Percentage Of Flowers Research Articles

Prevention of Flower Abortion and Leaf Damages in Anemone coronaria by Ca Supplements

Ca deficiencies induce a range of physiological disorders in plants. The disorders typically appear in young growing tissues that are characterized by high demand for Ca and restricted Ca supply due to low transpiration. In this study, we examined the effect of supplementing Ca by foliar spray and through the irrigation solution to Anemone coronaria plants, in order to evaluate if flower abortions and leaf damages that appear in the production fields are related to Ca deficiencies. With the goal to develop a preventive nutritional regime, four Ca treatments were evaluated. The supplemented Ca was applied with the fertigation solution in the concentrations of 60 or 110 ppm Ca; with the 60 ppm application an additional application of Ca by foliar application was tested in concentrations of 3 g/l Ca or 6 g/l Ca, as Ca(NO3)2. The plants were cultivated in a net-house, in soilless culture (Tuff) beds. Application of 110 ppm Ca compared to 60 ppm with the fertilizing solution increased the concentration of Ca in the leaf tissue, resulting in an increase in the quantity and quality of the flowers. Calcium supply by foliar spray, at both 3 g/l or 6 g/l Ca(NO3)2 caused leaf necrosis and did not improve yield production. Application of 110 ppm Ca reduced the concentrations of Mn, Cl and Na in the leaves. Application of Ca in the irrigation solution, or by foliar spray, did not reduce the percentage of non-marketable flowers. The identified lower concentrations of Ca in damaged compared to non-damaged leaves on the flower stem suggests that the damages to the flowers and the leaves is related to local deficiencies of Ca.

Effects of Plant Growth Regulators on Sex Expression and Flower Development in Pomegranates

The effects of external treatments with gibberellin, brassinosteroid and auxin on sexual determination and flower development in pomegranate (Punica granatum L. cv. Cekirdeksiz) were investigated. Eigth treatments with three growth regulators, viz., epibrassinolide at 0.01 and 0.1 ppm, homobrassinolide at 0.01 and 0.1 ppm, GA3 at 10 and 25 ppm, NAA at 5 and 15 ppm and control (water spray) were sprayed at the time of initiation of new sprouts. Effects of the plant growth regulators on the percent of the flowers types were not clear. Plants produced considerably more male flowers. Although no statistical importance was detected, it was clear that all growth regulators decreased bisexual flowers and increased male flowers. There were no significant effects of growth regulators on the formation of bisexual flowers at different positions in the plants. The percentage of single bisexual flower was significantly higher than terminal or lateral bisexual flower in a cluster in the control plants. Effects of the plant growth regulators on the size of the parts of the bisexual pistils were, however, found important. The smallest ovaries were obtained from 0.1 ppm HBr, base to sepal notch was the only characteristic which was not influenced by the treatments and stayed between 15 and 18 mm. Total pistil length of the bisexual flowers was greatest with EBr applications and the shortest with the HBr treatments (about 27.5 mm). Length of the style and stigma was mostly shorter, but 0.1 ppm EBr boosted it up comparably more than the rest of the applications including the control. Stigma, on the other hand, was widest in the control flowers, closely followed by all except 0.1 ppm EBr application.

Simple remote sensing detection of Corymbia calophylla flowers using common 3 –band imaging sensors

With Apis mellifera (the European Honey Bee) having an average forage radius of less than one kilometre from their hive, selecting the best location for beehives is critical for commercial beekeepers to optimise their honey production. In this study, we have used standard three-band digital cameras to develop and assess a simple parallelpiped algorithm to detect the flowers of the Corymbia calophylla tree in Western Australia, the largest source of honey in the state.The algorithm has been tested in a number of situations and, within the bounds of the study, works to a better than 90% classification accuracy for Digital Single Lens Reflex camera images of trees within 15 m distance, and often better than 95%.To determine how this approach could be used by Unmanned Aerial Vehicle platforms to detect flowering Corymbia calophylla flowering, image resolution was progressively degraded until flowers could not be detected. It was found that the cluster size of flowers (i.e. whether flowers occur individually or in groups) played an important role in determining the accuracy of flower detection, but overall a minimum resolution of 10 pixels per flower is required for reliable detection of flower pixels. While there is some improvement above this resolution, the effect is minimal. The key to accurate measurement of percentage flower cover is the accuracy of the classification of the background. If the background classification error is known for an image or scene, the percentage flower cover can be calculated with as little as 2% flower cover.Based on this study, UAV platforms with standard RGB cameras appear to be suitable for detection of Corymbia calophylla flowers if surveys are designed within the bounds described. Thus, UAV surveys may prove to be useful for beekeepers to optimise the location of their beehives amongst a choice of different locations.

