Bud Opening Research Articles

Phenological variability and resistance to late spring frost of common beech in the international provenance test in Bosnia and Herzegovina

The research aimed to determine the start, end and duration of leafing phases, the degree of plant damage caused by late spring frost, and the retention of leaves in autumn. The research was conducted in the international common beech provenance test in Bosnia and Herzegovina. The test contains eight provenances from Bosnia and Herzegovina, four from Germany, three from Serbia, two each from Croatia, Romania and Switzerland, and one from Hungary. Leafing phenology, canopy damage caused by late spring frost, and leaf retention were assessed in 2019. Most provenances started opening buds on 17 April 2019. Complete canopy damage affected the highest percentage of plants in provenance BW Bad Wildbad, Germany (68 %), and the lowest in provenance Konjuh Kladanj, Bosnia and Herzegovina (3.2 %). Provenance Herzogenbuchsee from Switzerland had the highest percentage of winter leaf retention (37.5 % of plants). The results can be used in choosing provenances that are resistant to low temperatures in zones of late spring and early autumn frost.

Features of growth and development of Abies alba Mill. seedlings in the conditions of Voronezh (Russia)

Phenological observations are one of the methods for studying the reaction of introduced species to new conditions and subsequent introduction into regional phytocenoses. This research wants to assess growth and development of Abies alba Mill., currentlyexotic in the Central Black Earth region of Russia. Seeds, obtained from individuals growing in the natural range (the Carpathians) in 1987 were sown in the university nursery. Then five-year-old seedlings were planted in the University arboretum. At the age of 22 the arboretum habitat was inferior to natural analogues. Phenological observations of bud opening and formation of annual growth coincide with the beginning of the growing season in natural plantings. High rates of seed germination (80%), high annual growth rates of seedlings (and transplanted plant) determined final success of silver fir in forest-steppe conditions. Precipitation has a dominant influence on growth and development, as shown by the correlation analysis between climate and growth, despite the fact that the species is drought-resistant in natural habitats. The study emphasizes the factors that control growth and development of silver fir. The use of this method of sowing is ecologically sound, which can further improve the success of species adaptation to the individual conditions of regional phytocenoses.

Investigation of Compost and Vermicompost of Water Hyacinth as Growing Media for Lily (Longiflorum×Asiatic)

Water hyacinth (Eichornia crassipes) is one of the ten most invasive weed species in the world that is spread over most of the tropical and subtropical regions. Due to the environmental and economic concerns associated with spreading of the water hyacinth, control its distribution is important issue. Water hyacinth can be used for composting and vermicomposting. In the present study, compost or vermicompost of water hyacinth was used as growing media for growing of lily plants (Longiflorum×Asiatic cv. ‘Nashville’). To do so, an experiment was conducted in a completely randomized design with nine treatments and four replications. Treatments included peat moss + perlite (2:1 v/v) as control and 25%, 50%, 75% and 100% of water hyacinth compost or vermicompost substitute for peat moss in control treatment. According to the obtained results, the tallest plants were observed in the control (55.50 cm) and 25% compost (55.25 cm) treatments. No significant difference was observed among 50, 75 and 100% compost and 25% vermicompost treatments. The highest number of open buds (3.50) was seen in 25% vermicompost. Results also showed that using 75% compost and 50% vermicompost increased nitrogen content of the leaf. Highest total phenol with 6.9 mg quer/g FW was recorded in 75% and 100% vermicompost. The maximum vase life (six days) was obtained in flowers grown in 25% vermicompost. In conclusion, water hyacinth compost or lower vermicompost percentages could be a substitute for peat as the growing media for lily plants.

DORMANCY PERIOD OF AGRICULTURAL PLANTS

Dormancy is the state of plants in which the growth processes are stopped, the intensity of metabolism decreases.
 Dormancy is expressed in a delay of the seeds germination, tubers, and buds opening. It is the normal physiological state
 of plants, and it should be considered as a hereditary biological adaptation to the unfavorable conditions of a particular season.
 Dormancy can be controlled by external conditions (exogenous or compulsory dormancy) or by the internal factors
 (endogenous, organic or deep dormancy). In addition, there are such types of dormancy as combined, winter, summer,
 extended, preliminary. In areas with harsh winters winter dormancy is a prevalent survival strategy for both herbaceous
 and woody plants. Winter dormancy is a certain physiological state of woody and shrub plants, in which the plant is able
 to withstand low negative temperatures of air and soil.

