Coffee Science (E-Journal)
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Using unmanned aerial vehicle and machine learning algorithm to monitor leaf nitrogen in coffee
Get PDFNitrogen is an essential element for coffee production. However, when fertilization do not consider the spatial variability of the agricultural parameters, it can generate economic losses, such as low productivity, and environmental impacts, such as pollution of air and eutrophication of water bodies. Thus, the monitoring of the nitrogen during different phases of the production is a key factor for the fertilization management, and remote sensing based on unmanned aerial vehicles imagery has been evaluated for this task. Thus, this work aimed to evaluate the potential of visible vegetation indices obtained from such images to monitor the spatial variability of the leaf nitrogen content in a coffee farm located in Divisa Nova Municipality, Minas Gerais. Therefore, we performed a leaf analysis using the Kjeldahl method to determine leaf nitrogen, and to process the images and produce the vegetation indices, we use Geographic Information Systems and photogrammetry software. As analyze methods, we used the Random Forest classification algorithm as an estimator and performed ordinary kriging to visualize the spatial variability as nitrogen content. Lastly, the Pearson correlation coefficient was employed to evaluate the relationship between the variables. However, the Random Forest models were unable to explain nitrogen variability, and we did not find any significant correlations between the tested vegetation indices and nitrogen content. Therefore, it is indicated the replication of the study in the vegetative phase of the coffee plants, with the establishment of different fertilization treatments, as well as the use of multispectral sensors and radiometric calibration techniques.
Keys words: Vegetation indices; RGB; machine learning; Coffea arabica
Canopy volume and application rate interaction on spray deposition for different phenological stages of coffee crop
Get PDFCoffee plants (Coffea arabica L.) present dense foliage that obstruct the entering of pesticides inside the plant canopy uniformly. Adjust the application rate concerning the plant canopy volume can be a way to make the pesticide applications more efficient. The objective of this study was to evaluate the deposition of spray solution on coffee leaves with different volumes of plant canopy and different application rates; additionally, to determine the specific volume indexes for different coffee phenological stages. The studies of coffee leaf deposition were performed on commercial fields of C. arabica - Topázio MG 1190 and Catuaí Vermelho IAC 99 cultivars, in different months. Three volumes of vegetation ranging from 8.572 to 16.200 m3 ha-1 - obtained from the calculation of tree-row volume (TRV) performed in 20 plants - and five application rates (200, 300, 400, 600 and 800 L ha-1) and in each phenological stage (maturation, post-harvest, grain filling) were evaluated in a randomized block design with five replications. A bright blue marker was added to the spray solution to be detected by spectrophotometry in order to study the spray deposition and losses to the soil. After the treatment applications, ten coffee leaves corresponding to the 1st pair of leaf from an orthotropic branch of each third of the coffee plant (upper, middle, lower) were randomly collected. Petri dishes were used to evaluate the losses to the soil. The TRV and leaf density should be considered together in the definition of the application rate for coffee protection. It is also possible to reduce the application rate to values close to 200 L ha-1. The volume indexes for each coffee phenological stage were defined for proper canopy wetting and low losses to the soil.
Key words: Coffea arabica L.; Spray losses to the soil; Spray volume; Tree-row volume; Volume index
Coffee protects cardiovascular health by maintaining the structure of coronary arterial wall intimal collagen
Get PDFThis study aimed to determine whether coffee consumption affects the structure of coronary arterial wall and protects against coronary artery disease (CAD) in atherosclerotic rat model induced by periodontitis. Rats (n = 21) were divided into three groups (i) Coffee group (periodontitis + coffee), (ii) Periodontitis group (no coffee), and (iii) Control group (no periodontitis, no coffee). A single dose of coffee suspension (representing one cup) was given daily by stomach sondation to the rats in the coffee group. The experiment was conducted for 5 wk. At the completion of the experiment, all of rats were sacrificed. Their hearts containing coronary arteries were removed and analyzed by histochemistry assay. In addition, the serum level of collagen degrading enzymes matrix metalloproteinase–2 (MMP–2) was also analyzed using Enzyme–link immunosorbent assay (Elisa). Results demonstrated that coronary atherosclerotic lesions including atheroma, stenosis, and vascular occlusion were rarely identified in the coffee group. The coronary arterial wall demonstrated relatively symmetrical intima-media thickness (IMT) and the lumen diameter remained adequate for blood flow. The intimal collagen was intact, dense and thick. MMP–2 level was significantly lower (P < 0.05) in the coffee group. In conclusion, coffee maintained the structure of coronary arterial wall particularly the intimal collagen, providing protection against CAD. This might also mediate the vascular resistance against rupture and thrombosis that might precipitate the occurrence of acute coronary syndrome (ACS).
