scholarly journals Perdas causadas por Coccus viridis (Hemiptera: Coccidae) em mudas de Coffea arabica L.

2009 ◽  
Vol 2 (2) ◽  
pp. 49-53 ◽  
Author(s):  
Flávio Lemes Fernandes ◽  
Marcelo Coutinho Picanço ◽  
Maria Elisa Fernandes ◽  
Tarcísio Visintin Galdino ◽  
Adriano Cirino Tomaz
Keyword(s):  
Leaf Area ◽  
Plant Height ◽  
Coffea Arabica ◽  
Dry Matter ◽  
Stem Leave ◽  
Coccus Viridis ◽  
Coffee Plants ◽  
Nutrient Solutions ◽  
Coffea Arabica L

Coccus viridis (Green) danifica plantas jovens e adultas de Coffea arabica Linnaeu. No entanto, nada se sabe sobre a magnitude dos danos causados por esta praga. Assim, este trabalho teve por objetivo estudar as relações entre o ataque de C. viridis e as perdas causadas por este inseto a C. arabica. Este trabalho foi conduzido em casa de vegetação na Universidade Federal de Viçosa. Foram utilizadas sementes da linhagem IAC 15 da variedade “Catuaí vermelho” de café (C. arabica). Para a confecção dos tratamentos esta praga foi criada em casa de vegetação separada do experimento. Os tratamentos foram: plantas infestadas e não infestadas por adultos e ninfas da cochonilha verde. As plantas foram nutridas com solução nutritiva. Durante 110 dias foram avaliados: números de adultos e de ninfas de primeiro, segundo e terceiro ínstares, área foliar, diâmetro do caule, altura das plantas em todas repetições. No final do experimento avaliou-se o peso das raízes, caule, folhas e total. Os pesos das raízes, matéria seca total, área foliar e diâmetro do caule de plantas não atacadas por C. viridis superaram em 1,31; 1,41; 1,50 e 8,93 vezes, respectivamente o peso de plantas atacadas. As variáveis selecionadas foram: diâmetro do caule (cm), área foliar (cm²), peso de raízes (g), ninfas, adultos e total das cochonilhas. Concluindo que a planta de C. arabica é afetada de forma diferente entre seus órgãos e que a ninfa de terceiro ínstar e adultos são as fases que mais causam danos a C. arabica. Losses Caused by Coccus viridis (Green) (Hemiptera: Coccidae) on Seedlings of Coffea arabica L. Abstract. Coccus viridis (Green) cause losses on seedling and old plants of Coffea arabica (Green). However, nothing is known about of the damages caused by this pest. Thus, the objective of this work was to evaluate the relations between atack of C. viridis and the losses caused by this insect. on C. arabica. This work was conduced in greenhouse at Federal University of Viçosa. Seed coffee plants line IAC 15, variety “Catuaí vermelho” (C. arabica) were used. The insects were reared into greenhouse and separated of the experiment. The treatments were: infested plants and no infested by adults and nymphs of the green scale. The plants were nourished with compound nutrient solutions. For 110 days evaluated: numbers of adults and nymphs of instar first, second and third, leaf area, diameter of stem and plant height in all repetition. At the end of the experiment were evaluated weights of root, stem, leave and total. The weight of root, total dry matter, leaf area and diameter of the stem at plants no attacked by C. viridis were 1.31, 1.41, 1.50 and 8.93 times more than weight attacked plants, respectively. The main variables were: diameter of the stem (cm), leaf area (cm²), weights of root (g), nymphs, adults and all cochineals. Also, parts of the plant (C. arabica) were damaged by nymphs (third) and adults of C. viridis.

scholarly journals DESENVOLVIMENTO DE MUDAS DE CAFEEIRO PRODUZIDAS EM TUBETES SOB MALHAS TERMO-REFLETORAS E MALHA NEGRA

Irriga ◽  
2018 ◽  
Vol 1 (1) ◽  
pp. 52 ◽  
Author(s):  
Vinícios Maia Costa ◽  
Marcos Vinícios Folegatti ◽  
Roberto Terumi Atarassi ◽  
Sérgio Nascimento Duarte ◽  
Nildo Da Silva Dias ◽  
...  
Keyword(s):  
Relative Humidity ◽  
Solar Radiation ◽  
Leaf Area ◽  
Coffea Arabica ◽  
Dry Matter ◽  
Significant Difference ◽  
Stalk Diameter ◽  
E Mail ◽  
Coffea Arabica L

