BBCH Scale Research Articles

Phenological Development Stages and Effective Temperature Total Demand in Bursa Siyahı Fig Variety

Temperature is one of the ecological factors limiting yield and quality in the care of the region where fig will be grown, as in many fruit species. The effective temperature total demand is one of the important parameters in determining the cultivation potential of a fruit species in any region. Temperature values are needed for the establishment of new orchards in the commercially important Bursa Siyahı fig variety. This study was carried out with the aim of determining the effective temperature total demand of Bursa Siyahı fig variety in Aydın conditions between the years 2019-2021. Although the sum of the effective temperature from bud burst to main crop ripening date on years, it was between 1314 oC-days, and the average of three years from bud bloom to leaf fall was 2506.18 oC-days. According to the BBCH scale, the main crop ripening date was 207 ± 2 days and 219 ± 2 days, although it varied between years. The total effective temperature during the harvest period was 1.040,07 oC-days, on average over three years. Optimum climate values should be taken into account in the garden facilities to be established in different regions with the table Bursa Siyahı fig variety, which has a high export value and economic importance.

Phenological description and thermal time requirement of tamarind (Tamarindus indica) in tropical conditions

AbstractTamarind is one of the highly valued fruit trees of the tropical world. Considering the potential of the crop, a precise standardised description of its growth stages and thermal time requirement were studied to ensure efficient agronomic practices. Phenological growth stages of tamarind are defined according to the BBCH (Biologische Bundesanstalt, Bundessortenamt und Chemische Industrie) scale using a three‐digit numerical system. The phenology of tamarind is characterised by eight principal growth stages: bud growth, leaf growth, shoot growth, inflorescence growth, flower development, fruit growth, fruit maturation and dormancy. Principal growth stages of tamarind are defined and described through 39 secondary growth stages. For each phenological stage, duration and thermal time were also ascertained. It is evident that thermal time for fruit growth and maturation of tamarind is substantially high, whereas inflorescence and leaf require less thermal time to complete their growth. The study could be of great help to tamarind growers and scientists for implementation of efficient agronomic management protocols as well as for assessing the response of critical phenological growth stages to temperature.

Phenological growth stages of Meconopsis aculeata Royle, an endangered medicinal plant of western Himalaya, using BBCH scale

Alpine plant species are perennial but have a shorter growing period according to prevailing habitat conditions that remain snow-covered during winter. In these areas, many of the species are important sources of valuable drugs. Phenological observations on Meconopsis aculeata were recorded at a weekly interval in Tungnath region of western Himalaya. Phenological studies in alpine plants are minimal, especially in Indian Himalayas thus, the present study was carried out to describe detailed phenological stages of M. aculeata in Tungnath region of the Indian Himalaya. The BBCH (Biologische Bundesantalt, Bundessortenamt, and Chemische Industrie) scale was used to characterize seven primary growth stages from seed germination to senescence, as well as secondary growth stages. These stages include stage 0 (germination phase), stage 1 (leaf development), stage 5 (Inflorescence emergence), stage 6 (flowering), stage 7 (fruit development), stage 8 (Fruit ripening) and stage 9 (Senescence). Due to the high market demand of medicinal plants in local and international markets, work on the various aspects of domestication and crop improvement is a dire need, therefore the detailed phenological growth stages of M. aculeata could be helpful and complimentary for local growers, breeders and researchers.

Influence of Climatic Factors on the Phenology of Chokeberry Cultivars Planted in the Pedoclimatic Conditions of Southern Romania

This paper aimed to study the adaptation of a crop to the specific climatic conditions of southern Romania, Pitești-Mărăcineni, Romania, in terms of the phenology of two chokeberry (Aronia melanocarpa) cultivars (‘Melrom’ and ‘Nero’). The BBCH (Biologische Bundesantalt, Bundessortenamt and Chemische Industrie) scale was used for phenological observations. The recorded data were statistically processed, calculating the average onset time and duration of fruiting phenophases and dormancy duration, average air temperatures, total solar radiation, and the cold and heat accumulation. Bud swelling was registered between 28 January and 8 February, budburst occurred starting on 3 March, while flowering began in stages, between 15 April and 1 May, and was completed between 27 April and 14 May. During the 154 days of 53–87 BBCH, the average air temperature, 16.1 °C, ranged between the extremes of −6.1 and 36.8 °C. The onset data and spring–summer phenophases were mainly related to the minimum air-temperature oscillations. The flowering timing shortened as the maximum temperature and total solar radiation increased. The relation between the environmental factors and the flowering strategy indicates the A. melanocarpa as a species adapted to the temperate continental climate of southern Romania.

