adjuvant label doses tested in this research. The coffeeleaves were collected from six year old plants ofCoffee Arabica cultivar Mundo Novo, grown under non- controlled environmental conditions at a spacing of 0.8 × 4.0 m, located in the College of Technology and Agricultural Science. Plants had uniform architecture with 2.0 m in height and 1.0 m in diameter of the canopy closer to the ground. Soil at this location is classified as Distrofic Ultisol (Santos et al., 2018). The climate, according to Köeppen’s classification, is Aw (tropical savanna, with a dry winter and hot, rainy summer). Coffee branches were removed from the trees and immediately carried to the laboratory. The base of the removed branches containing the leaves were kept into a 1 L pot filled with water before being sprayed, to avoid leaf dehydration. Mature coffeeleaves were removed from the branches and had their weights determined by analytical precision balance (Marten, model AY 220, São Paulo, SP, BR).
Wheat (Triticum aestivum ‘Oakley’) and maize (Zea mays ‘Lorena’) plants were sown in pots (TEKU- Container EC 17, volume = 2 L, Pöppelmann GmbH & Co. KG, Lohne, Germany) with a substrate prepared from peat and sand (5 plants for wheat and 1 for maize). Each pot was an experimental unit (EU) and was cultivated indoors. Each treatment consisted of 10 EUs, totaling 180 EUs, which were kept in a controlled environment under a temperature of 20 ± 5 °C and relative air humidity of 50 ± 10%. The plants received fertigation with a standard commercial fertilizer, according to the needs of each crop, during the entire period that they remained in the greenhouse. They were kept until they reached approximately 0.15 m in height, which was considered the ideal size for use in trials.
Considering the difficulties in coffee leaf rust control, investigations aimed at developing alternate control methods that can be integrated with genetic and chemical approaches are justified. Silicon (Si) may provide a viable alternative as its direct or indirect beneficial effects to plants under biotic and or abiotic stresses have been reported in a wide variety of crops such as barley, corn, cucumber, grape, rice, rye, strawberry, and wheat (Datnoff et al., 2007). In coffee, Pereira et al. (2009) reported no significant difference between coffee plants sprayed or not sprayed with potassium silicate, a soluble source of Si, for leaf rust severity. Indeed, potassium silicate spray did not increase activity of the enzymes chitinases, β-1,3-glucanases, peroxidases, polyphenol oxidases, phenylalanine ammonia- lyases, and lypoxigenases. In another study, Carré-Missio et al. (2009) grew coffee plants in a nutrient solution containing 0 (-Si) or 2 mmol Si/L (+Si) and inoculated them with H. vastatrix. According to these authors, Si concentration in leaf tissues of plants supplied with Si did not increase and there was no significant difference between -Si and +Si treatments for incubation period, latent period, number of pustules per leaf, pustule size, pustule expansion, and area under rust progress curve. The activity of chitinases, β-1,3- glucanases and peroxidases increased after inoculation with H. vastatrix, but their activities were not higher on leaf tissues of Si-supplied plants. Coffee plants can uptake Si through their roots (Silva et al., 2010), but translocate it inefficiently to shoots (Carré-Missio et al., 2009), depriving them of the multiple positive benefits brought by this element.
range 31.73 to 67.62 %. It was observed that h was significantly positively dependent on air flow rate in the linear term and negatively dependent on interaction coffee leaf extract concentrationand air flow rate. Increasing air flow rate, the relation air/wet particles were increased and the drying is improved and it is easier to obtain the dried particles. According to Wang and Langrish (2009), the collection efficiency of a spray-drying process is highly affected by loss of material that adheres to the walls of the spray equipment. Besides the studied variables, collection efficiency is still function of the typeof the formulation, dimensions of the chamber and the operational properties (solid content, viscosity and inlet air temperature) (tRuoNG; BHANDARI; HoWES, 2005). Vardin and Yasar (2012), in spray drying of pomegranate juice with maltodextrin, obtained collection efficiency from 2.3 to 76.3 % and observed that materials with great sugar content like fruits could be adhered to the dryer walls, with lower collection efficiency. The tests 9 and 14 presented the higher collection efficiency (67.62 and 65.87 %, respectively). In test 9, maltodextrin concentration was low (7.5 %), what means lower production cost and higher proportion coffee leaf extract/maltodextrin in the dried product.
