Effects of far-red light/temperature DIF and far-red light/temperature pulse combinations on height of lily hybrids

Summary

Potted bulbs of ‘Nellie White’, ‘Sunray’ and ‘Stargazer’ representing three lily hybrids [Easter (Lilium longiflorum Thunb.), Asiatic and Oriental, respectively], were forced in a glass greenhouse under three lighting regimes namely, 8.h photoperiod (8 PP) by using blackout between 1600 hours and 0800 hours to eliminate twilight; 8 PP extended with 1.h of low intensity far-red radiation (9 PP) at the beginning of the dark period; or ambient. All three lighting regimes were in a greenhouse with either a +5°C or a -5°c DIF (= T_day ±T night ) regime, while maintaining the same 24.h temperature. In a second experiment, two cultivars of each of the three lily hybrids were also grown under the same three lighting regimes with a constant day/night temperature but with either a 15°cor 25°c pulse for 3.h from 1500–1800.hours to coincide with the far-red supplementation for 9 PP. Both experiments were done during the winter and repeated the following year. Within each DIF treatment, plants which received light containing far-red at the end and start of the day (ambient) or beginning of night (9 PP) were taller than those under short day (8 PP). Plants grown under either 8 PP or ambient were taller under +DIF than under -DIF, except when 8 PP was extended with 1.h of far-red, in which case plant height was the same for either DIF. ‘Nellie White’ reacted the strongest to far-red as well as to DIF followed by ‘Sunray’ and then ‘Stargazer’. For ‘Nellie White’, the stem dry weight was increased by far-red radiation at the beginning of the dark period compared with short day or ambient, while the opposite was found for the leaf and bulb dry weights. However, total dry weight of plant was not affected by either DIF or lighting treatment. In the second experiment, plant height was not significantly affected by an end of day temperature pulse of -5°c for either the 9 PP or ambient regimes compared with a +5°c pulse.     

GA4+7 plus benzyladenine reduce foliar chlorosis of Lilium longiflorum

The effectiveness of two commercial formulations of gibberellin (GA) and benzyladenine (BA) for reducing foliar chlorosis on Easter lily (Lilium longiflorum Thunb.) was compared. On a per liter basis, plants were sprayed with 0, 100, 200, or 400 mg (BA equivalent) of Accel (GA₄₊₇:BA of 1:10) or Promalin (GA₄₊₇:BA of 1:1) when the crop leaf area index (LAI)=3. One group of plants was sprayed with 100 mg of Accel or Promalin (BA equivalent) per liter twice: once at LAI=3 and again 3 weeks later. Plants were harvested when the largest flower bud on each plant measured 13 cm in length, stored for 0 or 3 weeks at 2.5°C in the dark, and then moved into a post-harvest evaluation room at 21°C, where foliar chlorosis was monitored for 3 weeks. Senescence of some lower leaves on plants in every treatment was evident at harvest, and incidence of senescence increased during the 21 days of post-harvest evaluation. Cold storage increased the number of leaves senescing during the subsequent evaluation period. Application of Promalin or Accel significantly reduced leaf senescence compared to that of untreated plants. At harvest, 21% of the leaves on untreated plants were senescent, while plants treated with Promalin or Accel averaged 3 or 9% senescent leaves, respectively. Following 7 days of post-harvest evaluation, Promalin was more effective in preventing chlorosis than Accel at the 400 mg l⁻¹ (BA equivalent) level. Following 14 or 21 days of post-harvest evaluation, Promalin was more effective than Accel for the 100 mg l⁻¹ 2× and 400 mg l⁻¹ (BA equivalent) treatments.Plants in all Promalin and Accel treatments were taller than untreated plants 1 week after sprays were applied. At harvest, plants sprayed with Promalin were between 6 and 14 cm taller than untreated plants, but those treated with Accel were the same height as untreated plants.Neither Promalin nor Accel influenced the occurrence of malformed or aborted flowers in this study. However, cold storage significantly increased the number of plants with aborted buds and malformed flowers. Unstored plants averaged 0.16 aborted buds and 0.02 malformed flowers each, while those stored 3 weeks averaged 0.51 aborted buds and 0.18 malformed flowers each.     