Effects of Different Preservatives on Cut Flower of Luculia pinceana: A Novel Fragrant Ornamental Species

Luculia pinceana is a potential cut flower because of its long-term blooming inflorescences and charming fragrance. However, its narrow distribution area and unexplored wild status severely restrict its applications, thus leading to the scientific research of cut L. pinceana flowers. To our knowledge, there is no available published information about the postharvest fresh-keeping of L. pinceana. During this study, the cut flowers of L. pinceana were tested using nine preservatives with different concentrations of sucrose and 8-hydroxyquinoline (8-HQ) to evaluate the fresh-keeping effects. Through the investigation and analysis of vase life, bud opening and abortion rate, water balance, malonaldehyde (MDA) content, and peroxidase (POD) activity, we selected and identified the best vase solution for cut L. pinceana flowers. The results suggested that the preservative of 1% sucrose and 100 mg/L 8-HQ could significantly prolong the vase life of cut L. pinceana flower up to 9 days compared with water control. This solution positively affects flower bud blooming, delays flower senescence, improves the water balance, inhibits the MDA accumulation, and increases POD activity. Therefore, this preservative is suitable for the fresh-keeping of cut L. pinceana flowers. Our study is the first to report the effects of preservatives on cut L. pinceana flower. The results showed that the low-sugar-containing (1% sugar) preservatives can effectively improve the ornamental quality of fresh flowers and demonstrated that the postharvest fresh-keeping of L. pinceana requires low sugar and is insensitive to microorganisms.

Cesium uptake and translocation from tea cutting roots (Camellia sinensis L.)

To estimate the uptake of radiocesium (137Cs) by tea plant roots, 1-year-old rooted tea cuttings (Camellia sinensis L. cv. Yabukita) at the time of bud opening were cultivated hydroponically for 27 days in pots containing nutrient solutions with or without 137CsCl (600 Bq mL−1). Total 137Cs radioactivity of whole tea plants were 6.1 kBq g−1 dry weight. The plant/solution 137Cs transfer factors of different tissues were in the range of 2.6 (in mature leaves) to 28.2 mL g−1 dry weight (in roots), which were lower than those reported in wheat and spinach. In total, 69% of 137Cs remained in roots and 31% was transported from roots to shoots. The results indicated that 137Cs was preferentially translocated to new shoots, which are used for manufacturing tea, over mature leaves.

INCREASING THE HARMFULNESS OF THE ERIOPHYOID MITE ACULUS SCHLECHTENDALI (NALEPA), A PHYTOPARASITE OF APPLE TREE IN THE NON-BLACK EARTH ZONE OF RUSSIA

Apple rusty mite Aculus schlechtendali (Nalepa) (Eriophyidae) is an invasive parasite in the Central region of the Non-Black Earth Zone of Russia. At the beginning of the XXI century, there were only small foci of the phytoparasite, but at present it is widespread almost everywhere, periodically giving a massive outbreak of reproduction. The number of mites reaches 1000 and more mobile individuals per 1 leaf (25.5 per 1 cm2). The body is microscopic (160–175 microns), so it is very difficult to be detected. Also, with a small number of A. schlechtendali, symptoms of plant infection do not appear outwardly, which allows the active spread of the mite with planting or other plant material. To count the number of the parasite in the spring, the tops of annual growths up to 10 cm long were sampled at 10 discount sites (in order to view opening buds), and during the vegetation, 10 leaves (4-5th leaves from the top of the sprout) were taken from each discount site. Selected samples of buds and leaves were examined under an MBS-10 binocular microscope. A. schlechtendali is especially dangerous in nurseries and young fruiting plantations of apple trees; it feeds not only on leaves (from the underside) and young sprouts, but damages flowers and buds of the apple tree. Effective control of the parasite requires constant monitoring and strict quality control of the planting material.