ABSTRACT: The air included in droplets generated by spray nozzles directly int0erferes in transport, deposition andretentionof the droplets after its impact on the target. The objective of this study was to analyze the interference ofadjuvants in the amount of air included in droplets generated by spray nozzles. The treatments were composed by four spray solutions containing mineral oil, vegetable oil, surfactant and water, and three spray nozzles, two air induction typeand one pre-orifice. The air included was calculated by the difference between the volume ofspray mix (air plus liquid) and only the liquid, which was made by means of sprayed samples captured in a funnel and collected in a graduated cylinder. The surface tension was estimated by the gravimetric method using a precision scale and a graduated pipette. The surfactant provided the largest percentage of air included in the spray. For the surface tension, the mineral oil and the surfactant had the lowest values. It was concluded that the use ofadjuvants had a direct influence on the percentage of air included. In addition, products with greater ability to reduce surface tension and to form homogeneous solutions provided the increase in the percentage of air included in the droplet. KEYWORDS: application technology, air induction, pre-orifice, surface tension.
ABSTRACT: Pesticides are often applied under incorrect conditions such as inappropriate nozzles types and high spray volumes. Such errors result in spray drift and run off, causing inefficiency on the control of pests and diseases, beyond environmental contamination. Here we evaluate the influence ofspray volumes, nozzle types andadjuvantson the control of phoma andcoffee rust. The objective in this work was to evaluate the feasibility of reducing the volume of syrup in the absence and presence of adjuvant, using three spray nozzle types, analyzing the uniformity of the spray distribution to thirds of the plant and its penetration and effectiveness of phytosanitary products. The treatments were t arranged in a factorial 3 x 2 x 2 + 1, outlined in a randomized block design with three replications in a split plot. Treatments were three-pointed ontype empty cone (ATR Amarela; JA Preto e Disc-Core AD2AC23), two spray volumes (300 and 500 L ha -1 ), on absence and presence of
The importance of applying phytosanitary products to agricultural crops and the growing concern over safety and environmental responsibility have encouraged the development of new technologies aimed at reducing risks. There is a tendency to reduce the application volume, both to increase the operational capacity of application machines and to reduce water consumption (CHAIM, 2012). Lower application rates may increase product coverage and efficiency, increase the operational capacity of sprayers, and decrease production costs (TAVARES et al., 2017). Application technology is based on the correct application of the active ingredient in the target, in an economical way, affecting the environment as little as possible, in order to maximize efficiency. Studies related to spray equipment associatedwithspray volumes (MIRANDA et al., 2012), the potential ofadjuvants to reduce drift in agricultural spraying (OLIVEIRA et al., 2013) and the reduction in the spray volumes in coffee (SILVA et al., 2014; DECARO JUNIOR et al., 2015, GITIRANA NETO et al., 2016; SOUSA JÚNIOR et al., 2017), have been developed with promising results. The deposition and losses of applied products are influenced by the morphological characteristics of plants andleaves, such as hairiness, cuticular surface, shape and roughness, as well as plant architecture (SANTINATO et al., 2017). The use ofadjuvants can reduce the negative influence of the medium, from the preparation of the nozzle to the contact with the target, breaking physical and chemical barriers and facilitating the penetration of the insecticide.
The monitoring activity was according to a methodology adapted from Zampiroli et al. (2017); each plot was monitored separately, including the controls without insecticide application. A leaf in the third or fourth pair of plagiotropic branches was observed at the median height of the plant, on the north and south surfaces, where 60 leaves were sampled per plot, summing up to 240 leaves per treatment. Plants of the Mundo Novo cultivar aged five years were grown with a spacing of 3.5 m between rows and 0.9 m between plants.
Abstract: Natural polyphenols are important dietary antioxidants that significantly benefit human health. Coffeeand tea have been shown to largely contribute to the dietary intake of these antioxidants in several populations. More recently, the use ofcoffeeleaves to produce tea has become a potential commercial target, therefore prompting studies on the quantification of polyphenols in coffeeleaves. In this study a variety ofcoffee leaf species, at different development stages, were analyzed using ultra-high pressure liquid chromatography. The results demonstrate that both the botanical origin of the samples and their maturity influence significantly the concentrationof the antioxidants; for total chlorogenic acids a two-fold difference was found between different species and up to a three-fold variation was observed between young and mature leaves. Furthermore, the range of concentrations of chlorogenic acids in young leaves (35.7–80.8 mg/g of dry matter) were found to be comparable to the one reported for green coffee beans. The results provide important data from which potential new commercial products can be developed.