Screening ornamental lilies for resistance to Botrytis elliptica

The screening of ornamental lilies for resistance to fire, a disease caused by Botrytis elliptica (Berk.) Cooke, is discussed. Detached leaves from greenhouse-grown lilies were inoculated with spores of B. elliptica and incubated at 20°C and 100% relative humidity for 48 h. After incubation, the leaves were transferred to a growth-chamber. Percentage infection and lesion size, which were assessed 1 week after inoculation, varied with the fungal isolate used and with spore concentration. When 20 ornamental lily clones were tested for resistance, clones derived from Lilium longiflorum Thunb. (Easter Lilies) showed less variability in resistance than the more genetically diverse colored lily clones. A study carried out in the field generally confirmed results obtained with green-house-grown plants.     

Response of Lilium longiflorum to ancymidol bulb-dips

Plant height at flowering was reduced in Easter lily (Lilium longiflorum Thunb. cultivar ‘Nellie White’) by momentarily dipping the bulbs in 100 or 264 mg l^?1 solutions of ancymidol [α-cyclopropyl-α-(p-methoxyphenyl)-5-pyrimidinemethanol] prior to planting. The number of flowers was unaffected, and days to flower increased slightly at the highest concentration. This method of application is more effective than soil drench and foliarspray applications.     

百合在西藏林芝的引种栽培试验研究

对从兰州引进的里昂、布鲁拉诺、普莱托3个百合品种在西藏农牧学院温室进行了引种栽培试验研究,同时与当地品种卷丹做了对比.结果表明:卷丹种鳞萌芽期最早,布鲁拉诺和普莱托稍晚,里昂最晚.种鳞萌芽率:卷丹＝里昂(100%)＞布鲁拉诺(86.7%)＞普莱托(80%).4种百合的高生长进程表明,从出土至始花期是百合的高生长期,一般为49～50 d,高生长高峰期为5月中旬～6月初.4种百合的现蕾期依次是:普莱托最早,里昂稍晚,布鲁拉诺晚于里昂,卷丹最晚.     

The influence of exogenously applied 2,4-D and NAA on fruit drop reduction in pummelo cv. Thong Dee

ABSTRACT

Effect of 2,4-D and naphthalene acetic acid (NAA) on fruit drop reduction in pummelo cv. Thong Dee was investigated in the pummelo growing areas of Nakhon Pathom province, Thailand. Five similar sized and aged of pummelo trees were selected to set up the experiment. Ten mature branches with the same size from each pummelo tree were randomly selected around the canopy for 2,4-D (20 and 40 mg L^?1), NAA (20 and 40 mg L^?1) application and control. All treatments were applied to selected pummelo branches 2 times at full bloom and 2 months after fruit set. The results showed that 20 mg L^?1 NAA (14.84%) and 40 mg L^?1 NAA (12.26%) gave significantly higher percent of fruit retention at 6 months after fruit set. However, leaf total nonstructural carbohydrate concentration analysis showed that 40 mg L^?1 2,4-D (104.86 mg g^?1) and 20 mg L^?1 2,4-D (96.55 mg g^?1) gave significantly higher total nonstructural carbohydrate than those in control (78.44 mg g^?1). For fruit quality, 40 mg L^?1 2,4-D and 20 mg L^?1 2,4-D gave the highest peel weight with 435.55 and 358.57 g, respectively, and 40 mg L^?1 2,4-D gave the highest peel thickness with 20.25 mm, while 20 mg L^?1 NAA gave statistically higher total soluble solid than those in 20 mg L^?1 2,4-D and 40 mg L^?1 2,4-D. Therefore, 20 mg L^?1 of NAA sprayed 2 times at full bloom and 2 month after fruit set effectively reduced fruit drop and increased percentage of fruit retention in pummelo cv. Thong Dee.     