Corema album (L.) D. Don Phenological Growth Stages according to Extended BBCH Scale

ABSTRACT The wild dioecious plant Corema album, endemic to the Atlantic coast of the Iberian Peninsula, has potential to become a new crop and to integrate the berry fruit market. Due to its potential, the aim of this study was to propose a BBCH (Biologische Bundesanstalt, Bundessortenamt and CHemical Industry) scale for the species. Based on field observation, the principal growth stages were described and sequentially established. Photographs and stereomicroscope acquisition software were used to illustrate the phenological stages of male and female plants. The scale includes seven principal stages starting with bud development (stage 0), followed by leaf development (Stage 1), main stem elongation (Stage 3), inflorescence emergence (Stage 5), flowering (Stage 6), fruit development (Stage 7) and ending with fruit maturation (stage 8), with mesostages for male and female inflorescence (stage 5) and flower development (stage 6). Through field observations carried out in plants in different growth conditions, the proposition of this extended BBCH scale was made, to have a standardized system for Corema album phenological stages. This study will have an application especially in fields of agronomy and plant breeding and will also be a stepping stone for the inclusion of this species as a novelty crop in a nearby future.

Phenological documentation of Lantana camara L. using modified BBCH scale in relation to climatic variables

Lantana camara L. (Verbenaceae) is cultivated as an ornamental and hedge plant in many countries which is native to American tropics. It’s introduction to the Indian subcontinent dates back around 200 years ago. It is an invasive alien species that has a negative impact on native biodiversity. It is evident that management of L. camara is crucial for the conservation of biodiversity. Studying its phenological characteristics as they adapt to environmental circumstances through time and space will aid in the development of management goals and strategies. This study uses BBCH scale firstly to describe the phenology of L. camara, which is represented by nine Phenological Growth Stages (PGS) in response to environmental conditions during a 32-month period in Dehradun, Uttarakhand, representing its growth. To standardise morphological traits and the phenological observation, photographs of certain significant developmental stages on L. camara in addition to the descriptions have been illustrated. Researchers can utilise this uniform labelling method as a tool to help with weed management efforts. Phenological studies of this invasive weed species may be employed for tracking the gradual impact of climate change on biodiversity and its effect on the key phenological events in the lifecycle.

Effect of Azotobacter Chroococcum and Nitrogen Fertilization on Some Morphophysiological Traits, Grain Yield, and Nitrogen Use Efficiency of Safflower Genotypes in Rainfed Conditions

ABSTRACT The effects of Azotobacter chroococcum (A. chroococcum) and nitrogen (N) fertilization on root morphological traits, plant physiology, N uptake of plant, yield components, grain yield, and nitrogen use efficiency (NUE) of six safflower genotypes in rainfed conditions were examined. A factorial experiment was conducted based on the three replications of randomized complete block designs in two cropping years, 2015–2016 and 2016–2017, at Sarableh Agricultural Research Station, Ilam Province, western Iran. Experimental factors included seed inoculation with A. chroococcum using N chemical fertilizer at four levels (two treatments without using N fertilizers urea included control and seed inoculation with A. chroococcum and another two treatments received urea included seed inoculation with A. chroococcum + 50% N of urea source and 100% N of urea chemical source), and six safflower genotypes (312-S6-697, PI-401478, PI-253895, PI-306974, Padideh, and Sina). The results indicated that the highest grain yield, number of grains per boll, and photosynthesis rate were obtained with no significant differences in the treatments of 100% N fertilizer and seed inoculation with A. chroococcum + 50% N fertilizer use. Besides, inoculation with A. chroococcum + 50% N fertilizer had higher NUE than 100% N fertilizer application. Comparing the average genotypes suggested that Sina cultivar with the highest grain yield and NUE was recognized as the best cultivar among the studied genotypes. Therefore, the appropriate cultivars (Sina) with recommended 50% N fertilizer application with A. chroococcum was used to reach the sustainable agriculture under rainfed safflower cultivation. Abbreviations A. chroococcum: Azotobacter chroococcum; BBCH scale: Biologische Bundesantalt, Bun-dessortenamt and Chemische Industrie; N: Nitrogen; NUE: Nitrogen use efficiency

Phenological growth stages of ‘Barcelona’ hazelnut (Corylus avellana L.) described using an extended BBCH scale