small number of subjects in the subgroups (less than 12) do not permit a conclusion to be made. In a study with 60 diabetic patients, Mata et al. (11) observed higher calcium concentrations (>50 mg/L) in the saliva of DM patients than in matched healthy controls. The high sensitivity of the atomic absorbance spectrophotometer technique used to measure calcium electrolytes in saliva cannot be disre- garded. This technique can measure strong protein-cal- cium binding complexes and it is certainly much more sensitive than the specific ion electrode and probably more sensitive than the TLC photometer used by Reznick et al. (21). On the other hand, the ion-specific electrode directly measures free ionic calcium in saliva, which is of clinical relevance for the development of caries (27).
polymer reduced the drift when sprayed through AI nozzle, but not through XR nozzles. Their results are not in accordance with results from the present study because we observed that dicamba drift was reduced when polymer was added to the solution sprayed through nonair-induction nozzles. Oliveira et al. (2013) measured drift from 30 solutions withadjuvants sprayed through XR 8003 nozzle in a wind tunnel. Similarly to what was observed in the first run of the present study, the authors observed that vegetable oil reduced the drift, in comparison to the solution without adjuvants. Hilz & Vermeer (2013) reported that nozzle type has a more expressive influence on drift reduction than the formulated product or the spray additive. Drift-reducing adjuvants should be used when their effects are known, in order to avoid undesirable results, such as those observed for the combination between phosphatidylcholine and TTI nozzle. The effects of formulation andspray solution on drift using air-induction nozzles are less predictable, since the relationships between drift andspray characteristics for these nozzles are less understood (Miller & Butler Ellis, 2000).
Drought tolerance was assessed to study the ability of P. macrosporus to reduce C. coffeicola isolate LFP 37 survival in plant lesions under humidity variation to simulate field conditions (Köhl et al., 1995). Fungal growth, plant cultivation, and fungal spray were performed as described above. Immediately after antagonist application, wetness was interrupted. Thereafter, 10 leaves per treatment were placed on two layers of sterile dry filter paper in open Petri dishes in laminar flow cabinet for 9 h. The leaves were incubated for two different periods of interrupted wetness (0 and 61 h) after the antagonist application. (Köhl et al.,1995). After the dry period, the filter paper was wetted with 2 mL of sterile tap water. Then, the Petri dishes were closed and kept under the same conditions, as described above. After 7 days, number and germination of pathogen conidia were determined, as previously described. The experiment was set up in a completely randomized block design, using a factorial scheme (1 x 2) with P.macrosporus fungus and two different periods of interrupted wetness (0 and 61 h). Each treatment was represented by three replicates and each replicate was composed with 10 leaves per plot. 2.5. Antibiosis and volatile production test
greenhouses, reducing productivity as a consequence. Similar results, with lettuce shoot dry matter yield of 10.14, 7.69 and 3.29 g/plant were observed in an experiment with shading at zero, 18 and 50% respectively (Novo et al., 2008). There was also a reduction in biomass production of shoots of lettuce under protected environment when shading increased from 10 to 90%, falling from 225.7 to 81.0 g/plant (Byrne et al., 2002). The increase in fresh mass production showed a quadratic fit with lower elevation of the fresh weight by raising the PPF, while the dry weight gain followed a linear increase (Figure 1), showing that the difference between the models indicates greater water loss in plants without shading (PPF= 455 mol/m 2 /s). This can be verified by the
A strong positive correlation was observed between elec- trical conductivity and control scores, so that the higher the electrical conductivity value, the higher the weed control. It can be due to the interaction with the surface and plant metabo- lism, given the specific properties of leaf chemical composi- tion and the way the interaction takes place (KISSMANN, 1998). Items such as ion concentrationon the surface and inside cells, as well as the modification of morphological char- acteristics of epicuticle cells may alter the absorption or trans- location rate of molecules by plant structure and metabolism (PIGNATELLO; XING, 1995). Herbicide can be absorbed inter- and intracellularly, requiring more or less energy con- sumption. These pathways imply metabolic routes with ion exchange whose availability in the formulation may favor Table 3. Slicing of the significant interaction of electrical
were planted in plastic bags with dimensions of 10 x 30cm that contained treated soil, sand, and humus. Spraying was performed using two fungicides widely used in citrus production for the control of diseases such as citrus black spot; two insecticides used to control psyllid, HLB vector and other insects; and two miticides used to control the mite vector of citrus leprosis virus and other mites. Fungicides used were Cuprogarb 500 ® (copper oxychloride) at a dosage
manufacturers. The characteristics to be evaluated were the surface tension, electrical conductivity and pH of the solution. Average values were compared by Scott-Knott test at 0.05 significance. Given the significant interaction between factors, results for the plant protection products on the physico-chemical characteristics proved to be dependent on the adjuvantsand vice versa. Among the adjuvants, phosphatidylcoline + propionic acid resulted in the greatest reduction in the pH of the solution. Only the herbicide chlorimuron-ethyl had no effect on the surface tension of the solution, which was reduced by the remaining products. All the products affected electrical conductivity, the greatest increases being obtained with the herbicides 2,4-D dimethylamine and glyphosate.