Paclobutrazol application enhances antioxidant enzyme activities in pomegranate plants affected by cold stress

Paclobutrazol (PBZ) is a member of the triazole plant growth inhibitor group that is responsible for inducing tolerance to a number of biotic and abiotic stresses. An experiment was, therefore, conducted to test whether PBZ application at various concentrations (0, 25, 50, or 75 mg L^?1) through foliar spray or soil drench would protect pomegranate (Punica granatum) seedlings cv. Robab, subjected to freezing at ?3°C for 7 hours. PBZ improved the growth rate of pomegranate seedlings subjected to freezing stress and increased relative leaf chlorophyll content, chlorophyll fluorescence ratio, relative water content, soluble carbohydrate content, and enzyme activity of ascorbate peroxidase and guaiacol peroxidase compared with the control at the end of experiment. PBZ ameliorated the injury caused by freezing stress by inhibiting increases in proline content and leaf electrolyte leakage, which suggested that PBZ ameliorated the negative effect of freezing stress. The best protection was obtained from plants treated with PBZ at 50 or 75 mg L^?1. The most evaluated parameters were not affected by PBZ application method.     

滴灌施肥对‘特罗维它’甜橙生长结果的影响

 以卡里佐枳橙砧‘特罗维它’甜橙为材料,以每年撒施10次肥料为对照,研究了年施肥总量一定,不同滴灌施肥频率（每年4次、10次和16次）对树体生长、产量和品质的影响。2002—2007年的结果显示,仅个别年份的处理与对照的树干粗度、树高和冠径存在显著差异以外,到试验结束时,不同滴灌施肥频率对树干粗度、树高和冠径大小无显著影响,滴灌施肥与对照间的树体生长无显著差异。滴灌施肥可显著提高果实产量,处理的累计产量比对照高29.4% ~ 36.5%;增加滴灌施肥频率无显著增产作用;滴灌施肥对果实品质无显著影响。建议碱性紫色土柑橘园滴灌施肥频率为每年4次。     

Combined effects of leaf/fruit ratios and N and K fertigation levels on growth and distribution of nutrients in pot-grown persimmon trees

Responses of pot-grown persimmon trees (Diospyros kaki cv. ‘Fuyu’) with two different leaf/fruit (L/F) ratios and three different fertigation levels were studied. On July 2, the L/F ratios of 4-year-old trees were adjusted to 20 and 10 by fruit thinning. From July 4 to August 26, each pot was fertigated with a solution containing 0–0 g (none), 10–8 g (medium), or 20–16 g (high) of nitrogen (N) and potassium (K), respectively. The L/F ratio of 10 resulted in higher yields but smaller fruits containing lower soluble solids than the ratio of 20. The non-fertigated trees with the L/F ratio of 10 produced the smallest fruits, but the medium fertigation increased the size of the fruit at this ratio. The high fertigation level decreased fruit skin color at both ratios. Fruit dry weight increased the most among the tree components, accounting for 48–57% of the tree total dry weight at the L/F ratio of 20 and for 64–72% at the ratio of 10. The increase in tree total dry weight at the ratio of 10 was greater than that at the ratio of 20. The trees receiving medium fertigation had higher tree total dry weights than those receiving high fertigation, especially at the ratio of 10. As the L/F ratio changed to 10 from 20, the percentages of N and K partitioned to fruits in the non-fertigated trees increased from 38% to 51% and from 67% to 96%, respectively, of the tree total N and K increases; the percentage decreased with increasing fertigation level. Although fertigation significantly increased total N and K contents of the tree, the increase in K at the ratio of 10 was less in high fertigation rather than in the medium level. The results indicated that adjusting supplemental N and K was necessary to ensure fruit growth and N and K accumulation for trees with high fruit loads, but high levels of fertigation are not necessarily preferable.     

An efficient method for immature embryo rescue and plant regeneration from the Calli of Ziziphus jujuba ‘Lengbaiyu’

Hybrid breeding of Chinese jujube (Ziziphus jujube) is limited by embryo abortion. Improving the success of embryogenic progeny and immature embryo culture techniques could increase the breeding efficiency of new jujube varieties. We optimised the current immature embryo culture techniques by using immature embryos before the globular stage of Chinese jujube variety Lengbaiyu. The optimal growth media were as follows: for 30-day-old immature embryo growth, MS + IBA 0.8 mg·L^?1 + ZT 0.5 mg·L^?1 + GA₃ 7.0 mg·L^?1 + NAA 0.2 mg·L^?1 + LH 0.5 mg·L^?1 + 5% sucrose, with 22.22% embryonic growth rate and 0.41% plantlet formation rate; and for young embryo differentiation, MS + TDZ (0.8 mg·L^?1) + IAA (0.5 mg·L^?1) + sucrose (3%), with 81.12% differentiation rate. Thus, regeneration via callus induction effectively improved the efficiency of embryo rescue from young immature embryos in Lengbaiyu, which might provide new approaches for breeding Chinese jujube.     

