scholarly journals Suppression of emergence and growth of gorse (Ulex europaeus) seedlings by Fusarium tumidum

2006 ◽  
Vol 59 ◽  
pp. 12-17
Author(s):  
E. Yamoah ◽  
E.E. Jones ◽  
D.M. Suckling ◽  
G.W. Bourd?t ◽  
A. Stewart

The effect of Fusarium tumidum a potential mycoherbicide on gorse seedling emergence and growth was examined in three experiments In Experiment 1 F tumiduminoculated wheat grains (one two or three) were placed close to pregerminated gorse seeds at sowing Shoot and root dry weights of inoculated seedlings were lower than the control treatment at all three inoculum densities but there was no significant difference in percentage emergence In Experiments 2 and 3 two inoculated wheat grains were placed in contact with the seedlings at sowing Less than 50 of inoculated seedlings emerged compared with 97 in the control treatments from both experiments Soon after emergence about onethird of the inoculated seedlings that had emerged died from dampingoff disease caused by F tumidum Shoot and root dry weights of inoculated seedlings were significantly lower than the control treatment The results suggest that F tumidum can suppress gorse seedling emergence and growth

2020 ◽  
Vol 12 (18) ◽  
pp. 7573
Author(s):  
Ling Li ◽  
Hongguang Liu ◽  
Xinlin He ◽  
En Lin ◽  
Guang Yang

Winter irrigation affected the movement of soil moisture, temperature, and salt, which was an effective improvement measure widely used in seasonal freeze–thaw areas. In this paper, we investigated the effects of different salinized cotton fields (mild salinization (S1), 5.15 g·kg−1; moderate salinization (S2), 8.17 g·kg−1; severe salinization (S3), 11.15 g·kg−1) and different winter irrigation rates (W0, 0 m3·hm-2; W1, 3000 m3·hm-2; W2, 3600 m3·hm-2; W3, 4200 m3·hm-2) on soil moisture, temperature, salinity, and cotton growth in seasonal freeze–thaw areas. The results showed that the winter irrigation affected the temporal and spatial dynamics of soil moisture, temperature, and salinity, and the winter irrigation rate and degree of soil salinization were significantly correlated with soil moisture, temperature, and salinity (p < 0.01). Winter irrigation stabilized the soil temperature and reduced the freeze–thaw index of the soil. The heat conservation effect of winter irrigation increased with increasing winter irrigation rate and salinization degree, with the greatest effect on the freezing index of S2 and on the thawing index of S3. The soil water content and total salt concentration before spring tillage were significantly correlated with winter irrigation rate and degree of soil salinization (p < 0.05), and when the winter irrigation quota of different salinized cotton fields was greater than 3600 m3·hm-2, the moisture content of soil layer 0–100cm increased by more than 20%, and the desalination reached over 40%, compared with the values before winter irrigation. Winter irrigation improved the emergence rate and yield of cotton, with the soil salinization degree being significantly negatively correlated and winter irrigation rate significantly positively correlated with the emergence rate and yield of cotton fields in the following year (p < 0.01). Compared with the control treatment without winter irrigation, the average increases in cotton yield were W3 (53.32%) > W2 (45.00%) > W1 (29.36%). There was no significant difference in seedling emergence rate or yield between slightly and moderately salinized cotton fields under high winter irrigation rates (W2 and W3) (p > 0.05), although the seedling emergence rate and yield of severely salinized cotton fields increased significantly with increasing winter irrigation rate. In conclusion, winter irrigation proved to be a valuable treatment for severely salinized cotton fields, and the results of this study allowed us to determine the optimal winter irrigation rate for saline alkali cotton fields.


2013 ◽  
Vol 35 (2) ◽  
pp. 231-235 ◽  
Author(s):  
Fernanda Reolon Tonel ◽  
Patrícia Marini ◽  
Juliana de Magalhães Bandeira ◽  
Ana Carolina Silveira da Silva ◽  
Norton Victor Sampaio ◽  
...  

Aiming at verifying effects of priming on germination and emergence of seeds subjected to low temperatures, rice seeds (cv. IRGA 418) were primed into a KNO3 solution during 24, 48, and 72 h, at 20 °C; and into distilled water, for 24 h (control). Germination (G), first count of germination (FCG), and germination speed index (GSI) were the parameters assessed under temperatures of 17 °C, 20 °C and 25 °C. Besides, field emergence (FE), and emergence speed index (ESI) were also assessed under field conditions. A completely randomized design was used with treatments arranged in 4 x 3 factorial (treatments x temperatures) in all experiments. None statistically significant difference was found for seed germination within the 24 h imbibition period, under any of temperatures assessed; although after 48 and 72 h, at 17 °C, this variable has decreased. When seeds were imbibed in KNO3, during 48 and 72 h, the FCG and GSI were decreased, as compared to 24 h imbibition period, and for control treatment, at 17 °C and 25 ºC. After 24 h imbibition, the FE has not differed statistically from control treatment; as occurred for periods of 24 and 48 h imbibition for the ESI parameter. Priming in KNO3 does not cause beneficial effect on seed germination or on seedling emergence of rice.


