ABSTRACT In the initial phase of the coffee crop, the control of weeds and water availability for the establishment of the plants is a concern. The polyethylene cover can positively influence the chemical and biological characteristics of the soil and, consequently, the root system. The objective of this work was to evaluate the morphology of the root system of coffee plants using polyethylene mulching of different widths and colors. Coffee was planted in December 2016 using the cultivar Topázio MG-1190. A randomized repetitions design was used, with four blocks and five treatments, as follows: 1.20-m wide white/black mulching, 1.40-m white/black mulching, 1.20-m silver/black mulching, 1.40-m silver /black mulching, and no mulching. Total root dry matter per soil volume, total root length per soil volume, total root volume per soil volume, total root area per soil volume, specific root surface, specific root length, and mean root diameter were all evaluated. Roots with smaller diameters were concentrated in the 0-0.20 m depth layer, while in the 0.20-0.40 m depth layer, roots with larger diameters were found. Plants grown in 1.20-m silver/black mulching showed a greater surface area and a specific length of the roots.

ABSTRACT Remote monitoring of the management of coffee crops is necessary as the demand in decision-making, where the aim is to rise production based on sustainable management is in a constant growth. In this work, it was evaluated the potential of images obtained by low-cost sensors in the discrimination of sources and doses of mineral and organomineral fertilizers in coffee. The experimental design was in randomized blocks, with five blocks and six treatments, as follows: (T1) - 100% of the organomineral treatment; (T2) - 70% of the organomineral treatment; (T3) - 50% of the organomineral treatment; (T4) - 100% of mineral fertilization; (T5) - standard treatment of the farm and (T6) - 70% of mineral fertilization. After management, we used the Mapir 3 Survey3W camera coupled to an ARP drone – Phantom4 to take images of the experiment over a 12-month vegetative period. Combined with image taking, it was collected agronomic parameters of coffee growth and productivity for two crops and concluded that different fertilization doses did not significantly affect the analyzed parameters. Based on the supervised classification of multispectral images, it was possible to discriminate treatments with a higher degree of accuracy (86.66% accuracy) than when analyzing coffee growth parameters.

ABSTRACT Helicoverpa armigera (Hübner) is a polyphagous insect of difficult control and maize is an important host crop of this insect. Entomopathogenic nematodes (EPNs) are control agents of soil pests. This study aimed to verify the action of EPNs for the control of H. armigera pupae. Laboratory and greenhouse bioassays were conducted to select the concentration of nematode application and subsequently field test were conducted. It was obtained that Heterorhabditis amazonensis MC01 at the concentration of 400 infective juveniles (IJs) ·pupa-1 caused the highest mortality in a lower concentration, whereas for H. amazonensis JPM4, concentrations of both 200 and 400 IJs ·pupa-1 were similar causing pupae mortality. In the greenhouse, H. amazonensis MC01 caused mortality reached values of 80% after 10 days, at concentrations of 600 and 800 IJs ·pupa-1. The highest mortality caused by Steinernema carpocapsae was observed at eight days after the juvenile application, at a concentration of 600 IJs ·pupa-1, also reaching 80% mortality. In the field test, both forms of application were considered appropriate for H. amazonensis MC01, causing mortality rates of up to 80%.

Resumo: O objetivo deste trabalho foi avaliar o efeito de concentrações de silício e ágar no desenvolvimento in vitro de crista-de-galo (Celosia cristata) (Amaranthaceae). Análises fitotécnicas, anatômicas e ultraestruturais foram conduzidas em delineamento inteiramente casualizado, em arranjo fatorial 4x3, com quatro concentrações de ácido silícico (0,0, 0,5, 1,0 e 1,5 g L-1) e três de ágar (5,5, 8,0 e 10,5 g L-1), no total de 12 tratamentos com sete repetições. Explantes de C. cristata foram inoculados in vitro em meio de cultura Murashige & Skoog (MS ), com 30 g L-1 de sacarose. As análises foram realizadas 30 dias após a inoculação. As características fitotécnicas melhoram com a concentração de ágar a 8,0 g L-1, e a associação dessa concentração com 1,0 g L-1 de silício contribui ainda para a melhoria dos atributos anatômicos, principalmente a largura do limbo foliar e a espessura dos parênquimas paliçádico e esponjoso, o que colabora para o desenvolvimento de C. cristata. Nenhuma das combinações avaliadas de silício e ágar contribui para deposição de Si na epiderme foliar dessa espécie ornamental.