Key words: Acute coronary syndrome (ACS); Coronary artery disease (CAD); Histochemistry; Intima-media thickness (IMT); Matrix metalloproinase-2 (MMP-2)
Phytotoxicity and leaf anatomy of young coffee plants subjected to herbicides exclusively and in associations
Get PDFThe lack of human resources and the damage that weeds can cause to coffee plants are the causes of the growing demand for selective herbicides to be used in coffee farming. Thus, the objective of this study was to evaluate the phytotoxicity symptoms and leaf anatomical characteristics of young coffee plants submitted to application isolated herbicides and also in associations. An experiment was conducted in a protected environment in randomized blocks: four replications with coffee seedlings (Coffea arabica L.) cultivar “Topázio MG-1190”, grown in pots with a capacity of 11 liters of substrate. The herbicides applied, in isolation, were: pyrazosulfuron-ethyl (15 g ha-1), saflufenacil (49 g ha-1), imazetaphyr (100 g ha-1), iodosulfuron-methyl (3.5 g ha-1), chlorimuron-ethyl (15 g ha-1) and sethoxydim (184 g ha-1). The latter was used in associations with the others. In addition, a control without herbicides was used. Phytotoxicity symptoms were evaluated up to 49 days after application (DAA) and anatomical characteristics at 65 DAA. Saflufenacil alone and in association with sethoxydim caused visual phytotoxicity symptoms in the leaves and negatively influence in the characteristics of the epidermis thickness of the adaxial face (EAD), thickness of the palisade parenchyma (EPP), thickness of the spongy parenchyma (EPE) and thickness of the mesophyll (MES). The other herbicides, isolated or in associations, didn’t cause phytotoxicity symptoms, but had a negative influence in the anatomical parameters of the leaf blade, however they did not interfere with the paradermic parameters and the vascular bundle.
Key words: Coffea arabica; leaf; selectivity; symptoms
Rooting biostimulants for Coffea arabica L. cuttings
Get PDFIn the rooting process of Arabica coffee cuttings, plant hormones are used for inducing root formation. However, synthetic molecules cannot be used to form organic seedlings. The objective of this work was to evaluate the effect of nut grass extract and different concentrations and types of humic substances on Arabica coffee cuttings. Arabica coffee shoots were collected, and cuttings containing at least two buds were taken. The experiment had a three-factor design, 2 (without or with nut grass extract) x 2 (humic or fulvic acid) x 4 (0, 10, 25 and 50 mg.dm-³). The following vegetative data were evaluated: shoot height (cm), survival, remaining leaves, leaf pairs, vigor and number of shoots. The root length, area, volume, diameter, and fresh and dry mass were also evaluated. The enzyme activity of H+-ATPase, catalase, superoxide dismutase, alcohol dehydrogenase and esterase was also quantified. The results showed that the Arabica coffee cutting rooting rate was increased when treated with humic acid at a concentration of 10 mg.dm-³ in the presence of nut grass extract. The lowest oxidative stress was observed in the 10 mg.dm-³ humic and fulvic acid treatments, regardless of the use of the extract.
Key words: Root system; IBA; humic acid; fulvic acid; shoots
Estimation of genetic parameters and selection of Coffea canephora progenies evaluated in Brazilian Western Amazon
Get PDFCoffee has emerged as an economic alternative culture in the State of Acre, Brazil, but without a clonal variety recommended for the state to overcome the unevenness presented by seed crops. Thus, in order to estimate genetic parameters and indicate progenies of Coffea canephora to compose a clonal variety for the State of Acre, yield, vegetative vigor and plant height were evaluated in five harvests of a randomized complete block experiment with 46 progenies, 4 repetitions and 10 plants per plot by mixed model methodology (REML/BLUP). The harvests were evaluated individually, by the model that considers one harvest, one location and the mean of progenies, and joint analysis (all harvests), by repeatability model with stability and temporal adaptability by the harmonic mean of relative performance of genotypic values method (MHPRVG), with genotypic values of progenies grouped by the Tocher method. There was variability, with possibility of selection, only for grain yield. The yield was strongly affected by production bienniality, with high environmental influence and harvests mean ranging from 14.13±4.60 to 46.20±14.94 bags ha-1 and individual heritabilities from 0.10 to 0.44. Sixteen ‘Conilon’ coffee progenies with selection gains above 23% were selected. The MHPRVG method allows the refinement of progeny selection throughout the harvests, identifying the most adapted and stable.
Key words: ‘Conilon’ or ‘Kouilou’ coffee; Breeding; Mixed models
Hymenoptera associated with conilon coffee crops in Espírito Santo state, Brazil, with emphasis on the families Diapriidae, Platygastridae and Scelionidae
Get PDFInformation about parasitoid wasp fauna can help determine the most appropriate methods for maintaining the ecological balance in agroecosystems, as these organisms are efficient natural enemies of various agricultural pests. The aim of this study was to survey the Hymenoptera families in conilon coffee plantations intercropped with other crops, focusing on the Diapriidae, Platygastridae and Scelionidae families, in order to determine wasps that could possibly act as biological controls. The study was carried out in eight conilon coffee farms located in three municipalities (Linhares, Marilândia and Sooretama) in Espírito Santo state, Brazil, with field samples collected in May (dry season) and December (rainy season) 2014. Were collected 1084 Hymenoptera specimens distributed in 10 superfamilies and 25 families. Fourteen genera of Scelionidae were collected, with Telenomus (34%), Idris (15%), Trissolcus (14%) and Ceratobaeus (10%) as the most abundant genera; seven genera of Diapriidae were collected with Doliopria (41%), Basalys (22%) andTrichopria (20%) as the most abundant; and two genera of Platygastridae were collected: Leptacis (52%) and Synopeas (14%). The highest abundance of wasp individuals was found in coffee intercropped with rubber trees. Intercropped coffee cultivation could potentially attract more natural enemies, as well as egg parasitoids that are promising biological controls.
