Timing and Rates of Two Products Using Hydrogen Peroxide (H2O2) to Control Algae in Ebb and Flow Hydroponic Systems

Algae is not desirable in hydroponics and creates problems such as reduced yield and decreased dissolved oxygen, and affects the physiology of plants and, thus, needs to be controlled. An experiment was conducted in Ebb and Flow hydroponic systems to investigate the application timing and rates of two hydrogen peroxide products (Zerotol and PERpose Plus). Treatments included 35 mL weekly, 35 mL biweekly, 70 mL weekly, 70 mL biweekly, and a control with no application of hydrogen peroxide using a 40-gallon reservoir of water. Pepper ‘Early Jalapeno’ and ‘Lunchbox Red’ and tomato ‘Geronimo’ and ‘Little Sicily’ were used. The study was conducted in a split-plot design with two replications over time. Plant growth parameters, including plant height, flower number, net CO2 assimilation, fresh weight, and dry weight were recorded. Algae data, including dry weight, algae cell counts, and chl a were also measured. Results indicated that with increasing rate and timing of either product decreased algae counts, dry weight, and chl a values. However, weekly and biweekly application of 70 mL of both products were not different for algae quantification. In pepper, plant height, shoot fresh and dry weight, and root fresh and dry weight were found to be significantly greater with Zerotol 35 mL biweekly, Zerotol 70 mL weekly, PERpose Plus 35 mL biweekly, and PERpose Plus 70 mL weekly compared with the control. ‘Lunchbox Red’ was significantly greater than ‘Early Jalapeno’ in all growth parameters, except soil plant analysis development (SPAD). ‘Lunchbox Red’ had the greatest flower number, with weekly application of 70 mL PERpose Plus. In tomato, greatest flower number and SPAD were observed in ‘Geronimo’ with a weekly application of 70 mL PERpose Plus and 70 mL Zerotol, respectively. Greater shoot and root fresh and dry weight for both tomato cultivars were recorded with 35 mL biweekly or 70 mL weekly application with either product. The results from both plants as well as algae analysis suggest that weekly application of 70 mL of either Zerotol or PERpose Plus produced the best results in terms of controlling algae and improving the growth of pepper and tomato plants.

Debriding effect of amino acid-buffered hypochlorite on hard-to-heal wounds covered by devitalised tissue: pilot study

Objective: Wounds such as lower extremity ulcers are serious, costly and frequently hard to heal. Guidelines conclude that new dressings and treatments generally fail to show superiority compared with standard of care. Several mechanisms are probably responsible for impaired healing of hard-to-heal wounds, including inflammation and infection. Amino acid-buffered hypochlorite has presumed antiseptic and antibacterial properties and has been shown to be useful in the treatment of diabetic foot ulcers (DFUs). We evaluated the debriding effect of amino acid-buffered hypochlorite (ChloraSolv) on full skin hard-to-heal lower extremity ulcers covered with devitalised tissue (≥50%), with six applications over 5 weeks and follow-up at 12 weeks. Method: This was an open-label, single-arm, multicentre, pre-market pilot investigation. We recruited subjects with a lower extremity ulcer, covered with devitalised tissue (≥50%), who were candidates for cleansing and debridement/desloughing. There was a weekly application of the investigational device for five weeks. Follow-up for wound status evaluation was performed at 12 weeks from baseline. Results: We evaluated 57 subjects (33 males, 24 females, median age 73 years, range 51–90 years) (intention-to-treat). Of these, 61.4% had a leg ulcer and 38.6% a foot ulcer. The median wound size at baseline was 7.7cm2 (range 2.1–52cm2) with devitalised tissue coverage of 76.5%. After 5 weeks, a decrease of 72.7% in devitalised tissue was seen, and 71.4% of the subjects showed a decrease in devitalised tissue of ≥50% (evaluated independently using PictZar). At 12 weeks' follow-up the decrease in devitalised tissue was 84.4%. Wound-related pain was reported by ten subjects, resulting in 17 adverse events (AEs). Among these, 12 AEs from eight subjects were recorded as possibly or probably related to the investigational device and one AE was reported to have a causal relationship with the investigational device. Conclusion: This clinical study suggests that amino acid-buffered hypochlorite can be effective and well tolerated in the treatment of hard-to-heal lower extremity ulcers to dissolve and remove devitalised tissue.

