scholarly journals Influence of plants used in agricultural diversification on the nematode Heterorhabditis amazonensis

2021 ◽  
Vol 42 (6supl2) ◽  
pp. 3553-3566
Author(s):  
Natalia Ramos Mertz ◽  
◽  
Fernanda Soares Sales ◽  
Elsa Judith Guevara Agudelo ◽  
Alcides Moino Junior ◽  
...  

In an agricultural system, to increase natural biological control, plants that attract natural enemies can be grown alongside the main crop. However, the effects of these plants on entomopathogenic nematodes (EPNs), important agents for controlling soil pests, and the action of their conservation are unknown. To assess the impact of these plants on EPNs, two experiments were carried out in a greenhouse. The first measured the effect of Crotalaria spectabilis, Crotalaria breviflora, and Tagetes erecta on the persistence and infectivity of Heterorhabditis amazonensis isolate RSC 5 for 27 days, compared to a control treatment without plants. The second trial evaluated the effect of C. breviflora and T. erecta on the displacement of the nematode. Additionally, the influence of predator Calosoma granulatum in this system was evaluated. The plants did not influence nematode behaviour in terms of persistence, infectivity, or displacement. However, C. spectabilis allowed the most significant persistence of nematodes in the substrate for a short time, and T. erecta caused the fastest suppression of the initial population of infectives juvenile. In the second experiment, neither the predator nor the plants affected the nematode’s ability to move in the soil within 5 days. These results show that prior knowledge in agricultural diversification can help to control pests by inundative application of EPNs.

2021 ◽  
Vol 13 (12) ◽  
pp. 6673
Author(s):  
Lidia Luty ◽  
Kamila Musiał ◽  
Monika Zioło

The functioning of various agroecosystems is nowadays shaped by different farming systems, which may impair their functions, as well as being beneficial to them. The benefits include ecosystem services, defined as economic and noneconomic values gained by humans from ecosystems, through supporting soil formation and nutrient circulation, and the impact of agriculture on climate and biodiversity. Their mutual flow and various disturbances depend on the agroecosystem’s management method, which is associated with the type of management of agricultural land (AL) in individual farms. This paper raises a problem of transformation in the structure of three main farming systems in Poland, in 2004–2018, in relation to the implementation of 16 selected ecosystem services and their scale. Special attention was given to organic farming, as the most environmentally friendly and sustainable. The analysis demonstrates the increase in ALs in that type of production during the analyzed period of time. Disparities of transformation associated with the type of agricultural system were noticeable at the regional level, which were presented in 16 Polish voivodeships. The results of the analysis confirm that the organic system, which is an important carrier of various ecosystem services, gained a stable position. Moreover, areas with integrated farming still do not exceed 0.5% of total agricultural lands in such voivodeships. The analysis of factors influencing the deterioration or disappearance of selected environmental services characterizing agricultural systems indicates the need to depart from an intensive conventional management system.


Agronomy ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 867
Author(s):  
John P. Thompson ◽  
Timothy G. Clewett

In two experiments on a farm practicing conservation agriculture, the grain yield of a range of wheat cultivars was significantly (p < 0.001) negatively related to the post-harvest population densities of Pratylenchus thornei in the soil profile to 45 cm depth. In a third and fourth experiment with different rotations, methyl bromide fumigation significantly (p < 0.05) decreased (a) a low initial population density of P. thornei in the soil profile to 90 cm depth and (b) a high initial population of P. thornei to 45 cm depth, and a medium level of the crown rot fungus, Fusarium pseudograminearum, at 0–15 cm depth to a low level. For a range of wheat and durum cultivars, grain yield and response to fumigation were highly significantly (p < 0.001) related to (a) the P. thornei tolerance index of the cultivars in the third experiment, and (b) to both the P. thornei tolerance index and the crown rot resistance index in the fourth experiment. In the latter, grain yield was significantly (p < 0.001) positively related to biomass at anthesis and negatively related to percentage whiteheads at grain fill growth stage. One barley cultivar was more tolerant to both diseases than the wheat and durum cultivars. Crop rotation, utilizing crop cultivars resistant and tolerant to both P. thornei and F. pseudograminearum, is key to success for conservation farming in this region.


