Effect Of Application Time Research Articles

Effect of glucose, fructose, and sucrose on vase life, antioxidants enzymes, and some physiologic parameters of carnation cv. ‘Yellow Candy’ cut flower

Introduction: Carnation (Dianthus caryphyllus L.), from Caryophyllaceae family, is one of the most important cut flowers in the world that its short vase life reduces the economic value. Postharvest longevity of cut flowers can be prolonged using carbohydrates (sugars) in a vase jar. Cut flowers undergo some physiological and biochemical changes that often lead to an early senescence. To delay the aging process in cut flowers, it is necessary to evaluate many aspects of preparation for storage conditions, especially preservative solutions that affect the quality and longevity of these flowers. Many flowers are harvested before they are fully developed, to ensure a long postharvest life and to minimize mechanical damages that might occur during handling. The growth and development of flower buds on cut flowers require food (especially carbohydrates), which is stored in the leaves and stems. These stored carbohydrates can be mobilized for the flower bud to use but maybe they are insufficient when the buds are harvested at a tight-bud stage. To maintain metabolic activities, including respiration, even for cut flowers that have reached full development, it is necessary to provide adequate reserves to achieve acceptable postharvest life. When stored materials are low, leaves and flowers age faster and the petals fade. Under these conditions, supplements can be provided to the flowers by adding sugars such as glucose, fructose and sucrose to the vase solutions. However, it is important to note that a sugar solution is also suitable for the growth of microorganisms, so that an antimicrobial agent should be added to the vase solution as well. Many researches were carried out on prolonging the vase life of cut carnation flowers with different preservative solutions together with an antimicrobial agent. Studies on postharvest longevity of cut carnation flowers using sugars as preservative solutions is low. Therefore, the aim of the present study was to evaluate the effect of sugars (glucose, fructose and sucrose) and application time on vase life and some physiological parameters of carnation cv. “Yellow Candy” cut flowers.Materials and Methods: A factorial experiment based on completely randomized design in three replicates was performed in order to investigate the effect of different levels (0, 50 and 100 g/L) of three types of sugars (glucose, fructose, and sucrose) and two sugar application times (the first and second 24 h) on vase life of carnation cv. Yellow Candy cut flowers. Some other traits such as water uptake, dry mater, relative fresh weight, protein and carotenoid of petal, leaf chlorophyll, POD and SOD enzymes activity and MDA were also measured. The statistical analysis of data was performed using Statistical Package for Social Sciences (SPSS) v 16.0. Least significant difference (LSD) test at P < 0.05 was used to find out the significance of differences among the mean values.Results and Discussion: Results showed that the effect of different levels of sugars on all evaluated traits was significant. Each three levels of sugars at each two applied times caused to increase vase life and relative traits. Maximum vase life (18 days) was obtained in 50 g/L glucose at the first 24 h with no statistically significant differences with the 100 g/L sucrose and fructose at the first 24 h. The highest water uptakes and dry matter, the lowest POD and SOD activity and minimum MDA were obtained in treatment of 50 g/L glucose at the first 24 h. The highest petal protein content, chlorophyll a, b, and total chlorophyll were achieved in treatment of 50 g/L glucose at the second 24 h. The use of sugars at the first 24 h was more effective in improving the vase life than at the second one. Therefore, application of glucose, preferably in the early hours of harvesting flowers, can be recommended as a prolonged postharvest carnation Yellow Candy cut flowers. Positive effect of external holding solutions in vase jar particularly sugars together with an antimicrobial agent on prolonging the vase life of many cut flowers have been shown. Treatment of some cut flowers with sucrose increased glucose and fructose in petals. External sugars can be provided to cut flowers by dissolving a known amount of sugar, along with an antimicrobial agent, into the vase solution. The optimum concentration of sugar varies significantly depending on the flowers being treated. Concentration of 2% sugar is used to keep most flowers in the vase solution. However, some other flowers require higher concentrations, such as 4 to 6%. Some flowers are damaged when treated with concentrations higher than 1%. Therefore, it is important to examine each flower before treating it to determine the optimal concentration of sugars. Sugars are a source of energy and carbon for cut flowers and play an important role in decreasing the protein degradation and ethylene production, maintenance of osmotic balance, increasing water uptake, and finally delaying in senescence process.

