Control of phytonematodes is very hard and requires a combination of techniques to succeed. Alternative control through plant extracts may result in the discovery of nematicide substances. Research aimed at evaluating the effect of 33 plants submitted to aqueous extraction against Panagrellus redivivus in vitro. Concentrations were prepared at 1.25, 2.5, 5, 10, and 20%. Monitoring happened at 0, 6, 12, 24 and 30 hours after preparation. Counting considered dead nematodes subtracted from alive ones. Juveniles were also counted, and extract efficiency was expressed in percentage of control or stimuli. Data were submitted to variance analysis. Significant results got with the Scott-Knott test (5%), and multiple linear regression analysis. Extracts were observed acting as controllers, but also as stimulators to nematode reproduction. The best controlling performance was set by Carica papaya (-66% at 20%; -33.7% at 10%), Euphorbia milii (-37% at 20%), Psychotria carthagenensis (-25.5% at 2.5%), Clusia variegate (-22% at 20%), and Zamioculcas zamiifolia (-21.5% at 20%). Stimulator extracts were Mentha villosa at 10% (+148%) and 2.5% (+131.5%), followed by Aloe vera (+123% at 5%), Schinus molle (+112.5% at 10%), Schefflera arboricola (+93.5% at 5%), C. variegate (+89% at 5%), and S. molle (+88% at 5%). Some extracts kept population stable throughout the experiment, presenting lower control indexes. Besides an additive effect, there was an individual influence of concentration or time on control.
Biological control is a method of controlling pests through the use of other living organisms. The purposes of this study were to test Hohenbuehelia species as biological control agents against Panagrellus redivivus in vitro, evaluating nematodes influence on mycelia growth; establishing daily indexes for predation and growth and setting predation percentage. Five species previously identified as 436-Hohenbuehelia mastrucata (Nematoctonus hamatus), 528-H. bullulifera (not described so far), 581-H. paraguayensis (N. sp.), 582-H. sp. (N. sp.) and 631-H. portegna (N. campylosporus) were submitted to anamorphic purification directly from basidioma. Afterwards, 100 nematodes were added to each pure colony for predation test. Evaluation started right after 24 hours of nematode-fungus interaction. Immobilized and/or penetrated nematodes were counted and mycelia growth was measured. Results were subjected to variance analyses. Hohenbuehelia mastrucata had the best performance in growth speed, followed by H. portegna and H. paraguayensis; Nematodes multiplyied much but none specie grew more as an influence of their movement under mycelium, however all species formed trap devices and some of them produced adhesive or repelent substances. Trap devices were formed in control plates also. The plates of H. paraguayensis without nematodes grew more than treatments. Cumulative predation of H. portegna was the highest at 24 (195.5%) and 48 hours (235%). At the last evaluation day, H. paraguayensis preyed the same amount (185.75%) than H. portegna, followed by H. mastrucata (109.51%). Resulst of predation daily indexes displayed chronological activity for each isolate, where H. portegna was very reactive at first 24 hours, H. mastrucata raised its predacious activity in 48 hours being constant from this time on and H. paraguayensis pointed out itself at 72 hours. Other species presented low predation and growth indexes throughout experiment.
Companies have sought to improve, more and more, the quality control of the seeds produced, improving tests that evaluate the vigor of the seeds with greater speed and precision. The objective of the present work was to study the effects of imbibition time on the results of the electrical conductivity test to evaluate the vigor of millet seeds and to correlate with the other tests carried out. Six seeds lots of the ADR300 cultivar with different vigor levels were used. Germination, first germination count, accelerated ageing, emergence and emergence speed of seedlings in sand and electrical conductivity with variations in water volume were performed (50 And 75 cm 3 ), during the imbibition time of 2, 4, 6 and 8 hours, at 25 ºC. The time of 2 hours of the seed imbibition in 75 cm 3 in water proved to be efficient to evaluate the vigor of millet seeds in all lots tested.
Stored beans have active metabolism and respiration may cause significant quality losses. Therefore, some care is necessary during this period, aiming at maintaining the physiological quality of seeds, minimizing their deterioration and reducing their germinative power. Seed quality during storage may be influenced by environmental factors and the interaction of genotypes with the environment. The objective was to evaluate the germination and vigor of bean seeds after 90-days storage under different temperature conditions. The experiment was conducted under a completely randomized design, with four replications, in 3 × 2 factorial scheme, considering three storage temperatures (10 °C, 20 °C and 30 °C) and two storage times (0 and 90 days). For potential evaluation, the following characteristics were considered: moisture content, thousand seed mass, germination, electrical conductivity, accelerated aging and cold test. Numerical data were submitted variance analysis with averages compared by means test at 5% of significance. Results showed that storage temperature conditions directly affect physiological quality of bean seeds. Temperature of 10 °C provided better seed conservation whereas temperature of 30 °C promoted higher deterioration and reduced vigor.
Swine wastewater (SWW) is a residue from pig farming that presents a high load of nutrients and organic matter. The appliance of organic matter in soil alters the microbial dynamic and may suppress soilborn phytopathogens. This study aimed at evaluating the inhibition on mycelial growth of Sclerotinia sclerotiorum and Sclerotium rolfsii in vitro under SWW doses. Hereupon, three kilograms of a soil classified as red dystroferric latosol was collected and sieved. Half of it was autoclaved. SWW was incorporated at doses of 0 mL, 2.5 mL, 5 mL, 10 mL and 20 mL in both soil conditions, autoclaved and not autoclaved. Afterwards, 130 grams of each soil was separately put into Petri plates above what a thin layer (≅ 5 mL) of Water-Agar (2%) medium was carefully spread over. Above this agar layer, one disk (6 mm diameter) of pure mycelium from each fungal grown in Potato Dextrose Agar medium was individually placed on the center of each plate. Daily evaluations on mycelial growth measuring were taken and ended when mycelium in control plates (without SWW addition) reached plate borders. Results indicated that in autoclaved soil condition, the inhibition was proportional to the dose, what is to say that the higher the dose the less the mycelial growth. In not autoclaved soil there was no significant difference among treatments, suggesting stimuli on suppression effect for both pathogens caused by SWW. In addition, the confirmed potential of SWW as a suppressor of S. sclerotiorum and S. rolfsii leads to promising investigations on other phytopathogens hard to control.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.