Horticulturae ◽  
2021 ◽  
Vol 7 (6) ◽  
pp. 140
Author(s):  
Avela Sogoni ◽  
Muhali Jimoh ◽  
Learnmore Kambizi ◽  
Charles Laubscher

Climate change, expanding soil salinization, and the developing shortages of freshwater have negatively affected crop production around the world. Seawater and salinized lands represent potentially cultivable areas for edible salt-tolerant plants. In the present study, the effect of salinity stress on plant growth, mineral composition (macro-and micro-nutrients), and antioxidant activity in dune spinach (Tetragonia decumbens) were evaluated. The treatments consisted of three salt concentrations, 50, 100, and 200 mM, produced by adding NaCl to the nutrient solution. The control treatment had no NaCl but was sustained and irrigated by the nutrient solution. Results revealed a significant increase in total yield, branch production, and ferric reducing antioxidant power in plants irrigated with nutrient solution incorporated with 50 mM NaCl. Conversely, an increased level of salinity (200 mM) caused a decrease in chlorophyll content (SPAD), while the phenolic content, as well as nitrogen, phosphorus, and sodium, increased. The results of this study indicate that there is potential for brackish water cultivation of dune spinach for consumption, especially in provinces experiencing the adverse effect of drought and salinity, where seawater or underground saline water could be diluted and used as irrigation water in the production of this vegetable.


2010 ◽  
Vol 113-116 ◽  
pp. 1870-1873
Author(s):  
Xiao Dong Zhu ◽  
Jun Shen ◽  
Yu Liu

The removal efficiencies of 4 air-cleaning materials on formaldehyde and VOC emissions from particleboards were examined in this paper. The effect of activated carbon and photo catalyst on formaldehyde and VOC emissions removal was notable in short time. The effect of scavenger was obviously on formaldehyde removal for its synthetic mechanism. And the impact of bioenzyme on formaldehyde and VOC emissions from particleboards is dependent on the test conditions and it shows no impact on emissions in this experiment.


2015 ◽  
Vol 47 (3) ◽  
pp. 117 ◽  
Author(s):  
M.W. Khudhair ◽  
M.Z. Khalaf ◽  
H.F. Alrubeai ◽  
A.K. Shbar ◽  
B.S. Hamad ◽  
...  

Virulence of entomopathogenic fungi <em>Metarhizium anisopliae</em> and <em>Beauveria bassiana</em> were tested against Arabian Rhinoceros Beetle, <em>Oryctes agamemnon arabicus</em> larvae. Four concentrations (1×10<sup>5</sup>, 1×10<sup>7</sup>, 1×10<sup>9</sup> and 1×10<sup>11</sup> conidia/mL<sup>–1</sup>) of two locally isolated entomopathogenic fungi spore suspensions were used in this study via larval direct spraying. Results revealed that both isolates can cause high mortality rate reaching 100% after 29 days. However, <em>Beauveria bassiana</em> scored higher mortality rate in short time especially at the concentration of 1×10<sup>11</sup> conidia/ mL<sup>–1</sup> with lethal time (LT)<sub>50</sub> 12.75 and LT<sub>90</sub> 20.00; while, <em>Metarhizium anisopliae</em> caused the higher percentage of malformed adults. Moreover, both isolates affected insect’s life cycle particularly in the pupal stage which was reduced remarkably by almost 50% in comparison with the control treatment.