Field Response of Green Ash (Fraxinus pennsylvanica) and Honey Locust (Gleditsia triacanthos) to Aminocyclopyrachlor1

AbstractField trials were conducted to assess the impact of aminocyclopyrachlor on green ash (Fraxinus pennsylvanica Marshall) and honey locust (Gleditsia triacanthos L.) trees in an urban environment. Aminocyclopyrachlor is a relatively new, selective, plant-growth-regulator herbicide in the pyrimidine carboxylic acid family. Treatments were applied to Kentucky bluegrass (Poa pratensis L.) sod growing with and without trees present. Evaluations included determination of a safe spraying distance from target trees and the effect of application timing on tree response. This multi-year study showed that green ash was highly tolerant to aminocyclopyrachlor while honey locust developed severe injury in trees closest to applications. Honey locust trees up to 7 m (23 ft) from the tree trunk to the edge of the application displayed moderate to severe injury symptoms and fall treatment in October and November had the lowest tree injury compared to all other application timings. Honey locust trees exhibiting moderate to severe cosmetic injury would not be acceptable to landowners; recovery over time was minimal. Trees located 13 m (43 ft) away displayed no injury for any treatment timing. Soil analysis demonstrated that aminocyclopyrachlor dissipation was the same underneath green ash and honey locust trees, and that dissipation was faster in the presence of growing trees. Taken together, these results provide a basic groundwork necessary for improving aminocyclopyrachlor labels, and a better understanding of this herbicide's effect on certain woody species.Index words: Herbicide injury, aminocyclopyrachlor, herbicide fate, tree safety.Species used in this study: Green ash, Fraxinus pennsylvanica Marshall, honey locust, Gleditsia triacanthos L.Chemicals used in this study: Aminocyclopyrachlor.

Effects of adhesive application time and air blowing pressure on dentin bond strength of self-etch mode universal adhesives

The aim of this study was to investigate the effects of the active application time and air blowing pressure on the bond strength of universal adhesives. Three universal adhesive systems were used: Scotchbond Universal, Clearfil Universal Bond Quick, One coat 7 Universal. Flat dentin surfaces were obtained from 150 human molar teeth. The samples are randomly divided into groups according to the adhesives and the air blowing pressures (0.13 MPa, 0.27 MPa and 0.40 MPa) and then subdivided into groups according to different application times (5 s, 10 s, 20 s) (n = 5). For each adhesive system, a group without air blowing pressure was assigned as the control group (n = 5). The shear bond strength test was performed. Data were analyzed by ANOVA and Tukey HSD tests (p<0.05). There was no statistically significant difference in all variables and interactions except pressure variable (p<0.05). The bonding values of 0.13 MPa were significantly higher than 0.40MPa (p<0.05). Air blowing pressures have a significant effect on the bond strength of universal adhesive systems.

Winter cereal responses to dose and application timing of trinexapac‐ethyl

AbstractTrinexapac‐ethyl (TE) is a plant growth regulator commonly used in cereal production systems. It retards plant growth by inhibiting gibberellin (GA) biosynthesis, thereby reducing the risk of stem lodging. Lodging at the latter stages of crop development can compromise grain yield and quality. Thus, application of TE may protect yield and quality in winter cereals. A field study was conducted from 2014 to 2017 across the Canadian Prairies to determine the effects of TE dose and application timings on lodging, canopy architecture, grain yield, and quality of winter cereals. Trinexapac‐ethyl treatments consisted of 0.6× (60 g a.i. ha−1) and 1× (100 g a.i. ha−1), which were applied to two winter wheat (Triticum aestivum L.) cultivars, 'Flourish’ and ‘Moats’, and a fall rye (Secale cereale L.) cultivar ‘Hazlet’, at Feekes 5 and 7 growth stages. Compared with the control, TE application increased grain yield by 3–8%, reduced plant height by 5–10%, and shortened internode length. Plant height reductions were most notable when TE was applied at the 1× rate at Feekes 7. The most responsive crop was fall rye, which could be expected given its tall stature relative to the wheat cultivars. Most of the tested environments, including irrigation, did not induce heavy stem lodging; therefore, observations of positive yield responses in the absence of lodging were unexpected. Our findings suggest that there is a role for TE in winter cereal production systems, provided the magnitude of crop responses justifies the added input costs.