Abstract: The objective of this work was to evaluate the effect of silicon and agar concentrations on cockscomb (Celosia cristata) (Amaranthaceae) development in vitro. Phytotechnical, anatomical, and ultrastructural analyses were carried out in a completely randomized design, in a 4x3 factorial arrangment, with four silicic acid concentrations (0.0, 0.5, 1.0, and 1.5 g L-1) and three agar concentrations (5.5, 8.0, and 10.5 g L-1), totaling 12 treatments with seven replicates. Celosia cristata explants were inoculated in vitro in a Murashige & Skoog (MS) culture medium, with 30 g L-1 sucrose. The analyses were conducted 30 days after inoculation. Phytotechnical traits improve with agar concentration of 8.0 g L-1, and the association of this concentration with 1.0 g L-1 silicon also contributes to the improvement of anatomical attributes, especially of leaf blade width and thickness of the palisade and spongy parenchyma, which contributes to the development of C. cristata. None of the evaluated combinations of agar and silicon contributes to Si deposition on the foliar epidermis of this ornamental species.

RESUMO: Os nematoides entomopatogênicos (NEPs) são eficazes contra insetos de solo e têm sido usados em sistemas agrícolas. A ação de NEPs sobre grilos (Gryllus L.) (Orthoptera: Gryllidae) foi avaliada em condições de laboratório e campo, a fim de selecionar populações para aplicação em área de cultivo. Foram realizados testes de virulência com Heterorhabditis amazonensis RSC05, H. amazonensis MC01, Steinernema carpocapsae All (Weiser) e H. amazonensis GL, assim como verificadas a adequação da concentração de juvenis infectantes (100, 200, 400 e 600 juvenis infectantes por inseto) e a preferência alimentar sem chance de escolha e com chance de escolha, além do teste de campo utilizando armadilhas para amostragem dos insetos. Verificou-se que todos os isolados causaram mortalidade em Gryllus sp. selecionando-se H. amazonensis MC01 e S. carpocapsae All e que o aumento na concentração de juvenis infectantes resultou em mortalidade crescente dos insetos. Com relação aos testes de preferência alimentar, observou-se que, após 16 horas, não houve alimentação em nenhum dos tratamentos. Nos tratamentos com chance de escolha, constatou-se que houve alimentação dos grilos, independentemente da presença ou não de nematoides. Nos testes de campo, antes da aplicação de juvenis infectantes, foram encontrados 19 grilos vivos nas armadilhas, e após a aplicação dos NEPs em suspensão aquosa foram encontrados 2 grilos vivos. Dessa forma, concluiu-se que H. amazonensis MC01 foi promissor no controle de Gryllus sp. nas condições testadas.

ABSTRACT: Entomopathogenic nematodes are effective in controlling soil insects and they are used in agricultural systems. The virulence of entomopathogenic nematodes on crickets (Gryllus L.) (Orthoptera: Gryllidae) was evaluated under different conditions in order to select populations for application in the field. Virulence tests with Heterorhabditis amazonensis RSC05, H. amazonensis MC01, Steinernema carpocapsae All (Weiser) and H. amazonensis GL were performed. Evaluations were then made of the concentrations of infective juveniles (100, 200, 400 and 600 infective juveniles per insect); feeding preference with or without choice; and field tests using traps to evaluate insect sampling. All isolates were found to cause mortality in Gryllus sp., and H. amazonensis MC01 and S. carpocapsae All were selected; an increase in concentration resulted in increased insect mortality. Regarding the feeding preference tests, after 16 h there was no feeding in any of the treatments. In treatments with a chance of choice, it was verified that the crickets fed, independently of the presence of the nematodes. In the field tests, 19 live crickets were found in the traps, and, after application of entomopathogenic nematodes in aqueous suspension, 2 live crickets were found. Results suggested that H. amazonensis MC01 was promising in the control of Gryllus sp. under the tested conditions.

