phenological stages with latitude, longitude, and altitude | The coefficient of determination | The coefficient of correlation |
---|---|---|---|

The first stage, bud formation | Y = −339.172 + 3.780long + 5.323lat + 0.021E | 79 | 89 |

The second phase, bud break | Y = −387.248 + 4.494long + 5.771lat + 0.024E | 89 | 94 |

The third stage, flowering | Y = −425.621 + 4.822long + 6.434lat + 0.028E | 87 | 93 |

The fourth stage, fruit growth | Y = −1128.199 + 11.237long + 17.569lat + 0.071E | 89 | 94 |

The fifth stage, ripening | Y = −1632.420 + 17.530long + 21.394lat + 0.056E | 84 | 92 |

theastern regions occurs in 4 May to 22 May.

phenology (the fruit growing). This stage in the West and Southeast regions (West of Sabzevar and Kashmar) starts from 12 June to 1^{st} of August. In the northern and central areas such as Mashhad and small sections of Torbate jam, begins from 17 September to 10 October. ^{th} of December to 30^{th} of December.

The process of phenology | Bud break stage | Bud formation stage | Flowering stage | Stages of fruit growth | Fruit ripening stage | |||||
---|---|---|---|---|---|---|---|---|---|---|

Station | Z | PV | Z | PV | Z | PV | Z | PV | Z | PV |

Sabzevar | 0 | −1.6 | 0.1 | −1.1 | 0.0 | −1.7 | 0 | −2.7** | 0 | −2.3* |

Torbate Heydarieh | 0 | −3.1** | 0.0 | −2.9** | 0.0 | −2.9** | 0 | −3.6** | 0 | −3.2** |

Sarakhs | 0 | −3.4** | 0.0 | −3.1** | 0.0 | −2.3* | 0 | −2.6** | 0 | −2.4* |

Kashmar | 0 | −2.9** | 0.0 | −2.7** | 0.0 | −2.6** | 0 | −2.6** | 0 | −2.3* |

Neyshabur | 0 | −2.9** | 0.0 | −2.9** | 0.0 | −2.4* | 0 | −2.8** | 0 | −2.4* |

Mashhad | 0 | −3.2** | 0.0 | −3.1** | 0.0 | −2.1* | 0 | −2.3* | 0 | −2.8** |

Torbate jam | 0 | −2.7** | 0.0 | −2.7** | 0.0 | −2.3* | 0 | −1.8 | 0 | −1.1 |

Golmakan | 0 | −1.9* | 0.0 | −3.2** | 0.0 | −2.4* | 0 | −3** | 0 | −3** |

Ghoochan | 0 | −1.7 | 0.4 | −0.1 | 0.1 | −0.9 | 0 | −1.5 | 0 | −1.8 |

Gonabad | 0 | −3.9** | 0.0 | −3.9** | 0.0 | −3.5** | 0 | −3.3** | 0 | −2* |

The process of phenology | Bloom to bud formation stage | Bud formation and flowering stage | Flowering stage to fruit growth | Fruit growth process to ripening | ||||
---|---|---|---|---|---|---|---|---|

Station | Z | PV | Z | PV | Z | PV | Z | PV |

Sabzevar | 0.3 | 0.64 | −0.84 | 0.19 | −1.21 | 0.12 | 1.37 | 0.91 |

Torbate Heydarieh | 0.5 | 0.71 | 0 | 0.5 | −0.84 | 0.19 | 1.05 | 0.85 |

Sarakhs | 0.7 | 0.78 | −0.95 | 0.17 | −0.31 | 0.37 | 3.75** | 0.99 |

Kashmar | 0.4 | 0.68 | 0.26 | 0.60 | 0.05 | 0.52 | 2.16* | 0.98 |

Neyshabur | 0.5 | 0.69 | −0.33 | 0.36 | 1.35 | 0.91 | 2.67** | 0.99 |

Mashhad | 0.3 | 0.64 | 0 | 0.5 | 1.32 | 0.90 | 3.06** | 0.99 |

Torbate jam | 0.4 | 0.68 | 0.41 | 0.66 | 0.62 | 0.73 | 2.65** | 0.99 |

Golmakan | −0.9 | 0.17 | 0 | 0.5 | 2.37* | 0.99 | 2.69** | 0.99 |

Ghoochan | 0.2 | 0.58 | −0.95 | 0.17 | 1 | 0.84 | 3.01** | 0.99 |

Gonabad | 0.73 | 0.77 | 1.21 | 0.88 | −0.26 | 0.39 | 2.32* | 0.98 |

The process of phenology | Bud to bud formation stage | Bud formation and flowering stage | Flowering stage to fruit growth | fruit growth process to ripening | ||||
---|---|---|---|---|---|---|---|---|

Station | Z | PV | Z | PV | Z | PV | Z | PV |

Sabzevar | −0.6 | 0.2 | 0.6 | 0.7 | 0.4 | 0.6 | −0.7 | 0.2 |

Torbate Heydarieh | 0.1 | 0.5 | −0.1 | 0.4 | 1.7 | 0.9 | −0.8 | 0.1 |

Sarakhs | −0.4 | 0.3 | −0.1 | 0.4 | −0.1 | 0.4 | −0.3 | 0.3 |

Kashmar | −0.6 | 0.2 | −1.0 | 0.1 | 0 | 0.4 | −0.3 | 0.3 |

Neyshabur | 0 | 0.5 | 1.8 | 0.9 | 0.0 | 0.5 | −1.2 | 0.1 |

Mashhad | −0.0 | 0.4 | −0.5 | 0.3 | 0.0 | 0.5 | 0.1 | 0.5 |

Torbate jam | −1.3 | 0.0 | 0.0 | 0.5 | 0.4 | 0.3 | −0.4 | 0.3 |

Golmakan | −0.4 | 0.3 | 0.3 | 0.6 | 0.3 | 0.6 | −1.4 | 0.0 |

Ghoochan | −1.9* | 0.0 | 0.4 | 0.6 | 0.0 | 0.5 | −1.9 | 0.0 |

Gonabad | −1.7 | 0.9 | −2.2* | 0.9 | −0.5 | 0.2 | −0.2 | 0.4 |

The results of this study show that GDD in the uplands is less than the amount needed to ripen apples and therefore excluded from the scope of firm’s cultivation. Studying the maps of phenological stages shows that southern and southwestern regions in terms of supply of growing degree days are very suitable for apple cultivation areas and the period of growing apples is from germination to fruit ripening period from 13 March to 3 September in these areas. But in central and northern part due to the higher altitude and lower temperatures, the phenological stage begins later than the southern regions. In combination with the results of this study, it can identify favorable areas for apples in the studied area and based on that, the date of cultivation and the amount of production can be progressed. The analysis of the phenological stages shows Torbate Heydarieh stations in all phenological stages have a significant decreasing trend at 1% confidence level. Ghoochan station at all stages of phenology does not show any type of significant increase or decrease. The negative trend means that earlier period of renewed growth compared to the previous year has occurred sooner and has moved backwards. In all phenological stages, stations Mashhad, Golmakan and Torbate jam have the lower mean temperature and the average temperature is higher in Sabzevar station. The mean temperature trend analysis at all stations except Sabzevar and Ghoochan at the stage of growth to ripening fruit has a decreasing trend significantly at 1%. The central and northern parts have the most precipitation and the western and southern and southeastern part have the lowest precipitation.

Karami, M. and Asadi, M. (2017) The Phenological Stages of Apple Tree in the North Eastern of Iran. Computational Water, Energy, and Environ- mental Engineering, 6, 269-280. https://doi.org/10.4236/cweee.2017.63018