The effect of application times and temperatures of hydro-precooling on the respiration rate of cayenne pepper (Capsicum annuum ‘bird’s eye’)

Hydro-precooling is known as one of the methods to preserve quality during the storage period of agricultural products. Punctuality of the application and temperature of precooling water has a pronounced effect of the respiration rate of agricultural products. This research was intended to study the effect of application times and temperatures of the hydro-precooling process on the respiration rate of cayenne pepper (Capsicum annuum ‘Bird’s Eye’) during the storage period. Three different application times, just at harvesting, 12, and 24 hours after harvesting, and three water temperatures of 5°C, 10°C, and 15°C were studied in a completely randomized design with three replications. Chili samples were hydro-precooled by immersion method then loaded in the respirometer and stored in cold storage at the same temperature as precooled water temperatures. Oxygen and carbon dioxide changes were monitored using O2 and CO2 Gas Analyzer (Quantek 902D) every day for 21 days of storage period. It was found that storage time, precooling application time, water temperature, and their interaction significantly influenced the respiration rate of the samples. However, the respiratory quotient was only influenced by storage time and precooled product temperature (p<0.05). The treatment combination of precooling application just at harvesting and precooling temperature of 10°C resulted in the lowest respiration rate.

Effect of Acid Mixtures on Surface Properties and Biaxial Flexural Strength of As-Sintered and Air-Abraded Zirconia.

The aim of this work was to evaluate the effects of application time of an acid mixture solution on the surface roughness, phase transformation, and biaxial flexural strength of 3Y-TZP after sintering or air abrasion. For the biaxial flexural strength measurement, 220 3Y-TZP disk-shaped specimens were prepared after as-sintering or air abrasion. The etching solution comprised a mixture of hydrofluoric acid, sulfuric acid, hydrogen peroxide, methyl alcohol, and purified water. The samples were divided into 11 subgroups according to the etching times (Control, 1, 2, 3, 5, 8, 10, 12, 15, 20, and 30 min). The results showed that acid treatment on both as-sintered and air-abraded 3Y-TZP surfaces increased the surface roughness. However, it had no significant effects on the monoclinic phase or flexural strength of as-sintered zirconia. The monoclinic phase and flexural strength of air-abraded zirconia increased sharply after air abrasion; however, they gradually decreased after acid treatment, to a similar level to the case of the untreated surface. Surface treatment with acid mixture increased the roughness, but the lack of increase of monoclinic phase is thought to be because the loose monoclinic particles remaining on the surface were removed through the etching process.

Influence of reduced application time on bonding durability of universal adhesives to demineralized enamel.

This study aimed to assess the effect of application time on the microshear bond strength (μSBS) of three universal adhesives in demineralized and sound enamel before and after aging. Bovine teeth (192) were prepared where buccal surfaces were ground and divided into two groups (sound enamel and demineralized enamel). The specimens in each group were divided into 12 subgroups by combining 3 adhesive agents (All-Bond Universal, Scotchbond Universal, and Tokuyama Universal Bond) × 4 adhesion strategy. Each adhesive was applied with either prolonged (PA) or reduced (RA) application time in etch-and-rinse or self-etch mode. Bonded composites were subjected to μSBS testing after 24-h or 2-year water storage. The results were evaluated using four-way ANOVA and Tukey's post-hoc test (α = 0.05). The μSBS of adhesives to sound enamel in both etching modes was mostly similar to demineralized enamel, regardless of application time and aging time. At 24-h, all adhesives with PA in self-etch mode showed higher μSBS when compared with RA, except Tokuyama Universal Bond, but after 2-year aging, no significant difference was found in μSBS between RA and PA. The μSBS of adhesives with PA in etch-and-rinse mode depended on used adhesive and enamel condition compared to RA, regardless of μSBS testing time. PA of adhesives did not reveal a significant difference in μSBS to enamel, regardless of substrate type and etching mode. After 2-year aging, the bond strength of universal adhesives presented no significant difference between PA and RA treatments.

