scholarly journals Chemical management strategies for starry stonewort : a mesocosm study

2021 ◽  
Author(s):  
Kaytee Pokrzywinski ◽  
West Bishop ◽  
Christopher Grasso ◽  
Kaitlin Volk ◽  
Kurt Getsinger

US Environmental Protection Agency (USEPA) approved algaecides and herbicides are frequently utilized to manage nuisance algae and aquatic macrophytes. However, there is limited information available on the effectiveness of these products for the management of starry stonewort. Thus, the goal of this research was to discern effective chemical control products for later growth stages of starry stonewort using mesocosm studies. Eleven treatments were evaluated using various combinations of four copper-based products, endothall, diquat, and carfentrazone – all with USEPA registrations for use in aquatic sites. To assess treatment efficacy, water quality, photophysiology, biomass changes, and bulbil viability were evaluated. Nine of the eleven treatments yielded lower dissolved oxygen concentrations and higher specific conductance when compared to the control. Photophysiological response varied by condition, but seven of eleven treatments resulted in significantly lower fluorescent and maximum fluorescent yield. Five of these also exhibited significantly lower average photosynthetic yields, with combination treatments resulting in more drastic decreases. Ten of the eleven treatments had significantly less biomass compared to the control when measured via wet weight; however, only four treatments were significant when measured via dry weight. Lastly, all conditions utilizing copper-based products significantly reduced bulbil viability while non-copper products had no impact.

2020 ◽  
Vol 34 (6) ◽  
pp. 807-813
Author(s):  
Benjamin H. Lawrence ◽  
Jason A. Bond ◽  
Bobby R. Golden ◽  
Thomas W. Allen ◽  
Daniel B. Reynolds ◽  
...  

AbstractOff-target paraquat movement to rice has become a major problem in recent years for rice producers in the midsouthern United States. Nitrogen (N) fertilizer is applied to rice in greater quantity and frequency than all other nutrients to optimize rice yield. Two separate field studies were conducted from 2015 to 2018 in Stoneville, MS, to assess whether starter N fertilizer can aid rice recovery from exposure to a sub-lethal concentration of paraquat and to evaluate rice response to different N fertilizer management strategies following exposure to a sub-lethal concentration of paraquat. In both studies, paraquat treatments consisted of paraquat at 0 and 84 g ai ha–1 applied to rice in the two- to three-leaf (EPOST) growth stage. In the starter fertilizer study, N fertilizer at 24 kg ha–1 as ammonium sulfate (AMS) was applied to rice at spiking- to one-leaf (VEPOST), two- to three-leaf (EPOST), or three- to four-leaf (MPOST) growth stages before and after paraquat treatment. In the N fertilizer timing study, N fertilizer at 168 kg N ha–1 was applied in a single four-leaf to one-tiller (LPOST) application or two-, three-, and two four-way split applications. Despite starter N fertilizer applications, paraquat injured rice ≥41%, reduced height 57%, reduced dry weight prior to flooding 77%, delayed maturity 10 d, reduced dry weight at maturity 33%, and reduced rough rice yield 35% in the starter fertilizer study. Similarly, in the N fertilizer timing study, paraquat injured rice ≥45%, reduced height 14%, delayed maturity 10 d, reduced dry weight at maturity 44%, and reduced rough rice yield 50% for all N fertilizer management strategies. Both studies indicate that severe complications in growth and development can occur from rice exposure to a sub-lethal concentration of paraquat. In both studies, manipulation of N fertilizer management did not facilitate rice recovery from early-season exposure to paraquat.


2018 ◽  
Vol 7 (3) ◽  
Author(s):  
Nur Aprilyani Mukarlina Rizalinda

The Red betel (Piper crocatum Ruiz.) is one of the types of plants that can be used as a medicinal plant. The Red betel plant can be propagated through cuttings, but the ability of the Red betel leaves to stem cuttings rooted very low. The purpose of this research is to know the influence of the concentration of soaking onion extract and coconut water towards the growth of the stem cuttings of red betel. This study used a randomized complete design (RAL) factorial with two levels, namely the first  factor extract of onion (B)  that consists of 4 concentrations, namely control (0%), B1 (2,5%), B2 (4%), and B3 (5.5%). The second factor is cocnut water (K) consisting 0f 4 concentrations of control (0%), K1 (15%), K2 (20%) and K3 (25%), retrieved 16 combination treatments 3 replications  to obtain 48 units of the experiment. The results showed that the combination of onion extract 5.5% + 25% coconut water shows most good for the number of leaves, plant height, wet weight of heading, the heading dry weight, root weight of wet and dry weight of roots.