THE GROWTH AND DEVELOPMENT OF RASPBERRY CULTIVARS IN THE CONDITION OF UZBEKISTAN

In the article during the growing season the occurence of phenological phases, the buds formation, buds opening, the beginning of flowering, full flowering and the duration and the end of flowering, the time of flowering and the condition of the plants of the raspberry cultivars grown in Uzbekistan are evaluated in points. The results of research to study the beginning of fruit ripening, full ripening, the differences and quality indicators of fruits, the average and maximum weight of the fruit, acidity and sugar content of the fruit are given. Raspberry cultivars with high yields, depending on the ripening period of the fruit, are also recommended herein

INFLUENCE OF VARIOUS HOLDING SOLUTIONS ON VASE LIFE OF CHRYSANTHEMUM CV. PUJA

The present experiment entitled “Influence of various holding solutions on vase life of Chrysanthemum (Dendranthema grandiflora) cv. Puja” was carried out under Complete Randomized Design with three replications in the Horticulture Laboratory of School of Agricultural Sciences and Technology RIMT University, Mandi Gobindgarh, Punjab during 2020. The result showed that the vase life was significantly affected by different holding solutions. Among the various treatments, T10 (Sucrose 6% + Citric acid 300ppm) was resulted in minimum number of days taken (3.22 days) for bud opening, fresh weight of spike (11.04 g), flower height (6.89 cm), stem diameter (4.85 mm), minimum moisture loss (44.44%), maximum vase life (19.33 days) and dry weight of spike (2.46 g). Whereas, treatment T9 (Sucrose 4% + Citric acid 200 ppm) was resulted in maximum total solution consumption (24.00 ml). Maximum diameter of the flower on 6th, 9th and 15th days of experiment was recorded in treatment T10 (Sucrose 6% + Citric acid 300 ppm). Treatment T9 (Sucrose 4% + Citric acid 200 ppm) was also resulted in maximum diameter of the flower on 3rd and 12th day of trial. Treatment T10 (Sucrose 6% + Citric acid 300 ppm) was resulted in maximum weight of spikes on 3rd, 6th and 9th day of experiment. And also maximum weight of spikes on 12th and 15th days of trial was observed in treatment T9 (Sucrose 4% + Citric acid 200 ppm).

ИЗМЕНЕНИЕ ВИДОВОГО СОСТАВА, БИОЭКОЛОГИИ И ВРЕДОНОСНОСТИ ОСНОВНЫХ ФИТОФАГОВ ЯБЛОНИ В ЦЕНТРАЛЬНОМ РАЙОНЕ НЕЧЕРНОЗЕМНОЙ ЗОНЫ РОССИИ ПОД ВЛИЯНИЕМ КЛИМАТИЧЕСКИХ ФАКТОРОВ

The studies were carried out at the Federal State Budgetary Scientific Organization “Federal Horticultural Center for Breeding, Agrotechnology and Nursery” (FSBSI FRCHBAN) in 1995-2020. The aim of the research was to clarify the species composition, bioecology, and the characteristics of harmfulness of the main phytophages of apple trees in the Central Region of the Non-Black Earth Zone of Russia under climate change conditions. Route surveys were carried out in 5 regions of this zone - Bryansk, Kaluga, Moscow, Ryazan, Tula. When studying the bioecological features of the development and dynamics of summer of the codling moth and corrosive arboretum, along with other methods, pheromone traps were used. Trapping belts (sticky and corrugated paper) were used to signal the exit of the apple blossom beetle from wintering places, as well as the method of shaking off in the morning, at a temperature of no higher than 10˚С. The count of four-legged microscopic mites in the early spring period was carried out before the leaves blooming by the method of selecting the tops of annual growths up to 10 cm long, at 10 counting sites (to view the opening buds). During the growing season, 10 leaves were sampled (4 ... 5th leaves from the top of the shoot), at each registration area. The analysis of microscopic objects on the selected samples was carried out using an MBS-10 stereoscopic microscope. In the research area, new dangerous invasive apple phytophages were identified: corrosive arboreal tree Zeuzera pyrina L. (Lepidoptera: Cossidae), apple rusty mite Aculus schlechtendali Nalepa (Acariformes: Eriophyidae), apple felt mite Phyllocmespates malinus (Acariformes: Eriophyidae). The bioecology and harmfulness of autochthonous phytophages have changed significantly. The apple moth Cydia pomonella L. (Lepidoptera: Tortricidae) gives up to two generations, and the summer lasts up to 132 days. Red (Panonychus ulmi Koch. (Acariformes: Tetranychidae)) and brown (Bryobia redikorzevi Reck (Acariformes: Bryobiidae)) fruit mites, depending on weather conditions, develop in 4 ... 5 generations a year, common spider mite (Tetranychus urticae Koch. (Acariformes: Tetranychidae)) at 7. The prevalence of ticks reaches 100%, and the degree of damage to plants by them is up to 3-4 points. Damage to apple flowers by the weevil Anthonomus pomorum L. (Coleoptera: Curculionidae) reaches 60 ... 85%, the colonization of leaves and shoots by the red-gall aphid Dysaphis devecta Walk. (Homoptera: Aphididae) 35 ... 45%, fruit loss from apple sawfly Haplocampa testudinea Klug. (Hymenoptera: Tenthredinidae) 15%

