Bud Diameter Research Articles

Assessment of genetic diversity in Nelumbo nucifera genotypes

Aim: The present investigation assessed the level of genetic diversity in the lotus (Nelumbo nucifera Gaertn.) genotypes grown naturally in Bihar (India). Methodology: In situ observations on 21 quantitative traits were recorded with five replications from each sampling site and data was analysed in a Completely Randomized Block Design. Results: Among all the genotypes BRL-01, BRL-08, BRL-21, and BRL-22 showed significant variation in the number of petals per flower, weight of flower, and flower colour. High values of genetic parameters were calculated for number of petals per flower, rhizome weight, rhizome length and weight of the flower. Number of petals per flower, number of leaf venation and diameter of the flower bud showed a significant positive correlation with the weight of flower. Path analysis revealed a highest positive direct effect of leaf length on flower weight at genotypic level. Interpretation: High GCV for all traits indicates the existence of genetic variation. The traits coupled with high heritability and genetic advance indicate the positive response for selection, primarily driven by additive gene action. Therefore, selection for traits such as number of petals per flower, length of flower stalk and weight of flower may be useful for the development of improved variety for flower attributes. Key words: Correlation coefficient, Diversity, Genotypes, Lotus, Path analysis

8548 Breast Development in Infant Girls: Does Endogenous Estrogen Production During Minipuberty Play a Role?

Abstract Disclosure: M. Goldberg: None. S. Zhao: None. A. Kelly: None. V.A. Stallings: None. D.M. Umbach: None. W.J. Rogan: None. N. Shaw: None. D.P. Sandler: None. Background: Breast tissue, present at birth in most term infants, regresses during infancy but persists longer in girls than boys. In girls, this persistence is thought to be due in part to stimulation by estradiol (E2) produced during minipuberty, the postnatal activation of the hypothalamic-pituitary-gonadal axis. Empirical data are sparse, however. Because E2 concentrations in infant girls fluctuate, repeated E2 measures may be necessary to adequately characterize production across minipuberty and to detect effects on estrogen-sensitive breast tissue. Hypothesis: Higher average exposure to E2 during minipuberty is associated with larger breast bud diameter in late infancy in term females. Methods: We leveraged data from 136 girls from the Infant Feeding and Early Development (IFED) Study, a prospective cohort of reproductive development in term infants enrolled during 2010-2013 from the Philadelphia area. We measured E2 in serum samples collected at study visits every 2-4 weeks from age 2-32 weeks. We assessed breast bud diameter via ultrasound at the 32-week visit. For data analysis, we log2-transformed both E2 and breast bud diameter. For E2 concentrations below the limit of detection (2.99 pg/mL, 35% of samples), we applied multiple imputation. We first calculated the intraclass correlation coefficient (ICC) of repeated E2 to understand the relative magnitude of total variation from within subjects. We then calculated subject-specific mean of E2 across time and estimated associations with breast bud diameter at the 32-week visit using both age- and multivariable-adjusted linear regression models. We present results as percent change in breast bud diameter per doubling in average E2 concentration ([2β-1] x 100%). Results: Most infants were Black (71%) and formula-fed (76%). The median number of E2 measures per girl was 9 (range: 5-10). Most of the variation in E2 concentrations was due to within-individual variation (ICC=0.27). The geometric mean E2 concentration from 2-32 weeks of age was 5.1 pg/mL (95% confidence interval [CI]: 4.7-5.4). The median breast bud diameter at the 32-week visit was 13.7mm (range: 4.4-30.5). A doubling in average E2 concentration across minipuberty was associated with a 26% larger breast bud diameter (95% CI 10-43%). This association was similar after adjustment for feeding method, race, gestational age, neonatal weight, and breast bud diameter at the neonatal visit (percent change: 28%, 95% CI: 12-46%). Conclusions: Our results suggest that endogenous estrogen production in females during minipuberty stimulates the infant breast bud. More research is needed to investigate the potential biologic relevance of this hormonal stimulation of infant breast tissue to later breast development and risk of malignant and benign breast disorders. Presentation: 6/1/2024

Responses of Growth, Enzyme Activity, and Flower Bud Differentiation of Pepper Seedlings to Nitrogen Concentration at Different Growth Stages