Key words: Biodiversity; Biological control; Entomology; Parasitoid wasps
Insecticide application rate in coffee crop: qualitative and quantitative aspects and efficacy of leaf miner control
Get PDFLeaf miner is a key coffee crop pest in Central and South America countries, especially in Brazil, where the insect causes considerable production losses. In the management of this insect pest, insecticide applications at reduced rates are fundamental for the rational use of water. Thus, the aim of this study was to select a spraying system that ensures effectiveness of cyantraniliprole, cartape hydrochloride and beta-cypermethrin insecticides in the leaf miner control, good spraying quality with varying application rates and low impact on natural parasitism. The qualitative and quantitative aspects of spraying with the Blue spray marker were evaluated at the following rates: 28.1, 60.5, 80.2 and 180.0 L ha-1 and the efficacy of cyantraniliprole (100 g a.i. L-1), cartape hydrochloride (500 g a.i. kg-1) and beta-cypermethrin insecticides (100 g a.i. L-1). Pest infestation and parasitism were determined before and after applications. Application rate interferes with qualitative aspects and spray deposition levels. Rates between 80.2 and 180.0 L ha-1 are the most suitable for the control of this insect. Cyantraniliprole insecticide is effective in controlling L. coffeella up to 45 DAA at rate of 180 L ha-1. The impact of cyantraniliprole, cartape hydrochloride and beta-cypermethrin insecticides on L. coffeella natural parasitism varies with application rates and time after application.
Key words: Brilliant blue marker; beta-cypermethrin; cartape hydrochloride; cyantraniliprole; Leucoptera coffeella
Spatial dynamics of coffee production in the state of Parana, Brazil
Get PDFCoffee is a commodity of great economic importance for Brazil and for the state of Paraná. In the 1960s and 1970s, Paraná was responsible for half of coffee production in Brazil. However, after 1975, with the occurrence of what was called the “black frost” (geada negra), there was considerable reduction in the area devoted to coffee growing in Paraná. In this context, the aim of this study was to examine the spatial dynamics of coffee production in Paraná, identifying the microregions that have specialized in the activity, and analyze the evolution and spatial distribution of production in the period from 2003 to 2018. To do so, the locational quotient (LQ) method was applied, principal component analysis (PCA) was performed, and cluster analysis was carried out. A reduction in planted area and of the amount of coffee produced in Paraná was found. The results of the LQ denote changes in the spatial dynamics of coffee production, with reduction from 14 to 9 microregions specializing in the activity, and they are concentrated in the North Central and Pioneiro regions of Paraná. Two principal components that explained 88.06% of the total variability of the data were identified: the first formed by microregions with high participation in rural credit, and the second by microregions near the processing industries. Four groups were defined based on their degree of specialization, rural credit, and location of coffee industries. This trajectory implies gains in yield and reinforces the importance of investments in technology as a determining factor in development of the coffee production chain.
Key words: Regional analysis; agricultural economics; value chain; technological change; structural transformation
Use of foliar fertilizers as attenuators of injuries caused by glyphosate drift in young coffee plantations
Get PDFGlyphosate is the most used product for weed control in young coffee planting rows. The application is carried out in a directed way, avoiding the contact of the product with the crop. However, drift and consequent plant injuries frequently occur. An alternative to reduce these injuries is the use of attenuators capable of reducing the negative effects caused by this herbicide. Therefore, the objective of this study is to verify the efficiency of foliar fertilizers (Fertiactyl Pós® and Crop+) as attenuators of the toxic effects caused by the use of glyphosate in the coffee crop. Thus, coffee seedlings were subjected to different doses of the mixture of Fertiactyl Pós® with glyphosate and Crop+ with glyphosate. The treatments were applied on top of the plants. The percentage of coffee intoxication was evaluated at 14, 21, 28, 35, 42 and 70 days after application. At 90 days after application, height, leaf area and shoot and root dry matter were evaluated. Higher doses of glyphosate (1440 and 2880 g ha-1) without the use of attenuators caused intoxication levels close to 80% at 28 and 90 DAA. The use of Fertiactyl Pós® and Crop+ reduced the injuries caused by the application of glyphosate, regardless of the dose of herbicide and fertilizers, but with different levels of action. All the morphological variables measured suffered a negative action with the isolated use of glyphosate, with a tendency to recover when the attenuators were applied. It is concluded that the two attenuators were efficient in suppressing the deleterious effects of glyphosate on coffee plants affected by this herbicide. However, the attenuator Crop+ showed better recovery results. For 720 g ha-1 of glyphosate, the dose most used in the field, 8 L ha-1 is recommended for Fertiactyl Pós® and 4 L ha-1 for Crop+.
Key words: Coffea arabica; Crop+; Fertiactyl Pós®; Injury; Weed control