Seasonal changes in the woody plants development in an urbanized environment

The features of the phenological development of woody plants in green urban plantations in the dry steppe zone have been studied. The phenological phases of woody plants and shrubs are described and analysed: the beginning of bud swelling, the beginning of bud opening, the beginning of leaf opening, the beginning of flowering, the end of flowering, the beginning of fruit ripening, and mass loss of mature fruits. The onset of phenological seasons for the steppe zone has been determined. Formed groups of plants according to the terms of leafing and flowering. The calendar dates of the onset of phenological phases of trees and shrubs in an industrial urban environment are analysed. The sum of effective temperatures for the main phenological phases of woody plants in the steppe zone has been determined. Decorative dendrological groups have been developed for phenological phases of leafing and flowering of woody plants for urban landscaping in the dry steppe zone. Practical recommendations are given for grouping plants by flowering time for landscape construction.

Features of spring vegetation of hazel leaves in the foothills of the Republic of Adygea

The article provides information about one of the areas of work associated with hazel carried out by the Adygh branch of the Federal State Budgetary Institution of Science «Federal Research Center «Subtropical Scientific Center of the Russian Academy of Sciences». The territorial location of this institution is the foothills of the Republic of Adygea, where the objects of the research, i.e. forms and varieties of hazel are located. The institution has been studying hazel since 1995. The article provides data on the collection site where the best forms and known varieties of hazel grow. At the collection site, phenological observations of hazel were carried out from 2017 to 2019. The information is given on the number of forms and varieties of hazel growing on the collection site, on the features of spring vegetation of leaves. The expression «spring vegetation of hazel leaves» implies several spring phenological phases of hazel, such as «beginning of leaf bud swelling»; «massive swelling of leaf buds»; «beginning of leaf bud opening» and «the maximum length of the leaf plate is 5 cm». The meteorological indicators of the studied period from 2017 to 2019 have been indicated. The article discusses the prospects of certain forms and varieties for various breeding purposes. Based on the data presented, it has been concluded that: 2017 was the most unfavorable of the three years of research in the meteorological plan; the earliest leaf vegetation during the three years of research was observed in the «Zakatala» variety; the leaf reaches 5 cm in the «Trapezund» variety and the «Futkurami» variety the very first, and the 20/15 form.

Involvement of Ethylene in Physiological Processes Determining the Vase Life of Various Hybrids of Mokara Orchid Cut Flowers

There is limited information about the postharvest performance and physiology of Mokara orchid cut flowers, which are a special group of artificially created trigenetic hybrids of Vanda × Arachnis × Ascocentrum. Therefore, we first characterized the patterns of various physiological parameters during vase life of five Mokara hybrids, which differ in their longevity. Then, we examined the effects of ethephon and ethylene inhibitors on these physiological parameters, and on parameters of the ethylene biosynthesis pathway, during vase life of two selected Mokara hybrids, “Moo-deang” and “Dao-lai”, which showed significant differences in their vase life duration and senescence symptoms. The results demonstrate that the differences in vase life longevity among the five Mokara hybrids are due to differences in their ethylene production rates, which regulate flower development processes expressed in bud opening and floret senescence. The results clearly show that ethylene is involved in the regulation of the Mokara flower senescence, and pretreatment with ethylene inhibitors significantly improved their vase life longevity. Thus, ethylene seems to be the main factor that determines the longevity differences of the Mokara hybrids, rather than their water relations parameters. This study can serve as a research tool for developing effective postharvest treatments for Mokara hybrids.

