Optimum Vegetative Growth Research Articles

Microelements content in leaves of raspberry cv. Willamette as affected by foliar nutrition and substrates

Raspberry (Rubus idaeus L.) cultivar Willamette has long been the most commonly grown raspberry cultivar in Serbia, which is owing to high adaptability of the cultivar to respective agro-environmental conditions. Massive dieback of full bearing plantings is a major problem in raspberry growing hence quality planting material is a must when establishing new raspberry plantings. The study was conducted under protected conditions (in screenhouse) on plants obtained by micropropagation in vitro. In order to achieve optimal vegetative potential, plants were grown for two consecutive years (2004–2005) on two substrates (Steckmedium and Seedling) using three foliar fertilizers (Wuxal, Murtonik and Ferticare). The study revealed optimal vegetative growth in plants studied, excess manganese (150.60-214.52 mg/g), optimum iron content (94.00-123.50 mg/g), and zinc (28.60-31.00 mg/g) and copper (3.10-4.00 mg/g) deficiencies, based on the referent values of microelements content. The assessment of nutritional status of plants by the DOP index suggested significant differences in microelements imbalance when different foliar fertilizers and substrates are applied.

Growth, photosynthesis and podophyllotoxin accumulation of Dysosma versipellis in response to a light gradient and conservation implications

Dysosma versipellis (Hance) M. Cheng ex Ying (Berberidaceae) is a rare and vulnerable, perennial herb endemic to China with pharmaceutical significance. Increasing habitat loss and over-exploitation of the plant has severely affected the plant’s in situ conservation, necessitating ex situ conservation and commercial cultivation. The light regime is a critical environmental factor contributing to successful ex situ conservation via efficient production of biomass and secondary metabolites. We investigated the responses of 2-year-old D. versipellis plants to a light gradient in terms of leaf morphology, growth, biomass production, photosynthesis and podophyllotoxin (PTOX) accumulation. D. versipellis responded to the light gradient in terms of plant height, leaf size, leaf photosynthesis and PTOX accumulation. Plants demonstrated optimal vegetative growth, photosynthetic capability, and PTOX production, under a light intensity equal to 30% full sunlight. Half full sunlight led to the lowest production of PTOX despite having no obviously different effects on growth. Full sunlight was able to cause leaf death in mid-summer (July), although these plantlets did not significantly differ in growth or biomass production before July and new leaves emerged in August. D. versipellis is therefore proposed to be a shade-tolerant plant, well adapted to variations in irradiance. Irradiance of 10%–50%, particularly ca. 30% full sunlight is strongly recommended for ex situ conservation and commercial cultivation.

잦은 강우 조건에서 유기질자재에 따른 유기재배 벼의 수량과 질소이용효율

BACKGROUND: This study was conducted to investigate growth and yield of organically grown rice under a typhoon during a fall. The treatments included NPK chemical fertilizer, compost, oilcake, oilcake 2X, hairyvetch, and vetch+rye. METHODS AND RESULTS: Nutrient applications were made at rates equivalent to approximately 0.9 kg of actual N per acre. Oilcake and hairyvetch treatments had the lowest C:N ratio, but compost had the highest C:N ratio of 34:1. Rice treated by organic nutrient sources had great growth and development at the beginning of the growing season but had depressed growth and yield at the harvest. Oilcake 2X-treated rice in early growing season, especially, showed better growth and development than rice treated by other nutrient sources but was severely lodged at the harvest season due to the typhoon. Compost treatment with high C:N ratio slowly released inorganic N and produced poor rice growth and yield; however, it recued rice lodging. N uptake was the greatest for the oilcake 2X and vetch+rye treatments but the lowest for the compost, which was the similar pattern to the N use efficiency; the greatest and lowest N use efficiency was observed for the oilcake 2X (55%) and compost (5%), respectively. CONCLUSION(s): Rice lodging should be prevented by reducing the excessive nitrogen supplement, resulting from the lower C:N ratio of the organic materials as well as prevented by the radical midsummer drainage. Vetch+rye treatment with 25:1 of C:N had optimum vegetative growth and reduced rice lodging, which increased N use efficiency and yield.