Com o objetivo de estabelecer as faixas críticas de teores foliares de nitrogênio (N) e potássio (K) para lavouras cafeeiras em produção fertirrigada, foi conduzido um experimento no campo experimental do Setor de Cafeicultura do Departamento de Agricultura da Universidade Federal de Lavras. Os tratamentos constaram de cinco níveis de adubação aplicados via fertirrigação: 30%, 80%, 130%, 180% e 230% da recomendação de N e K para cafeeiros cultivados em sequeiro em Minas Gerais. Foi utilizado o delineamento em blocos casualizados com quatro repetições. Com os resultados das características de crescimento (altura de planta e diâmetro de caule), análises foliares e produtividade foram estabelecidas faixas críticas das concentrações de nutrientes nas folhas. Os resultados obtidos foram: a) nitrogênio (g kg-1): 32,39 a 32,40 em janeiro/fevereiro; 33,60 a 33,61 em março/abril; 27,39 a 27,42 em maio/ junho; 24,23 a 24,24 em julho/agosto; 26,06 a 26,09 em setembro/outubro e 26,50 a 26,51 em novembro/dezembro; b) potássio (g kg-1): 20,08 a 20,14 em janeiro/fevereiro; 17,89 a 17,91 em março/abril; 15,93 a 15,96 em maio/junho; 15,29 a 15,35 em julho/agosto; 16,61 a 16,64 em setembro/outubro e 20,58 a 20,64 em novembro/dezembro.

With the aim of establishing critical ranges for the leaf nitrogen (N) and potassium (K) levels in fertigated coffee crops under production, an experiment was carried out in the experimental area of the Sector for Coffee Cultivation of the Department of Agriculture at the Federal University of Lavras, in Brazil. Treatments consisted of five levels of fertilizer applied through fertigation: 30%, 80%, 130%, 180% and 230% of the recommended amounts of N and K for rainfed coffee grown in Minas Gerais. A randomised block design with four replications was used. Critical ranges for nutrient concentrations in the leaves were established from the results of growth characteristics (plant height and stem diameter), leaf analyses and productivity. The results obtained were: a) nitrogen (g kg-1): 32.39 to 32.40 for January/February; 33.60 to 33.61 for March/April; 27.39 to 27.42 for May/June; 24.23 to 24.24 for July/August; 26.06 to 26.09 for September/October and 26.50 to 26.51 for November/December; b ) potassium (g kg-1): 20.08 to 20.14 for January/February; 17.89 to 17.91 for March/April; 15.93 to 15.96 for May/June; 15.29 to 15.35 for July/August; 16.61 to 16.64 for September/October and 20.58 to 20.64 for November/December.

A micropropagação de frutíferas de clima temperado pode gerar plantas livres de vírus e num curto espaço de tempo. Objetivando-se aprimorar técnicas de propagação in vitro de amoreira-preta e videira, foram testadas diferentes concentrações de boro e zinco, adicionados ao meio de cultivo. O meio foi constituído de sais DSD1, acrescido de 30 g L-1 de sacarose e 7 g L-1 de ágar, e o pH ajustado para 6,4 antes da autoclavagem a 121ºC e 1 atm por 20 minutos. Os tratamentos consistiram de segmentos nodais de amoreira-preta cv. Tupy, do porta-enxerto de videira 'Kobber' e de concentrações de ácido bórico (0; 1,0; 2,0 e 4,0 mg L-1) e sulfato de zinco hidratado (0; 1,0; 2,0 e 4,0 mg L-1), em todas as combinações possíveis. Segmentos nodais de plantas preestabelecidas in vitro foram excisados e inoculados em tubo de ensaio, contendo 15 mL do meio de cultura. Posteriormente, os tubos de ensaio foram transferidos para sala de crescimento a 27 ± 1ºC, irradiância de 35 mmol.m-2.s-1 e fotoperíodo de 16 horas. O delineamento experimental utilizado foi inteiramente casualisado, utilizando-se 4 repetições com 12 explantes cada. Após 70 dias de cultivo in vitro verificou-se que, melhores resultados na micropropagação de amoreira-preta cv. Tupy (Rubus sp.) foram obtidos na ausência de ácido bórico e sulfato de zinco hidratado em meio de cultura DSD1. Com 4,0 mg L-1 de ácido bórico adicionado ao meio, verificou-se maior número de folhas e comprimento de raízes do porta-enxerto de videira 'Kobber' (Vitis sp.).

