Bud Opening Research Articles

Host plant phenology drives risky larval dispersal in an outbreaking insect defoliator

Abstract Dispersal away from natal sites allows individuals to find suitable foraging sites to complete their development and successfully reproduce. Drivers of risky dispersal behaviour in forest landscapes by young larvae of outbreaking defoliators are not well understood. We assessed dispersal behaviour of young spruce budworm larvae in relation to spring budburst phenology of primary and secondary hosts, balsam fir and black spruce, respectively. We tested whether tree species and presence of suitable feeding sites influenced dispersal away from source branches and subsequent redistribution of insects. Laboratory experiments showed that dispersal is an active behaviour during which larvae disperse away from source trees without open buds, regardless of species. Establishment on sink branches was highest when they possessed open buds and the source did not. In the field, larval dispersal was higher from black spruce than from balsam fir and larval establishment was more persistent on balsam fir. The decision to disperse occurs before budburst of either host species. Larvae disperse preferentially away from black spruce whose old needles are too tough for larval mining, compared to balsam fir that can be mined for sustenance and refuge while larvae await budburst. While black spruce is a suitable host species after its buds expand, phenological defences drive larval dispersal away from this host plant. These findings are the first to show how risky dispersal behaviour in larval Lepidoptera is facultative and is determined by local food availability.

Floral biology and breeding behaviour of Melia azedarach L.: imperative for hybridization

Abstract Melia azedarach L. commonly called Maha Neem is an economically and industrially important tree species with global significance. Although species possess versatile importance worldwide, information on reproductive biology and breeding system is scarce and limited for eastern coastal plain of India. Therefore, current study provides a detailed report on reproductive biology of M. azedarach. Maha Neem was found to bear violet to whitish violet, slightly fragrant, 14.99 ± 0.05 mm. long and 17.01 ± 0.08 mm. wide flowers. This tree commenced opening of floral buds during March and continued until May with a peak during March-end. The anthesis of species peaked between 08:00 and 10:00 am, which coincides with insect activity. Anthers were observed to dehisce during or shortly before anthesis; however, stigma started receptivity before anthesis and continued invitation up to 12 h after anthesis. Pollen viability ranged from 96.67 ± 1.6% to 98.26 ± 1.2 at the time of anthesis; after that decreased rapidly. Pollen: ovule ratio of 1096.38 ± 108.70 indicated the possibility of autogamy. The breeding system of M. azedarach revealed that fruit sets under natural pollination (NP) were significantly higher than Xenogamy. However, substantial difference was not reported in fruit set percentage under natural pollination and Autogamy, which is strong evidence in favour of self-pollination. Moreover, Maha-Neem is entomophilous with frequent visits by Apis and Syrphid flies. Current findings will be helpful in designing potent conservation strategies and planning successful breeding programmes.

Commercial processing of Oriental lilies affects bud opening and metabolic dynamics

Lilies are a high value cut flower typically producing 4–5 flowers per stem, but the opening of young buds of Oriental hybrid lilies is often affected in cut flowers. Commercial treatment includes harvesting of the stem when the oldest bud is closed and at turning colour, approximately 2 ds before it would open on the plant. Stems are then rehydrated, stored chilled for up to 72 h and transported dry. To understand the effect of commercial treatment onu the nutrient status metabolomes were compared throughout bud opening from different positions on the stem. At each developmental stage the metabolomic profile was affected by bud position and commercial treatment. Starch accumulated as long as buds remain closed; upon bud opening starch content declined. Reciprocally, sugar levels rose during flower opening and were affected by edge/ midrib location and commercial treatment. Glucose, fructose and sucrose levels remained higher in opened flowers still on the plant. AMY2 (amylase) transcript levels rose as did those of two sugar transporters (MST6 and SWEET7). Commercial processing therefore impacts on the metabolome and the ability to accumulate sugars in the opening flower bud. Commercial treatment delayed bud opening and the effect was dependent on the position of the bud on the stem. However, it had little impact on the rate of cell expansion during flower opening. Cell expansion in the different areas of the adaxial epidermis was unaffected by the commercial treatment. Furthermore, edge and adaxial tepal cells expanded faster during opening. Expression of cell expansion related genes (EXPA1 and LoPIP1) fell as flowers opened. This differential cell expansion in the tepal sectors could underpin the transition of a convex to a concave tepal shape during opening. In conclusion, commercial processing mainly affects the early stages of bud opening. Sugar and metabolite accumulation is compromised by commercial treatment, but this did not affect the capacity for cell expansion in the tepal. Furthermore, our data indicate that differential cell expansion in the different sectors of the tepals is important in lily flower opening, and that this is associated with starch breakdown and sugar accumulation.