A wide range of hazelnut (Corylus avellana) cultivars are produced around the world. Cultivars are often listed by the time of bloom, from early to mid and late season. To date, phenological stages have been recorded using alphanumerical codes, although data analysis is difficult with such codes. This study converted the alphanumerical codes to fully numerical codes using the Biologische Bundesanstalt Bundessortenamt und Chemische Industrie (BBCH) scale. A hazelnut BBCH scale was created for the cultivar 'Barcelona', which is considered a reference for phenological stages. The scale was constructed with at least two digits (0 to 9) for the main growth stages and three digits for female flowering and fruit development. The first number indicates the general growth stage, the second number indicates the growth stage at a specific time, and the third digit, when present, indicates the proportion at that stage on the tree. The hazelnut BBCH scale describes in 38 stages within 7 of the 10 available stages. The BBCH stages used are 5 (inflorescence emergence), 6 (flowering), 0 (bud development), 1 (leaf development), 7 (fruit development), 8 (fruit ripening), and 9 (senescence). The hazelnut is unusual in that it flowers in winter. Thus, the scale was extended from flower initiation (spring to summer of the year before harvest), male and female flowering (winter before harvest) and bud and leaf development (spring before harvest). During the spring before harvest, and summer before harvest, fruit developmental stages and fruit ripening are monitored and finally, senescence finalises the hazelnut life cycle in autumn after the harvest. Thus, the BBCH hazelnut cycle has a duration of at least 18 months and gives a good idea of hazelnut development. Finally, this new scale will add new information on the kernel development stages which were not evaluated in the former phenological scale. It will help producers to have a better idea of the fruit ripening and potential harvest date.

Development of a uniform phenology scale (BBCH) in hazelnuts

Several methods are used to monitor phenological events in crop plants, and the BBCH scale ("Biologische Bundesanstalt, Bundessortenamt und Chemische Industrie") is a widely used one. However, a BBCH scale does not exist for hazelnut. In this manuscript, we used the BBCH monograph for mono- and dicotyledonous and woody plants to propose a BBCH scale for hazelnut. We list the standardized plant development stages and show the equivalent descriptors in the UPOV and Bioversity International (IPGRI) lists and the development stages published in France and Italy. The proposed monograph covers eight of the ten principal BBCH stages, starting with dormant buds (stage 0) and ending with harvested nuts (stage 9).

Phenological growth stages of “pawpaw” [Asimina triloba (L.) Dunal, Annonaceae] according to the BBCH scale

The “pawpaw” [Asimina triloba (L.) Dunal] is a deciduous fruit tree native to eastern North America where it is produced at a limited commercial scale. It is particularly interesting due to its tropical flavor and powerful aroma, unique features for a fruit crop adapted to temperate climates. Although the “pawpaw” is still an underutilized fruit crop, it has a clear niche for expansion in regions with temperate climates. However, appropriate phenological comparisons in different regions are hampered due to the lack of a standardized phenological coding system in this species. Thus, in order to fill this gap, in this work, we describe with detail the phenological growth stages of the “pawpaw” by using a two-digit decimal coding system, according to the extended BBCH-scale (Biologische Bundesanstalt, Bundessortenamt und Chemische Industrie). The BBCH code allows to easily identify the standard phenological stages under field conditions, a useful tool for management of fruit crops and essential for the expansion of “pawpaw” to other growing areas.

Olive reproductive phenology in a warm and humid region of Santa Catarina, Brazil

Olive cultivation has been spread across Brazil subtropical regions, but yields have been variable through years and locations. The objectives of this work were to characterize the reproductive phenology and quantify some productive indexes of three olive cultivars (Arbequina, Arbosana and Koroneiki) in the warm, humid subtropical climate of western Santa Catarina, Brazil. Shoots of the three cultivars were marked and the quantitative indices of flowering and fruiting were observed periodically. At the same time, the reproductive phenology was evaluated following the BBCH scale, during three seasons, in Chapecó. Reproductive budburst varied from 0 to 32%, which resulted in a relatively low number of flowers per meter of shoot if compared to traditional growing regions, unlike fruit set rates (3.69 to 11.39%), which were similar. Compared to other regions, flowering time was early: inflorescences started to grow from end of June to mid-July, depending on the year. Then maturation was precocious as well, from the end of December to mid-March, and it was later in Koroneiki. The low flowering intensity with risk of frost damages discourages the production initiative in the region.