of a response to rapid changes in temperature without enough time for conditioning (thermal stress). Empirical analyses of copepod feeding field data (Peters and Downing, 1984; Saiz and Calbet, 2011) have shown that, compared with other variables such as food concentra- tion, temperature had a weaker control over copepod feeding rates, likely as a consequence of physiological adaptation to habitat condition. This fact may suggest that the populations invading the North Atlantic in recent years might be better adapted to colder waters than the population we worked with, caught off western Iberia. Examples of physiological adaptation in copepods have been well studied in the calanoid Eurytemora affinis (e.g. Ketzner and Bradley, 1982; Petersen and Lee, 2003). There is also evidence that co-existing copepod species, as demonstrated for some Temora and Centropages species, may have more similarities in their abundance, body size and reproduction cycles than congeners living in different habitats (Halsband-Lenk et al., 2004).
Innate immunity provides the first line of defence against infection and includes physical and chemical defensive barriers as well as cellular barriers, namely phagocytes (macrophages and dendritic cells), granulocytes (neutrophils, eosinophils, basophils or mast cells) and natural killer (NK) cells (1). These cells express on their surface pattern recognition receptors (PRRs), that recognize conserved pathogen-associated molecular patterns (PAMPs) (2). Phagocytic cells internalize antigens through the endocytic pathway and process them into peptides in association with major histocompatibility complex (MHC) molecules. MHC-class II are expressed mostly by antigen-presenting cells (APC), manily macrophages, dendritic cells (DCs), and B cells. These cells are professional in antigen processing and presentation, both critical for T cell activation (1,3). Furthermore, innate activated cells produce a myriad of inflammatory cytokines and chemokines pivotal for the polarization of the appropriate subsequent immune response, directly impacting on effector function of T cells (1,2).
ABSTRACT: Asian citrus psyllid, Diaphorina citri, is considered the most important citrus pest worldwide, as it transmits Huanglongbing – serious citrus disease. New efficient and sustainable strategies to control this pest have been investigated and the use of entomopathogenic fungi has become a promising alternative. The objective of this study was to evaluate the effects of adju- vants a) Tween 80 at 0.01 % (v/v); b) Silwet L77 at 0.025 % (v/v) and c) KBRAdj at 0.075 % (v/v) on adhesion, germination and pathogenicity of Isaria fumosorosea ESALQ-1296 (5 × 10 6 conidia mL –1 ). Female adults of D. citri used in this experiment were sprayed on Citrus limonia seedlings. The sprayed insects were analyzed through scanning electron microscopy (SEM) to identify the most susceptible integument regions for fungus attachment and the effect ofadjuvants used. In the pathogenicity test, adjuvants Silwet L77 and KBRAdj presented a higher efficiency than Tween 80. Fungi adhered predominantly to the ventral posterior (abdomen) region in comparison with the dorsal anterior (thorax) region. In addition, adjuvants Silwet L77 and KBRAdj presented faster germination (< 48 h) of I. fumosorosea spores when compared to Tween 80 (> 72 h). Co- nidial germination in the dorsal part of the thorax of the insects was observed only with adjuvant KBRAdj 72 h post inoculation.
Although poorly studied, the bacterial halo blight is an important disease in the major coffee-producing states of Brazil. External damage and anatomical changes onleaves were measured in seedlings of Coffea arabica cv. Mundo Novo, susceptible to Pseudomonas syringae pv. garcae, by using histological sections obtained at 10 and 20 days after inoculation (DAI). The changes on the epidermis were smaller than the lesions measured in the mesophyll, irrespective of the evaluated colonization period, showing that the internal damage caused by the bacterium represent twice the damage observed externally. From the inoculation site, lysis occurred on the epidermal cells andon the palisade and