Chrysanthemum (Dendranthema grandiflorum cv. Jinba) shoot branching is determined by bud outgrowth during the vegetative growth stage. The degree of axillary bud outgrowth is highly influenced by environmental conditions, such as nutrient availability. Here, we demonstrated that phosphorus (Pi) starvation significantly reduces axillary bud outgrowth in chrysanthemum. A strigolactone (SL) biosynthesis gene, DgCCD7, was isolated and characterized as an ortholog of MAX3/DAD3/RMS5/D17. By using ultra-performance liquid chromatography coupled with mass spectrometry (UPLC-MS), three putative SLs were identified and levels of all three SLs showed strong increase under Pi starvation conditions. Determinations of the distribution of SLs and regulation of DgCCD7/8 in response to Pi changes in root indicate that SL acts systemically. However, temporal expression patterns of biosynthesis and signaling genes in nodes revealed that Pi starvation causes a local response of SL pathway. Treatment of node segments with or without auxin and Pi revealed that in the absence of exogenous auxin, Pi delayed axillary buds outgrowth and up-regulated local SL pathway genes. These data indicated that an auxin-SL regulatory loop responded to Pi starvation for delaying bud outgrowth locally, root biosynthesized SLs were transported acropetally and functioned in shoot branching inhibition under Pi starvation. We proposed that SLs contributed to chrysanthemum shoot branching control in response to Pi-limiting conditions in a systemic way.

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Impacts of strigolactone on shoot branching under phosphate starvation in chrysanthemum (Dendranthema grandiflorum cv. Jinba).

STUDIES ON POST HARVEST HANDLING OF CUT HYDRANGEA (Hydrangea macrophylla Thunb.) AS INFLUENCED BY PRE-HARVEST FERTILIZATION

Two varieties of African marigold ( Tagetes erecta L.) were evaluated for three seasons from 2014 to 2015 to study the effect of season and pinching on growth and yield parameters of African marigold. The growth characters studied were plant height, number of primary branches, number of secondary branches, leaf area, chlorophyll content and total biomass. The yield parameters studied included days to first flowering, days to 50% flowering, days to first harvest, flower weight, number of flowers per plant, flower yield per plant and duration of flowering. The analysis of variance revealed highly significant difference between pinched and non pinched plants for characters like plant height, number of primary branches, number of secondary branches, leaf area and total biomass. High variability was also found for yield parameters like days to first flowering, days to 50% flowering, days to first harvest, and flower yield per plant, indicating that pinching had significant positive effect on growth, flowering and yield of African marigold. High variability was also found among different seasons in the growth and yield parameters studied. Plant height, leaf area, and total biomass were significantly high in S2 (monsoon); days to first flowering, days to 50% flowering, and days to first harvest were significantly low in S3 (post monsoon); whereas, number of flowers per plant, and duration of flowering were significantly high in S1 (pre monsoon)

Impact of seasons and pinching on growth and flowering in African marigold (Tagetes erecta L.)

INTEGRATED NUTRIENT MANAGEMENT STUDIES IN CHRYSANTHEMUM (Dendranthema grandiflora Tzvelev) UNDER CHHATTISGARH PLAINS

Carnation production in Colombia, the world’s main exporter, takes place entirely in naturally ventilated greenhouses. This type of structure presents non-homogeneous microclimate conditions which differentially affect crop growth and development, which is why this issue has been of great research interest in recent years. The objective was to determine the microclimatic behavior of a passive spatial-type greenhouse used in Colombia for carnation production. The experimental approach included the collection of meteorological data in the external environment through a weather station and in the inside of the greenhouse through a grid of 40 sensors uniformly distributed in a horizontal plane. Data processing to determine the spatial variability of temperature, relative humidity and vapour pressure deficit (VPD) is done by using geostatistical techniques and predicting these variables at unsampled points through the ordinary Kriging method. The main results obtained allowed us to determine that the conditions generated inside the greenhouse are not the optimal ones recommended for carnation production and that, in addition, the behavior of the variables studied shows a heterogeneous distribution, obtaining spatial variations in the horizontal profile evaluated for the night period of 0.5 °C, 9.1% and 1.5 kPa and for the daytime period of 7.2 °C, 42.6% and 1.5 kPa for temperature, humidity and VPD respectively.

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Analysis of the microclimatic behavior of a greenhouse used to produce carnation (Dianthus caryophyllus L.)

Soil physico-chemical properties and microbial population were assessed to get the knowledge of the effect of integrated nutrient management in chrysanthemum (Dendranthema grandiflora Tzvelev) flower production system in the mid-hill conditions of Himachal Pradesh. Plants of chrysanthemum cultivars Purnima and Ajay were grown in open field condition with 17 different nutritional regimes during 2009 and 2010. The experiment was laid out in factorial randomized block design, replicated thrice. Findings revealed highest amount of available soil N (373.04 kg/ha), K (283.18 kg/ha) and organic carbon content (1.260 %) in the plots receiving 30 g/m 2 each of NPK + vermicompost (1 kg/m 2 ) + biofertilizers. Maximum available soil P (39.86 kg/ha) was recorded with the application of 22.5 g/m 2 each of NPK + vermicompost (1kg/m 2 ) + biofertilizers. No significant change was observed in soil pH and electrical conductivity due to different treatments. Azotobacter population (10.50 × 106 cfu/g of soil) and phosphorus solubilizing bacterial count (12.83 × 106 cfu/g of soil) were maximum with the application of 15 g/m 2 each of NPK + vermicompost (1 kg/m 2 ) + biofertilizers. However, maximum arbuscular mycorrhizal fungi spore count (196.58 per 20 g of soil) was observed with the application of vermicompost (1 kg/m 2 ) + biofertilizers. The overall multifaceted effects of different integrated nutrient management treatments that facilitated beneficial soil conditions in the present study also reflected the significant increase in the flower yields of both Purnima and Ajay even over the ad-hoc recommended treatment (30 g/m 2 each of NPK).