Quality Characteristics of Semi-Moist Apricot-Cornflakes: Effect of Different Composite Coating Application and Storage Time

The effect of different composite coatings on quality of semi-moist apricot cubes mixed with cornflakes was investigated during 180 days of storage. The apricot cubes were osmotically dehydrated (OD) and coated before hot-air drying (HAD) at 60 °C. Chitosan-bees wax (CBW) and whey protein isolate-bees wax-oleic acid (WPI-BW-OA) coatings were applied after HAD and the samples were added to cornflakes. Application of OD and pectin-ascorbic acid (Pec-AA) coating (prior to HAD) and WPI-BW-OA coating (after HAD) led to significant retention of total phenol compounds, β-carotene and antioxidant activity in apricot cubes compared to uncoated and CBW-coated samples. WPI-BW-OA-coated samples gave significantly higher L* values (lighter color) and b* values (more creamy or yellowish color) and lower a* values (less reddish color) and browning values than control followed by CBW-coated apricots at any time of storage (p &lt; 0.05). The rate of apricot moisture loss and cornflakes moisture gain was higher in uncoated apricot cubes, followed by CBW- and WPI-BW-OA-coated samples. Application of WPI-BW-OA coating was effective in retaining the crispness measured by lower firmness (Fmax) values in cornflakes upon storage. Based on the obtained results, WPI-BW-OA coating allowed effectively preserving the quality characteristics of semi-moist apricot cubes and cornflakes components in the mixed state.

The impacts of contact force, power and application time on ablation effect indicated by serial measurements of impedance drop in both conventional and high-power short-duration ablation settings of atrial fibrillation

sBackgroundThis study aimed to clarify the interrelationship and additive effects of contact force (CF), power and application time in both conventional and high-power short-duration (HPSD) settings.MethodsAmong 38 patients with paroxysmal atrial fibrillation who underwent first-time pulmonary vein isolation, 787 ablation points were collected at the beginning of the procedure at separate sites. Energy was applied for 60 s under power outputs of 25, 30 or 35 W (conventional group), or 10 s when using 50 W (HPSD group). An impedance drop (ID) of 10 Ω was regarded as a marker of adequate lesion formation.ResultsID ≥ 10 Ω could not be achieved with CF < 5 g under any power setting. With CF ≥ 5 g, ID could be enhanced by increasing power output or prolonging ablation time. ID for 30 and 35 W was greater than for 25 W (p < 0.05). Ablation with 35 W resulted in greater ID than with 30 W only when CF of 10–20 g was applied for 20–40 s (p < 0.05). Under the same power output, ID increased with CF level at different time points. The higher the CF, the shorter the time needed to reach ID of 10 Ω and maximal ID. ID correlated well with ablation index under each power, except for lower ID values at 25 W. ID with 50 W for 10 s was equivalent to that with 25 W for 40 s, but lower than that with 30 W for 40 s or 35 W for 30 s.ConclusionsCF of at least 5 g is required for adequate ablation effect. With CF ≥ 5g, CF, power output, and ablation time can compensate for each other. Time to reach maximal ablation effect can be shortened by increasing CF or power. The effect of HPSD ablation with 50 W for 10 s is equivalent to conventional ablation with 25 W for 40 s and 30–35 W for 20–30 s in terms of ID.