DESENVOLVIMENTO DE MUDAS DE CAFEEIRO PRODUZIDAS EM TUBETES SOB MALHAS TERMO-REFLETORAS E MALHA NEGRA VINÍCIUS MAIA COSTA1; MARCOS VINÍCIUS FOLEGATTI2; ROBERTO TERUMI ATARASSI3; SÉRGIO NASCIMENTO DUARTE4; NILDO DA SILVA DIAS5 E CLAUDIO RICARDO DA SILVA6.  [1] Mestre em Agronomia, Depto. de Engenharia de Biossistemas, ESALQ-USP, Piracicaba – SP. E-mail: [email protected]. Titular, Depto. de Engenharia de Biossistemas, ESALQ-USP, Piracicaba – SP. E-mail: [email protected] de Ciências Agrárias, UFU, Av. Amazonas, s/n, Bloco 2E, Campus Umuarama, 38400-902, Uberlândia-MG. E-mail: [email protected]. Associado, Depto. de Engenharia de Biossistemas, ESALQ-USP, Piracicaba – SP. E-mail: [email protected] Associado 2, Departamento de Ciências Ambientais e Tecnológicas, Universidade Federal Rural do Semi-Árido, Mossoró, RN. E-mail: [email protected] de Ciências Agrárias, UFU, Av. Amazonas, s/n, Bloco 2E, Campus Umuarama, 38400-902, Uberlândia-MG. E-mail: [email protected].  1 RESUMO Este experimento avaliou, em casa de vegetação, o desenvolvimento de mudas de cafeeiro produzidas em tubetes, sob o efeito de malhas utilizadas para sombreamento. Os tratamentos foram a tradicional malha negra 50% e as malhas termo-refletoras com atenuação da radiação solar de 40, 50, 60 e 70%. O delineamento experimental adotado foi em blocos casualizados contendo os 5 tratamentos, com 4 repetições, totalizando-se assim 20 parcelas. Os resultados mostram que temperatura do ar pouco variou no microclima protegido das parcelas, assim como a umidade relativa do ar e a transmissividade global (TRG) e fotossinteticamente ativa (TRFA). Verificou-se que malhas com menor atenuação da radiação solar apresentaram em geral maior transmissividade. A área foliar não apresentou diferença significativa entre os tratamentos; já para altura da planta e diâmetro do caule, verificou-se que as mudas produzidas sob as malhas termo-refletoras 40 e 50% foram superiores àquelas produzidas sob malha negra 50% e malhas termo-refletoras 60 e 70%, respectivamente. Nas avaliações de matéria seca, verificou-se que as mudas produzidas sob as malhas termo-refletoras 40% e 50% e malha negra 50% acumularam mais matéria seca comparativamente àquelas produzidas sob malhas termo-refletoras 60 e 70%. Assim, concluiu-se que as malhas termo-refletoras 40 e 50% e negra 50% apresentaram melhores resultados que as malhas termo-refletoras 60 e 70%. Palavras-chave: Coffea arábica L., sombreamento, ambiente protegido.  COSTA, V.M.; FOLEGATTI, M.V.; ATARASSI, R.T.; DUARTE, S.N.; DIAS, N.S.; SILVA, C.R. DEVELOPMENT OF COFFEE SEEDLINGS PRODUCED IN PLASTIC TUBESUNDER TERMO-REFLECTIVE AND BLACK SCREENS   2 ABSTRACT This experiment evaluated, in greenhouse conditions, the development of coffee seedlings produced in plastic tubes, under the effect of screens used for shading. The treatments were the traditional black screen 50% and the thermo reflective screens with attenuation of the solar radiation of 40, 50, 60 and 70%. The adopted experimental delineation was randomized blocks with 5 treatments and 4 replicates, making up 20 parcels. The result showed that the temperature of air gently varied in the parcels, as well as the air relative humidity.  Relating to global transmissivity (TRG) and photosynthetically active transmissivity (TRFA), it was verified that screens with less attenuation of the solar radiation presented higher transmissivity in general. The leaf area did not present significant difference among the treatments and seedlings height and stalk diameter, the seedlings produced under thermo-reflective screens 40% and 50% were superior to those produced under black screen 50% and thermo-reflective screen 60% and 70%. In the evaluations of dry matter, the seedlings produced under thermo-reflective screens 40% and 50%, and black screen 50% comparatively accumulated more dry matter than those produced under thermo-reflective screens 60% and 70%. Thus, it can be concluded that the thermo-reflective screens 40% and 50% and black screen 50% presented better results than the thermo-reflective screens 60% and 70%. Keywords: Coffea arábica L., shading, greenhouse.