The concentration of nitrogen fertilizer is matched with the nutrient requirements in different growth stages of plants, which coordinates their vegetative and reproductive growth. In this study, the influences of nitrogen concentration before and after initiation of flower bud differentiation (first and second stage, respectively) on pepper seedling quality were studied. The chlorophyll a content, sucrose synthase activity, and sucrose phosphate synthase activity of pepper seedlings grown under moderate nitrogen (15 mmol L−1) in the first stage combined with high nitrogen (25.61 mmol L−1) in the second stage were 15.7%, 39.3%, and 34.6% higher than those of the same nitrogen concentration (15 mmol L−1) in the first and second stages treatment, respectively. The regression model also showed that the values of flower bud diameter, shoot fresh weight, root fresh weight, and glutamine synthetase activity of pepper were high under the condition of moderate nitrogen in the first stage and higher nitrogen in the second stage. In addition, the results of comprehensive evaluation showed that moderate nitrogen (15 mmol L−1) in the first stage and high nitrogen (25.61 mmol L−1) in the second stage treatment ranked first, which improved carbon and nitrogen metabolism, increased biomass accumulation, and promoted the flower bud differentiation and flowering of pepper seedlings.

Determining the Effect of Growing Media on Growth and Flowering of Rose

The present study aimed to determine the effect of Growing Media on Growth and Flowering of Rose. The study investigation was carried out in the Experimental Farm, Dept. of Horticulture, Assam Agricultural University, Jorhat for the year 2022-2023 with a view to assess the effect of growing media on growth and flowering of rose (Variety Revival). The experiment was carried out in Completely Randomized Design consisting of 9 treatment combination viz., T1 {Sandy loam + Sand + FYM @ 1:1:1 (w/w)}, T2 {Loam soil + Sand + FYM @ 1:1:1 (w/w)}, T3 {Clay loam + Sand + FYM @ 1:1:1 (w/w)}, T4 {Sandy loam + Sand + Vermicompost @ 1:1:1 (w/w)}, T5 {Loam soil + Sand + Vermicompost @ 1:1:1 (w/w)}, T6 {Clay loam + Sand + Vermicompost @ 1:1:1 (w/w)}, T7 {Sandy loam + Sand + Vermicompost (10% substituted with Cocopeat) @ 1:1:1 (w/w)}, T8 {Loam soil + Sand + Vermicompost (10% substituted with Cocopeat) @ 1:1:1 (w/w)}, T9 {Clay loam + Sand + Vermicompost (10% substituted with Cocopeat) @ 1:1:1 (w/w)}, which were replicated three times. The test crop positively responded to the growing media and the highest performance was observed for the treatment T8. Stem girth, number of nodes, intermodal length, leaf area and leaf area index, days taken to bud visibility, bud sprouting, half bloom and full bloom, length of stalk and diameter of bud, number of flowers, number of petals per flower and flowering duration (self-life) and diameter of flower were significantly enhanced by the treatment T8.

Evaluation of Different Hybrid Tea Roses (Rosa x hybrida) under Prayagraj Agro-climatic Conditions

An experiment was carried out in the Department of Horticulture, Naini Agricultural Institute, Sam Higginbottom University of Agriculture, Technology and Sciences, Prayagraj, from November, 2022 to March, 2023. The experiment was conducted in Randomized Block Design (RBD) with fifteen hybrids, replicated thrice. It was reported that hybrid H4 (Fatura) performed better in parameters like plant height (71.2 cm), number of branches (5), stalk length (35.10 cm), stalk girth (5.4 mm), bud diameter (2.7 cm), number of cut flowers per plant (5), vase life of the cut flowers (11 days), number of cut flowers per hectare (1,02,040), gross return (Rs 5,10,200 per ha), net return (Rs -2,36,354 per ha) and benefit cost ratio (0.7:1). However, days taken to first bud initiation (36 days) and days taken to first bud initiation to tight bud stage (13 days) were better in hybrid H5 (Brazil). Hence for quality cut flower production, vase life, yield, and economics, hybrid Fatura performed better under Prayagraj agro-climatic conditions.