2017 ◽  
Vol 2 (2) ◽  
pp. 147
Author(s):  
Triswanto Sentat ◽  
Susiyanto Pangestu

Kersen leaf (Muntingia calabura L.) contains tannins, flavonoids and polyphenol compounds allegedly have analgesic effect. The objective was to determine the analgesic effect of ethanol extract of kersen leaves and to determine the most effective analgesic dose. This study was an experimental research. Leaves were extracted with ethanol 70% and the analgesic effect test was divided into 5 groups: negative control treatment (distilled water), positive control (mefenamic acid 2.6mg/kg), kersen leaf ethanol extract first dose (100mg/kg), second dose (200mg/kg) and tthird dose (400mg/kg). Giving treatments by oral, after 30 minutes, the mices were given a pain inductor with 0.5% acetic acid by intra peritonial administration. Analgesic power was calculated by counting the number of writhing in mice for 1 hour. The results showed that the ethanol extract of cherry leaf has analgesic effect. From the calculation of the first dose analgesic power (42.9%), second dose (59.4%) and the third dose 69.9%. Statistical test results kruskal wallis value of p=0.011 (p<0.05) showed a significant difference between all analgesic treatment groups. The conclusion of this study is all of the ethanol extract had analgesic effects on male white mice, whereas a dose of 400mg/kg is the most effective analgesic dose.


2015 ◽  
Vol 8 (1) ◽  
pp. 79-83
Author(s):  
MJ Uddin ◽  
MMH Khan

Experiments on hogplum beetle, Podontia 14-punctata were carried out to find out the suitable insecticide(s) with appropriate dose(s) for suppressing both larvae and adults. Results revealed that the highest mortality (100%) was found in 1st instar larvae after 24 hours at each dose of superior 505EC and the lowest mortality was in T4 treated leaves. The highest mortality was also found in 2nd, 3rd, 4th and adult stages of hog-plum beetle by T5 and T6 treatments. No mortality was observed in control treatment in laboratory trial. The mean number of larvae ranged from 1.5 to 7.6 per square meter of quadrate at one week after last spray. No significant difference was observed among treatments regarding percent leaf infestation at one day before 1st spray. The percent leaf infestation ranged from 5.01 to 9.82 at one week after last spray. The lowest percent (5.87%) leaf infestation was found in T6 treated plants while the highest percent (15.76%) leaf infestation was found in untreated control plants. The highest mortality was observed in T5 and T6 treated plants at all larval instars and no significant difference was found between two doses of each insecticide under field condition. The results of field trial also revealed that the minimum dose (0.75 ml L-1 of water) of Superior 505 EC is sufficient to suppress the field population of larvae and adults of Podontia 14-punctata effectively. Finally, it may be concluded that the highest mortality was found in all larval instars and adult stage of hog-plum beetle after 24 hours at each dose of superior 505 EC (T5 and T6 treatments) both in laboratory and field trials.J. Environ. Sci. & Natural Resources, 8(1): 79-83 2015


2015 ◽  
Vol 60 (3) ◽  
pp. 263-275 ◽  
Author(s):  
Fardin Nasri ◽  
Arsalan Fadakar ◽  
Mahmood Saba ◽  
Bayzid Yousefi

Rosa damascena is very important for essential oil production, medicinal properties and it is also widely cultivated as a garden rose. The Rose species is mainly propagated by stem cutting. In the present study, the effect of different levels of 0, 500 and 1,000 mg l-1 (quick dip method for 20 s) of indole butyric acid (IBA) on the rooting of 12 wild genotypes (including: Kurdistan 1 to Kurdistan 12) of R. damascena was investigated. The results show that the rooting ability of R. damascena differs significantly between the twelve genotypes. The highest rooting (79.56%) and callus production (69.08%), number of roots (8.33), root fresh and dry weights (361.80 and 244.74 mg, respectively) were recorded in Kurdistan 5 genotype with 1,000 mg l-1 IBA. The maximum root length (5.84 cm) was observed in Kurdistan 5 genotype with 500 mg l-1 IBA that showed a significant difference compared to the control treatment (0.96 cm). The highest number of leaves per bud (7.33 at 500 mg l-1 IBA) and number of buds (5.00 at 1,000 mg l-1 IBA) were recorded in Kurdistan 1 genotype. The current study demonstrated that the different genotypes of R. damascena were in a difficult-toroot state, which suggests that cutting treatment with 1,000 mg l-1 IBA overcame the problem of the difficult-to-root state, and it can also enhance the rooting percentage in the studied genotypes.