A new species of Psidium and notes on Neomitranthes from the state of São Paulo, Brazil

Psidium riobonito, a new species of Myrtaceae from the Atlantic Forest of the northeastern portion of the Brazilian state of São Paulo, was collected in High Montane Dense Ombrophilous Forest and is described here. Morphological characters assign the new species to Psidium sect. Apertiflora, due to its leaves with brochidodromous veins, marginal vein parallel to the margin, inflorescences in auxotelic racemes, flowers with open buds with 5 calyx lobes, in addition to dark purple fruits when ripe, with few seeds. Psidium riobonito is morphologically close to P. involutisepalum and P. myrtoides, but differs by the marginal veins 2 to 5 mm from the margin (vs. 1 to 2 mm in P. myrtoides and 1.5 to 2 mm in P. involutisepalum), glabrous or glabrescent leaves when mature (vs. pubescent or sparsely pubescent mainly along the midrib on the abaxial surface in P. myrtoides and sparsely pubescent in P. involutisepalum), pedicels 14–26 mm long (vs. 3–12 mm in P. myrtoides and 8–10 mm in P. involutisepalum). The relationship of P. riobonito to morphologically close species, comments on its taxonomy, ecology and informal conservation status, and a table with morphological characteristics of P. sect. Apertiflora are also provided. We also present for the first time the descriptions of the fruits of Neomitranthes capivariensis and N. pedicellata.

Effect of Crude Oil Polluted Soil on the Reproductive Growth of Plantain (Musa paradisiaca L.)

Soil polluted by crude oil is detrimental to the survival of plants and microbes. Plantain (Musa paradisiaca L.) is a major important food crop, showing tolerance to abiotic and biotic stress. This study investigated the impact of soil polluted with Bonny Light crude oil (BLCO) on the reproductive growth of two plantain cultivars. Crude oil was added to agricultural soil on which plantain suckers were planted. Reproductive growth was then periodically assessed. The number of suckers was significantly higher in French plantain plants grown on polluted soil in comparison with control. False Horn plantain plants on unpolluted soil produced more suckers in comparison to the plants on polluted soil. Also, the time between planting to flower bud appearance and flower bud appearance to bud opening reduced in plants on polluted soil in both cultivars in comparison with the control. Statistically, there was an insignificant decrease in the fruit size of False Horn plantain on polluted soil compared with the control while there was an appreciable increase with a significant effect in fruits size of French plantain on polluted soil compared with the control. Generally, French plantain tolerated the stress induced by crude oil pollution of soil in its reproductive growth more than False Horn. The reproductive growth of False Horn and French plantain cultivars show that there could be varied response to crude oil polluted soil.