Effects of GA 3 on promotion of flowering in Kalanchoe spp.

Abstract Some species of Kalanchoe, including those of sections Kalanchoe and Bryophyllum do not flower naturally. This barrier to flowering might hinder hybridization and breeding. The role of gibberellin acid (GA3) in promoting flowering was investigated, and the effects of GA3 treatment on flowering under different temperatures were determined. The findings indicated that flowering was promoted in 100% of the K. sexangularis, K. nyikae, K. marnieriana, K. longiflora, and K. × richaudii plants treated with different GA3 gradients. The percentage of flowering in K. marnieriana and K. nyikae increased with increasing concentrations of applied GA3. The number of days taken to flower in K. nyikae and K. sexangularis decreased with increasing concentrations of applied GA3. In K. × richaudii treated with 100 mg L−1 GA3 flowers appeared the earliest. The number of flowers of K. sexangularis and K. × richaudii increased, while that of K. nyikae decreased, with increasing GA3 concentrations. GA3-treated K. nyikae, K. poincarei, and K. sexangularis plants showed higher percentages of flowering at 25/20 °C (day/night) than at higher temperatures. The findings from this study confirmed that GA3, applied in a broad range of concentrations, promotes floral induction in the studied species, affecting mainly the number of days taken to flower and the number of flowers produced. However, the GA3-treated plants had reduced flowering at higher temperatures. These findings can be applied in the regulation of flowering and breeding of Kalanchoe in future.

A New Gall Midge Species of Asphondylia (Diptera: Cecidomyiidae) Inducing Flower Galls on Clinopodium nepeta (Lamiaceae) From Europe, Its Phenology, and Associated Fungi.

A new gall midge, Asphondylia nepetae sp. n. Viggiani (Diptera: Cecidomyiidae), causing flower gall on Clinopodium nepeta (L.) Kuntze (Lamiaceae), is described from Europe. The morphological characteristics of adult, larvae, and pupa are described and illustrated. Molecular approach (by sequencing 28S-D2, ITS2, and COI) confirmed that A. nepetae is a distinct species. The development of the gall is always associated with the presence of the fungus Botryosphaeria dothidea (Moug.: Fr.) Ces. and De Not. (Botryosphaeriales: Botryosphaeriaceae). The new species can complete several generations per year, on the flowers of the same host plant and its adults emerge from late spring to autumn. Pupae overwinter inside peculiar flower galls in a state of quiescence. The impact of the pest is highly variable with a percentage of flowers infested that ranged between 3 and 57.5% in the sampled years. Insect mortality was, at least in part, due to parasitoids that attack the young stages of the midge. Among them, the dominant species was Sigmophora brevicornis (Panzer) (Chalcidoidea: Eulophidae).

INFLUENCE OF SOME PRESERVATIVE SOLUTIONS ON VASE LIFE AND POSTHARVEST QUALITIES OF LIMONIUM CUT FLOWERS

The present study was conducted at the Postharvest Lab. of Ornamental Plants and Landscape Gardening Res. Dept., Hort. Res. Inst., Giza, Egypt in March of 2016 and 2017 seasons, to examine the effect of some pulsing solutions on improving the quality of limonium cut flowers.Limoniumcut flowerswere pulsedin silver thiosulfate (STS) at 500 mg/l for 1/4 and 1/2 h, silver nitrate (AgNO3) at 500 mg/l for 1/4 and 1/2 h, AgNO3 at one g/l for 1/4 and 1/2 h, sodium benzoate at 250 mg/l for 12 and 24 h, sodium benzoate at 500 mg/l for 12 and 24 h, daminozide at 25 mg/l for 12 and 24 h and daminozide at 50 mg/l for 12 and 24 h followed by transferring to a holding solution 8-hydroxyqunoline sulphate (HQS) at 200 mg/l + sucrose (20 g/l). Distilled water was used as a control treatment. The obtained results indicated that treatment of Limonium sinuatum cv. Girlie Wings cut flowers treated by STS at 500 mg/l for 1/2 h enhanced water uptake, relative fresh weight, dry weight percentage of cut flowers, floret opening percentage, pigments content, total carbohydrate percentage and total phenols as well as inhibiting growth of all isolated microorganisms and improved quality of flowers, followed by cut flowers treated with STS at 500 mg/l for 1/4 h then AgNO3 500 mg/l for 1/2 h.