Mycelial Propagation and Molecular Phylogenetic Relationships of Commercially Cultivated Agrocybe cylindracea based on ITS Sequences and RAPD

This study evaluated the optimal vegetative growth conditions and molecular phylogenetic relationships of eleven strains of Agrocybe cylindracea collected from different ecological regions of Korea, China and Taiwan. The optimal temperature and pH for mycelial growth were observed at 25°C and 6. Potato dextrose agar and Hennerberg were the favorable media for vegetative growth, whereas glucose tryptone was unfavorable. Dextrin, maltose, and fructose were the most effective carbon sources. The most suitable nitrogen sources were arginine and glycine, whereas methionine, alanine, histidine, and urea were least effective for the mycelial propagation of A. cylindracea. The internal transcribed spacer (ITS) regions of rDNA were amplified using PCR. The sequence of ITS2 was more variable than that of ITS1, while the 5.8S sequences were identical. The reciprocal homologies of the ITS sequences ranged from 98 to 100%. The strains were also analyzed by random amplification of polymorphic DNA (RAPD) using 20 arbitrary primers. Fifteen primers efficiently amplified the genomic DNA. The average number of polymorphic bands observed per primer was 3.8. The numbers of amplified bands varied based on the primers and strains, with polymorphic fragments ranging from 0.1 to 2.9 kb. The results of RAPD analysis were similar to the ITS region sequences. The results revealed that RAPD and ITS techniques were well suited for detecting the genetic diversity of all A. cylindracea strains tested.

Functional connection between histone acetyltransferase Gcn5p and methyltransferase Hmt1p

Histone acetylation and methylation are linked to a variety of nuclear activities, most notably transcriptional regulation. Both synergistic and antagonistic relationships between these two modifications have been reported in different systems. Here we show that the budding yeast histone H4 arginine 3 (R3) methyltransferase Hmt1p binds acetylated histones H3 and H4, and importantly, that acetylated H4 is a significantly better methylation substrate for Hmt1p. Kinetic studies show that acetylation at any of the four acetylatable lysine residues of histone H4 results in more efficient methylation. Among the four, K8 acetylation imposes the strongest effect on reducing K M, consistent with the observed acetylation-stimulated interaction. In vivo, hmt1Δ cells rescue the transcriptional defect caused by GCN5 deletion, indicating that one of the functions of Gcn5p is to neutralize the negative effect of Hmt1p. Mutating either K8 or R3 to alanine causes similar growth defects in selective histone and gcn5 mutant background, suggesting that these two residues function in the same pathway for optimal vegetative growth. Together, these results reveal a functional connection between histone acetylation, methylation, and two of the responsible enzymes, Gcn5p and Hmt1p.

Differential sensitivity of canola ( Brassica napus) seedlings to ultraviolet-B radiation, water stress and abscisic acid

Responses of canola ( Brassica napus L.) seedlings to three ultraviolet (UV)-B levels [0 (zero), 5 (ambient) and 10 (enhanced) kJ m −2 d −1], two watering regimes (well-watered and water-stressed), and two abscisic acid (ABA) levels (with and without application) were investigated. Overall, enhanced UVB and water stress negatively affected plant growth and physiology, but ABA had very little effect. Enhanced UVB decreased stem height, leaf area, plant dry matter, water use efficiency and wax content, but increased concentrations of chlorophyll a, carotenoids and flavonoids, and ethylene evolution. Water stress reduced stem height and diameter, leaf area, plant dry matter, leaf weight ratio and shoot:root weight ratio under zero and ambient UVB. Water stress also reduced chlorophyll a and carotenoids in plants exposed to enhanced UVB. ABA with watering regime had significant interactive effects only on leaf dry matter and wax content. We found that enhanced UVB and water stress adversely affected B. napus seedlings. Interaction between these two factors affected plant performance. In this interaction, ABA had little significant role. Also, optimum vegetative growth and biomass were achieved under ambient UVB.