Transcriptomic Analysis of Sex-Associated DEGs in Female and Male Flowers of Kiwifruit (Actinidia deliciosa [A. Chev] C. F. Liang & A. R. Ferguson)

Kiwifruit (Actinidia deliciosa [A. Chev.], C.V. Liang & A. R. Ferguson, 1984) is a perennial plant, with morphologically hermaphroditic and functionally dioecious flowers. Fruits of this species are berries of great commercial and nutritional importance. Nevertheless, few studies have analyzed the molecular mechanisms involved in sexual differentiation in this species. To determine these mechanisms, we performed RNA-seq in floral tissue at stage 60 on the BBCH scale in cultivar ‘Hayward’ (H, female) and a seedling from ‘Green Light’ × ‘Tomuri’ (G × T, male). From these analyses, we obtained expression profiles of 24,888 (H) and 27,027 (G × T) genes, of which 6413 showed differential transcript abundance. Genetic ontology (GO) and KEGG analysis revealed activation of pathways associated with the translation of hormonal signals, plant-pathogen interaction, metabolism of hormones, sugars, and nucleotides. The analysis of the protein-protein interaction network showed that the genes ERL1, AG, AGL8, LFY, WUS, AP2, WRKY, and CO, are crucial elements in the regulation of the hormonal response for the formation and development of anatomical reproductive structures and gametophytes. On the other hand, genes encoding four Putative S-adenosyl-L-methionine-dependent methyltransferases (Achn201401, Achn281971, Achn047771 and Achn231981) were identified, which were up-regulated mainly in the male flowers. Moreover, the expression profiles of 15 selected genes through RT-qPCR were consistent with the results of RNA-seq. Finally, this work provides gene expression-based interactions between transcription factors and effector genes from hormonal signaling pathways, development of floral organs, biological and metabolic processes or even epigenetic mechanisms which could be involved in the kiwi sex-determination. Thus, in order to decode the nature of these interactions, it could be helpful to propose new models of flower development and sex determination in the Actinidia genus.

Influence of Nitrogen Nutrition on Fatty Acids in Oilseed Rape (Brassica napus L.).

The aim of the study was to evaluate the effect of nitrogen nutrition on the content of fatty acids and selected qualitative parameters (nitrogenous substances, ash, crude fiber) in winter oilseed rape (Brassica napus L.). The experiment was carried out at the Vígľaš—Pstruša Research and Breeding Station in 2008–2009 and 2009–2010 by complete block design with four repetitions. Nitrogen fertilization was applied at four levels, plus an untreated control (after agrochemical soil analysis) by DAN 27 (Dolomite Ammonium Nitrate): 100, 120, 140, and 160 kg/ha N. Application date was in BBCH scale phase 59–60. The fatty acid contents (MUFA—monosaturated fatty acids; PUFA—polyunsaturated fatty acids) were determined by gas chromatography in the extracted fat, which is determined by extraction method. Within the result evaluation, statistically significant increases in the contents of linoleic and linolenic acids were recorded in all variants treated by nitrogen fertilizer, which is positive in terms of the use of rapeseed oil for food and energy purposes. The statistically significant decrease of oleic acid after the application of nitrogen fertilizers is negative for industry use of rapeseed oil.

Phenological Stages of Development of Cornus L. S. Str. Species (Cornaceae) According to BBCH Scale

Under conditions of pronounced dynamic climate change, the scope of phenological data is constantly expanding and increasingly extends beyond local regions. For the international integration of phenological research, a standardized description of the stages of plant development and their identical coding is used – the BBCH scale (Biologische Bundesanstalt, Bundessortenamt und CHemische Industrie). Phenophases of seasonal development, according to BBCH, are already unified for many different in origin, nature of ecology, and economic use of plants of common and little-known species and crops, including fruit. According to the BBCH scale, we described the seasonal stages of development of 23 cultivars of Cornus mas L. selection gene pool of the M.M. Gryshko National Botanical Garden of the National Academy of Sciences of Ukraine, genotypes of C. officinalis Siebold & Zucc., nine genotypes of C. sessilis Torr. ex Durand, as well as three genotypes of the artificial hybrid from crossing C. officinalis × C. mas. Phenological monitoring was carried out in NBG (Ukraine) two or three times a week for three seasons (2018–2020) from the beginning of vegetation (bud development) to November and the beginning of winter dormancy. In the studied species of the subgenus Cornus, as in some other stone fruit plants, there are eight of the ten main stages of seasonal development. In all studied species and cultivars of dogwood at the beginning of the growing season generative buds in their development significantly ahead of vegetative and plants begin seasonal development from the development of inflorescences and flowering (principal growth stage 5 and principal growth stage 6, respectively). Different species and varieties differ in the calendar dates of onset and duration of certain major stages of development. The obtained data are important for further studies of adaptive capabilities of Cornus species and cultivars in different climatic conditions, for practical use of genetic resources of studied Cornus species and cultivars, as well as for the introduction of little-known Cornus species and their use in agricultural production, pharmacology, ornamental and landscape gardens.