scholarly journals Effect of glyphosate and P on the growth and nutrition of Coffea arabica cultivars and on weed control

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yanna Karoline Santos da Costa ◽  
Nagilla Moraes Ribeiro ◽  
Guilherme Cesar Pereira de Moura ◽  
Artur Rodrigues Oliveira ◽  
Silvano Bianco ◽  
...  
Keyword(s):  
Leaf Area ◽  
Weed Control ◽  
Coffea Arabica ◽  
Dry Matter ◽  
The Other ◽  
Soil P ◽  
Growth And Nutrition ◽  
P Content ◽  
Urochloa Decumbens ◽  
Coffee Plants

AbstractThe effect of the phosphorus (P) and glyphosate interactions on the growth and nutrition of Arabica coffee cultivars (Coffea arabica), as well as on the control of Ipomoea grandifolia and Urochloa decumbens, was evaluated. Catuaí-Amarelo/IAC-62 and Catuaí-Vermelho/IAC-144 cultivars did not show glyphosate poisoning, regardless of the soil P content. However, glyphosate reduced the growth of Catuaí-Vermelho/IAC-144. In addition, the soil P content influenced the height, leaf area and dry matter of Catuaí-Amarelo/IAC-62, and the absorption of P and Ca in both cultivars. On the other hand, glyphosate efficiently controlled U. decumbens but not I. grandifolia. Glyphosate effectiveness on I. grandifolia decreased as the soil P content increased. In addition, the soil P content and the glyphosate influenced the P content in I. grandifolia and U. decumbens plants. The soil P content influenced the growth and absorption of other nutrients by coffee plants as well as glyphosate effectiveness on weed control.

scholarly journals EFFECT OF IRRIGATION ON ROOT DEVELOPMENT OF COFFEE PLANTS

Irriga ◽  
2019 ◽  
Vol 24 (2) ◽  
pp. 378-391
Author(s):  
Marcelo Rossi Vicente ◽  
Everardo Chartuni Mantovani ◽  
André Luís Teixeira Fernandes ◽  
Júlio Cesar Lima Neves ◽  
Edmilson Marques Figueredo ◽  
...  
Keyword(s):  
Root System ◽  
Root Development ◽  
Coffea Arabica ◽  
Crop Yields ◽  
Root Length Density ◽  
Block Design ◽  
Minas Gerais ◽  
Root Weight ◽  
Coffee Plants ◽  
Coffea Arabica L