Phytosulfokine α (PSKα) delays senescence in cut rose flowers by keeping intracellular ATP and ROS homeostasis

During bud opening of rose flowers, higher TOR along with lower SnRK1 expression was concomitant with sufficient cellular ATP provision, while during petal senescence of rose flowers, lower TOR along with higher SnRK1 expression was concomitant with insufficient cellular ATP supplying. During bud opening, higher TOR expression might ensure sufficient cellular ATP provision by promoting H+-ATPase, Ca2+-ATPase, SDH, and CCO activities. During petal senescence, higher SnRK1 expression might ensure for insufficient cellular ATP supplying which was associated with higher AOX, UCP1, ProDH and IVDH expression. By PSKα application, triggering TOR along with suppressing SnRK1 expression could be responsible for sufficient cellular ATP provision by promoting H+-ATPase, Ca2+-ATPase, SDH, and CCO activities accompanied by suppressing ProDH and IVDH expression. In addition, higher AOX and UCP1 expression might ensure lower H2O2 accumulation in cut rose flowers by PSKα application. By PSKα application, retarding senescence and extending vase life of cut rose flowers was associated with maintaining membrane integrity indicated by lower electrolyte leakage and MDA accumulation. Our results suggest the potential of TOR/SnRK1 signaling pathways as an effective endogenous anti-senescence molecular mechanism for extending the vase life of cut rose flowers.

Multi-Walled Carbon Nanotubes Improve the Development of Chrysanthemum × morifolium (Ramat.) Hemsl. ‘Jinba’ Inflorescences

The application of cut flower preservation technology can significantly enhance both the ornamental and economic value of fresh-cut flowers. Research on vase solutions has become a concentrated area in current studies on cut flower preservation. Multi-walled carbon nanotubes (MWCNTs), as a type of carbon nanomaterial with bactericidal and membrane-penetrating properties, can be used as a component in vase solutions. This supplementation of energy substances aims to improve antioxidant enzyme activity, thereby enhancing the postharvest quality of cut chrysanthemums. In this study, deionized water and a standard preservative solution were employed as control groups to compare the effects of MWCNTs applied at different concentrations, combined with common preservatives such as sugar and 8-hydroxyquinoline, on the postharvest flowering and preservation of Chrysanthemum × morifolium ‘Jinba’. By observing the distribution of MWCNTs in the tissues surrounding the cut and changes in water content, carbon sources, osmoregulatory substance levels, and the expression of relevant key genes, a formulation with excellent postharvest treatment effects was identified. Preliminary investigations into its action and mechanism were also conducted. The results indicated that the combined treatment with 5 mg L−1 MWCNTs, 30 g L−1 sucrose, and 0.2 g L−1 8-hydroxyquinoline effectively promoted water and sugar uptake in chrysanthemum flowers, accelerating bud opening, maintaining larger inflorescence diameter, and extending the vase life. Ultimately, this enhanced the ornamental value of cut chrysanthemums. These research findings provide theoretical and experimental foundations for the application of multi-walled carbon nanotubes as auxiliary additives to improve the ornamental quality of cut flowers.

РЕЗУЛЬТАТЫ ИЗУЧЕНИЕ СОРТА ВИНОГРАДА ДУРМАН НА КОЛЛЕКЦИИ В НИЖНЕМ ПРИДОНЬЕ

The results of a 16-year study of the autoch-thonous Don grapevine variety Durman are pre-sented in comparison with the control variety Risling Rejnskij. The research was carried out in 2008−2023 at the Don ampelographic collec-tion named after Ya.I. Potapenko (Novocher-kassk, Rostov region). The varieties are culti-vated in a grafted (Kober 5 BB) cover crop. The study was carried out using generally ac-cepted methods in viticulture and National standards. According to the results of long-term observations, the Durman grapevine varie-ty has a high agrobiological potential in the cli-matic conditions of the Lower Don region (66% of open buds, 77% of fruitful shoots, fruiting coefficient 1.2, average bunch weight 173 g, yield 11.3 t/ha). The average estimated yield of the Risling Rejnskij variety was 4.5 t/ha, which is 2.5 times less than that of Dur-man variety. Durman variety has an early-medium ripening period (133 days). Upon reaching technological maturity, it accumulates 20.7 g/100 cm3 of sugars with a titratable acidi-ty of 6.5 g/dm3. Dry white wine from Durman variety is pale straw in color, the aroma has muscat-spicy tones, the taste is harmonious and full. Wine tasting score: 8.6 points. The wine from the control Risling Rejnskij variety re-ceived a score of 8.7 points. The article presents data from the molecular genetic passport of Durman variety (for six microsatellite loci). Based on the results of the studies, it was con-cluded that Durman grapevine variety is advis-able to use for producing high-quality dry white wines, as well as a mother form in breeding for crop quality. The disadvantage of this variety is functionally female type of flower, so it is rec-ommended to grow it in mixed plantings, inside an array, to improve the quality of pollination.