Vegetative Growth of Four Strains of Hericium erinaceus Collected from Different Habitats

Vegetative growth of four different strains of Hericium erinaceus was observed. The temperature suitable for optimal mycelial growth was determined to be 25°C, with growth observed in the extend temperature range of 20~30°C. The different strains of this mushroom showed distinct pH requirements for their optimum vegetative growth, with the most favorable growth observed at pH 6. Considering vegetative mycelial growth, PDA, YM, Hennerberg, Hamada, and Glucose peptone were the most favorable media, and Czapek Dox, Hoppkins, Glucose tryptone, and Lilly were the most unfavorable media for these mushroom strains. With the exception of lactose, most of the carbon sources assayed demonstrated favorable vegetative growth of H. erinaceus. For mycelial growth, the most suitable nitrogen source was alanine and the most unsuitable was histidine. Oak sawdust medium supplemented with 10~20% rice bran was the best for mycelial growth of the mushroom.

Nitrogen, Phosphorus, and Potassium Requirements for Optimizing Growth and Flowering of the Nobile Dendrobium as a Potted Orchid

Experiments were conducted to determine how nitrogen (N), phosphorus (P), and potassium (K) rate and fertilizer termination time affect the growth and flowering of a Dendrobium nobile Lindl. hybrid, Dendrobium cv Red Emperor ‘Prince’. Nitrogen, P, and K were tested in separate experiments as a factorial combination of five rates and three termination dates (1 Sept., 1 Oct., and 1 Nov. 2005). Nitrogen and K rates were 0, 50, 100, 200, and 400 mg·L−1. Phosphorus rates were 0, 25, 50, 100, and 200 mg·L−1. Levels of the nutrients not being tested were held constant. For all nutrients, ending fertilization on 1 Sept. resulted in greater or similar pseudobulb thickness compared with ending fertilization on 1 Oct. or 1 Nov. Pseudobulbs grew taller as the N rate increased, peaking at 100 and 200 mg·L−1. There were interactions between the N rate and fertilizer termination time on all reproductive characteristics. For all fertilizer termination times, flower number increased once N was applied. When ended on 1 Nov., 200 and 400 mg·L−1 N caused a delay to reach anthesis. All P rates resulted in taller plants with equally more nodes when compared with 0 mg·L−1. As the K rate increased from 0 to 100 mg·L−1, plant height increased, with no further increase at higher rates. The number of leaves remaining increased as N and K rates increased up to 200 mg·L−1. Total flower number and flowering node number increased as the K rate increased to 100 mg·L−1 (terminated on 1 Sept.) or 50 mg·L−1 (terminated on 1 Oct. or 1 Nov.). In the fourth experiment, only N was ended at four termination times, whereas all other nutrients continued to be supplied until flowering. Control plants received all fertilizer elements until flowering. The duration of N application did not affect vegetative or flowering characteristics. No aerial shoots were observed as a result of prolonged application of N at all rates. In summary, 100 mg·L−1 N, 25 mg·L−1 P, and 100 mg·L−1 K are recommended for optimal vegetative growth and reproductive development of Dendrobium cv Red Emperor ‘Prince’.

SELECTION OF SEEDLING ROOTSTOCKS FOR APRICOT AND ALMOND

Seedlings from apricot and almond are the most widely used rootstocks for these species in the Mediterranean basin. However, selection studies on almond and apricot seed sources aimed at producing homogeneous seedlings with good vegetative growth and which are easy to graft have not been frequent. In France, 'Manicot GF 1236' seedlings have been selected as rootstocks for apricot. On the other hand, in some countries, several almond cultivars have been identified as good rootstocks, because germination of seeds resulted in homogeneous plants with uniform growth in the nursery. The present study is aimed at selecting seedling rootstocks for apricot and almond. The selection criteria are optimum vegetative growth and homogeneity. These criteria will allow their certification. Seedlings from apricot came from seeds of nine clones of the cultivar 'Canino'. Seedlings from almond came from seeds of two clones: 'Atocha 0288' and 'Garrigues 0764'. Seeds from 'Manicot GF 1236', 'Canino' from canning enterprises and 'Nemaguard' peach were used as a control of homogeneity and growth. Germination and vegetative growth percentages were recorded. Data were analysed by ANOVA and the intraclonal homogeneity was studied by means of variance comparison. Seedlings from the apricot clone 'Canino 9-7' and from the almond clone 'Garrigues 0764' showed better characteristics than the other seedlings assayed, hence they are proposed as apricot and almond seedling rootstock candidates for producing certified plants, once the sanitary status is checked and the result is satisfactory.