Assessment of genetic divergence for quantitative traits in thermo tolerant tomato (Solanum lycopersicum L.) genotypes

In the present study, 21 thermo tolerant tomato (Solanum lycopersicum L.) genotypes were evaluated to delineate the extent of genetic diversity through 10 quantitative traits. The genotypes were categorized into 4 distinct clusters using D2 statistics. Cluster IV had the maximum number (10) of genotypes, where all heat tolerant genotypes grouped together, followed by cluster I (5). Intra cluster analysis revealed that the cluster IV had highest distance, while the inter cluster distance was maximum between cluster III and cluster IV (6.53) indicating the presence of wide range of variability among genotypes of the cluster. Cluster IV recorded maximum cluster mean for yield (579.0), average fruit weight (33.33) and fruit set per cent (54.8) and the cluster III recorded highest mean value for days to 50 percent flowering (67.33). Principal component analysis showed that the first two principal components (PC’s) accounting for 77.6 per cent of total variation. On the basis of inter cluster distance, cluster mean and principal component analysis observed in the present study, a crossing programme involving genotypes from cluster IV will be promising one for developing heat tolerant tomato hybrids.

Effect of Seeding Rate On Growth And Yield Of Okra (Abelmoschus Esculantus) In Zuru Northern Guinea Savanna Of Nigeria

Field experiment was carried out during 2010 rainy season to find the effect of seeding rate on the growth and yield of okra (Abelmuschus esculentus) in Zuru Northern Guinea Savannah. Zuru is located in Zuru Local government area of Kebbi State (Latitude 11o 251 to 11o 551 North and Longitude 4o 51 to 5o 251 East of the equator). The experiment consisted of three treatments that is planting okra at one plant per stand (S1), two plants per stand (S2) and three plants per stand (S3). The experiment was laid out in randomized complete block design (RCBD) and the treatments replicated three time. The result of the experiment has shown that plant height and number of leaves/plant at 3, 6 and 9 weeks after planting ( WAP) were significantly influenced by seeding rate (P<0.05). At 3, 6 and 9 WAP tallest plants were obtained from okra plants planted at three plants/stand (27.83, 54.0 and 77.0cm) respectively followed by okra planted at two plant/stand (24.77, 50.67 and 74.33 leave/plant respectively ). However, more number of leaves/plant were obtained from okra plant at one plant/stand (9.67, 24.67 and 48.0 leaves/plant respectively) followed by okra planted at two plants/stand (8.33, 18.33 and 36.33 leaves/plant respectively). Seeding rate had significant influence on time of 50 percent flowering with one plant/stand first attaining 50 percent flowering stage just within 36.33 days followed by okra planted at two plants/stand (38 days). The mean fresh fruit yield of okra was also significantly influenced by seeding rate with the highest yield of fresh fruits obtained from three plants/stand (83.34/ha) followed by okra planted at two plants/stand (55.56/ha). However, the result of the findings recommends that, okra should be planted at two plants/stand for medium sized and marketable okra fresh fruits since at three plants/stand leads to the production of undersized fresh fruits which do not often attract customers. At one plant/stand, there seemed to be early fruiting and bigger sized fresh fruits but low total yield due to underutilization of land resource/space. Planting at one plant/stand should therefore be avoided

Flowering and fruiting phenology of Kemenyan toba (Styrax sumatrana J.J.Sm.) in AekNauli forest, North Sumatra

The observation on flowering, fruiting phenology and germination of Kemenyan toba (Styrax sumatrana) has not been widely reported. It isrequired to support the breeding activities for this tree improvement, the most Non-Timber Forest Product commodity in Lake Toba Catchment Area, North Sumatra. The objectives of the research were to identify the development of flowering, fruiting andto calculate the number of fruits that germinate for S. sumatrana in certain cycle period. The flowering and fruiting observation were conducted on ten sample trees in Aek Nauli forest from July 2012 to February 2013. The seeds viability was observed from January to November 2014 in the greenhouse. The study showed that the flowering development occurred for 30 to 152 days, began from the growing of generative buds, the flower’s shoots and bursts were developed, and young fruits were matured. All of processes proceeded for 30 to 152 days. The average percentage of flowering is 53.5%, and 72.8% for flowering to fruiting, and 47.3% for young to mature fruit. The percentage of mature fruit to germinate was 89.3%.