Study of the peculiarities of the main phenological growth and development phases, as well as commercial qualities of fruits of rare citrus taxa under conditions of humid subtropics of Russia

The citrus collection of the FRC Subtropical Research Center of the RAS includes 144 genotypes and contains rare species and cultivars that are of great interest for use in production, breeding, and ornamental horticulture. The research examined 13 rare taxa: Citrus aurantifolia, C. aurantifolia ‘Foro’, C.×latifolia, C.×bergamia, C. ichangensis, C. limon ‘Del Brasil’, C.×limonelloides, C.×limetta ‘Chontipico’, C. maxima ‘Sambokan’, C. medica, C. medica var. sarcodactylus, C.×meyeri, C.×myrtifolia. The research established the times and differences in the passage of the main phenological phases, namely bud opening and flower-bud formation, flowering, second and third active growth, fruit ripening. The beginning of the growing season of the studied objects was registered in the second and third decades of March; the difference between the early onset for C. aurantifolia (16.03) and the late onset for C. ichangensis (01.04) is 14–20 days. Two active growth periods were established for C. ichangensis, C. limon ‘Del Brasil’, C. maxima ‘Sambokan’, and C. medica, while the other citrus taxa under study had three periods of active growth. According to their flowering dates, taxa with early (April 11–13), middle (April 18–19), and late (April 23–28) flowering time were identified. Long flowering (29–36 days) is typical for taxa with early flowering. Remontant taxa, i. e. C. aurantifolia, C. aurantifolia ‘Foro’, C.×latifolia, C.×bergamia, C.×limonelloides, C.×limetta ‘Chontipico’, C. limon ‘Del Brasil’, C.×meyeri were identified. From the beginning of the growing season to fruit ripening, the effective heat summation was determined to be 4710–5250 ℃. The study also identified taxa with late fruit ripening, namely C. medica and C.×myrtifolia (third decade of December – first decade of January). The taxa with the best commercial qualities and biochemical composition of fruits were C. maxima ‘Sambokan’, C.×meyeri, and C.×limetta ‘Chontipico’.

1-MCP microbubbles reduce chlorophyll degradation and maintain the quality of Dendrobium cv. Burana Jade orchid flowers

The effect of 1-methylcycloprepene microbubbles (1-MCP-MBs) on reducing chlorophyll degradation, prolonging vase life and maintaining the quality of Dendrobium cv. ‘Burana Jade’ inflorescences was investigated. The inflorescences were immersed in 50 ppm 1-MCP-MBs or tap water (control) for 5 min and then held at 23 ± 1 °C for 12 days. The 1-MCP-MB-treated inflorescences exhibited increased water uptake and significantly higher fresh weight than the controls. The results also showed that 1-MCP-MBs remarkably delayed bud opening and flower abscission, accompanied by suppression of ethylene production and a lower respiration rate than that of controls. Additionally, the treatment maintained the green color (hue angle value was comparable to initial storage day) of the inflorescences by delaying chlorophyll degradation related to inhibition of chlorophyllase and Mg-dechelatase activities. 1-MCP-MBs prolonged the vase life of Dendrobium cv. ‘Burana Jade’ up to 12 days, which was 2-fold longer than that of the control (approximately 5 days only). The results suggest that 1-MCP-MBs have the potential to be another alternative to conventional methods (fumigation) in prolonging vase life and maintaining the quality of Dendrobium orchids with the advantage of a shorter treatment time.