Gypsy Moth Management with LdMNPV Baculovirus in Cork Oak Forest

(1) Research Highlights: Applications of a species-specific baculovirus is a promising method to control the gypsy moth and regulate its population dynamics in forest ecosystems. (2) Background and Objectives: Cork oak protection against the Lepidopteran defoliator Lymantria dispar requires an appropriate forest ecosystem management program, involving the application of eco-sustainable microbial products during population outbreaks. The species-specific multicapsid nucleopolyhedrovirus (LdMNPV), agent of natural epizootics in gypsy moth populations, represents an option that was investigated in a multi-year field study, involving viral applications either from the ground or by aerial treatment. (3) Materials and Methods: Efficacy trials against L. dispar populations were conducted in 2018 and 2019 in Sardinia, according to a randomized block design. Each year, two trials were conducted, applying a baculovirus commercial formulation with an atomizer from the ground and assessing the effects of different doses and application timing, respectively. An aerial application trial distributing LdMNPV at ultra-low volumes (2 L/ha) was also conducted in 2019 to assess the virus efficacy at a larger field scale. (4) Results: In both years, a significant increase in larval mortality was detected in plots treated with higher viral occlusion body (OB) doses and with an earlier application targeting younger larvae, in comparison with untreated controls. Due to an observed retrogradation phase of the target pest in 2019, no significant differences in larval density between areas treated from a helicopter and control were detected, but in the few weeks following application, a meaningful vitality decrease in larval samples from treated plots was observed. (5) Conclusions: Based on the results of this study, the use of LdMNPV in forest protection programs against gypsy moth can be worth consideration in multi-year integrated program strategies to modulate population dynamics.

Effect of dose and plant growth regulator application time on agronomic traits and yield components of Lamuru maize

The climate change of dry months for growth and production of corn, demanding the use of growth regulators. Atonic are generally known to increase metabolism and plant growth regulators. However, the optimal application time and dosage according to the location of planting in maize are unknown. This study determines the dosage and optimal time of atonic spray application to increase yield components. The study was conducted in Latosol soil in the dry land of Installation for Research and Assessment of Agricultural Technology (IP2TP) Bacan South Halmahera, North Maluku, from March to July 2019. The study was arranged in a factorial randomized block design with three replications. The first factor consists of the dose of atonic spray consisting of 4 levels, namely: 0.25cc/l, 0.50cc/l, 0.75cc/l and 1.00cc/l. The second factor is the atonic spraying time which consists of 3 levels, namely: 28 days after planting (dap), 49 dap, and 77 dap. The results showed that atonic spraying with a dose of 50cc/l at 28 dap produced the highest weight per 1000 corn seeds significantly different from spraying at 49 and 77 dap at various atonic doses. Spraying carried out at age 77 dap requires a higher atonic dose of 1cc/l to produce a weight per 1000 corn and it was correlated with leaf area at 49 dap (r=0.682) and with air temperature in July (r=0.35). High humidity (87.4%) in July was negatively correlated with plant height (r=-0.41) and weight of filled corncob (r=-0.37).

Effects of growing degree day based trinexapac‐ethyl application on ultradwarf hybrid bermudagrass putting green quality and ball roll

AbstractApplication of plant growth regulators to hybrid bermudagrass [Cynodon dactylon (L.) Pers. × Cynodon transvaalensis Burtt Davy] putting greens is a common management practice used to reduce clipping yield and improve aesthetic and functional turfgrass quality. Growing degree day (GDD) models have explored the effects of plant growth regulator application timing on ultradwarf hybrid bermudagrass clipping yield. However, there is a need for research evaluating effects of GDD‐timed plant growth regulator applications on turfgrass quality and ball roll. A field study was conducted in summer 2018 at three locations (Knoxville, TN; Raleigh, NC; and Starkville, MS) to determine the effects of trinexapac‐ethyl (TE) applied according to a GDD model on ultradwarf hybrid bermudagrass putting green quality and ball roll compared to calendar‐based treatment (i.e., weekly or twice‐weekly). For GDD applications, TE was applied at either 20 or 33 g ha−1. GDD based applications were made once 220 GDD (base 10°C) accumulated after each treatment. TE was applied at either 20 or 33 g ha−1 for weekly treatments and rate reduced to either 14 or 16 g ha−1 for the twice‐weekly treatment. In all locations, TE applied on a 220 GDD10C schedule resulted in turfgrass quality greater than or equal to that of the weekly and twice‐weekly applied treatments. Ball roll distance was slightly lower in plots treated with TE every 220 GDD10C compared to the weekly and twice‐weekly treatments, although differences may be negligible to golfers (13 to 23 cm). Ball roll distance was negatively correlated with clipping yield (−0.37 to −0.69). Turfgrass managers choosing to regulate ultradwarf hybrid bermudagrass greens with TE should consider applying on a GDD rather than calendar‐based interval to achieve improved turfgrass quality without sacrificing ball roll distance.