Influence of medium-nitrogen level on growth periodicity of Ilex crenata Thunb. ‘Helleri’

Ilex crenata Thunb. ‘Helleri’ plants were grown in sand culture and supplied daily with nutrient solutions of 10, 40, 70 or 100 mg l^?1 nitrogen (N). Plant growth at all rates of N was characterized by an initial period of simultaneous shoot and root dry weight accumulation, followed by shoot elongation, root growth cessation, and major accumulations of N and dry weight. Plants grown at the greater N rates accumulated more N and exhibited a higher shoot-to-root ratio as a result of greater shoot than root growth. Plants grown at the higher N applications initiated extension growth before plants grown at lower N levels.     

Split root fertigation enhances cucumber yield in both an open and a semi-closed greenhouse

We investigated the hypothesis that split root fertigation (SRF) approach could provide complementary benefits over traditional fertigation (TF) in terms of water use, vegetative growth and yield formation in the high radiation season and under two atmospheric conditions in a greenhouse. Plants of cucumber (Cucumis sativus L. cv. Cumuli) were grown in a traditional high-wire cultivation system in a peat growing medium. In the SRF method the root system of a plant was separated into two compartments over the crop cycle. One compartment received fertigation solution with low EC (1.2 dS m⁻¹) and the other compartment solution with high EC (3.5 dS m⁻¹) value. In the TF method the EC value of fertigation solution was 2.4 dS m⁻¹. The atmospheric conditions included an open (ventilated) and a semi-closed (cooled) greenhouse. The employment of cooling resulted in an enhancement of the average CO₂ in a semi-closed (810 ppm) over an open (530 ppm) greenhouse resulting in a yield improvement (37%). SRF improved water uptake in both atmospheric conditions and water use efficiency (WUE) in an open greenhouse. The water uptake in SRF was highest in the root part with the low EC values, namely 61% in the open and 66% in the semi-closed greenhouse. In both atmospheric conditions, SRF decreased flower abortion, leading to an improved fruit set with a small effect on vegetative growth. SRF increased yield by 21% in the open and 17% in the semi-closed greenhouse compared to TF in corresponding greenhouses.     

Influence of Different Soilless Substrates to Morpho-physiological Characteristics and Yield Relations in Strawberries

Some of the advantages of soilless production systems over conventional systems are higher yield, better pest control management and more efficient labor use. Among berries, strawberry responds quite well to soilless production systems. Major yield-affecting factors for strawberries in soilless systems may be listed as; growing medium, source and types of plantlets, density of plants and efficiency of fertigation system. The present research was conducted with strawberry plants (Fragaria x ananassa ‘Camarosa’) grown in four different media; (1) Cocopeat (C), (2) Peat (P) and (3 and 4) 1:1 mixtures with Pumice (Pu), to evaluate the effects of soilless media on marketable yield and root-shoot morpho-physiological parameters. Correlation measurements were made to assess if there is any interaction between yield and any tested morpho-physiological feature. The experiment was conducted in greenhouse, using frigo plantlets (11.6 plantlet/m²) planted in July and through 1 June of following year. Results showed that growth medium had an effect on yield, numbers of developed leaves, shoot-root dry mass, number and length of roots. Yield was correlated with these morphological features. Growth medium also had an influence on plant nutrient accumulations i.?e., shoot accumulation of nitrogen (N) and potassium (K) and root accumulation of phosphorus (P) and all the micro-nutrients that with exception of boron (B). There were some interactions between yield and plant nutrient content of tissues determined by correlation analyses. The most striking were negative correlations with yield and shoot N–K amounts and positive correlation with yield and root P amount. Some positive correlations were also found between yield and copper (Cu), manganese (Mn) and zinc (Zn) contents of both shoot and root tissues. Boron (B) contents was correlated only with the root tissues. The medium which had the best overall performance for soilless strawberry production was C?+?Pu and should be recommended to be used with frigo plantlets of ‘Camarosa’.     