2018 ◽  
Vol 109 (4) ◽  
pp. 479-489 ◽  
Author(s):  
R. Sattari Nasab ◽  
M. Pahlavan Yali ◽  
M. Bozorg-Amirkalaee

AbstractThe cabbage aphid, Brevicoryne brassicae L. (Hem: Aphididae), is an important pest of canola that can considerably limit profitable crop production either through direct feeding or via transmission of plant pathogenic viruses. One of the most effective approaches of pest control is the use of biostimulants. In this study, the effects of humic acid, plant growth-promoting rhizobacteria (PGPR), and integrated application of both compounds were investigated on life table parameters of B. brassicae, and the tolerance of canola to this pest. B. brassicae reared on plants treated with these compounds had the lower longevity, fecundity, and reproductive period compared with control treatment. The intrinsic rate of natural increase (r) and finite rate of increase (λ) were lowest on PGPR treatment (0.181 ± 0.004 day−1 and 1.198 ± 0.004 day−1, respectively) and highest on control (0.202 ± 0.005 day−1 and 1.224 ± 0.006 day−1, respectively). The net reproductive rate (R0) under treatments of humic acid, PGPR and humic acid + PGPR was lower than control. There was no significant difference in generation time (T) of B. brassicae among the tested treatments. In the tolerance test, plants treated with PGPR alone or in integrated with humic acid had the highest tolerance against B. brassicae. The highest values of total phenol, flavonoids, and glucosinolates were observed in treatments of PGPR and humic acid + PGPR. Basing on the antibiosis and tolerance analyses in this study, we concluded that canola plants treated with PGPR are more resistant to B. brassicae. These findings could be useful for integrated pest management of B. brassicae in canola fields.


2017 ◽  
Vol 8 (2) ◽  
Author(s):  
Jéssica Dutra Vieira ◽  
Paulo Roberto Diniz Da Silva ◽  
Valdir Marcos Stefenon

The indoleacetic acid produced by symbiotic bacteria is an important phytohormone signaling microbe-plant interaction, being therefore essential for rhizoremediation. In this study, the effect of different concentrations of copper ions on the bacterial growth and indoleacetic acid production was investigated in two strains of Mesorhizobium loti in in vitro conditions, aiming to determine critical concentrations of this heavy metal for rhizoremediation of contaminated soils using this bacterium. The experiment consisted on a control culture without copper and three treatments supplemented with 10 mg.L-1, 20 mg.L-1 or 50 mg.L-1 of CuSO4. For both strains, the growth stopped after 48h and no significant difference was observed across treatments. The production of indoleacetic acid by the control treatment without copper was significantly higher in comparison to the copper- containing treatments. Mesorhizobium loti SEMIA806 and SEMIA816 are resistant to up to 50 mg.L-1 of CuSO4 in the culture medium, presenting effective growth. The synthesis of indoleacetic acid was strongly reduced but not excluded by ions copper in the medium. So, it is expected that environmental copper found in the soil up to the concentration of 50 mg.L-1 will not preclude the symbiotic interaction between M. loti and leguminous host plant in rhizoremediation enterprises.


2017 ◽  
Vol 38 (1) ◽  
pp. 335 ◽  
Author(s):  
Rodolfo Carletto ◽  
Mikael Neumann ◽  
Danúbia Nogueira Figueira ◽  
Guilherme Fernando Mattos Leão ◽  
Egon Henrique Horst ◽  
...  