Pectin-derived oligosaccharins effects on flower buds opening, pigmentation and antioxidant content of cut lisianthus flowers

Most flower buds do not open after the cut flower has been separate from the plant without having an external energy source. Sugar added in vase solutions usually has positive effects; however, it can also elicit and generate greater senescence. The objective of this paper was to determine the effects of sucrose, another external elicitor such as oligosaccharins, and the synergy of these compounds applied in vase solutions on the opening and pigmentation of lisianthus (Eustoma grandiflorum cv. 'Mariachi blue') flower buds. Different vase solutions were applied, including a negative control (water alone) and a positive control (commercial Floralife Crystal Clear®). The treatments were sucrose (4 %), pectin-derived oligosaccharins (Pectimorf® at 1 mg L−1 and 2 mg L−1), and the combination (2 mg L−1 oligosaccharins and 4 % sucrose). Physical and biochemical parameters were evaluated in flowers and leaves. Results suggest that oligosaccharins and sucrose synergy caused greater bud opening (12 % greater than negative control) and flower diameter (74 mm, 20 % greater than negative control), produced more intense color in young flowers, and modified antioxidant compounds content. These effects allow for prolonging vase life, maintaining the appearance, and increasing the color and flower size of lisianthus during postharvest as compared to water or sucrose alone treatments.

温度和光周期协同作用对蒙古栎幼苗春季物候的影响

植物物候对气候变化非常敏感，但关于物候对不同气候因子协同作用的响应机制仍不清楚。为此，以蒙古栎为研究对象，针对蒙古栎物候的主要影响因子温度和光周期，利用大型人工气候室，模拟研究了温度与光周期协同作用（对照、增温1.5℃、增温2.0℃，不同光周期（10 h、14 h、18 h）及其协同作用（对照处理、增温1.5℃×18 h、增温1.5℃×10 h、增温2.0℃×18 h、增温2.0℃×10 h））对蒙古栎春季物候的影响与机制。结果表明：（1）相同水分条件下，不同升温程度对蒙古栎幼苗春季物候的影响不同。温升1.5℃促进蒙古栎幼苗春季物候（芽膨大期、芽开放期、展叶始期和展叶盛期）提前；而温升2.0℃则对不同春季物候的影响不同，表现为促进芽休眠解除和芽开放，但抑制叶片展开。（2）相同水分条件下，不同光周期对蒙古栎幼苗不同春季物候的影响存在差异。长光周期对蒙古栎幼苗展叶盛期影响最大，短光周期对芽膨大期影响最大，但均表现为抑制作用。（3）相同水分条件下，温度升高与光周期增加协同作用有助于促进蒙古栎幼苗春季物候提前，但温度升高与光周期缩短协同作用则对春季物候有抑制作用。（4）蒙古栎幼苗春季物候变化与前期气候胁迫程度存在显著正相关，表明前期气候因子也是物候变化的重要影响因子。研究结果丰富了蒙古栎物候响应多气候因子协同作用的认知，有助于促进物候模型的完善。;Plant phenology is very sensitive to climate change. However, the interactive effects of different climatic variables on plant phenology are still unclear. Thus, taking Quercus mongolica as the research object, we studied the interactive effects of different warming and changing photoperiod (control treatment (CK), 1.5℃ warming, 2.0℃ warming; different photoperiods (10 h, 14 h, and 18 h); CK, 1.5℃ warming×18 h, 1.5℃ warming×10 h, 2.0℃ warming×18 h, 2.0℃ warming×10 h) on the spring phenology of Quercus mongolica seedlings based on the experimental data of large artificial climate simulation chamber in the context of global warming. The results are as follows:(1) Under the same water condition, different warming had different effects on the spring phenology of Quercus mongolica seedlings. The 1.5℃ warming promoted the spring phenology, including bud swelling (BS), bud opening (BO), first full leaf (F1), and 50% leaves unfolded (LU) stages. The influence of 2.0℃ warming on different spring phenology was different. 2.0℃ warming promoted the release of bud dormancy and leaf BO, but inhibited the leaf extension. (2) Under the same water condition, the effect of different photoperiods on the spring phenology of Quercus mongolica seedlings was different. The long photoperiod had the greatest influence on the 50% LU stage, while the short photoperiod had the greatest influence on the BS stage, but they all showed negative effects. (3) Under the same water condition, prolonging photoperiod under warming treatments was helpful to promote the spring phenology of Quercus mongolica seedlings, including the BO, F1 and 50% LU stages. While shortening of photoperiod under warming treatments inhibited the spring phenology of Quercus mongolica seedlings, including the BS, F1 and 50% LU stages. (4) There was a significant correlation between spring phenological changes of Quercus mongolica seedlings and previous climate stress, implying that the previous climatic variables should be the significantly controlling factors to phenological changes. The results could enrich the cognition of the interactive effects of multiple climatic variables in Quercus mongolica phenology, and are helpful to promote plant phenology simulation.