Soil Organic Carbon Dynamics in Semi-Arid Irrigated Cropping Systems

Insufficient characterization of soil organic carbon (SOC) dynamics in semi-arid climates contributes uncertainty to SOC sequestration estimates. This study estimated changes in SOC (0–30 cm depth) due to variations in manure management, tillage regime, winter cover crop, and crop rotation in southern Idaho (USA). Empirical data were used to drive the Denitrification Decomposition (DNDC) model in a “default” and calibrated capacity and forecast SOC levels until 2050. Empirical data indicates: (i) no effect (p = 0.51) of winter triticale on SOC after 3 years; (ii) SOC accumulation (0.6 ± 0.5 Mg ha–1 year–1) under a rotation of corn-barley-alfalfax3 and no change (p = 0.905) in a rotation of wheat-potato-barley-sugarbeet; (iii) manure applied annually at rate 1X is not significantly different (p = 0.75) from biennial application at rate 2X; and (iv) no significant effect of manure application timing (p = 0.41, fall vs. spring). The DNDC model simulated empirical SOC and biomass C measurements adequately in a default capacity, yet specific issues were encountered. By 2050, model forecasting suggested: (i) triticale cover resulted in SOC accrual (0.05–0.27 Mg ha–1 year–1); (ii) when manure is applied, conventional tillage regimes are favored; and (iii) manure applied treatments accrue SOC suggesting a quadratic relationship (all R2 &gt; 0.85 and all p &lt; 0.0001), yet saturation behavior was not realized when extending the simulation to 2100. It is possible that under very large C inputs that C sequestration is favored by DNDC which may influence “NetZero” C initiatives.

Targeting Ascophyllum nodosum (L.) Le Jol. extract application at five growth stages of winter wheat

Seaweed extracts are a category of biostimulant products that have the potential to promote plant growth and thus, have given a promise to develop more resilient systems of crop production that make efficient use of water and nutrients. This field study evaluated the effect of application timing of an Ascophyllum nodosum extract on nutrient uptake and grain yield of winter wheat when the extract was applied singly in five growth stages from 2017 to 2019. Analysis by orthogonal polynomial contrasts indicated that extract application significantly increased yield or biomass in all three site-years. Application at the tillering stage increased average yield by 17%, grain nutrient accumulation (N, P, K) by 21–24%, and N-use efficiency by 11% over the three site-year period, but extract effects were not consistent between site-years both in terms of optimal growth stages of application and magnitude of crop responses. While grain yield increased by 39% with extract application at tillering in 2017, yield gains ranging from 16 to 22% were obtained at the stem elongation and booting stages in 2018. These differences were likely the result of site-year variations in weather patterns and soil properties. Among macro-nutrients, only grain N accumulation was linearly correlated to grain yield across site-years indicating that increased soil N uptake and/or remobilization to the reproductive organs was a key process of the A. nodosum mode of action. An economic analysis indicated that the average return over extract cost was higher than that of the zero-extract control by €79-100 ha-1 when the extract was applied at the tillering or stem elongation stage and assuming higher dilution rates recommended by the industry. Even greater economic benefits can result if N rates are substantially reduced without an adverse effect on yield gains.