Qualidade de mudas de mamoeiro Formosa (Carica papaya L.) produzidas em substratos com rejeitos de mica na composição e fertilização com urina de vaca

<p class="Normal1">Although papaya (Carica papaya L.) is one of the most expressive crops of Brazilian fruit, there is no information on the production of seedlings of this species on substrates with muscovite tailings (mica) and the use of cow urine as an organic fertilizer. The objective of this research was to evaluate the influence of substrates with different proportions of mica and with the use of cow urine as organic fertilizer on the quality of Formosa papaya seedlings. The experimental design was completely randomized in a 5 x 2 factorial arrangement, corresponding to the percentages of 0.0%; 25.0%; 50.0%; 75.0% and 100.0% mica in the substrate with and without weekly application of cow’s urine diluted in water (5.0%) and fifteen repetitions. The variables analyzed were stem height / diameter ratio, total leaf area, shoot dry mass, root dry mass, total dry mass, leaf biomass allocation, stem biomass allocation, root biomass allocation and Dickson quality index. Formosa papaya seedlings with better agronomic quality were produced with substrate with 48.3% mica in the composition and weekly application of cow urine diluted in 5.0% water </p>

Effect of biofertilizer on soil fertility and lettuce nutrition

This work aimed to evaluate the effect of the application of efficient microorganisms (EM), in the form of a biofertilizer, on soil fertility and leaf nutrition of lettuce during two crop cycles. One of the biggest challenges of organic production is the fertilization of crops. EMs are considered an alternative, sustainable, safe and low-cost technique to increase the productivity of organic foods, and their use is a good option for agroecological management. For the capture of the EMs and the production of the biofertilizer, a rice substrate was used, according to the methodology used by Brazilian Ministry of Agriculture, Cattle and Supplying (MAPA, in Portuguese: Ministério da Agricultura, Pecuária e Abastecimento). Soil samples were collected at the beginning of the first cycle and at the end of the second cycle. The samples were sent for chemical analysis, in order to evaluate possible changes in the concentration of Ca, Mg, K, P and Zn, as well as the levels of CTC, base saturation, organic matter and pH. For leaf analysis, leaf concentrations of the following nutrients were observed: N, P, K, Ca, Mg, S, B, Cu Fe, Mn, Zn. The results were satisfactory for the treatment that received weekly application of efficient microorganisms, which resulted in a greater increase of the elements K, Zn and Ca in the soil. As for leaf concentrations, there was a significant difference for N and P (48 and 9.2 g kg-1, respectively) in the treatment used with biofertilizer.

Entomological Efficacy of Aerial Ultra-Low Volume Insecticide Applications Against Aedes aegypti (Diptera: Culicidae) in Mexico

A cluster-randomized controlled trial quantified the entomological efficacy of aerial ultra-low volume (AULV) applications of the insecticide chlorpyrifos against Aedes aegypti in Puerto Vallarta, México, during November–October 2017. The trial involved 16 large (1 × 1 km) clusters distributed between treatment-control arms. Primary endpoint was the abundance of Ae. aegypti indoors (total adults, females, and blood-fed females) collected using Prokopack aspirators. After four consecutive weekly cycles of AULV, all adult Ae. aegypti infestation indices were significantly lower in the treatment arm (OR and IRR ≤ 0.28). Efficacy in reducing indoor Ae. aegypti increased with each weekly application cycle from 30 to 73% (total adults), 33 to 76% (females), and 45.5 to 89% (blood-fed females). Entomological indices remained significantly lower in the treatment arm up to 2 wk after the fourth spraying round. Performing AULV spraying can have significant and lasting entomological impact on Ae. aegypti as long as multiple (ideally four) spray cycles are implemented using an effective insecticide.