1969 ◽  
Vol 60 (1) ◽  
pp. 91-100 ◽  
Author(s):  
Charles S. Nicoll

ABSTRACT The response of the pigeon crop-sac to systemically acting prolactin (injected subcutaneously) was evaluated by measuring the wet weight of the responsive lateral lobes of the organ and by determining the dry weight of a 4 cm diameter disc of mucosal epithelium taken from one hemicrop. Of several different injection schedules tested, administration of prolactin in four daily injections was found to yield optimal responses. When compared with a graded series of prolactin doses, measurement of the mucosal dry weight proved to be a better method of response quantification than determination of the crop-sac wet weight with respect to both assay sensitivity and precision. The submucosal tissue of the crop-sac was estimated to constitute about 64 % of the total dry weight of the unstimulated organ and it was found to be relatively unresponsive to prolactin stimulation in comparison with the mucosa. The lipid content of the mucosal epithelium was determined using unstimulated crop-sacs or tissues which showed varying degrees of prolactin-induced proliferation. The fat content of the mucosal epithelial cells increased only slightly more rapidly than the dry weight or the defatted dry weight of the mucosa. Suggestions are made for the further improvement of the systemic crop-sac assay for prolactin.


2020 ◽  
Vol 13 (2) ◽  
pp. 83-92 ◽  
Author(s):  
A. Adam

SummaryEnhancement of the resistance level in plants by rhizobacteria has been proven in several pathosystems. This study investigated the ability of four rhizobacteria strains (Pseudomonas putida BTP1 and Bacillus subtilis Bs2500, Bs2504 and Bs2508) to promote the growth in three barley genotypes and protect them against Cochliobolus sativus. Our results demonstrated that all tested rhizobacteria strains had a protective effect on barley genotypes Arabi Abiad, Banteng and WI2291. However, P. putida BTP1 and B. subtilis Bs2508 strains were the most effective as they reduced disease incidence by 53 and 38% (mean effect), respectively. On the other hand, there were significant differences among the rhizobacteria-treated genotypes on plant growth parameters, such as wet weight, dry weight, plant height and number of leaves. Pseudomonas putida BTP1 strain was the most effective as it significantly increased plant growth by 15-32%. In addition, the susceptible genotypes Arabi Abiad and WI2291 were the most responsive to rhizobacteria. This means that these genotypes have a high potential for increase of their resistance against the pathogen and enhancement of plant growth after the application of rhizobacteria. Consequently, barley seed treatment with the tested rhizobacteria could be considered as an effective biocontrol method against C. sativus.


2018 ◽  
Vol 7 (1) ◽  
pp. 28
Author(s):  
Yetti Elidar

Research on the response of roots of palm sugar palm seeds (Arenga pinnata) in nurseries at doses and intervals of Nasa liquid organic fertilizer. Aims to determine the dosage, interval and combination of dosages and fertilization intervals with Nasa liquid organic fertilizer which can provide the best dry weight of the roots in the nursery. The research design used was a Completely Randomized Design (CRD) with 3x3 factorial experiments and each treatment was repeated 8 (eight) times, consisting of: the first factor was the treatment of POC Nasa dose in a concentration of 3 cc POC Nasa per liter of water (D) consists of 3 levels, namely: d1 = 300 ml POC Nasa, d2 = 400 ml POC Nasa, d3 = 500 ml POC Nasa, while the second factor is the treatment of POC Nasa Interval (I) consisting of 3 levels, namely: i1 = 2 once a week, i2 = once every 3 weeks, i3 = once every 4 weeks. The results of the POC Nasa dose study had a significant effect on leaf wet weight, leaf dry weight, root wet weight and root dry weight. The best dose at this level are: d2 (400 ml of Nasa liquid organic fertilizer), the interval of liquid organic fertilizer Nasa has a significant effect on leaf wet weight, leaf dry weight, root wet weight and root dry weight. The best dose at this level is: i1 (once every 2 weeks). The treatment combination has no significant effect on all parameters. 


2020 ◽  
Vol 51 (4) ◽  
pp. 1231-1238
Author(s):  
Zeki & Ridha

This study was aimed to investigate the ability of N.oleander to remove Cadmium (Cd) from wastewater. A prolonged toxicity test was performed in a single exposure and run for 65 days with various concentrations of Cd. Plants were grown in sand medium and irrigated with simulated wastewater contaminated with Cd, using different concentrations (0, 10, 25, 50, 75 mg/L), which were chosen based on previous preliminary test. The results of physical observation of the plants didn’t show any withering symptoms. The Cd concentration in plants increased, while in water decreased. The results of plant analysis showed that Cd concentration in plant shoots (stems and leaves) was higher than that in roots for almost all exposure doses along the test duration. The concentration of Cd in water decreased significantly from the first week of the test and become (0 mg/l) on day-35 for 10 and 25 mg/l exposure doses, while exceeded the permissible limits for 50 and 75 mg/l exposure doses and were 0.14 and 0.91 mg/l, respectively. Wet weight and dry weight of Oleander decreased with increasing Cd concentration level except for 10 mg/l exposure dose where the plant wet weight and dry weight increased at the end of the test. Bioaccumulation factor (BAF) and Translocation Factor (TF) was found to be greater than 1, indicating that Oleander is a successful hyperaccumulator for Cd.


Plants ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1495
Author(s):  
Muhammad Javaid Akhter ◽  
Bo Melander ◽  
Solvejg Kopp Mathiassen ◽  
Rodrigo Labouriau ◽  
Svend Vendelbo Nielsen ◽  
...  