Nitrogen and biodegradator application to trigger ratoon growth and production of rice (Oryza Sativa)

Increasing the rice harvest index to 5 times a year through ratoon system was an effort to fulfill food sufficient. Currently, ratoon productivity was only 40-50% lower than it’s parent plant. Utilization of rice stump biodegradator and nitrogen in the ratoon system could be applied to increase ratoon productivity. The aimed of this research was to trigger tillers formation and production of ratoon through application of biodegradator and nitrogen. The experiment arranged in split plot design. The first factor was time of biodegradator application (main plot), i.e at harvest, 3 days after harvest, and 6 days after harvest, while the second factor was time of nitrogen application (sub plot), i.e 3 days before harvest, at harvest, and 3 days after harvest. The dosage of biodegrator and nitrogen were the same for all treatments, i.e 2.2 ml.plot−1 and 8.3 g N.plot−1 respectively. Collecting data was consisted of number of tillers, number of productive tillers, number of leaves, number of grains per panicle, and weight of 1000 seeds. The results showed that all data observed were non-significantly different among treatment of biodegradator, nitrogen, as well as the combination. It was assumed that the dosage of biodegradator and nitrogen were not sufficient to trigger tillers formation of ratoon, so that the effect of application time of biodegradator and nitrogen were not significant.

Shortening Internodes Near Ear: An Alternative to Raise Maize Yield

Plant growth retardants (mainly with active ingredient of ethephon) prevent maize (Zea mays L.) lodging as plant density increases, but frequently reduce grain yield if lodging is not a problem, in relation to application time. To explore the effects of ethephon application time on maize yield, literature published in the past 35 years concerning ethephon or ethephon-related plant growth retardant in maize were collected for meta-analysis. In addition, field experiments, including ethephon application time from 8- to 15-leaf stages, were conducted in 2018 and 2019. Exogenous application of ethephon decreased lodging as a function of reduced plant and ear height and enhanced bending strength and rind penetration resistance of basal stem internodes. Lodging rate was at the lowest level at the 8–10 leaf application of ethephon and then significantly increased with the delayed application. The degree of reduction of internode length was related to application time; ethephon application at n-leaf stage started to work at the n-2 internode and reduced the n internode length the most. Grain yield increased with the delayed application time and reached the highest level with application at the 14-leaf stage in 2019 (32.6%) compared with control treatment, mainly owing to the increased kernel/ear and kernel/m2. The internode length from the plant bottom to the top was negatively correlated with kernel/ear and kernel/m2, and the correlations were significant nearby and below the ear. Applying ethephon after the 13-leaf stage can avoid damaging floret number (potential kernel number per ear), at which time floret initiation has terminated. Besides, delayed ethephon application enabled stem growth to compete less with floret growth by reducing stem internode elongation during the critical period, and accelerated photosynthate partitioning from leaves to the ear, providing enough assimilate for kernel formation and growth. Taken together, delayed ethephon application (i.e., after 60% leaf age index) in combination with lodging resistant hybrids can further raise maize yield in the context of continuously increased plant densities.

Strong potential of slurry application timing and method to reduce N losses in a permanent grassland

Livestock manure is a major source of nitrogen (N) for plants, but also of ammonia (NH3) and nitrous oxide (N2O) emissions to the atmosphere, and nitrate (NO3−) leaching to groundwater. Slurry application practices targeted at reducing each of these N losses individually are relatively well known. Yet, our understanding of the potential relationships between N loss pathways is far from being complete. In this field study on grassland, we tested the effect of slurry application timing (autumn vs. winter vs. spring) and method (injection vs. broadcasting) and their interactions on N2O emissions, NH3 volatilization and NO3− leaching, as well as on plant N uptake. We found that autumn application increased NO3− leaching by 65 % compared with winter and spring due to 63 % higher rainfall following application. On average, autumn application reduced plant N uptake by 26 %. N2O emissions after winter slurry application were 43 % higher that after either spring or autumn applications. Slurry application method had no effect on NO3− leaching. Slurry injection led to 32 % higher N2O emissions compared with broadcast application. Slurry injection decreased NH3 volatilization only in autumn when the soil was relatively dry before application, but not in winter or spring when the soil was wet. Changes in slurry application timing led to variations in total N losses of up to 146 %, and application method of up to 19 %, highlighting the great potential of slurry application practices to steer an efficient N management. Overall, autumn application should be avoided to promote more sustainable grassland production; however, if slurry must be applied in autumn, injection should be recommended to reduce NH3 volatilization.