Componentes de aroma floral em Rhododendron fortunei e sua regulação pela expressão gênica de S-adenosil-L-metionina: ácido benzóico carboxil metil transferase (BAMT)

ABSTRACT: Rhododendron fortune belongs to a scented Rhododendron species native to China, which produces fragrant flowers of great ornamental and environmental values for landscaping or indoor beautification. However, the scents in Rhododendron fortuneihave not yet been investigated, let alone the mechanism of the formation of these fragrance in the flowers. In this study, we measured the scents in terms of its volatile components and contents (VOC) in Rhododendron fortuneiat four different flowering stages and in different tissues of the plant by headspace solid-phase micro-extraction combined (HS-SPME) with gas chromatography-mass spectrometry (GC-MS). Then the characteristic aromatic values, which reflects the degree of scent perception by human, of each VOC in the plant was calculated according to its respective aromatic thresholds. Results showed that three main VOCs measured from highest to lowest are methyl benzoates, terpenes and fatty acid derivatives. Their content increased after the flower bud opening and reached the highest at half to full blossom. In a flower most VOC contents were measured in petals and only trace amount in other tissues such as stamen, pistil. A small amount of VOCs was determined in leaves as well.All aromatic values were almost corresponded to the contents of three main VOCs, indicating that the flower fragrance arises truly from these VOC components. S-adenosyl-L-methionine: benzoic acid carboxyl methyl transferase (BAMT) catalyzes the final step to form methyl benzoates. To understand the mechanism of the formation of this main type fragrance and its regulation, we firstly isolate a gene of RfBAMT from petal of Rhododendron fortuneiby using homologous cloning and RACE technology. The full length of its cDNA was 1383 bp，with an open reading frame of 1104 bp, encoding a total of 368 amino acids. The phylogenetic tree analysis showed that RfBAMT was the closest to the BSMT of Camellia japonica, belonging to methyltransferases family. Then we measured the expression level of RfBAMT again at four flower developmental stages and in different flower tissues and leaves. The results showed that the expression level of this gene was highly positively correlated with the emitted content of methyl benzoates in the flowering, implying that RfBAMT plays a pivotal role in the formation and regulation of methyl benzoates in Rhododendron fortune.Thisresearchshowed that the RfBAMT was cloned and identified in our study and its expression level was highly positively correlated with the emitted content of methyl benzoates in the flowers and leaves, which indicated this gene may play an important role on regulation of methyl benzoate synthesis in Rhododendron fortunei.

Effect of aminoethoxyvinylglycine addition on the floral bud opening of Ranunculus asiaticus L cultivars

Objective: To evaluate the effect of aminoethoxyvinylglycine (AVG) additions on several growth variables of R. asiaticus in a greenhouse under a typically dry environment of the Mexicali valley.
 Design/methodology/approach: The variables determined were, bud opening rate, flower diameter, height of stem and bud growing rate and completely randomized block experimental design under a 2 by 4 factorial arrangement and three replicates was used for setting up the treatments with rates AVG of 0,100,150 and 200ppm over La Belle Deep Rose (DER) and La Belle Dark Orange (DAR) R. asiaticus cultivars.
 Results: The optimal dose of AVG for reducing flower bud diameter on both cultivars were those of 200 and 100 ppm respectively. Also, AVG addition had a significant effect in reducing stem height and growing rate for both cultivars.
 Limitations on study/implications: The use of AVG has shown good results as inhibitor of ethylene synthesis and extension of shelf life in carnations, snap dragons (Antirrhinum), ripening of fruits, and to reduce abortion of female flowers in certain species of walnuts, so, based on the above and considering the lack of information regarding the use of AVG inhibitor in the opening of Persian Buttercup flower buds was used AVG in R. asiaticus.
 Findings/conclusions: AVG addition on plants of R. asiaticus had a significant effect reducing growth, both in diameter and height in the La Belle Deep Rose (DER) and La Belle Dark Orange (DAR) varieties