2008 ◽  
Vol 56 (2) ◽  
pp. 169-178
Author(s):  
U. Sangakkara ◽  
S. Nissanka ◽  
P. Stamp

Smallholders in the tropics add different organic materials to their crops at different times, based on the availability of materials and labour. However, the time of application could have an effect on the establishment and early growth of crops, especially their root systems, which has not yet been clearly identified. This paper presents the results of a study conducted under greenhouse conditions using soils from a field treated with three organic materials at 4 or 2 weeks before or at the planting of maize seeds, corresponding to the times that tropical smallholders apply these materials. The organic materials used were leaves of Gliricidia sepium and Tithonia diversifolia or rice straw, incorporated at a rate equivalent to 6 Mt ha −1 . A control treatment where no organic matter was added was used for comparison. The impact of the treatments on soil properties at the planting of maize seed and detailed root analysis based on root lengths were carried out until the last growth stage (V4). The addition of organic matter improved the soil characteristics, and the impact of adding Gliricidia leaves was most pronounced when incorporated 2 weeks before planting. The benefits of leaves of Tithonia or rice straw on soil quality parameters were clearly evident when added 4 weeks before planting. Organic matter enhanced the root number, root length, root growth rate and branching indices. All the organic materials suppressed the growth of maize roots when applied at planting, suggesting the existence of allelopathic effects, which could result in poor growth. The most benefits in terms of root growth were observed with Tithonia .


2007 ◽  
Vol 5 (2) ◽  
pp. 283-294 ◽  
Author(s):  
Philip D. Sloane ◽  
Lauren W. Cohen ◽  
Christianna S. Williams ◽  
Jean Munn ◽  
John S. Preisser ◽  
...  

A randomized controlled trial evaluated the impact of different methods of water agitation on clinical and microbiological outcomes in 31 nursing home residents. Four conditions were tested: a) whirlpool tub, jets on, using standard soap products; b) ultrasound tub, ultrasound on, using the standard soap products; c) ultrasound tub, ultrasound on, using specialized soap and skin conditioner; and d) either tub (randomized), water circulation off, using standard soap products (the control condition). Outcomes of interest included skin microbial flora, water microbial flora, skin condition, time spent bathing, and staff satisfaction. Resident skin condition and skin microbial flora did not differ between the four treatments. The tubs also did not differ in terms of bacterial colonization; however, there was a non-statistically significant trend for the highest counts to occur in whirlpool tubs after being idle overnight. The ultrasound and whirlpool tubs were preferred by staff over the control treatment (still water) in terms of sound and overall suitability. In addition, staff reported that the ultrasound tub using enhanced skin cleansers made bathing residents easier and faster than the same tub using standard cleansers.


2012 ◽  
Vol 36 (2) ◽  
pp. 671-679 ◽  
Author(s):  
Igor Rodrigues de Assis ◽  
Luiz Eduardo Dias ◽  
Emerson Silva Ribeiro Jr ◽  
Walter Antônio Pereira Abrahão ◽  
Jaime Wilson Vargas de Mello ◽  
...  

Acid mine drainage (AMD) is an environmental concern due to the risk of element mobilization, including toxic elements, and inclusion in the food chain. In this study, three cover layers were tested to minimize As, Fe and S mobilization from a substrate from former gold mining, containing pyrite and arsenopyrite. For this purpose, different layers (capillary break, sealant and cover layer) above the substrate and the induction of a geochemical barrier (GB) were used to provide suitable conditions for adsorption and co-precipitation of the mobilized As. Thirteen treatments were established to evaluate the leaching of As, Fe and S from a substrate in lysimeters. The pH, As, Fe, S, Na, and K concentrations and total volume of the leachates were determined. Mineralogical analyses were realized in the substrate at the end of the experimental period. Lowest amounts of As, Fe and S (average values of 5.47, 48.59 and 132.89 g/lysimeter) were leached in the treatments that received Na and K to induce GB formation. Mineralogical analyses indicated jarosite formation in the control treatment and in treatments that received Na and K salts. However, the jarosite amounts in these treatments were higher than in the control, suggesting that these salts accelerated the GB formation. High amounts of As, Fe and S (average values of 11.7, 103.94 and 201.13 g/lysimeter) were observed in the leachate from treatments without capillary break layer. The formation of geochemical barrier and the use of different layers over the sulfide substrate proved to be efficient techniques to decrease As, Fe and S mobilization and mitigate the impact of acid mine drainage.


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