Culture Studies of Alexandrium affine (Dinophyceae), a Non-Toxic Cyst Forming Dinoflagellate from Bahía Concepción, Gulf of California

Alexandrium affine (Inoue et Fukuyo) Balech, isolated from Bahia ConcepciOn (Gulf of California), was studied to determine the effect of environmental factors on cyst germination and vegetative growth. Alexandrium affine was homothallic and isogamous, and formed cysts in nutrient-deficient (N- or P-limiting) medium. The maturation period of newly formed cysts varied between two weeks and three months, depending on the storage temperature, with colder temperatures prolonging the process. The rate of germination increased with increasing temperature, and was not significantly influenced by light. Germination experiments suggest a broad temperature window for A. affine cysts, ranging from 5 to 25 °C. The optimal vegetative growth rates were 0.25 to 0.34 day - 1 at 20-30 °C. No vegetative growth was observed below 15 °C or above 35 °C. With HPLC toxin analyses, we confirm that this species does not produce saxitoxins. These data on the dormancy, excystment, and growth characteristics seem to be regulated by the environmental constraints of this subtropical bay.

Vegetative growth and conidium production by Monilinia oxycocci in vitro

The effects of various natural agar media, light, and temperature on mycelium growth of and conidium production by Monilinia oxycocci were examined in the laboratory under controlled conditions. Vegetative growth and sporulation were affected differentially by these factors. Optimum vegetative growth and formation of stromata occurred on potato dextrose agar at 20–24 C in the dark. The minimum and maximum temperatures for mycelium growth were 4 and 32 C, respectively. Production of conidia was best on V8 juice agar. The greatest numbers of conidia were produced at 16 C, but abundant conidium production was most consistent at 20 C. The influence of light on sporulation was inconsistent among trials and differed among media and isolates. However, on V8 juice agar at 20 C, production of conidia was most abundant in the dark. In general, considerable variability occurred with M. oxycocci throughout the study—among replicates of individual isolates, among isolates within a trial, and among trials with the same isolates. The highly variable nature of M. oxycocci in vitro appears to be an inherent characteristic of this plant pathogenic fungus.

Potassium and calcium nutrition improves potato production in drip-irrigated sandy soil

The response of Spunta potato (Solanum tuberosum L.) plants to different rates of potassium (60 and 120 kg Fed-1 ) in presence or absence of Ca nutrition was studied. The study was performed in sandy-loam soil under a drip-irrigation system during fall seasons of 1996 and 1997 years. Plants fertilised with high rate of K (120 kg K. Fed-1) showed 25-30% increase in fresh weight of tubers and lower fresh weight of foliage at 75 and 90 days after planting (DAP) as compared to those of low K (60 kg K. Fed-1). This resulted in at least 50% higher tuber/foliage ratio of high K treated plants at 75 and 90 DAP. Also, plants that received higher rate of K showed 10-20% increase in multiplication rate as compared to those plants that received low K. High K fertilised plants consistently gave 10-20% more tuber yield than those receiving lower dosage. The marketable yield exhibited the same trend as total yield. Compared with low rate of K application, high rate increased yield of medium (28-60 mm) and over-sized tubers (> 60 mm) by about 15 and 40%, respectively. Calcium showed fluctuating effect on all yield parameters during the two seasons of study. The injection of soluble form of calcium fertiliser increased calcium concentration in peel and medulla tuber tissues as compared to non-calcium treated plants even in soil which contained enough calcium for vegetative growth. It is concluded that K nutrition is a key factor for potato production in sandy soils and studies with emphasis on the relationship between soil exchangeable K and K fertilisation rate as well as variety requirement for different production purposes should be continued. Our results also suggest a potential for improving tuber Ca-content by application of soluble form of calcium fertiliser during bulking even in soil containing sufficient calcium for optimum vegetative growth. Key Words: Egypt, mineral nutrition, sandy soils, spunta potato (African Crop Science Journal 2001 9(1): 147-156)

Influence of Photoperiod, Photosynthetic Photon Flux, and Temperature on Growth of Canary Island Ivy