Effect of preservative solutions on postharvest of Eustoma Grandiflorum floral stems during refrigerated storage

Preservative solutions contribute to flowers post-harvest quality and longevity, having different effects according to the species, cultivar, cold storage period and the solution composition. This work aimed to determine the preservative solution more effective on opening flower and longevity on flower cut stems of E. grandiflorum, submitted to two cold storage periods. The experiment was arranged in a 2x4x10 factorial, with two storage periods, five and ten days; four preservative solutions, water (100%); sodium hypochlorite (25 ml L-1) + sucrose (10%); aluminum sulfate (250 mg L-1) + sucrose (10%); and silver nitrate (50 mg L-1) + sucrose (10%); and ten evaluation dates. Cut stems from the cultivar ‘White Excalibur’ were placed taken to cold storage for 5 and 10 days at 5°C and 78% of relative humidity. After cold storage, the stems were distributed to glass pots containing different preservative solutions. Every two days, visual evaluations were performed, verifying the opening flower and longevity. An illustrative scale were used to assess the opening of flowers buds, with grades ranging from 1 to 5. For the longevity, the number of days that flowers remained viable in the preservative solutions until the disposal was considered. The cold storage periods do not affect opening flower and longevity of ‘White Excalibur’ floral stems. Silver nitrate + sucrose and aluminum sulfate + sucrose were the preservative solutions that provides better post-harvest quality and longevity, with higher opening flowers and extended viability.

Warm Bulb Storage Optimises Flowering Attributes and Foliage Characteristics in Amaryllis belladonna L.

Amaryllis belladonna is an autumn-flowering bulbous geophyte endemic to the Western Cape, South Africa. The species’ erratic flowering disposition and brief flowering period upon maturity limit its economic productivity and competitiveness within the traditional genera of cut flowers and potted plants. However, it can be an attractive, eco-friendly, seasonal addition to the specialty floriculture market. A 10-month study evaluated the effects of a warm storage period on A. belladonna bulbs’ flowering yield, flowering time, quality characteristics, and foliage growth. The experiment comprised dormant flower-sized bulbs randomly assigned to one of six storage regimes of either a 0- (no storage control), 4-, 6-, 8-, 10-, or 12-week interval periods at a continuous warm temperature of 23 ± 1 °C before planting into pots between mid-November 2021 and mid-February 2022 in the greenhouse. The results showed that flowering production (64.3% flowering after the 12-week storage), flowering time (anthesis occurring 9 days after the 10- and 12-week storage), and quality attributes (number of florets in the inflorescence, scape diameter, inflorescence fullness ratio, and pot longevity) of A. belladonna scapes were significantly impacted by warm bulb storage, but not foliage growth. Irrespective of bulb storage, inflorescence abortion occurred. An extended bulb storage did not advance the flowering time despite a greater harvest and shorter cultivation periods after planting. This study established that a cumulative temperature range during bulb dormancy is crucial for supporting the A. belladonna inflorescence maturity’s energetic demands and the opening of floret buds. Bulbs should be stored at elevated temperatures for at least 8–10 weeks to attain the best floret-quality attributes and longevity. However, for an economical and sustainable greenhouse and specialty cut flower production, 12-week warm bulb storage is recommended to achieve the optimal anthesis in the shortest interval for this seasonal single-harvest species after planting.