Flower Initiation Pattern, Developmental Stages, and Seed Morphology of Paraphalaenopsis Labukensis P.S. Shim, A. Lamb & C.L. Chan, An Endangered Orchid in Sabah

Background Paraphalaenopsis labukensis P.S. Shim, A. Lamb & C.L. Chan is a monopodial epiphytic species that can only be found in Sabah. P. labukensis orchids have unique characteristics in that it has a long floral lifespan as compared to other orchid species. The flower developmental pattern of P. labukensis greatly influenced capsule formation and seed maturation. Objective The present research was conducted to record the initiation of flower initiation, and floral morphology, and to observe the flowering and capsule development, as well as the effect of different capsule ages on asymbiotic seed germination. Methods A total of three individual plants of P. labukensis were observed. The flowering stages were characterized by quantitative parameters such as length of inflorescence, diameter, and length of buds, the number of flowers produced, and the length of the capsule formed. All the data were recorded through direct observation. Results Overall, twelve morphological landmark that define each stage of floral development was recorded. Based on the observation, P. labukensis inflorescence was asymmetric and in the shape of a panicle. The number of flowers varied among inflorescences, ranging from 3–5, that blossomed at different times. Furthermore, early capsules appeared 40–90 days after pollination (DAP). Then, 120 DAP of the capsule was selected as the most suitable capsule age for germination as it had reached its maturation period. Conclusion Identifying the duration of the whole flowering developmental process will aid in the production of capsules to attain a reliable and adequate seed source for in vitro seed germination.

The correlation between the developmental stages of pea microspores and the morphology of flower buds

To investigate the correlation between microspore development stage and the appearance and morphology of flower organs in Pisum sativum, the novel pea materials YP58 and YW90 were employed as experimental subjects. Flower buds exhibiting varying diametral ranges were chosen for cytological examination, and the saffron solid green staining method was employed to discern the diverse developmental stages and morphological attributes of microspores. Furthermore, the association between flower bud size and microspore development stage was examined. The findings revealed that the microspore development in both pea materials predominantly encompassed the microspore mother cell stage, tetrad stage, early and middle mononuclear stage and late mononuclear stage, each displaying distinct features. Notably, the development duration of microspores exhibited a close correlation with the longitudinal diameter of the flower bud. The correlation between microspore development progression and the longitudinal diameter of the flower bud was consistent in both pea materials. Therefore, the longitudinal diameter of the flower bud can serve as a primary indicator for assessing the microspore development stage.

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

Exogenous application of gibberellic acid on lateral bud emergence in pineapple propagated through stem cuttings

The effects of gibberellic acid (GA3) on lateral bud emergence in pineapple stem is still not known. Hence, this study was conducted. ‘MD2’ pineapple stems were sectioned into vertical halves. The first half served as the control (untreated). Whereas the other halves were soaked in 500 ppm GA3 for 2 hrs. The study was performed in two trials. Results in both trials show that untreated stem sections produced lateral buds after one week. In contrast, the GA3 treatment prevented the development of buds. In trial 1, only 2 out of 18 stem sections (11.11%) soaked in 500 ppm of GA3 produced buds after one week. In trial 2, GA3-treated stem sections failed to produce buds. The average number of buds emergence per stem section and diameter of lateral buds were consistently better in untreated pineapple stem sections. These findings implied that the exogenous application of GA3 could prevent the emergence of lateral buds in the pineapple stem.

Influence of Biochar on Growth, Yield and Quality of Broccoli

Broccoli is one of the most important, nutrient-rich vegetables among cole crops which belong to the family Brassicaceae. It is known to be a healthy and delectable vegetable which is rich in many nutrients. Biochar is considered as a potential substitute for soil organic matter (SOM). Biochar addition to low organic carbon soils can act as a feasible solution to keep soil biologically active for the cycling of different nutrients. The application of biochar could improve soil fertility, increase crop yield, enhance plant growth and microbialabundance, and immobilize different contaminants in the soil. Due to thelarge surface area of biochar, which generally depends upon the types of feedstock and pyrolysis conditions, it helps to reduce the leaching of fertilizers from the soil and supplies additional nutrientsto growing crops. In view of the above importance all possible issues related to biochar application should beconsidered. Previous literature review shows that applying biochar to the broccoli plant improved only the leaf area and root length with significant changes. The highest yield per plot (4.49 kg), bud weight (499.37g), bud diameter (16.55 cm), and yield per hectare (14.98 t ha-1) of broccoli was found to be significant in biochar treated plot (T2: PSB 100 L/ha + Biochar 30 t ha-1). Considering classification of the flowering heads by categories, M (manure pellet) + EB (enriched-biochar amended soil and organic fertilizer) + AND (manure pellet and enriched-biochar amended soil treated with organic fertilization) treatments showed a higher number of first category flowering heads with regard to other treatments. Therefore, the use of biochar is an effective approach for potential nutrient reservoir for plants and a good amendment to improve soil properties.