The effects of selected environmental factors [temperature, photosynthetic photon flux (PPF), and photoperiod] that contribute to optimal vegetative growth of Canary Island ivy (Hedera canariensis Willd.) were investigated. Experiments were conducted in growth chambers at constant day/night temperatures of 16 and 26 °C. The greatest number of leaves (6.1) and plant height (38.0 cm) were achieved with PPF of 210 μmol·m-2·s-1 and an 8-hour photoperiod at 16 °C. The greatest branch number (3.9), leaf area (41.4 cm2) and leaf chlorophyll content (1.02 mg·cm-2) were achieved with a PPF of 210 μmol·m-2·s-1 with a 12-hour photoperiod at 16 °C. Under normal greenhouse or field conditions, Canary Island ivy rarely branches; however, a PPF of 210 μmol·m-2·s-1 also induced branching.

The effects of lifting date, chilling duration and forcing temperature on vegetative growth and fruit production in the Junebearing strawberry cultivar Elsanta

SummaryThe effects of different durations of cold storage (0, 2, 4, 6, 8, 10 and 12 weeks at –2°C and +3°C) on strawberry plants cv. Elsanta from two different lifting dates (6 November and 6 December) were investigated, to determine the chilling required for optimum growth and development. With greater durations of chilling, the petiole length, leaf weight and runner production of plants were increased. The chilling requirement for optimum vegetative growth was saturated after 6–8 weeks. For chilling durations up to six weeks there was no difference between the two cold storage temperatures, but with larger durations subsequent vegetative growth of the plants stored at –2°C was reduced compared with plants stored at +3°C. The vegetative growth after cold storage of plants lifted on 6 December was greater than that of plants lifted on 6 November. Cold storage temperature did not affect the number of flowers produced per plant, fruit number or fruit weight. However fruit number and fruit weight were both greater in plants lifted on 6 November than in those lifted on 6 December. In a second experiment, the effects of chilling duration on growth and fruiting at three forcing temperatures were studied. There was no significant interaction between chilling duration and temperature during forcing, and while eight weeks chilling was optimum for vegetative growth, in terms of fruit production four weeks chilling was optimum. Overall, these results indicate that there may be an important interaction between fruit set and vegetative vigour and that field chilling is more effective than cold store chilling in promoting vegetative growth. The results also show that the optimum chilling requirements for vegetative vigour and fruit production are different, and that chilling becomes more important when the temperature during forcing is low.

550 PB 122 SOIL MOISTURE REQUIREMENTS FOR OPTIMAL GROWTH OF VEGETABLE AMARANTH

In literature, amaranth is described as a stress tolerant crop. However, most of the investigations have been concerned with the production of grain crop. The soil moisture regime which promotes maximum vegetative growth is yet to be established. During 1993, the vegetative growth response of amaranth to different soil moisture levels was determined in a greenhouse study. Amaranth cultivar Hin Choy was grown in Dothan sandy loam soil at four soil moisture levels of 6.0, 9.0, 12.0 and 14.0% (w/w) in a randomized complete block experiment with ten replications. Plant height, leaf number, leaf area, leaf fresh and dry weight, stem fresh and dry weight, root fresh and dry weight, leaf-stem ratio, and stem fresh and dry weight were recorded. All parameters gained significantly with each increment in the soil moisture level up to 12%. There was no difference in plant response between 12% and 14% soil moisture. The study indicated that for optimum vegetative growth, amaranth requires a moisture stress free soil environment.

711 (PS 6) EFFECT OF NITROGEN FERTILIZATION ON GROWTH AND YIELD OF AMARANTH

This study was conducted to establish the optimum level of N fertilization for the production of vegetable amaranth, Amaranthus tricolor, in middle Georgia. The soil fertilization treatments consisted of 0, 45, 90 and 135 kg N ha-1, applied in two equal doses, first at 18 days after planting and again when plants were 5 weeks old. Accession RRC 241 was planted on 19 June in randomized complete block design with four replications. The crop was harvested 48 days after planting and data on leaf number, leaf fresh weight, stem fresh weight, and green yield were collected. Green yield for treatments 0, 45, 90 and 135 kg N ha-1 were 5.3, 10.7, 13.2 and 13.5 Mg ha-1, respectively. Regression of N fertilization on all vegetative components were significant. A linear response was seen for stem fresh weight, a quadratic response for green yield and cubic responses for leaf number and leaf fresh weight. The R2 values for leaf number, leaf fresh weight, stem fresh weight, and green yield were 0.61, 0.63, 0.29 and 0.85, respectively. The results indicate that 90 kg N ha-1 of fertilization should provide optimal vegetative growth in amaranth.