The micropropagation of temperate fruit trees may generate virus-free plants with the additional advantage of a shorter period of time compared to the traditional culture. Aiming to improve the in vitro propagation of blackberry and grapevine, different boron and zinc concentrations added to the culture medium were tested. The culture medium was constituted of DSD1 salts, added of 30 g L-1 sucrose and 7 g L-1 agar, and the pH adjusted to 6.4 before the sterilization at 121ºC and 1 atm per 20 minutes. The treatments consisted of blackberry plants cv. Tupy, the grapevine rootstock 'Kobber' and concentrations of boric acid (0; 1.0; 2.0, and 4.0 mg L-1) and zinc sulfate (0; 1.0; 2.0, and 4.0 mg L-1), mixed in all possible combinations. Nodal segments of in vitro cultivated plants were excised and inoculated in tubes with 15 mL culture medium. After that, the tubes were transferred to a growth room at 27 ± 1ºC, irradiance of 35 mol.m-2.s-1 and photoperiod of 16 hours. The experiment was arranged in a completely randomized design, using four replications with 12 plants each. After 70 days of in vitro cultivation it was verified that the best results for the micropropagation of blackberry cv. Tupy (Rubus sp.) were obtained in the absence of boric acid and zinc sulfate mixed in the DSD1culture medium. With 4.0 mg L-1 boric acid added to the culture medium higher number of leaves and length of roots of the grapevine rootstock 'Kobber' (Vitis sp.) was observed.

O Brasil tem 20% do seu território ocupado com solo de cerrado no quaL a elevada acidez e a toxicidade pelo alumínio dificultam a sua utilização para cultivo. Objetivou-se, com a realização deste trabalho, avaliar oito porta-enxertos de videira quando submetidos a diferentes níveis de alumínio em solução nutritiva, com a finalidade de selecionar os genótipos mais tolerantes ao alumínio. As estacas dos porta-enxertos de videira, com comprimento de 30cm, foram mantidas por 30 dias em câmara fria. Após esse período, foram hidratadas com água + AIB, por 24 horas na concentração de 2000 mg L-1, sendo colocadas posteriormente para enraizar em vermiculita + areia (1:1), durante 60 dias e, a seguir, transferidas para os vasos com volume de 3,5 L, nos quais estava a solução nutritiva. As estacas dos genótipos: ‘Gravesac’, ‘IAC766’, ‘420A’, ‘IAC572’, ‘RR101-14’, ‘Kobber 5BB’, ‘1045P’ e ‘1103P’ foram submetidas aos seguintes tratamentos de alumínio (0, 10, 20 e 40 mg L-1 de Al). Após 40 dias de cultivo, foram avaliados comprimento da parte aérea, peso seco da parte aérea, comprimento do sistema radicular, peso seco do sistema radicular e peso seco da estaca. O delineamento experimental utilizado foi o DIC, em esquema fatorial 8x4 com 5 repetições, perfazendo um total de 160 parcelas experimentais. Maior comprimento da parte aérea é obtido pelo genótipo ‘IAC766’, na ausência de alumínio e pelo genótipo ‘420A’, com a dosagem de 40 mg L-1. Maior comprimento do sistema radicular é obtido pelo genótipo Gravesac, na dosagem de 10 mg L-1;. Quanto ao peso da matéria seca do sistema radicular, o ‘1045P’ mostra-se pouco sensível na dosagem de 10 mg L-1 . As cultivares IAC572, IAC766 e 1103P apresentam crescimento do sistema radicular semelhante na ausência ou na presença do alumínio, o que faz supor uma boa resistência à toxicidade deste elemento.

Brazil presents 20% of this territory occupied with savannah soil, that due to your high acidity and toxicicity for the aluminum hinder your use for cultivation. It was aimed at with this work to evaluate eight grapevine rootstock when submitted at different levels of aluminum in nutrition solution, with the purpose of selecting the most tolerant genotype to the aluminum. The grapevine rootstock with 30cm length were maintained by 30 days in cold camera. After this period they were moisturized with water + AIB for 24 hours in the concentration of 2000 mg L-1, being placed later to take root in vermiculite + sands (1:1) for 60 days and to proceed transferred for the vases with 3.5L of volume where the nutrition solution was contained. The genotype ‘Gravesac’, ‘IAC766’, ‘420A’, ‘IAC572’, ‘RR101-14’, ‘Kobber 5BB’, ‘1045 P’ and ‘1103P’ were submitted to the following treatments of aluminum (0, 10, 20 and 40 mg LA-1). After 40 days of cultivation were appraised the lengths of the aerial part, dry weight of the aerial part, length of the radicular system, dry weight of the radicular system and dry weight of the rootstock. The experimental designed was DIC in factorial 8x4 with 5 repetitions with 160 experimental portions. The largest length of the aerial part is obtained by the genotype ‘IAC766’ in the absence of aluminum, and for the genotype ‘420A’ with the 40 mg L-1. Larger dry weight of the aerial part and weigh dry of the rootstock ‘IAC572’ is obtained with 40 mg L-1. The largest length of the radicular system was obtained by the ‘Gravesac’ with 10 mg L-1. With relationship to the dry weight of the radicular system of the ‘1045 P’ shown a little sensitive in the concentration of 10 mg L-1. The cvs. ‘IAC572’’, ‘IAC766’ and ‘1103P’ presente a similar growth of the radicular system in the absence or presence of aluminum, the one that does suppose a good resistance to the toxicicity of this element.