Evaluation of Tabernaemontana divaricata Accessions for Loose Flower Production

Crepe jasmine or East Indian rosebay or pinwheel flower, Tabernaemontana divaricata originated from India is a popular large shrub or a small tree grown in tropical and sub-tropical gardens for its beautiful glossy foliage and mild fragrant waxy white, ornamental flowers. It produces flowers throughout the year, except in winter but profusely during summer season. Rather than the opened flowers, the unopened flower buds are commonly used as an alternate to Jasminum sambac buds in off-season. The present investigation was carried out at the Department of Floriculture and Landscape Architecture, Horticulture college and Research Institute, Tamil Nadu agriculture university, Coimbatore during 2022-2023. Randomized Block Design was used with three replications with the objective of investigating promising genotypes of Tabernaemontana divaricata, collected based on the type of petals from different locations for loose flower production. In the study totally 12 accessions were collected and named from Acc. No. 1 to 12. They are evaluated for their vegetative and floral parameters such as plant height, leaf length, leaf width, no. of branches, plant spread in EW & NS direction. Floral parameters include bud length, bud diameter, stalk length and no. of petals/flower. Out of the collected accessions, Acc. No. 2 & 5 are suitable for veni arrangement and Acc. No.10 & 11 are suitable for garland making. Buds of acc. No.4 & 6 are similar to Jasminum sambac and J. auriculatum buds.

BAP and Kinetin Application for In Vitro Bud Induction of Vanilla (Vanilla planifolia Andrews.) from Stem Node Explants in the Initiation Stage

Due to the scarcity of seedlings, vanilla farming in Indonesia is not at its best. The goal of this study was to comprehend how BAP and Kinetin affected the introduction of vanilla buds as a sustainable seedling strategy. The study is carried out at Salatiga, Central Java, Indonesia, at the Plant Tissue Laboratory of the Plantation Seeds Center and the Plant Tissue Laboratory of Diponegoro University’s Physiology and Plant Breeding Laboratory. A completely randomized design (CRD) 5 x 3 with two replications was utilized in the study. The first factor is BAP concentration: B0 = 0 mg.L−1, B1 = 0.6 mg.L−1, B2 = 1.2 mg.L−1, B3 = 1.8 mg.L−1, and B4 = 2.4 mg.L−1. The second factor is Kinetin concentration: K0 = 0 mg.L−1, K1 = 1 mg.L−1, and K2 = 2 mg.L−1. The result shows addition of BAP is able to shorten the day of bud emergence at 8 days. The addition of BAP and Kinetin did not significantly affect the number of buds. Application of BAP 1.44 mg.L−1 was able to increase bud length. There is interaction between Kinetin 2 mg.L−1 and the addition of BAP 2.4 mg.L−1 resulting in the largest bud diameter with a linear regression form. There is interaction between Kinetin 0 mg.L−1 and BAP 1.2 mg.L−1 resulting in the highest number of roots.

Response of Carnation Varieties (Dianthus caryophyllus) to Mycorrhizal Fungi under Naturally Ventilated Polyhouse Conditions in Prayagraj, India

The present investigation entitled, Response of carnation varieties (Dianthus caryophyllus) to mycorrhizal fungi under naturally ventilated polyhouse conditions in Prayagraj was conducted at horticulture research field, Department of Horticulture, Naini Agricultural Institute, Sam Higginbottom University of Agriculture, Technology and Sciences, Prayagraj, U.P, during the winter season (2022). The experiment was laid out in Factorial Randomized block design (FRBD) with 3 varieties and 5 VAM treatments in 15 treatments and each replicated thrice. From the present investigation, Variety-3 (Kiro-yellow) treated with 10g VAM per plant performed better for plant height (55.44cm), primary branches (7.22), bud diameter (21.72mm), and yield per plant (5.74). In terms of flower diameter (6.16cm) and vase life (13.33 days) Variety-1 (Cervantes) treated with 10g VAM performed better. In terms of first bud initiation Variety-2 (Baltico-White) treated with 5g VAM per plant showed better performance (59.11 days).