Extractants for assessing the availability of copper to Chrysanthemum morifolium cultivar ‘Yellow Mandalay’ growing in soil-less media

Concentrations of copper (Cu) in saturation extracts containing diethylenetriamine-N,N,N',N'',N''-pentaacetic acid (DTPA), and in 2 mM DTPA (1:1.5 by volume) extracts, increased linearly with additions of Cu (as CuSo 4·5H 2O) to peat, Pinus radiata bark and composted sawdust. It look ∼4 days for extractable Cu levels to stabilize after Cu had been added to the substrates. Chrysanthemum morifolium cultivar ‘Yellow Mandalay’ had chlorotic leaves and reduced vegetative growth, when grown in media comprised mainly of composted Eucalyptus marginata sawdust, if saturation extracts containing DTPA and 2 mM DTPA (1:1.5 by volume) extracts of the media contained less than ∼1 and 0.25 mg l −1 Cu, respectively. However, under the conditions of this experiment, maximum reproductive growth was possible only if the extracts contained at least ∼ 11.7 and 5.1 mg l −1 Cu, respectively. The results suggest that additions of Cu to soil-less media to be used for growing flowering plants should be higher than when only vegetative growth is needed, and should be in the range 10–20 mg l −1. Critical Cu concentrations in bulked leaves associated with optimum vegetative and reproductive growth were 2.4 and 10.3 mg kg −1, respectively.

INFLUENCE OF GENOTYPE AND ENVIRONMENT ON YIELD COMPONENTS OF PRIMOCANE-FRUITING RED RASPBERRIES WITH EMPHASIS ON TEMPERATURE AND DAY LENGTH.

`Autumn Bliss', `Heritage' and `Redwing' were grown in a controlled environment setting at three day/night temperature regimes (30/25, 25/20, 20/15C) at either 12 or 16 hour photo periods. Vegetative (height, diameter, node number, leaf area, leaf, cane and root dry weight) and reproductive (precocity, numbers of fruiting laterals, flower number and dry weight) parameters were analyzed. Optimum vegetative growth was obtained when plants were subjected to short photoperiods (12 hrs) and cool (20/15C) or moderate (25/20C) day/night temperatures. Reproductive characteristics were enhanced when grown under long photoperiods (16 hrs) and moderate temperatures. High temperatures (30/25) reduced cane height due to a decrease in internode length with the greatest reduction occurring under long photo periods. Precocity and flowering was enhanced by long photoperiods especially at cool and moderate temperatures. This may have implications for the reproductive potential of these cultivars when grown in north temperate areas where high temperatures are common for most of the summer.

Effects of soil and foliar applications of urea on productivity and the tree nitrogen status of apricot

SummaryA field trial was laid out on full bearing ‘New Castle’ apricot trees during 1981–84 with three levels of nitrogen (200, 400, 600 g tree1) and four modes of application (soil application alone and supplemented with 1–3 urea sprays, each containing 5 1 aqueous solution of 1% urea to each tree). 400 g N, supplemented with two foliar sprays of urea, the first applied in the second week of April, when the leaves were fully expanded and the second after two weeks resulted in optimum vegetative growth, larger fruit, higher yield and improved tree N status.

Tolypocladium cylindrosporum (Deuteromycotina: Moniliales), a fungal pathogen of the mosquito Aedes australis. I. Influence of temperature, pH and salinity on the growth and sporulation of the fungus in the laboratory.

The New Zealand strain of Tolypocladium cylindrosporum was cultured on Sabouraud dextrose agar medium under varying regimes of growth conditions. The isolate exhibited good tolerances to temperature (4-35 degrees C), pH (3-10) and salinity (0-7% NaCl). Optimal vegetative growth and sporulation were recorded between a temperature range of 20-30 degrees C, pH of 5-6 and a salinity level of 0-2% NaCl. The North American isolate of the fungus showed similar tolerances, while the European isolate was less tolerant.