EFFECT OF IRRIGATION ON ROOT DEVELOPMENT OF COFFEE PLANTS     MARCELO ROSSI VICENTE1; EVERARDO CHARTUNI MANTOVANI2; ANDRÉ LUÍS TEIXEIRA FERNANDES3; JÚLIO CÉSAR LIMA NEVES4; EDMILSON MARQUES FIGUEREDO5 E FÁBIO TEIXEIRA DELAZARI6   1 Instituto Federal do Norte de Minas Gerais, Campus Salinas, Fazenda Varginha, Rodovia Salinas – Taiobeiras, Km 2, 39560-00, Salinas, Minas Gerais, Brasil, [email protected] 2 Departamento de Engenharia Agrícola e Ambiental, Universidade Federal de Viçosa, Campus Universitário, Viçosa, 36570.900, Minas Gerais, Brasil, [email protected] 3 Universidade de Uberaba, Av. Nenê Sabino, n° 1801, 38055-500, Uberaba, Minas Gerais, Brasil, [email protected] 4 Departamento de Solos, Universidade Federal de Viçosa, Campus Universitário, Viçosa, 36570-900, Minas Gerais, Brasil, [email protected] 5 Bahia Farm Show, Av. Ahylon Macedo, n° 919, 97810-035, Barreiras, Bahia, Brasil, [email protected] 6 Departamento de Fitotecnia, Universidade Federal de Viçosa, Campus Universitário, Viçosa, 36570-900, Minas Gerais, Brasil, [email protected]     1 ABSTRACT   Increasing the development and deepening of the root system in coffee crops ensures higher water and nutrient uptakes as a result of improved soil utilization, ultimately leading to greater crop yields and longevity. The aim of this study was to evaluate the effect of irrigation levels on the root system of drip-irrigated coffee plants in western Bahia State (BA), Brazil. The experiment was carried out on Café do Rio Branco farm, located in Barreiras - BA, using adult plants (approximately 3.5 years old) of coffee variety Catuaí Vermelho IAC 144. The experiment was set up as a randomized block design with three treatments corresponding to the irrigation depths of 75, 100 and 150% as determined using Irriplus software. After the fourth harvest, the coffee root system was assessed to determine root length density (RLD) and root weight density (RWD) in different sampled layers. A greater concentration of roots (RLD and RWD) was observed in the surface layer (0-20 cm) and under the lateral line (at 30 and 70 cm from the orthotropic branch). The irrigation depth of 75% provided the highest concentration of roots (RLD and RWD) in the 0-10 cm layer.   Keywords: Drip irrigation, Coffea arabica L, root system.     VICENTE, M.R.; MANTOVANI, E.C.; FERNANDES, A.L.T.; NEVES, J.C.L.; FIGUEREDO, E.M.; DELAZARI, F.T EFEITO DA IRRIGAÇÃO NO DESENVOLVIMENTO RADICULAR DO CAFEEIRO     2 RESUMO   Um maior desenvolvimento e aprofundamento do sistema radicular garante ao cafezal um aumento da absorção de água e nutrientes devido a maior exploração do solo, com isto maior produtividade e longevidade da lavoura. O objetivo deste trabalho foi avaliar os efeitos de diferentes lâminas de irrigação sobre o sistema radicular do cafeeiro irrigado por gotejamento na região Oeste da Bahia. Realizou-se o trabalho na fazenda Café do Rio Branco, localizada em Barreiras - BA em cafeeiros adultos, aproximadamente 3,5 anos de idade, da variedade Catuaí Vermelho IAC 144. O experimento ocorreu no delineamento em blocos casualizados, composto de 3 tratamentos, correspondentes à 75, 100 e 150% da lâmina de irrigação determinada pelo software Irriplus. Após a quarta safra, procedeu-se às avaliações do sistema radicular do cafeeiro, onde foi determinada a densidade de comprimento radicular - DCR e a densidade radicular – DR em diferentes camadas amostradas. Observou-se maior concentração de raízes, DCR e DR, na camada superficial (0-20 cm) e sob a linha lateral (30 e 70 cm de distância do ramo ortotrópico). A lâmina de irrigação correspondente a 75% proporcionou maior concentração de raízes (DCR e DR) na camada de 0 a 10 cm.   Palavras - chaves: Irrigação localizada, Coffea arábica L, sistema radicular

scholarly journals Effect of leaf Water potential on cold tolerance of Coffea arabica L.

2002 ◽  
Vol 45 (4) ◽  
pp. 439-443 ◽  
Author(s):  
Lázara Pereira Campos Caramori ◽  
Paulo Henrique Caramori ◽  
João Manetti Filho
Keyword(s):  
Water Potential ◽  
Leaf Water Potential ◽  
Coffea Arabica ◽  
Experimental Period ◽  
Leaf Water ◽  
Regional Variability ◽  
Wide Range ◽  
Coffee Plants ◽  
Coffea Arabica L ◽  
Severe Leaf

Young coffee plants from cultivar Mundo Novo of Coffea arabica were grown without irrigation for 32 consecutive days, to evaluate the effect of leaf water potential on damage caused by low temperatures, under controlled conditions. A wide range of leaf water potentials were evaluated, from - 0.45MPa (wet soil) at the beginning of the experimental period, to - 4.8MPa (severe leaf wilting) at the end. Results showed that under moderate water stress, there was a higher frequency of undamaged plants and lower frequency of severely damaged plants. These results help explain part of the regional variability observed after a frost and stress the importance of new studies associating cold and drought tolerance in coffee.