Effect of Shoot Bending at Different Time on Production and Quality of Hybrid Tea Rose Cultivar Minu Pearle

A field experiment was undertaken from September to March for two consecutive years (2020 and 2021) to find out the best time for shoot bending in Hybrid Tea rose. Growth and development of rose cultivar Minu Pearle, was significantly influenced by shoot bending at different time (4th week of September to 4th week of December). Among the treatments tallest plants & maximum leaf area was produced in plants bended on T5 whereas, the plant canopy was registered to be maximum in 2nd week of December. The highest rate of shoot elongation at 15 & 30 days after shoot bending was noted in second week of November and October respectively. Application of shoot bending on 2nd week of October recorded early blooming and slowest flower bud emergence was registered in T5whereas, delayed sepal reflex and maximum days taken to attain cup shape was observed in T6. In terms of flower quality parameters like length and diameter of flower bud and pedicel and weight of individual flower, T5 proved to be superior. Shoot bending applied on 2nd week of November (T4) produced long and thick stalks. Among the treatments maximum number of flowers, longest self and vase life, highest dry matter production from leaves and stem, greater chlorophyll and anthocyanin content was observed in T5.

Effects of different plant growth regulators as the foliar application on growth and flower quality of potted rose (Rosa chinensis Jacq. cv. Nhung)

This study was conducted to evaluate the different concentrations of Naphthalene acetic acid (NAA), Benzyladenine (BA) and Gibberellic acid (GA3­) as foliar applications on growth and flower quality of potted rose Nhung (Rosa chinensis Jacq. cv. Nhung). The experiment was constructed in a completely randomized design, that included seven treatments, such as control (sprayed water), NAA, BA and GA3 at two different concentrations of 25 and 50 ppm, in six replications, with one plant/pot for each replication. The chemical solutions were applied three times at an interval of fifteen days. The results revealed that some plant growth regulators increased the growth and flowering time of rose cv. Nhung. Using pre-harvest foliar sprays of NAA and BA at 25 and 50 ppm concentrations showed maximum bud diameter, flower diameter and flowering duration as compared with the control treatment. The concentration of GA3 foliar application at 25 ppm increased plant growth (the height of flowering branches and Spad values) without affecting flower quality values and the flowering duration in comparison with the control treatment.

Influence of potting media composition on quality flower production of petunia (Petunia hybrida)

An experiment was conducted at Banda University of Agriculture & Technology, Banda to evaluate the effect of different growing media compositions containing cocopeat, Vermicompost, FYM, Leaf Mold, Perlite, and vermiculite in different ratios on vegetative growth and flowering of petunia plant. The results revealed that, the maximum root length and root spread were observed in media composition T5 [Cocopeat + Vermicompost + Vermiculite (2:1:1)] whereas, vegetative growth with no of leaves per plants, no of branches per plant and plant spread in T4 [Cocopeat + Perlite + Vermicompost (2:1:1)]. The better flower quality parameters like flower diameter, flower bud diameter, stalk length of flower were observed in T5 media containing Cocopeat + Vermicompost + Vermiculite (2:1:1) while minimum days taken to bud initiation (60.75) and first flower opening (66.66) in T2 [Soil + Sand + Vermicompost (2:1:1)]. However, plants showed the significant root growth, vegetative growth with better flowering time and quality was highest in media containing Cocopeat + Vermicompost + Vermiculite (2:1:1). Therefore, the findings suggest that for quality flower production of potted petunia growing media composition of T5 [Cocopeat + Vermicompost + Vermiculite (2:1:1)] was ideal with better plant morphological development and sustained flowering for display.

MAINTAINING THE QUALITY OF CARNATION CUT FLOWERS DEPENDING ON TEMPERATURE

In the assortment of cut flowers, carnations (Dianthus caryophyllus L.) fall in the first places, with a large number of varieties, of various colors, being appreciated on the cut flowers market. Carnations flowers that cannot be sold immediately after harvest, being a time of year when the market offers an abundance of cut flower species, they are prone to rapid depreciation under normal environmental conditions. Carnation is an important ornamental plant, which is used as a potted plant as well as a cut flower. One factor that influences the shelf life is temperature. From the flowering stage to the total depreciation of the inflorescence, it plays an important role. In this experiment, the flowers were harvested on two different dates for about a month. The temperatures at which the varieties were kept had 6 graduations (from 10 to 22 °C). The parameters followed were: bud height, corolla height above the calyx, bud diameter and flower stem length. Storing flowers in water at 4 °C for 6 to 15 days, did not increase the diameter of the flower bud. In flowers kept at 22 °C for 6 days, the values of several parameters of cell senescence fell below the values of fresh flowers. However, in flowers kept at 4 °C there was no expected slow decrease in these parameters, but rather an increase above the levels found in fresh flowers. We conclude that storage at low temperatures has effects on carnation cut flowers, other than slowing down the aging process.