Winter cereals are mainly used for human and animal nutrition and several studies are now exploring their potential as conserved forage (hay and silage). Among the winter cereal species available for cultivation in the south of Brazil, which is major winter cereals producer in the country, the wheat cv. BRS Umbu has attracted special attention. However, few studies have investigated the potential of this cultivar for silage production. The aim of this study was to evaluate the production and quality of silage from the dual-purpose wheat, BRS Umbu, subjected to different cut managements treatments: T1 - without cut (control), T2 - one cut and T3 - two cuts. Each plot represented an experimental unit in a randomized block design, with 5 replicates per treatment. Two representative samples were collected from each plot to determine morphological segmentation (stem, leaf and ear) and dry matter (DM) content of the whole plant and its morphological components. At the time of opening of the silos, food chemical analysis and pH determination were performed. Forage mass production decreased by 26.88% and 67.82%, respectively, with one and two cuts, compared to control. The DM content of the ensiled plant was 49.9 g kg-1 for the control, 54.7 g kg-1 with one cut and 63.2 g kg-1 with two cuts, at the time of ensiling. Management cuts changed the morphological components of the plants, with a lower proportion of stem (28%) in plants subjected to two cuts. The control treatment showed fewer leaves in ensiled plant (9.6%) and intermediate amount of stalk (52.8%), and was significantly different (p < 0.05) to treatment of a cut. Regarding feed chemistry evaluations, no significant difference (p > 0.05) was observed for mineral matter (MM), crude protein (CP) and hemicellulose (HEM) between the different cutting regimens. However, neutral detergent fiber (NDF) and acid detergent fiber (ADF) decreased (p < 0.05) as the number of cuts increased. The control treatment showed higher NDF and ADF content (563.2 and 357.9 g kg-1 DM, respectively) and lower amount of total digestible nutrients (TDN) and net energy of lactation (NEL). However, the estimated milk production (EMP) was superior for this treatment (22,447 l ha-1), demonstrating the high impact of reduced forage mass production with increased number of cuts.


2015 ◽  
Vol 33 (3) ◽  
pp. 405-412 ◽  
Author(s):  
P. V. SILVA ◽  
P. A. MONQUERO ◽  
F. B. SILVA ◽  
N. C. BEVILAQUA ◽  
M. R. MALARDO

ABSTRACT This study aimed to understand the influence of sowing depth and the amount of sugarcane straw on the emergence of weed species Luffa aegyptiaca Miller (Cucurbitaceae); Mucuna aterrima Piper & Tracy (Fabaceae - Leguminosae) and Ricinus communis (Euphorbiaceae). A completely randomized design with a 5 x 4 x 3 factorial layout with four replications was used, at five sowing depths (0, 2, 4, 8 and 10 cm), four different amounts of sugarcane straw (0, 5, 10 and 15 t ha-1) and three different evaluation periods (7, 14 and 21 days after sowing). After sowing, different amounts of sugarcane straw (0, 5, 10 and 15 t ha-1) were deposited on soil. Seedling emergence was analyzed at 7, 14 and 21 days after sowing, counting the number of seedlings that had emerged. At the end of the trial, weed height (cm), leaf area (cm2) and shoot dry mass (g) were measured. In relation to emergence ability, studied species presented different responses according to sowing depth and to the amount of sugarcane straw deposited on the soil. For the L.aegyptiacaand M.aterrima, no significant difference was observed in the interaction between depth and sugarcane straw, showing the adaptation of these species to no-burn sugarcane system. For R.communis, seeds placed at 0 cm of sugar cane straw depth were observed to favor the emergence of seedlings.


2009 ◽  
Vol 6 (7) ◽  
pp. 1167-1180 ◽  
Author(s):  
A.-V. Lavoir ◽  
M. Staudt ◽  
J. P. Schnitzler ◽  
D. Landais ◽  
F. Massol ◽  
...  

Abstract. The effects of water limitations on the emission of biogenic volatile organic compounds are not well understood. Experimental approaches studying drought effects in natural conditions are still missing. To address this question, a throughfall displacement experiment was set up in a natural forest of Quercus ilex, an evergreen Mediterranean oak emitting monoterpenes. Mature trees were exposed in 2005 and 2006 either to an additional drought, to irrigation or to natural drought (untreated control). In both years, absolute monoterpene emission rates as well as the respective standard factors of the trees exposed to normal and additional drought strongly declined during the drought periods. Monoterpene emissions were lower in year 2006 than in year 2005 (factor 2) due to a more pronounced summer drought period in this respective year. We observed a significant difference between the irrigation and additional drought or control treatment: irrigated trees emitted 82% more monoterpenes during the drought period 2006 than the trees of the other treatments. However, no significant effect on monoterpene emission was observed between normal and additional drought treatments, despite a significant effect on leaf water potential and photochemical efficiency. During the development of drought, monoterpene emissions responded exponentially rather than linearly to decreasing leaf water potential. Emissions rapidly declined when the water potential dropped below −2 MPa and photosynthesis was persistently inhibited. Monoterpene synthase activities measured in vitro showed no clear reduction during the same period. From our results we conclude that drought significantly reduces monoterpene fluxes of Mediterranean Holm oak forest into the atmosphere due to a lack of primary substrates coming from photosynthetic processes.


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