The effect of grafting on nitrogen use in determinate field-grown tomatoes

Grafting tomato (Solanum lycopersicum L.) onto disease resistant rootstocks has grown in use in North America over the past two decades. Rootstocks have traditionally been bred and used for their resistance packages to numerous soil-borne diseases but some rootstocks appear to improve scion yield and vigour in comparison to non-grafted plants in conditions lacking disease challenge. In this study, the tomato rootstocks ‘Maxifort’ or ‘RST-106’ were used to determine if vigour improved ‘Tribute’ scion traits, especially yield, and if marketable yield could be maintained in grafted plants at reduced nitrogen fertiliser inputs. Plants were grown in an open-field plasticulture production system at five rates of nitrogen from 0 kg ha^?1 to 224 kg ha^?1 applied via drip irrigation. Marketable yield was significantly affected by nitrogen rate and rootstock in both years. ‘Tribute’ grafted onto ‘Maxifort’ rootstock had the greatest, most consistent impact and increased marketable yield 15% and 30% in 2013 and 2014, respectively, compared to the non-grafted ‘Tribute’. Our findings suggest that some rootstocks can increase scion growth and yield but do not differentially respond to decreased nitrogen rates.     

Biochemical and morphometric analysis of Rosa tomentosa and Rosa rubiginosa during application of liquid culture systems for in vitro shoot production

Two liquid culture systems, rotary shaker (RS) and temporary immersion system (TIS) for the propagation of Rosa rubiginosa and Rosa tomentosa were investigated and compared with solid medium culture. Shoot tips were grown on basic Murashige and Skoog medium with 20 mg dm^?3 Fe EDDHA, 1 µM BA, 1.5 µM GA₃ and 3% sucrose for six weeks. Of the different culture systems, liquid cultures resulted in better growth and development of roses. Both RS and TIS cultures improved biomass growth, multiplication rate, leaf blade area and plant height; however, RS reduced the shoot dry mass content. There were no changes in the content of chlorophyll a, b, a + b in plants developed in the tested systems. Use of a solid medium favoured the accumulation of phenolic compounds, soluble sugars, and carotenoids, but it was accompanied by browning and necrosis of shoots. Plants propagated in TIS were characterised by the high content of phenolic compounds and soluble sugars, but they had the highest multiplication rate. Use of TIS resulted in eight times the number of shoots for R. tomentosa and twice as many for R. rubiginosa compared to solid medium.     

Flower initiation and node development of axillary buds,growth partitioning,and bleeding sap production of young apple trees as affected by fertigation

SUMMARY

Node and flower development in axillary buds of one year old 'Elshof trees, growth and dry-matter partitioning, and bleeding sap production were examined in unfertigated field-grown trees as well as in fertigated field- and pot-grown trees. Flower initiation in axillary buds was delayed by approximately 40 d as compared with spur buds, and the critical node number within the bud was only 14 or 15 against 19 nodes in spur buds. Fertigated trees exhibited increased node development, axillary flower-bud densities, extension shoot growth and trunk increments, and decreased root/top ratios. The seasonal shoot development was markedly hastened in fertigated trees, and the amount of bleeding sap was increased. Especially, trees fertigated in pots, using a nitrogen application range of 14 to 420 ppm N, had high bleeding sap concentrations of nitrogen, phosphorus and calcium. Flower-bud initiation of apple is discussed in terms of bud development, shoot growth and root activity.     