Performance of Different Varieties of Jasmine (Jasminum sambac) under Prayagraj Agro-climatic Conditions

The present investigation entitled Performance of different varieties of jasmine (Jasminum sambac) under Prayagraj agro-climatic conditions. was undertaken in the Department of Horticulture, Sam Higginbottom University of Agriculture, Technology And Sciences, Prayagraj, during August, 2021 to October, 2022. The experiment was laid out in Randomized Block Design (RBD) with 07 varieties, replicated thrice. The variety V4 (U.P. Local) performed significantly better for all the growth parameters like plant height (95.57 cm), number of leaves (118.50), plant spread (60.45 cm), and number of branches (24.50). Variety V5 (Gundumalli) was found superior in terms of bud diameter (24.83 mm), shelf life (5.58 days), average flower bud weight (0.75 g), flower yield per plant (1.46 kg), flower yield per hectare (58.4 q), and benefit cost ratio (4.15) ). So this variety can be used for better quality, flower yield and benefit cost ratio. Hence the variety V5 (Gundumalli) can be recommended for commercial cultivation under Prayagraj agro-climatic conditions.

Estimating heat tolerance of buds in southeastern US trees in fire-prone forests

BackgroundTraits of mature trees, such as bark thickness and texture, have been documented to promote resistance or resilience to heating in fire-prone forests. These traits often assist managers as they plan and promote prescribed fire management to accomplish specific land management objectives. Species are often grouped together as pyrophobes or pyrophytes as a result of these features. Nonetheless, little is known about species-specific traits of other structures, such as bud diameter, length, mass, moisture content, and surface area, that might be related to heat tolerance. Many prescribed fires are utilized in the eastern United States to control regeneration of less desired species, which could apply a more mechanistic understanding of energy doses that result in topkilling mid-story stems. In this study, we investigated potential relationships between terminal bud mortality from lateral branches of midstory stems and species-specific bud features of six eastern US deciduous trees. Characterized at maturity as either pyrophytes or pyrophobes, each was exposed to different heat dosages in a laboratory setting.ResultsBud diameter, length, mass, moisture content, and surface area differed by species. Bud percent mortality at the first heat flux density (0.255–0.891MJm−2) was highest for two pyrophobes, chestnut oak (Quercus montana Willd.) and scarlet oak (Quercus coccinea Münchh). For the second heat flux density (1.275–1.485MJm−2), bud percent mortality was highest for these species and red maple (Acer rubrum L.). Principal component analysis suggested that bud surface area and length differentiated species. Red maple, chestnut oak, and scarlet oak produced clusters of buds, which may explain their more pronounced bud mortality. Yellow-poplar (Liriodendron tulipifera L.) was also present in that cluster, suggesting that its unique bud architecture of pre-emergent leaves may have elicited responses most similar to those of the clustered buds.ConclusionsContrary to expectations, lateral buds of species regarded as pyrophytes at maturity displayed some of the highest values of bud percent mortality when heated at two heat flux densities generated in a laboratory. Their responses may be related to clustering of their lateral buds. Testing of additional species using these methods in a laboratory setting, and perhaps additional methodologies in the field, is warranted.

Study on Positions of Twin Scales and Growth Regulators on Propagation of Narcissus (Daffodil) cv. Stamen Cream

Study was carried out to evaluate the influence of position of twin scales and growth regulators on propagation of Narcissus (Daffodil) cv. Stamen creamx. Results of the study reveals that out of eight treatment combinations tested in the experiment minimum days for callus initiation (26.00 days),root initiation (36.50 days) and bud initiation (44.50 days) after incubation resulted with combination of outer scales treated with IBA 100 ppm. Further maximum number of buds per chip (2.00), bud diameter (11.95 mm), bud length (2.76 cm) and bud weight (0.41g) were recorded with the same treatment. Inner scales treated with IBA 100PPM resulted with maximum days for callus initiation (37.50 days), root initiation (48.00 days) and bud initiation (60.50 days) after incubation. Least number of buds per chip (1.00), minimum bud diameter (7.45 mm), bud length (1.30 cm) and bud weight (0.19 g) were also recorded with same treatment. Most of the differences among the treatments for almost all recorded parameters were statistically significant.