Microbial dynamics and physico-chemical properties of soil in the rhizosphere of chrysanthemum (Dendranthema grandiflora) as influenced by integrated nutrient management

Carnation cv. Master plants fertilized with 250 ppm N and K fertigation through urea and MOP + 250 ppm NPK foliar spray through a water soluble fertilizer Sujala (19 : 19 : 19 NPK) once a week is improved flowering as well as quality parameters and proved superior over the earlier recommended practices and the rest of the treatments. DOI: http://dx.doi.org/10.3329/bjb.v44i1.22736 Bangladesh J. Bot. 44 (1): 133-137, 2015 (March)

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Effects of fertilization on quality flower production and foliar nutrient content of carnation (Dianthus caryophyllus L.) cv. Master

Effects of different growth regulators and their application time on production of quality flower and seed production of marigold (Tagetes erecta L.) were investigated. Experimental factors include nine foliar applications of growth regulators viz., Control (no application), two doses each of GA3, salicylic acid, benzyl adenine, cycocel, and two application times viz., (i) application at 25 DAT, (ii) application at 50 DAT. Results suggest that foliar spray of 250 ppm gibberellic acid enhanced growth, and improved seed yield and quality parameters of marigold. Among the times of application tested, it was observed that application at 25 days after transplanting (DAT) gave superior values for all the flower and seed parameters under study.

/pdf/effects-of-plant-growth-regulators-on-quality-flower-and-l9an1uqmaf.pdf

Effects of plant growth regulators on quality flower and seed production of marigold (Tagetes erecta L.)

The present investigation was conducted at the Research Farm of The Department of Floriculture and Landscaping, Dr Yashwant Singh Parmar University of Horticulture and Forestry, Nauni, Solan, Himachal Pradesh during the year 2010 and 2011 to ascertain the response of carnation (Dianthus caryophyllus L.) cv Master to different doses and methods of application of water soluble fertilizer Sujala (19:19:19 NPK). The plants receiving treatment of 250 ppm N and K fertigation through urea and MOP + 250 ppm NPK foliar spray through Sujala once a week (T13) showed significant increase in the vegetative growth characteristics (plant height and stem length) as well as stimulated flowering parameters, viz. reduced the number of days to bud formation, first flowering, enhanced both the number of flowers per plant and flower size, reduced the number of days to harvesting stage, increasing the duration of flowering, weight of cut flower stem per plant and vase life in comparison to the recommended practices.

Response of carnation (Dianthus caryophyllus) cv Master to water soluble fertilizer Sujala (19:19:19 NPK)

The investigation was carried out to study the effect of different planting dates and spacing on growth and yield of African marigold cv. ‘Pusa Narangi Gainda’. The treatments comprised of four planting dates, viz., 1st September (D1), 1st October (D2), 1st November (D3) and 1st December (D4) and three plant spacings, viz., 40×20 cm (S1), 40×40 cm (S2) and 40×60 cm (S3). The experiment was laid out in Factorial Randomized Block Design with twelve treatment combinations replicated thrice. Number of primary branches per plant (16.89), plant spread (48.33 cm), flower diameter (6.89 cm), number of flowers per plant (50.10), weight of flower per plant (466.35 g), flower yield per plot (20.97 kg) and flower yield per hectare (25903.31 kg) were found to be statistically higher in 1st October planting. Among various spacings, 40×20 cm recorded significantly maximum flower yield per hectare (26483.56 kg ha−1) than 40×40 cm and 40×60 cm spacing. Other growth parameters like number of primary branches per plant (13.43), plant spread (41.13 cm), and flower diameter (6.32 cm) was found to be significantly higher in 40×60 cm. However, duration of flowering (43.25 days) was found to be significantly higher in 40×40 cm spacing which, in turn, was statistically at par with 40×60 cm spacing. Further, the interaction effect of planting dates and spacing on plant height, plant spread, number of primary branches per plant, flower diameter, number of flowers per plant, weight of flower per plant and flower yield per hectare was found to be significant.

Nomita Laishram

Papers

Microbial dynamics and physico-chemical properties of soil in the rhizosphere of chrysanthemum (Dendranthema grandiflora) as influenced by integrated nutrient management

Effects of fertilization on quality flower production and foliar nutrient content of carnation (Dianthus caryophyllus L.) cv. Master

Effects of plant growth regulators on quality flower and seed production of marigold (Tagetes erecta L.)

Response of carnation (Dianthus caryophyllus) cv Master to water soluble fertilizer Sujala (19:19:19 NPK)

Studies on effects of planting dates and spacing in African marigold (Tagetes erecta L.)