Cautery Disbudding Iron Application Time and Brain Injury in Goat Kids: A Pilot Study.

Cautery disbudding is a painful procedure performed on goat kids to prevent horn growth that may result in brain injury. Thermal damage to the cerebral cortex of the brain and subsequent neurologic disease is a primary concern. Cautery iron application time may affect transmission of heat to the brain; however, research in this area is scarce. Therefore, the objective of this pilot study was to evaluate the effect of iron application time on brain injury of goat kids. A total of six buck and doe kids <9 days of age were obtained from a commercial dairy and transported to an Iowa State University research facility. Kids received a different randomly assigned application time (5, 10, 15, or 20s) on each horn bud. Kids were disbudded using an electric cautery iron (under isoflurane general anesthesia). After a 5-day observation period, the kids were euthanized, and magnetic resonance (MR) images were acquired to evaluate brain injury. Additionally, four of the six kids were presented for gross examination and two kids were selected for histopathologic examination. From the MR images, white matter edema was observed subjacent to four treated areas, representing application times of 5 s (one horn bud), 15 s (one horn bud), and 20 s (two horn buds). With the exception of the horn bud that received 5 s, which had white matter edema restricted to a single gyrus, the remaining three groups had a branching region of edema. No bone abnormalities were identified on any kids. Gross evidence of discoloration and hemorrhage on the cerebral hemispheres was observed on two horn buds that received 20 s, two horn buds that received 15 s, and one horn bud that received 10 s. Microscopic lesions consisting of leptomeningeal and cerebrocortical necrosis were observed in sections of brain from all groups. Lesions were most severe with 20 s. In conclusion, all application times used in this study resulted in some level of brain injury; however, using 15 s or more resulted in more severe and consistent brain injury. These results indicate that extended iron application time may increase the risk of brain injury in cautery disbudded kids.

Effect of application time and concentration of silver diamine fluoride on the enamel remineralization.

BackgroundSilver diamine fluoride has attracted attention because of its clinical success in arresting dental caries. Thus, the aim of this study was to evaluate the effect of different application times and concentrations of silver diamine fluoride (SDF) on deciduous tooth enamel remineralization. Material and MethodsBlocks of deciduous tooth enamel were categorized into six groups of 11 each: 2 control groups: intact enamel, and demineralized enamel; 38% SDF and 30% SDF which were subdivided according to application times (1 and 3 min). The microhardness of samples was determined, and all groups except the intact enamel group were subjected to pH cycling to produce initial carious lesions. The 38% and 30% SDF solutions were applied to the enamel for 1 or 3 min. After pH cycling and SDF treatments, the microhardness was again determined. Samples were sectioned to evaluate the cross-sectional microhardness. Furthermore, internal porosity of the samples was examined using micro-CT. Data were statistically analyzed by analysis of variance followed by Tukey’s test, and linear regression analyses were performed. ResultsThere was no difference in enamel remineralization based on surface and cross-sectional microhardness. The 30% SDF solution applied for 3 min promoted significantly less pores than the other groups. ConclusionsThe 1-min application time promoted enamel remineralization regardless of the SDF concentration (30% or 38%). Key words:Cariostatic agents, dental caries, primary tooth, tooth remineralization.

Effect of Application Timing on the Efficacy of Spinosad Against Chilli Thrips on Potted Cleyera, 2019

Effect of Application Timing on the Efficacy of Spinosad Against Chilli Thrips on Potted Cleyera, 2019