An evaluation of dehydrated human amnion/chorion membrane allografts for pressure ulcer treatment: a case series

Objective: Pressure ulcers (PU; also known as pressure injuries) affect about three million adults in the US and cost an estimated $11 billion dollars annually to treat. Prevention is most desirable, however, once a patient develops a PU, the focus shifts to effective treatment and rapid closure to improve health outcomes. We sought to evaluate outcomes in 10 patients with category II and III PUs treated with dehydrated human amnion/chorion membrane (dHACM) allografts. Method: All patients were treated with weekly application of dHACM plus standard wound care (SoC) and followed for eight weeks. Results: Of the PUs, two were category II and eight were category III. The average PU size at dHACM initiation was 3.42±1.76cm2. After the first application of dHACM 7/10 (70%) of PUs responded to treatment with a reduction in wound size. Within two weeks of dHACM initiation into the plan of care, 4/10 (40%) of PUs had reduced in size by >50%. By week four, 60% of PUs (6/10) had reduced in size by >50%. Overall, during the eight week evaluation period, 9/10 PUs reduced in size, three of which healed completely. Conclusion: dHACM allografts appear to be a viable treatment option for category II and III PUs.

Tillage, compaction and wetting effects on NO3, N2O and N2 losses

Denitrification is sensitive to changes in soil physical properties that affect solute transport, air content and gas diffusion. Using lysimeters, containing intact soil from intensively tilled (IT) and no-tilled (NT) soil used to grow forage crops, we examined how simulated animal treading at different moisture contents (above and below field capacity; &gt;FC and &lt;FC respectively) affected losses of nitrous oxide (N2O), dinitrogen (N2) and nitrate (NO3). We applied 15N-labelled NO3 (250kg N ha–1) to the soil surface after treading (applied at 220 kPa to 40% of the soil surface), or to untrodden soil. Drainage occurred following weekly application of water over the experiment (two pore volumes over 84 days). Treading at &gt;FC greatly increased denitrification, especially from IT soil and produced the greatest amount of N2 (64kg N ha–1), N2O (8.2kg N ha–1), as well as the lowest N2O to N2O+N2 ratio (0.08) and NO3 leaching (136kg N ha–1 below 30cm). In both the uncompacted or compacted soils &lt;FC, emissions of N2O were greater (1.5–2.7% of N applied) and the N2O to N2O+N2 ratios were closer to 0.2 compared to compaction at &gt;FC. Treading at &lt;FC had minimal or no effect on denitrification compared to untrodden soil. Fluxes of N2 and N2O were strongly influenced by the weekly irrigation–drainage cycle. The N2 production and reduction in NO3 leaching were best correlated with increases in microporosity and reduced saturated hydraulic conductivity following treading. Although recovery of 15N was high (84.3%), the remainder of the balance was likely lost as either N2 or, of greater concern, as N2O. Practically, animal trampling on wet soils, especially when recently cultivated, should be avoided.

Frequency of fungicide application for controlling downy mildew in seedless grape plant ‘BRS Vitória’

Different application frequencies of metalaxyl + mancozeb were evaluated to control downy mildew in vine plants ‘BRS Vitória’ in two experiments conducted in Jales, São Paulo, one in the production cycle and another in branches formation cycle. In experimental design of randomized blocks, five treatments were compared (1- two weekly applications; 2- one weekly application; 3- one application every 14 days; 4- one application every 21 days; 5- applications after sporulation) with four replications, each plot with three plants. According to the analysis of the area under the disease progress curve (AUDPC), in both experiments, there were statistically significant differences between the disease control levels provided by the different treatments (P = 0.05), being the control more efficient when there were two weekly sprayings with metalaxyl + mancozeb, followed by one weekly spraying. Regarding the number of sprayings of the treatment “spraying after sporulation” there was a reduction of over 90% when compared to standard treatment, “two weekly sprayings.” This reduction, however, did not result in a significant increase in the percentage of affected leaf area, which was less than 3%, causing no damage to the plant and not interfering with the quality and the physicochemical characteristics of clusters.