Correlation and path analysis studies in hybrids of Line x Tester for yield and yield component traits in sesame (Sesamum indicum L.)

The experimental material comprised of 12 sesame genotypes of six lines (black/brown seed) and six testers (white seed). Crosses were made in Line x Tester fashion and thirty six hybrids were developed. The 36 F­1­­­s along with parents were utilized for this study to assess the relationship and effects between yield and its components traits. Biometrical data were recorded on twelve characters viz., days to fifty percent flowering, plant height, number of branches per plant, number of capsules on main stem, number of capsule per plant, capsule length, number of seeds per capsule, height of first node from base, height of first capsule, thousand seed weight, single plant yield and oil content. Correlation analysis revealed that there was a positive significant association of seed yield with number of capsule per plant. Path analysis revealed that the trait number of capsule per plant exhibit high positive direct effect on single plant. From this study it was observed that number of capsule per plant made the most contribution to seed yield and should therefore be used as a selection index for sesame improvement.

Improvements in Alfalfa (Medicago sativa L.) Seed Production with Warming Climatic Conditions on the Northern Altiplano of La Paz, Bolivia

Alfalfa (Medicago sativa L.) has been cultivated since 1948 on the Northern Altiplano of La Paz, Bolivia. It is grown largely for forage rather than seed since the cold negatively affects fruit production. During the 2001/2002 season, an experimental plot with a complete random block design (5 × 2 m) and four replicates, was established at the Estacion Experimental Belen (the Belen Research Station) on the Northern Altiplano at an altitude of 3824 m, in which 11 varieties of alfalfa were planted with the aim of examining their seed-producing potential. These crops were left uncut between sprouting (August) and harvest. Maximum and minimum and mean daily temperatures were recorded over the growing season, and compared to those recorded for 1949/50 (just after alfalfa was first introduced). All the varieties showed good percentage flowering rates (mean 80%). In May 2002, 1 m2 samples were harvested from each experimental unit and air dried in the normal environment. The seeds were separated out by threshing, weighed, and the percentage able to germinate determined in the laboratory. The variety Valador produced the greatest seed yield (76 kgha-1) followed by Ranger (51 kg.ha-1). Historical records show no alfalfa seed to have been produced in the late 1940s/early 1950s. The variety UMSS produced the seeds that most often germinated (57%); those of the other varieties were commonly hard or immature. The temperatures recorded for the 2001/2002 season were notably warmer than those for 1949/50; temperature is known to influence alfalfa seedproducing capacity. The present results show that alfalfa seed can now be produced on the Northern Altiplano. This might be due to the higher temperatures currently recorded in the region, which might increase the presence of pollinating insects as well as improve plant and seed metabolism.

Effects of the percentage of terminal flowering on postharvest fruit quality in mango (Mangifera indica) ‘Calypso’™

The objective of this study was to investigate the relationship between the percentage of flowering terminals, crop load and postharvest fruit quality in the mango cultivar 'Calypso'™ (B74) grown at Dimbulah in North Queensland. The percentage of flowering terminals was manipulated experimentally by removing flowers at anthesis to give eight treatments in which trees had 5, 10, 20, 30, 40, 60, 70 or 80% of their terminals with flowers. Fruit were sampled at harvest, ripened at 23°C and, at eating ripe, were assessed for fruit number and yields per tree and fruit quality parameters including: fruit size (length, width and depth), fruit weight, background skin colour, blush colour, flesh colour, total soluble solids (TSS), dry matter and internal physiological disorders (jelly-seed, soft nose). The 5% crop load treatment (removing 95% of inflorescences from terminals) significantly reduced the average fruit yield per tree. Average fruit weights were highest in trees with 5 and 10% of terminals flowering, followed by trees with 20% of terminals flowering. There was no difference in average fruit weight between trees with 30, 40, 60, 70 or 80% of terminals flowering. Average fruit length increased significantly in trees with 5, 10 and 20% of terminals flowering compared with those with larger numbers of flowering terminals, with the longest in the 5% treatment. Fruit length was similar in treatments with 30% or more terminals flowering. Similar trends were observed for fruit width, with the widest (89.35 mm) and deepest (80.53 mm) fruit found in the 5% treatment. Although the comparative results between treatments confirmed that the highest values of fruit TSS, dry matter and percentage of blush colour occurred in fruit from trees with only 5% of terminals flowering, observations did not differ significantly among treatments.