scholarly journals Effect Of Planting Geometry On Growth Of Rice Varieties

2017 ◽  
Vol 5 (4) ◽  
pp. 423-429 ◽  
Author(s):  
Mohan Mahato ◽  
Bishnu Bilas Adhikari
Keyword(s):  
Growth Rate ◽  
Leaf Area Index ◽  
Leaf Area ◽  
Plant Height ◽  
Dry Matter ◽  
Dry Matter Accumulation ◽  
Rice Varieties ◽  
Area Index ◽  
Crop Growth Rate ◽  
Planting Geometry

A field experiment was conducted under humid subtropical agro-climatic condition of Nepal during rainy season of 2014. The experiment was laid out in to two factor Randomized Complete Block Design with  three replications consisting three drought tolerant rice varieties (Sukhadhan-4, Sukhadhan-5 and Radha-4) and four planting geometry (15 cm × 10 cm, 15 cm × 15 cm, 20 cm × 15 cm and 20 cm × 20 cm). The results revealed that the highest plant height and maximum leaf area index was recorded in planting geometry 15 cm × 10 cm in all growth stages. Whereas, planting geometry 20 cm × 15 cm produced the maximum number of tiller m-2 in all growth stage.  While planting geometry 20 cm × 15 cm and 20 cm × 20 cm produced statistically similar crop growth rate and dry matter accumulation in all stage of growth. Regarding the varieties, Sukhadhan- 4 showed highest plant height up to 75 DAT and plant height was statistically similar to Radha - 4 in 60 and 75 DAT. But maximum number of tiller m-2, leaf area index, crop growth rate and dry matter accumulation were recorded in Sukhadhan – 5 varieties. Int. J. Appl. Sci. Biotechnol. Vol 5(4): 423-429

scholarly journals Evaluation of growth and yield of selected hybrid and inbred rice varieties grown in net-house during transplanted aman season

1970 ◽  
Vol 34 (1) ◽  
pp. 67-73
Author(s):  
M SH Islam ◽  
MSU Bhuiya ◽  
AR Gomosta ◽  
AR Sarkar ◽  
MM Hussain
Keyword(s):  
Leaf Area ◽  
Plant Height ◽  
Dry Matter ◽  
Dry Weight ◽  
Growth And Yield ◽  
Rooting Depth ◽  
Rice Varieties ◽  
Root Dry Weight ◽  
Matter Production ◽  
1000 Grain Weight

Pot experiments were conducted during T. aman 2001 and 2002 (wet season) at Bangladesh Rice Research Institute (BRRI) in net house. Hybrid variety Sonarbangla-1 and inbred modern variety BRRI dhan-31 were used in both the seasons and BRRI hybrid dhan-l was used in 2002. The main objective of the experiments was to compare the growth and yield behaviour of hybrid and inbred rice varieties under controlled condition. In 2001, BRRI dhan-3l had about 10-15% higher plant height, very similar tillers/plant, 15-25% higher leaf area at all days after transplanting (DAT) compared to Sonarbangla-1. Sonarbangla- 1 had about 40% higher dry matter production at 25 DAT but had very similar dry matter production at 50 and 75 DAT, 4-11% higher rooting depth at all DATs, about 22% higher root dry weight at 25 DAT, but 5-10% lower root dry weight at 50 and 75 DAT compared to BRRI dhan-31. The photosynthetic rate was higher (20 μ mol m-2/sec-1) in BRRI dhan-3l at 35 DAT (maximum tillering stage) but at 65 DAT, Sonarbangla-l had higher photosynthetic rate of 19.5 μ mol m-2 sec-1. BRRI dhan-3l had higher panicles/plant than Sonarbangla-1, but Sonarbangla-1 had higher number of grains/panicle, 1000-grain weight and grain yield than BRRI dhan-31. In 2002, BRRI dhan-31 had the highest plant height at 25 DAT, but at 75 DAT, BRRI hybrid dhan-l had the highest plant height. Sonarbangla-1 had the largest leaf area at 25 and 50 DAT followed by BRRI dhan-31, but at 75 DAT, BRRI dhan-31 had the largest leaf area. The highest shoot dry matter was observed in BRRI dhan-31 followed by Sonarbangla-1 at all DATs. Sonarbangla-1 had the highest rooting depth and root dry weight at all DATs. BRRI dhan-31 gave the highest number of panicles/plant followed by Sonarbangla-I, BRRI hybrid dhan-l had the highest grains/panicle followed by BRRI dhan-31 and Sonarbangla-I had the highest 1000-grain weight followed by BRRI dhan-31. The highest amount of grains/plant (34.6 g) was obtained from BRRI dhan-31. Key Words: Shoot dry matter; root dry weight; leaf area; photosynthesis; grain yield. DOI: 10.3329/bjar.v34i1.5755Bangladesh J. Agril. Res. 34(1) : 67-73, March 2009