Fatty Acid Composition in Fractions of Total Lipids from the Buds of Plants of the Betula L. Genus by the Opening Phases

The fatty acid composition (FAC) of fractions of organic compounds isolated from total lipids (TL) by successive solvents—chloroform, acetone, and methanol, taken as neutral lipids (NL), glycolipids (GL), and phospholipids (PL)—was studied by the phases of the opening of buds in plants of the Betula L. genus [1]. It was found that the FAC of the TL fractions of opening buds of trees with morphological features of Betula pubescens Ehrh., Betula pendula Roth, and Betula pendula Roth var. carelica (Mercklin) Hamet-Ahti is represented mainly by unsaturated fatty acids (USFAs) (up to 88% of the total fatty acids). Linolenic and linoleic acids (up to 55 and 47% of the total fatty acids, respectively) constituted the main share of USFAs. Palmitic acid predominated quantitatively among saturated fatty acids (SFAs) (up to 42%). The content of linoleic acid in all SL fractions decreased with the development of buds in all three birches, while the content of linolenic acid in the composition of the GL and PL fractions increased. In birches differing in morphological characteristics, the specific features of the FAC from the SL fractions of the buds were studied by the opening phases.

Studies of genetic variability, quantitative, and qualitative traits of Lilium cultivars (Lilium x hybrida) under shade net in North-West Himalayan region of India

Abstract An experiment was conducted to study genetic variability and performance of nine exotic lilium cultivars (Lilium x hybrida) for suitability for commercial cultivation in North Western hilly regions of Uttarakhand at Research Station and KVK, Lohaghat, GBPUA&T, Pantnagar, Champawat, Uttarakhand India. Bulbs of nine lilium hybrid cultivars viz., Acapulco (Pink), Sorbonne (White), Yelloween (Yellow), Tresor (Orange), Brindisi (Pink), Blackout (Red), Pavia (Yellow), Ercolano (White) and Samur (Pink) were selected as experimental material. There was significant difference in days taken for bud initiation among nine cultivars. It is evident from data that minimum days take for bud initiation in cultivar Blackout (44 days) followed by Tresor (45 days). The maximum number of flowers per plant reported in cultivars Acapulco (10.20) followed by Yelloween (8.20) and Sorbonne (7.80) which is at par with Blackout (7.40) and Pavia (7.20). Maximum vase life was recorded with Acapulco (12.4 days) followed by Sorbonne (11.80 days) which is at par with Yelloween (11.8 days) while Minimum vase life was recorded with Ercolano (8.40 days) and Tresor ( 8.40 days). Mean value was found maximum for flower stem length (87.29) and minimum mean value was exhibited by number of flowers per plant. Heritability value was found maximum for characters like days to flower bud opening followed by length of flower stalk and days taken to bud initiation.