Effects of culture conditions on in vitro bulblet induction in the medicinal plant Amana edulis (Miq.) Honda

Amana edulis (Miq.) Honda is an important medicinal plant with a variety of anti-cancer properties, and it is of great importance to improve its reproductive rate through micropropagation technology to meet increasing demand. In the present study, in order to establish a rapid in vitro bulblet propagation protocol for A. edulis, an L₁₆ (4⁵) orthogonal design was used to investigate the effects of sucrose, 6-benzyladenine (6-BA), α-naphthaleneacetic acid (NAA), and macro-elements on bulblet induction. The results show that the sucrose concentration was the crucial factor for A. edulis bulblet initiation, followed by 6-BA and macro-elements, while NAA had the weakest effect. The optimal medium for in vitro bulblet induction was Murashige and Skoog medium supplemented with 0.1 mg·L^?1 6-BA, 0.01 mg·L^?1 NAA, and 100 g·L^?1 or 80 g·L^?1 sucrose (pH 5.8), in which A. edulis shoot clusters (without roots) were cultured at 5(±2)°C for 35 d or 60 d and then incubated at 23(±2)°C for 90 d. The entire cultivation process occurred in the dark. The present study demonstrates that this protocol can be used for the propagation of A. edulis.     

Mineral nutrient requirements and effects of CO2 enrichment on Gerbera microcuttings

Summary

The effects of CO2 concentration (350 and 1200 μmol mol^-1), growing media (peat + perlite, 3:1, peat + coco dust, 1:1; and coco dust alone), and concentration of nutrient solution (EC 2.1 and 2.8 mS cm^-1) on growth of gerbera microcuttings, leaf nutrient content, and the chemical properties of the growing media were investigated. Plants grown in peat + coco dust had the highest dry weights of leaves and roots. There were no significant differences in the fresh and dry weights of leaves and roots due to concentration of nutrient solution. CO₂ enrichment increased all growth variables, except leaf number. Leaf nutrient content of gerbera cuttings and chemical properties of growing media after eight weeks of growth, with reference to all treatments, are discussed and presented as tables.     

Effects of temperature and daylength on growth and flowering of roselle, Hibiscus sabdariffa L.

Hibiscus sabdariffa L. was found to show an ambiphotoperiodic reaction, flowering both in short days and in extremely long days, but remaining vegetative (at least at 21–25° C) in a 16 h day. Flowering had a dual effect on growth. When floral induction was strong, lateral buds developed into flowers and the number of branches was proportionally reduced. The first stage of floral induction, however, was accompanied by a decrease of apical dominance. Plants shifted to long days after only a short stay at an inductive daylength, and plants moved to short days after a prolonged stay in long days, formed many more branches and a much greater vegetative mass than plants grown in continuous short days or long days.Plants were already sensitive to daylength in the cotyledon stage. Floral induction was not carried over from short days into long days. After marginal induction, floral buds reverted to vegetative shoots, or aborted and were replaced by a shoot from the axil of a bract.In short days, seedlings form shallowly three-lobed leaves until the generative stage, when only entire leaves are formed. In long days, the leaves are deeply five-lobed, also when the plant flowers.     

Flowering,vegetative growth and mineral nutrition of pot chrysanthemums in sawdust and peat-life media

Plants of Chrysanthemum morifolium Ramat ‘Mountain Peak’, ‘Goldstar’ and ‘Cir Bronze’ were grown in sawdust, sawdust mixed with Ca(NO₃)₂ 7 weeks before planting and held at 20°C (unheated), or at 43°C (heated), and in a sphagnum-peat/vermiculite mix (peat-lite). C:N ratios for the sawdust media at planting were 265.9, 125.7 and 123.3, respectively. Plants grown in each medium received nutrient irrigation containing macro- and microelements, with N at 150, 200 or 250 mg l^?1.Days to full flower development, and flower diameter at harvest were not influenced by medium or irrigation N concentration. Plants grown in peat-lite produced the thickest and longest stems, although the stature of plants in all media was judged to be commercially acceptable. Plants grown in unheated sawdust pre-mixed with Ca(NO₃)₂ produced the thinnest and shortest stems.Leaf concentrations of N, P, K and Mg at harvest were highest in plants grown in peat-lite. Accumulation of Ca, B, Fe, Mn, Cu and Zn was more variable. With the exception of P, foliar nutrient concentrations in all plants were optimal or above published optimal ranges. The onset of flower senescence occurred an average of 1 day earlier in sawdust-grown plants.