Influence of Different Pulsing Solutions on Postharvest Life of Tuberose (Polianthes tuberosa L.) cv. Prajwal

Tuberose flower (Polianthes tuberosa L.) is a perennial and bulbous flowering plant, related to the Amaryllidaceae family and now it is placed in family Agavaceae. The investigation entitled “Influence of different pulsing solutions on postharvest life of tuberose (Polianthes tuberosa L.) cv. Prajwal” was carried out at the experimental farm and laboratory of Department of Floriculture and Landscape Architecture, College of Horticulture, SVPUAT, Meerut during the year of 2021-22 & 2022-23. Experiment was laid out in Completely Randomized Design with 10 treatments and 3 replications. In the present experiment we aimed at prolonging the vase life and improving the quality of cut spike of tuberose by Pulsing or hydration procedure using different noble treatments in tuberose, as the main challenge was to reduce abscission of buds, initiation of bud opening mechanism and leaf yellowing due to the sensitivity, vascular infections, high rate of respiration and inhibition of ethylene production. These differences in physiological behavior of cut stem dipped in different pulsing solution are very important to consider when developing post harvest physiology of tuberose. In the present finding we have primarily focused and observed under the light of pertinent literature available substantiated with robust evidence thus we derived the overall best treatment for different parameters for improving the vase life of tuberose that were recorded under the treatment T9 (Sucrose 15% + 8-HQC 300 ppm) followed by the treatment T6 (Sucrose 10% + 8-HQC 300 ppm) and T8 (Sucrose 15% + 8-HQC 200 ppm) resulted in most of the postharvest parameters such as amount of pulsing solution consumed (13.16, 15.82 ml), days taken to opening of floret (2.53, 2.54 days), floret diameter (3.38, 3.40 cm), vase life (10.78, 10.80 days), weight change/loss in cut spike (13.29 %, 14.52 %), fungal infection, fragrance score (2.95, 2.96), freshness index (4.97, 4.98) and moisture content (89.89, 85.60, 83.21%).

Nanobubbles in vase water inhibit transpiration and prolong the vase life of cut chrysanthemum flowers.

Nanobubble (NB) water has been shown to promote the growth of several types of plants and animals, but the mechanism underlying this promoting effect remains unclear. The present study evaluated the mechanism by which NBs maintain the freshness of cut flowers by keeping cut chrysanthemum (Chrysanthemum morifolium Ramat.) flowers at the bud stage in vase water containing air NBs. The condition of petals and leaves was assessed to determine the vase life of these cut flowers. The NB treatment delayed bud opening and petal senescence of the inflorescences. Water absorption and transpiration by cut flower stems were lower in NB water than in distilled water (DW). Furthermore, when all the leaves were removed from the cut flower stems, no significant difference in vase life was observed between NB water and DW. These findings indicate that the inhibition of transpiration from leaves prolonged the vase life of NB-treated cut chrysanthemum flowers. In the early stage of the treatment, NB treatment significantly reduced transpiration without closing stomata, suggesting that the reduction in transpiration observed in the NB-treated plants might be due to the suppression of cuticular transpiration, defined as water loss through the epidermis. Surface tension, one of the important driving forces of water movement in plants, was not affected by the presence of NBs in water. To our knowledge, this is the first report to show that transpiration from leaves is inhibited by NB treatment.

THE TRANSITION PERIODS OF PHENOLOGICAL PHASES AND YIELD INDICATORS IN NEW DEVELOPED LEMON VARIETIES AND HYBRIDS

In this article, the transition periods of phenological phases and yield indicators in lemon varieties and hybrids are studied. During research, the beginning of bud opening of lemon varieties was observed from February 23 (Meyer). Flowering in the varieties began on March 11, in the first-fruits of Uzbekistan and the yielding variety of Uzbekistan. Average duration of flowering in varieties was 41 days. The second growth period of shoots (16/V-30/V) began, the duration of which was 26-36 days. The beginning of fruit ripening in varieties and hybrids of lemon was determined on October 14 in the first variety of Uzbekistan and hybrid No. 34-85. For the first time, full ripening of fruits was found in hybrid No. 34-85 (4/X1).