Effect of various levels of nitrogen on growth, yield and quality of fodder maize

2017 ◽  
Vol 2 (02) ◽  
pp. 197-200
Author(s):  
Rajeev Kumar ◽  
Sanjeev Kumar ◽  
Anil Kumar ◽  
B. B. Singh ◽  
Ravendra Singh ◽  
...  
Keyword(s):  
Field Experiment ◽  
Leaf Area ◽  
Plant Height ◽  
Crude Protein ◽  
Dry Matter ◽  
Growth Yield ◽  
Forage Yield ◽  
Fresh Weight ◽  
Yield And Quality

A field experiment was conducted in the Department of Agricultural Botany, Janta Mahavidiyalaya Ajeetmal, Auraiya (C. S. J. M. University, Kanpur) during 2014, to evaluate the effect of various levels of nitrogen on growth, yield and quality of fodder maize. 3 treatments were taken up (viz.,T1 75, T2 100 and T3 125 kg nitrogen ha-1 along with control (T0).Plant height, dry matter accumulations (t ha-1), forage yield (t ha-1) increased with increasing levels of nitrogen, while stem diameters (cm), leaf area (cm2), fresh weight (g), crude protein percent decreased with increasing levels of nitrogen.

Influence of primed seed and varying seed rate on growth and productivity of soybean (Glycine max L.) under different planting techniques

2018 ◽  
Author(s):  
Rupinder Kaur Jassal ◽  
Harmeet Singh
Keyword(s):  
Leaf Area Index ◽  
Leaf Area ◽  
Plant Height ◽  
Seed Yield ◽  
Dry Matter ◽  
Seed Priming ◽  
Dry Matter Accumulation ◽  
Area Index ◽  
Active Radiation ◽  
Seed Rate

An experiment was conducted at Punjab Agricultural University, Ludhiana during 2015 and 2016 to study the effect of priming, different seed rate on growth and seed yield of soybean planted under bed and flat method. The study was planned in factorial split plot design, keeping two planting techniques (flat sowing and bed sowing) and two seed priming treatments ( non primed seeds and 100 ppm GA3 primed seeds) in main plot and three seed levels ( 50, 62.5 and 75 kg ha-1) in sub plot. The objective of the study was to evaluate the effect of seed priming on growth and productivity under different planting techniques with the use of varying seed rates. The results revealed that growth attributes viz. emergence count, plant height, dry matter accumulation, leaf area index and photosynthetic active radiation interception (%) was significantly higher under bed planting technique as compared to flat sowing method. The pooled seed yield was increased by 15.6 % in bed planted soybean crop as compared to flat planted crop. Soybean seeds primed with 100 ppm GA3 recorded significant results in all the growth parameters. Primed seed recorded increase in yield 15.3 % than non primed seeds. Seed rate of 62.5 kg ha-1 recorded significantly higher emergence count, plant height, dry matter accumulation, leaf area index and photosynthetic active radiation interception (%) which was statistically similar in results with 75 kg ha-1 seed rate in both the two years. Pooled seed yield of 62.5 kg ha-1seed rate was 4.61 % higher than 75 kg ha-1 and 12.6 % than 50 kg ha-1 seed rate.

scholarly journals Evaluación de plaguicidas para el manejo de plagas del café Coffea arabica L. en Jinotega, Nicaragua