Chemical thinning of flowers and fruits of the peach cultivar Coral with hydrogen cyanamide

ABSTRACT: Chemical treatment is a mean to accomplish fruit thinning; although its efficiency depends on the compound used, application time, and dosage. Effect of the chemical hydrogen cyanamide (CH2N2) on the thinning of flowers and fruits of the peach cultivar Coral was assessed in this study. Treatments consisted of five doses of CH2N2 (0, 0.2, 0.4, 0.6, and 0.8%) spray application to the point of run-off, at two stages (50% and 100% flowering). The experiment was conducted in a completely randomized design with six replicates and one plant per plot. The following parameters were assessed: percentage of flowers thinned at 25 days after spraying, percentage of fruits thinned, fruiting index, production per plant, fruit mass, diameter and length, flesh firmness, soluble solids (SS) and titratable acidity (TA). Concentrations of 0.6 and 0.8% CH2N2application at 50% flowering resulted in thinning 84.4 and 84.7% of the flowers and 0.4% CH2N2 at 100% flowering thinned 87.3%, values close to index assessed in manual thinning (88.0%) experiments. The highest production per plant was recorded for treatments with CH2N2 application at 50% flowering, resulting from a high percentage of flowers opening after spraying the chemical thinner. As such, flowers opening late were not affected by the chemical, thereby ensuring a higher fruiting index. Peach yield with 50% CH2N2 was not significantly different from yield observed for manual treatment, and 0.6% spray was reported to be the optimal dosage. Treatment with 0.6% CH2N2 application at 50% flowering was not significantly qualitatively different from manual thinning. CH2N2 application is efficient for the thinning of ‘Coral’ peach flowers and fruits.

Enhanced flowering of sacred lotus (Nelumbo nuciferaGaertn.) by extending the photoperiod with supplemental lighting techniques

Sacred lotus (Nelumbo nucifera Gaertn.) is one of the most popular cut flowers in Thailand and other Asian countries, commonly used for religious purposes. However, basic knowledge regarding the control of flowering is relatively lacking. The effects of photoperiod on growth of N. nucifera were investigated using a completely randomized design experiment with six day-length conditions: 1) 11 h for 2 months, 2) 11 h for 1 month and then to 13 h for 1 month, 3) 11 h for 1 month and then 15 h for 1 month, 4) 13 h for 1 month and then 11 h for 1 month, 5) 13 h for 2 months and 6) 13 h for 1 month and then 15 h for 1 month. Each pot was planted with 90 stem cuttings, filled to 2/3 of the pot level with natural clay soil and then filled to 3/4 of the pot level with tap water after planting. The stolons were grown under natural conditions (ambient temperature 30/18°C with an 11 h day length in mild winter from January-February 2013). Night interruption after 6:00 pm was used to induce a long day-length condition (13 and 15 h). None of photoperiod conditions affected the total number of leaves. However, extending the photoperiod from 11 to 15 h and from 13 to 15 h and a constant photoperiod of 13 h produced the largest leaves. Shortened photoperiods from 13 to 11 h decreased the flowering percentage and number of flowers. Extended photoperiods from 11 to 13 h, 11 to 15 h and 13 to 15 h only increased the flowering percentage compared with that of constant photoperiods of 11 and 13 h. Nevertheless, the extended photoperiod delayed the date of visible flowering.