Desenvolveu-se, este trabalho, no intuito de aprimorar técnicas de propagação in vitro de amoreira-preta. Testou-se em um experimento a influência de cinco diferentes concentrações de ANA (0; 0,1; 0,5; 1,0 e 1,5 mg L-1) e cinco de GA3 (0; 2; 4; 6 e 8 mg L-1), adicionadas ao meio de cultura MS, sob a amoreira-preta cultivar Ébano e; num segundo experimento testaram-se seis diferentes concentrações de ANA (0; 0,1; 0,5; 1,0; 1,5 e 2,0 mg L-1) e duas cultivares de amoreira-preta (Tupy e Brazos), no crescimento in vitro de plântulas. Segmentos nodais com 2 cm, de plântulas preestabelecidas in vitro, foram excisadas e inoculadas, em meio MS. O experimento foi inteiramente casualisado, utilizando-se três explantes por repetição e quatro repetições por tratamento. O pH do meio foi ajustado para 5,8 depois da adição de 6 g L-1 de ágar e 30 g L-1 de sacarose, ocorrendo depois a autoclavagem a 121ºC e 1 atm por 20 minutos. Após a inoculação, os tubos de ensaio foram mantidos por 60 dias, em sala de crescimento a 27 ± 1ºC, irradiância de 35 mmol.m-2.s-1 e fotoperíodo de 16 horas, avaliando-se assim o número de folhas, número de raízes, comprimento da maior raiz, comprimento da parte aérea, peso da matéria fresca e seca da parte aérea. Altas concentrações de GA3 associadas a baixas de ANA promoveram maior comprimento da parte aérea da amoreira-preta, cultivar Ébano. Maior comprimento da parte aérea de 'Brazos' foi verificado na presença de 1,0 mg L-1 de ANA. Verificou-se surgimento de calos na cultivar Ébano em todas as concentrações de GA3 associadas a 0,5-1,5 mg L-1 de ANA e nas cultivares Tupy e Brazos em todas as concentrações de ANA. Melhores resultados na micropropagação da amoreira-preta cultivares Tupy e Ébano foram obtidos com a adição de 1,0 mg L-1 de ANA e melhores resultados no enraizamento da amoreira-preta cultivar Ébano foram obtidos com baixas concentrações de ANA e na ausência de GA3.

This work was developed with the aim of improving technics of in vitro propagation of blackberry. So, one tested in an experiment the influence of five different ANA concentrations (0; 0,1; 0,5; 1,0 and 1,5 mg L-1) and five AG3 (0; 2,0; 4,0; 6,0 and 8,0 mg L-1), added to the culture medium MS, to the blackberry cv. Ebano and; in a second experiment was tested six different ANA concentrations (0; 0,1; 0,5; 1,0; 1,5 and 2,0 mg L-1) and two blackberry cv. (Tupy and Brazos), in vitro plants growing. Nodal segments with 2 cm, of in vitro plants, were excised and inoculated, in a MS culture medium. The experiment was entirely randomized blocks using three explants by repetition and four repetitions per treatment. The pH of the culture medium was adjusted for 5.8 after the addition of 6 g L-1 agar and 30 g L-1 sucrose, happening sterilization later at 121ºC and 1 atm per 20 minutes. After the inoculation, the tubes were maintained by 60 days, in growth room at 27 ± 1ºC, irradiance of 35 mol.m-2.s-1 and photoperiod of 16 hours, being evaluated the number of leaves, number of roots, length of the largest root, length of the aerial part, dry weight of the fresh and dry matter of the aerial part. High concentrations of AG3 associated to low concentrations of ANA promoted larger length of the aerial part of the blackberry cv. Ebano. Larger length of the aerial part of ' Brazos' was verified in the presence of 1.0 mg L-1 ANA. Appearance of callus was verified in blackberry cv. Ebano in all the AG3 concentrations associated to 0.5-1.5 mg L-1 ANA and in cv. Tupy and Brazos in all the ANA concentrations. Better results in the blackberry micropropagation cv. Tupy and Ebano were obtained with the addition of 1.0 mg L-1 ANA and better results in the blackberry rooting cv. Ebano were obtained with low ANA concentrations and AG3 absence.