Codification and description of the phenological growth stages of red-fleshed pitaya (Hylocereus polyrhizus) using the extended BBCH scale- with special reference to spines, areole, and flesh color development under field conditions

Pitaya (Hylocereus spp.) has become a global fruit crop, particularly in Southeast Asia, with two main species cultivated over recent decades; the white-fleshed pitaya (H. undatus) and the red-fleshed pitaya (H. polyrhizus). Although the morphological description of the phenological stages of white-fleshed pitaya (H. undatus) has been recorded using a three-digit numerical system as per the Biologische Bundesanstalt, Bundessortenamt und Chemische Industrie (BBCH) scale rule; however, the description of spine development, an important characteristic of bud burst under the areole is lacking. Additionally, the description scale for flesh color change caused by the accumulation of the betalain pigment, which is important for its nutrition value in red-fleshed pitaya, is lacking. This study investigated the phenological stages of a red-fleshed pitaya, an allied species with remarkable similarity to white-fleshed pitaya, “Da Hong” (also called “Big Red”), using the BBCH scale to provide uniform phenology-related information and develop a more suitable scale for the scientific studies and crop practices of red-fleshed pitaya. Furthermore, at each stage, the development of the spine and flesh color to address fruit developmental characteristics owing to its red flesh was simultaneously assessed and recorded. The flesh started to grow at the first stage of fruit development (code 711). The flesh color changed at the final phase of fruit development (code 719) and at the first phase of fruit peel maturity (code 811). The peel color in the flesh and mesocarp changed completely in the final phase (code 819), indicating the completion of fruit maturity. This important phenological stage scale may be used in growth, development, and physiology studies, and in orchard management, including field practice, nutrition management, and pest and disease control.

Phenological Assessment for Agronomic Suitability of Some Agastache Species Based on Standardized BBCH Scale

Increasing interest in medicinal plants encourages the growers to consider extending their range of cultivated species. Acclimatization and adaptation of species introduced for cultivation in new areas remain a challenge of modern agriculture. One of the first steps for optimizing the cultivation technology is determining the plant phenology in the local conditions. Therefore, the aim of this research was to provide a standardized phenology scale for Agastache sp. and to apply it in assessing the suitability for cultivation in a local environment of some valuable Agastache species: Agastache scrophulariifolia, Agastache rugosa, Agastache mexicana, Agastache foeniculum and Agastache rugosa ‘After Eight’. During the vegetation period, nine growth stages were identified: germination/emergence, leaf development, formation of side shoots, stem elongation, inflorescence emergence, flowering, fruit development, fruit maturity, senescence and beginning of resting. Observations conducted over two years revealed that the vegetation period increased from 168.8 ± 3.51 days in the first year to 199.0 ± 1.82 days in the second year. In both vegetation periods, the flowering phenophase predominated, but the abundance of precipitations shortened the flowering duration in the second year. The duration of phenophases was highly influenced by growing degree days. Phenological assessment based on a standardized scale can be a useful tool for evaluating cultivation potential and the planning of technological resources.

Castor bean (Ricinus communis L.) responses to drought stress and foliar application of Zn-nano fertilizer and humic acid: grain yield, oil content, antioxidant activity, and photosynthetic pigments