Conditioning Machine Learning Models to Adjust Lowbush Blueberry Crop Management to the Local Agroecosystem.

Agroecosystem conditions limit the productivity of lowbush blueberry. Our objectives were to investigate the effects on berry yield of agroecosystem and crop management variables, then to develop a recommendation system to adjust nutrient and soil management of lowbush blueberry to given local meteorological conditions. We collected 1504 observations from N-P-K fertilizer trials conducted in Quebec, Canada. The data set, that comprised soil, tissue, and meteorological data, was processed by Bayesian mixed models, machine learning, compositional data analysis, and Markov chains. Our investigative statistical models showed that meteorological indices had the greatest impact on yield. High mean temperature at flower bud opening and after fruit maturation, and total precipitation at flowering stage showed positive effects. Low mean temperature and low total precipitation before bud opening, at flowering, and by fruit maturity, as well as number of freezing days (<−5 °C) before flower bud opening, showed negative effects. Soil and tissue tests, and N-P-K fertilization showed smaller effects. Gaussian processes predicted yields from historical weather data, soil test, fertilizer dosage, and tissue test with a root-mean-square-error of 1447 kg ha−1. An in-house Markov chain algorithm optimized yields modelled by Gaussian processes from tissue test, soil test, and fertilizer dosage as conditioned to specified historical meteorological features, potentially increasing yield by a median factor of 1.5. Machine learning, compositional data analysis, and Markov chains allowed customizing nutrient management of lowbush blueberry at local scale.

Efficacy of different primers on growth and yield of tulip (Tulipa gesneriana L.)

Tulip (Tulipa gesneriana L.) is an important and highly valuable flower of the cut flower industry. The most critical step in its cultivation is to break dormancy in order to initiate the growth, especially in tropical and sub-tropical areas of the world. Therefore, the current research was conducted to break bulb dormancy and foster the growth of tulip in Potohar region with the help of different primers. The objective of this study was the selection of best primer at appropriate concentration level to enhance growth, yield and vase life of the flower. Tulip bulbs were treated with different primers: T0 (distilled water), T1 (chitosan @ 5 g/L), T2 (gibberellic acid @ 0.15 g/L), T3 (humic acid 160 g/L), T4 (imidacloprid 19 g/L) and T5 (salicylic acid 0.1 g/L) for 24 hours, respectively. The experiment was laid out using Complete Randomized Design (CRD) with three replications. Statistical results revealed that characteristics including early germination, plant height, number of leaves, stalk length, fresh and dry weight of flower, weight of bulbs, diameter of bulbs and number of daughter bulbs were significantly increased in T2. Whereas, leaf area, diameter of stem and flower was maximum in T0. Plants under T3 showed an increase in chlorophyll content of leaves. While floral characteristics like early formation and opening of flower bud, more number of flowers and vase life were improved in T1. Thus, statistical results showed that priming can effectively help to improve morpho-physiological attributes of tulip.

Estimating the trajectories of vine cordons in full foliage canopies for automated green shoot thinning in vineyards

Green shoot thinning in vineyards is carried out annually aiming to produce high-quality grapes. Recently, mechanical machines are used for green shoot thinning to reduce labor costs which causes 10–85% variation in shoot removal efficiencies due to the difficulty in precisely positioning the thinning end-effector to cordon trajectories. Automatically controlling the position and orientation of thinning end-effector to follow the cordon trajectories is expected to increase the performance and efficiency of these machines. However, during most of the green shoot thinning season (between first week of bud opening to the fourth week of shoot growth), cordons are occluded by shoots/leaves making it extremely challenging to determine the trajectories of cordons. In this study, we presented a deep learning based novel approach to estimate the trajectories of cordons during the thinning season in real field conditions. First, deep residual network (ResNet) and Faster region-based convolutional neural network was used to detect visible segments of full foliage grapevine canopies. Then, location information of detected visible segments were used to estimate the trajectories of cordons. This approach was evaluated using ground truth images collected from different growth stages of green shoots in real vineyard environment. The proposed approach achieved a correlation coefficient of 0.993, 0.991, and 0.987 in estimating cordon trajectories with the test dataset from weeks 2 to 4, respectively, of shoot growth.