La Calera ◽  
2020 ◽  
Vol 20 (34) ◽  
pp. 20-28
Author(s):  
María Nohelia Matus Miranda ◽  
Edgardo Jiménez-Martínez
Keyword(s):  
Coffea Arabica ◽  
Hypothenemus Hampei ◽  
Coccus Viridis ◽  
Coffea Arabica L

El café (Coffea arabica L.) es de mucha importancia para Nicaragua, tanto económica, como social y ambiental, representando aproximadamente el 25% de las exportaciones. La caficultura es considerada una de las principales fuentes de empleo, alcanzando 63% en las zonas rurales y alrededor del 14% a nivel nacional. El cultivo de café es vulnerable a plagas artrópodas y agentes microbiológicos que afectan hojas, tallos, raíces y frutos, causando pérdidas en los rendimientos. La broca del fruto del café (Hypothenemus hampei, Ferrari) (Coleoptera: Curculionidae) es el principal insecto plaga del café en el país por su daño causado y los elevados costos económicos destinados en su manejo. Siguiendo en importancia, la cochinilla (Planococcus spp) (Hemiptera: Pseudococcidae), que infesta brotes foliares y florales, en infestaciones severas, causa amarillamiento de hojas, marchitamiento de yemas y aborto de frutos. Finalmente, las escamas (Coccus viridis, Green) (Hemiptera: Coccidae), insectos con amplio rango de distribución y abundantes en época seca, causan pérdidas por vigor, enanismo y reducción del número de frutos por planta. Este estudio, tuvo el propósito de contribuir al manejo de plagas del café a través de la evaluación de insecticidas químicos, botánicos y biológicos. Las variables evaluadas fueron, número de frutos brocados y número de escamas y cochinillas por planta. Los resultados indican que los mejores insecticidas para el manejo de broca del café, escamas y cochinillas fueron Galil seguido de Cormoran y Ecobiol, los cuales fueron, además, los tratamientos más rentables

scholarly journals UNTERSUCHUNGEN ÜBER DIE GESCHWINDIGKEIT DES WASSERAUFSTIEGES IM SPROFI UND DEN BLATTFLÁCHENZUWACHS VON COFFEA ARABICA L. UND CITRUS AURANTIUM SINENSIS ENGLER IN VERSCHIEDENEN KLIMAZONEN KOLUMBIENS

2016 ◽  
Vol 5 ◽  
Author(s):  
Richard Michler
Keyword(s):  
Leaf Area ◽  
Sea Level ◽  
Water Transport ◽  
Coffea Arabica ◽  
Maximum Rate ◽  
Water Movement ◽  
Diurnal Variations ◽  
Citrus Aurantium ◽  
Climatic Regions ◽  
Coffea Arabica L

The total increase of leaf area and the rate of water movement in the stems of Coffea arabica L. and Citrus aurantium sinensis Engler were deter- *) Gekürzte Fassung einer am 18. 12. 1969 von der Naturwissenschaftlichen Fakultat der Universitát Giessen als Dissertation angenommenen Abhandlung. mined in various climatic regions of Columbia. During the rain season the maximum rate of water transport decreased with increasing height above sea level. This effect was observed to be more evident in Citrus than in Coffea. At the end of the dry season however, the maximum rate of water movement was measured in 1250 m (Citrus) and 1850 m (Coffea) above sea level. In case of sunshine the maximum values were higher than in case of clouded sky. The most considerable increase of total leaf area was reached at Coffea in 1850 m and at Citrus in 1250 m respectively. With reference to the water economy the cultivation of Citrus could be forced in sea levels about 1250 m with simultaneous displacement of Coffea cultivation to colder climatic regions. Diurnal variations showed, that if the intensity of radiation increased suddenly, the rate of water movement in the stems of Citrus trees accordingly increased. With Coffea trees different results were obtained. During the morning the rate of water transport in trees always increased. At noon the values either remained high or varied in irregular intervals. Moreover, in the hot climatic regions diurnal variations sometimes showed two maximums of rate of water flow in the stems of Coffea arabica. Above all, the type of observed diurnal variations depended on the sea level distance of the measuring point, the season, the intensity of radiation and the species of plant.

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