Varietal Evaluation of Carnation (Dianthus caryophyllus) in Naturally Ventilated Polyhouse under Prayagraj Agro-climatic Condition

Carnation, scientifically known as Dianthus caryophyllus, is a popular and attractive flowering plant that belongs to the Caryophyllaceae family. Native to the Mediterranean region, carnations are now cultivated all over the world for their beauty and fragrance. Therefore, present investigation was carried out at the Department of Horticulture, Naini Agricultural Institute, Sam Higginbottom University of Agriculture Technology and Sciences, Prayagraj, Uttar Pradesh during the Winter-2022-23 with a view to determine the performance of different varieties of carnation for its growth and flowering under ventilated polyhouse. Under this experiment, overall, 6 varieties were used comprising of variety Cerventes, Master, Magno, Baltico, Realism and Kiro. It was concluded that variety Baltico (white) reported significantly better performance compared to other varieties, in terms of Growth parameters like plant height was seen in cervantes (25.19 cm), number of leaves were maximum in master (20.94), number of internodes was highest in realism (18.49), number of branches were seen to be maximum in baltico (4.47), Kiro was found to be less suited variety for Prayagraj agro climatic condition due to metabolic activity. Flowering parameters like days to first flower bud break (65.33 days), days taken for first flower bud opening (66.00 days) was seen in Master, Flower Stalk length was seen highest in Realism (40.80 cm), number of flowers per plant was seen in cervantes (5.17), number of days taken for flower senescence on plant was seen highest in kiro (15.40 days), the vase life in carnation was seen to be the highest in master (0.40 days).

THE INFLUENCE OF MINIMAL NPK FERTILISATION ON THE QUANTITY AND QUALITY OF APPLE YIELDS

During an annual cycle, fruit trees go through developmental stages, characterised by a higher demand for some mineral elements, called critical periods, which coincide with the phenophases of bud opening and shoot initiation. Research on mineral nutrition in fruit growing has highlighted that the maximum consumption of nutrients is during the period of shoot growth, fruit development and differentiation of fruit buds. In apple, flowering is influenced more by the time of fertiliser application and the form of nitrogen than by the amount applied, as apple has high requirements for the element phosphorus in the phenophases of intense shoot growth and wood maturation. Fertilisation with NPK increased apple yield for both fertilisation treatments compared to the unfertilised control treatments. After applying 270 kg·ha⁻¹ NPK in the first year of the experiment, very significant production increases were obtained, 4.46t·ha⁻¹, with a content of 16% dry matter, 13.13°Brix soluble matter and a titratable acidity of 0.465 mg malic acid/100 g.

A study on the effect of silver nitrate and 8-hydroxyquinoline citrate pulsing solutions on Lilium cut flowers

Lilium is one of the most important cut flowers in commercial markets, giving customers ornamental value. Fresh flowers, a highly perishable item, need more care and proper treatment for their longer post-harvest life and due to this, the end users face the post-harvest losses of cut flowers. Such losses can be minimized by using preservative chemical, which plays an important role in increasing the vase life of flowers. To increase the post-harvest life of lilium cut flowers cv. ‘Pavia’, the present investigation was aimed to study the effect of different combinations and concentrations of silver nitrate at 50, 75 and 100 ppm and 8-hydroquinoline citrate at 100, 150 and 200 ppm pulsing solutions with 20 % sucrose. Three replications were completely randomised with 16 treatments and one control. Silver nitrate showed better results in flower bud opening, flower bud opening to complete flowering, flower size, bloom life, dry weight and dry matter percentage. Among the treatment concentrations, AgNO3 at 50 ppm with 20% sucrose showed the most effective result on enhancing the selected parameters and improved flower quality during post-harvest life. Among the treatment combinations, 8-HQC at 100 ppm + AgNO3 at 75 ppm with 20 % sucrose showed better results. These findings will be useful to researchers, farmers, and end users to retain the ornamental value of lilium cut flowers for longer than usual.