RESPONSE OF DIFFERENT VARIETIES OF FABA BEAN TO PLANT SOURCE ORGANIC FERTILIZERS

A Field experiment was conducted during winter season at 2015 – 2016 at the experimental farm, department of Field Crop, College of Agriculture, University of Baghdad / Jadriyah to investigate effect of Organic Fertilizers preparation from weed plants on various broad bean varieties behavior and relationships with seed yield and its components. A randomized complete block design (RCBD) arranged according to split-plots used with three replicates including four organic fertilizers prepared from weeds Licorice (Glycyrrhiza glabra), Mallow (Malva rotundifolia), Purslane (Portulaca oleracea), European Heliotropic (Heliotropium europaeum), chemical fertilizer and control (without fertilizer) treatments, main plots included three varieties of Bean (Netherlands, Spanish and Locality ). The results showed that application of fertilizers significantly effect on studied characters, the treatment of Glycyrrhiza glabra gave higher rate of yield 3417 Kg ha-1, and There were no significant differences between Glycyrrhiza glabra and chemical fertilizer (NPK) at seed yield. Application of NPK showed highest No. of branches per plant, leaf area, thus reduction the flower portion percentage (4.02%) and increase pod numbers per plant and seed number per pod compared to control treatment. The results showed significant differences between varieties. The Spanish variety gave highest means of No. of branches per plant and leaf area per plant, thus reducing the flower portion and increase the number of pods per plant, number of seeds per pod and seed yield 3231 Kg ha-1. The Netherland variety gave higher weight of 100 seeds 47.94 g than the other varieties. Also, the most of characters were significantly influenced by interaction between varieties and fertilizers.

Off-Season Flower Induction in Mango Fruits Using Ethephon and Potassium Nitrate

Seasonality in mango production is a major factor contributing to high postharvest losses reported in the value chain. Oversupply during the high season is one of the factors that contribute to the high postharvest losses (≥ 50%) in the supply chain in Kenya. Effective strategies to address seasonality can contribute significantly to postharvest loss reduction. Efficacy of two flower induction chemicals, potassium nitrate (KNO3) and ethephon on reproductive growth parameters and yield components were evaluated on two mango varieties: ‘Apple’ and ‘Ngowe’. KNO3 was applied at two concentrations (2 and 4%), and ethephon (600 and 1000 ppm) then compared to control (water). They were applied to trees which failed to flower/set fruit in 2014 season. There effect was established from reproductive growth parameters: days to flowering, number of panicles per tree, fruit set per 20 panicles, fruit fall and hormonal effect. KNO3 (4%) and ethephon increased percentage flowering in both ‘Ngowe’ and ‘Apple’ and AEZs (Agro-Ecological Zones), significantly (p < 0.05) shortened time to flowering and increased fruit set. The findings show that KNO3 and ethephon can be used to induce flowering/fruiting in mango fruits. These technologies can therefore be applied to induce off-season mango production to address seasonality and reduce postharvest losses during the peak season.

Variability, character association and path coefficient analysis of green pod yield and its related traits in pea (Pisum sativum L.)

Genetic variability, character association and path coefficient studies were carried out for yield and yield contributing characters for twenty-four diverse genotype of pea. The results revealed a wide range of phenotypic variation, along with high heritability in pea. Highest pod yield per plant was recorded in VRP-229 followed by VRP-372 and VRP-305. The characters namely, plant height and weight of seeds per pod showed high magnitude, while number of pods per plant, number of branches per plant and pod yield per plant showed moderate magnitude for phenotypic and genotypic coefficient of variation. The heritability and genetic advance were high for days to first pod initiation, plant height and pod yield per plant indicating its additive gene action for their expression. Character association studies revealed that pod yield per plant exhibit positive and highly significant correlation with number of pods per plant, number of branches per plant and days to fifty percent flowering. The path coefficient studies also revealed that maximum positive direct effect was observed through number of pods per plant followed by days to first flowering, single pod weight and pod length towards yield indicated that these characters may be considered as the most reliable selection indices while making selection for high yielding genotypes.

Effect of growing media and fertilization on sugarcane flowering under artificial photoperiod.