Castor bean is considered as an important non-edible oilseed crop and source of castor oil, which has many applications ranging from cosmetics to the biofuels industry. Humic acid (HA) results from organic matter decomposition and is beneficial to plant growth and development. In the present study, a two-year experiment was conducted in Damghan, Iran, to study the physiological responses of castor bean to foliar application of zinc nano-chelate (Zn-nano) and HA under drought stress. The drought stress was used as the main treatment in three levels: normal irrigation as control, irrigation up to 75 BBCH scale (Biologische Bundesantalt, Bundessortenamt und Chemische Industrie) (mild stress), and irrigation up to 65 BBCH (severe stress). Foliar application of HA in three levels (non-application, application of the recommended rate and two times more than the recommended rate), as well as Zn-nano fertilizer in two levels (application at 1.5 part per thousand (ppt) and non-application) as subplots. The drought stress, HA, and Zn-nano fertilizer could significantly affect the number of capsules, the number of seeds, 100-seed weight, seed yield, oil yield, protein percentage and yield, activities of catalase (CAT), superoxide dismutase (SOD), and peroxidase (POD), and chlorophyll a (Chl a), chlorophyll b (Chl b), and total chlorophyll (total Chl) contents. In addition, severe drought stress resulted in reducing the number of capsules (33.9%), the number of seeds (32.7%), 100-grain weight (16.0%), as well as seed (43.0%), oil (59.3%), and protein (29.9%) yield. Based on the results, the highest yield components, oil and protein contents, and photosynthetic pigments were achieved in the foliar application of HA (recommended rate) and Zn-nano fertilizers under normal irrigation during the second year. Further, the foliar application of Zn-nano fertilizer led to a decrease in the activities of CAT, SOD, and POD enzymes. According to partial regression analysis, the recommended rate of HA application the changed the nature of relationships governing the characteristics, especially under drought stress conditions. Finally, the foliar application of HA (recommended rate) and Zn-nano fertilizers could create an excellent resistance to drought stress in castor under dry and semi-arid climate conditions by improving yield and yield components and physiological traits.

An intensive study plot to investigate chestnut tree reproduction

Key messagePollination is a key step for fruit production. To provide a tool for future in-depth analysis of pollination in chestnut, we describe in detail a chestnut orchard (location, genotype, phenotype and seed-set of all trees).ContextChestnuts, which are insect-pollinated trees, have been massively planted around the world for nut production. Orchards are planted with clonal varieties selected from crosses between the European chestnuts (Castanea sativa) and Japanese chestnuts (C. crenata) or Chinese chestnuts (C. mollissima) because these two last species are tolerant to blight and ink diseases.AimsTo characterize chestnut genetic resources and accurately model male and female fitness as well as pollen exchanges in orchards, we characterized all chestnuts of the INRAE chestnut germplasm collection located near Bordeaux (France).MethodsAll chestnut trees were geolocated and genotyped using 79 SNP and 98 SSR loci. We scored their flowering phenology using chestnut BBCH scale and precisely described their phenotype (height, diameter a breast height (DBH), canopy diameter…), their capacity to produce pollen (flower type, catkins length…) and their fruit production (number of burrs, seed-set…).ResultsWe geolocated 275 trees and genotyped 273 of them. We identified 115 unique genotypes and assigned each genotype to species. To assess phenology, we evaluated 244 trees twice a week, for 6 weeks from early June to mid-July. We also described tree phenotypes with 11 variables, pollen production with 5 variables and fruit production with 3 variables. All measures were recorded in 2018 except seed set that was measured two consecutive years, in 2018 and 2019.ConclusionThe data collected is very detailed and allows modelling precisely pollen exchanges between trees. Parts of this data have been successfully published in scientific articles.Data are available at: https://data.inrae.fr/dataset.xhtml?persistentId=doi:10.15454/GSJSWWAssociated metadata are available at:https://metadata-afs.nancy.inra.fr/geonetwork/srv/fre/catalog.search#/metadata/02c5ca07-1536-4f89-9a0c-9e8d44a91287

Phenological growth stages of Gaúcho tomato based on the BBCH scale

Phenological growth stages of Gaúcho tomato based on the BBCH scale

Maximum, Minimum, and Daily Air Temperature Range in Orchards: What Do Observations Reveal?

This study was designed to better understand vegetation’s impact on air maximum (Tmax), minimum (Tmin), and daily temperature range (DTR), as well as seasonality and variability. We selected a flat, under synoptic-scale, northern Serbian region with an operational network of automated weather stations (AWS) for the study. Data were collected directly from the eighteen AWSs placed in the orchard canopy during 2013–2018. Meteorological data, plant phenological data in the form of the BBCH scale, and orchards’ soil characteristics data were collected. Environmental factors influencing the temperature were classified as static (slow or unchangeable) and dynamic (fast-changing). The impact of both factors on maximum, minimum, and daily temperature range and its variability were analyzed. Results show that static factors (like soil texture) affect the annual variation of Tmax, Tmin, and DTR rather than its variability over the season. The dynamic factors, mainly coming from the plant’s phenology, substantially affected the seasonal variability of these variables. Studies like this suffer from missing data and sparse spatial coverage by the AWS network. Therefore, the alternatives of orchard micrometeorological data, nearest climatological station, and ERA5-Land reanalysis data are tested. Both data sets showcased limitations in their applicability, while reanalysis data deviated more from the in-situ measurements, both seasonally and regionally.