Vulpia myuros has become an increasing weed problem in winter cereals in Northern Europe. However, the information about V. myuros and its behavior as an arable weed is limited. Field and greenhouse experiments were conducted in 2017/18 and 2018/19, at the Department of Agroecology in Flakkebjerg, Denmark to investigate the emergence, phenological development and growth characteristics of V. myuros in monoculture and in mixture with winter wheat, in comparison to Apera spica-venti, Alopecurus myosuroides and Lolium multiflorum. V. myuros emerged earlier than A. myosuroides and A. spica-venti but later than L. multiflorum. Significant differences in phenological development were recorded among the species. Overall phenology of V. myuros was more similar to that of L. multiflorum than to A. myosuroides and A. spica-venti. V. myuros started seed shedding earlier than A. spica-venti and L. multiflorum but later than A. myosuroides. V. myuros was more sensitive to winter wheat competition in terms of biomass production and fecundity than the other species. Using a target-neighborhood design, responses of V. myuros and A. spica-venti to the increasing density of winter wheat were quantified. At early growth stages “BBCH 26–29”, V. myuros was suppressed less than A. spica-venti by winter wheat, while opposite responses were seen at later growth stages “BBCH 39–47” and “BBCH 81–90”. No significant differences in fecundity characteristics were observed between the two species in response to increasing winter wheat density. The information on the behavior of V. myuros gathered by the current study can support the development of effective integrated weed management strategies for V. myuros.


Toxics ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 182
Author(s):  
Ruchi Bansal ◽  
Swati Priya ◽  
Harsh Kumar Dikshit ◽  
Sherry Rachel Jacob ◽  
Mahesh Rao ◽  
...  

Cadmium (Cd) is a hazardous heavy metal, toxic to our ecosystem even at low concentrations. Cd stress negatively affects plant growth and development by triggering oxidative stress. Limited information is available on the role of iron (Fe) in ameliorating Cd stress tolerance in legumes. This study assessed the effect of Cd stress in two lentil (Lens culinaris Medik.) varieties differing in seed Fe concentration (L4717 (Fe-biofortified) and JL3) under controlled conditions. Six biochemical traits, five growth parameters, and Cd uptake were recorded at the seedling stage (21 days after sowing) in the studied genotypes grown under controlled conditions at two levels (100 μM and 200 μM) of cadmium chloride (CdCl2). The studied traits revealed significant genotype, treatment, and genotype × treatment interactions. Cd-induced oxidative damage led to the accumulation of hydrogen peroxide (H2O2) and malondialdehyde in both genotypes. JL3 accumulated 77.1% more H2O2 and 75% more lipid peroxidation products than L4717 at the high Cd level. Antioxidant enzyme activities increased in response to Cd stress, with significant genotype, treatment, and genotype × treatment interactions (p < 0.01). L4717 had remarkably higher catalase (40.5%), peroxidase (43.9%), superoxide dismutase (31.7%), and glutathione reductase (47.3%) activities than JL3 under high Cd conditions. In addition, L4717 sustained better growth in terms of fresh weight and dry weight than JL3 under stress. JL3 exhibited high Cd uptake (14.87 mg g−1 fresh weight) compared to L4717 (7.32 mg g−1 fresh weight). The study concluded that the Fe-biofortified lentil genotype L4717 exhibited Cd tolerance by inciting an efficient antioxidative response to Cd toxicity. Further studies are required to elucidate the possibility of seed Fe content as a surrogacy trait for Cd tolerance.


Plants ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1204
Author(s):  
Xinqiao Zhan ◽  
Yichun Qian ◽  
Bizeng Mao

Dendrobium catenatum, a valuable Chinese herb, frequently experiences abiotic stresses, such as cold and drought, under natural conditions. Nonphosphorus glycerolipid synthase (NGLS) genes are closely linked to the homeostasis of membrane lipids under abiotic stress in plants. However, there is limited information on NGLS genes in D. catenatum. In this study, a total of eight DcaNGLS genes were identified from the D. catenatum genome; these included three monogalactosyldiacylglycerol synthase (DcaMGD1, 2, 3) genes, two digalactosyldiacylglycerol synthase (DcaDGD1, 2) genes, and three sulfoquinovosyldiacylglycerol synthase (DcaSQD1, 2.1, 2.2) genes. The gene structures and conserved motifs in the DcaNGLSs showed a high conservation during their evolution. Gene expression profiling showed that the DcaNGLSs were highly expressed in specific tissues and during rapid growth stages. Furthermore, most DcaNGLSs were strongly induced by freezing and post-freezing recovery. DcaMGD1 and DcaSQDs were greatly induced by salt stress in leaves, while DcaDGDs were primarily induced by salt stress in roots. Under drought stress, most DcaNGLSs were regulated by circadian rhythms, and DcaSQD2 was closely associated with drought recovery. Transcriptome analysis also revealed that MYB might be regulated by circadian rhythm and co-expressed with DcaNGLSs under drought stress. These results provide insight for the further functional investigation of NGLS and the regulation of nonphosphorus glycerolipid biosynthesis in Dendrobium.


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