The USDA-ARS Sugarcane Variety Development Program in Houma, LA aims to maximize the number of panicles available for crossing through artificial manipulation of the environment. In a three-year study, the effect of growing media, fertilizer treatment, and their interaction on sugarcane flowering (% of panicles emerged), and number of days to flowering (DTF) under an artificial photoperiod treatment were assessed. The commercially-available sugarcane cultivar, ‘HoCP 96–540’ was planted in 2.8-L pots and subjected to the standard local photoperiod treatment. The cultivar was planted in four growing media (RediEarth Seedling and Germination Mix, Fafard, Metro-Mix®902, and Metro-Mix®900) and subjected to three different fertilizer applications. In the control treatment, fertilizer application was stopped prior to the commencement of the photoperiod treatment as practiced in some sugarcane breeding programs. The continuous treatment consisted of an application of a 10 ml solution of a NPK three times a week between June and October. The partial treatment consisted of applications of the same NPK solution applied post-initiation between September and October. Nitrogen starvation prior to the commencement of the photoperiod treatment is generally accepted to improve flower initiation; thus the standard practice is to cease nitrogen application two weeks prior to beginning a photoperiod regime. The growing media used in this study did not have a significant effect on days to flowering or percent panicle emergence. In our study, the control fertilizer treatment showed a flowering percentage across all growing media types of 21.2% less than a continuous fertilization regime. Furthermore, a significant trend was observed between fertilization treatments and days to flowering, with the continuous treatment producing panicles, on average across growing media, four days earlier than the control treatment, and six days earlier than the partial treatment. Evidence across this three-year experiment indicates that we should consider modifying plant nutrition management as soil fertility was found to be inadequate.

Olive floral development in different hedgerow positions and orientations as affected by irradiance

Irradiance received within the olive hedgerow canopy varies with respect to row orientation, spacing and hedge dimensions. These orchard management criteria offer the opportunity for improving productivity based on understanding the responses of yield-determining processes to irradiance. How irradiance influences inflorescence and flower development, the initial steps in fruit formation, are fundamental components of these processes. In this study we evaluated flowering and fruiting parameters in 5 hedgerow positions (defined by hedgerow side and vertical layer above soil) for N–S (North-South) and E–W (East–West) olive hedgerows (cv. Arbequina). The canopy layers and orientations provided a wide gradient of irradiance received and the relationship of estimated mean daily irradiance for annual and for short periods during floral development and initial fruit set was explored. The numbers of inflorescences and fruits per layer increased from the less illuminated base to more illuminated upper canopy layers. Axillary bud number per shoot also increased toward more illuminated positions, while the proportion of floral buds was unresponsive to the irradiance microenvironment at different positions within the hedgerows. Inflorescence length, node and flower number per inflorescence, and perfect flower percentage increased with position illumination. Ovary quality, indicated by ovule differentiation, was consistently high, independent of position, but ovary size showed some slight significant increases with illumination, mainly in the endocarp. Flowers/inflorescence, fruits/fruiting inflorescence and inflorescence and fruit number per position correlated positively and significantly with estimated irradiance similarly for annual and short periods (r range from 0.49 to 0.86). Despite improved flowering parameters with greater irradiance, no consistent differences among positions were found for percentage of inflorescences bearing fruit and fruit number per inflorescence. Instead, our results indicated that different fruit numbers among canopy positions were primarily due to an irradiance effect on vegetative growth, causing more and longer fruiting shoots and therefore more total flowering sites (nodes) per layer, with only a small contribution by inflorescence structure and flower quality.

Light quality during night interruption affects morphogenesis and flowering in geranium

We investigated the effects of light quality during night interruption (NI) on morphogenesis, flowering, and the transcription of photoreceptor genes in the geranium Pelargonium × hortorum L.H. Bailey ‘Ringo 2000 Violet’ (day neutral plant, DNP). Plants were grown in an environment-controlled chamber under a constant light intensity of 180 μmol·m-2·s-1 PPF. The light was supplied by white (W) light emitting diodes (LEDs) to create long day (LD, 16 h light/8 h dark), short day (SD, 10 h light/14 h dark), or SD with a 4 h night interruption (NI) conditions. The NI was provided by green (NI-G), blue (NI-B), red (NI-R), far-red (NI-Fr), or white (NI-W) LEDs at a significantly reduced intensity of 10 μmol·m-2 ·s-1 PPF (only 5.5% of the intensity of the main light source). Plant height was greatest under NI-Fr. The percent flowering was not affected by light quality during NI, and all plants flowered under all treatments. Among NI treatments, days to visible flower buds (DVB) increased under NI-Fr. All photoreceptor genes except phyB and FTL were highly expressed under normal LD conditions. Under the NI treatment with different qualities of light, these photoreceptor genes were expressed at even higher levels, except under NI-B, as compared to SD. These results suggest that morphogenesis, flowering, and the expression of transcription factor genes are affected by light quality during NI. Light quality during NI in the DNP geranium has more pronounced effects on morphogenesis than on flowering.