ABSTRACT. Intensive weed management is one of the most common practices in coffee cultivation areas. Consequently, some problems, such as soil degradation and the selection of herbicide resistant weed, have increased over time, but, if properly managed, weeds at coffee planting inter-rows can offer benefits of erosion control, nutrient recycling and crop sustainability. The aim of this study is to evaluate the effect of different weed management strategies on the productivity and coffee grain size, i.e., quality. The experiment is installed onto a resprouting Coffea arabica L. site, four years after it was established. Treatments are implanted at planting inter-row Urochloa ruziziensis, Pueraria phaseoloides, and spontaneous vegetation maintained by mowing, herbicides, and weeding. To measure dry matter accumulation, samples are taken with a 0.25 m2 square template at plots maintained by mowing and herbicide application. To evaluate the yield and granulometry, coffee fruits are harvested, processed and classified in a set of 14 sieves (grouped in flat or “moca” shapes). The methods of controlling herbicide and weeding show significance in relation to grain production, with the production of grains having a higher market value standing out, when compared with the other treatments. The accumulation of dry matter above soil, in treatments with herbicides and spontaneous vegetation positively influenced the early coffee productivity (2018), and with U. ruziziensis and spontaneous vegetation, positively influenced the productivity of late harvest (2019). The accumulation of dry matter on the soil tends to be positively linked to coffee productivity, especially in periods when there is a shortage of rain in the region under study; however, it cannot be stated that this influence relationship (causality) has a direct positive effect between dry matter mass production and productivity of future coffee plantations.

ABSTRACT Pre-emergence herbicides, such as indaziflam, have agronomic efficiency when available in the soil solution, mainly in the superficial layer (0-10 cm), the region with the highest concentration of weed seed bank. However, information about the sorption of indaziflam in Brazilian soils still is scarce, since most studies available in the literature were conducted in soils of temperate regions. The objective of this study was to estimate the sorption of indaziflam using high-performance liquid chromatography (HPLC) and bioassay in a Latossolo Vermelho-Amarelo (Oxisol) and in a Cambissolo (Inceptisol), at pH values of 5.1 and 6.1. In the biossay, Sorghum bicolor was used as an indicator plant. Quantitative indaziflam data were obtained by HPLC, and the sorption and desorption coefficients were determined in the soils using Freundlich isotherms. Increasing the pH of the two soils from 5.1 to 6.1 resulted in reductions of C50 and sorption coefficient values. Desorption, a parameter estimated only by HPLC, showed an inverse behavior to that of sorption, that is, the lowest desorption was observed in the condition of highest sorption. It is concluded that the increase in pH of the studied soils reduces indaziflam sorption, influencing the recommendations of this herbicide, from both the agronomic and the environmental points of view. When the goal is to verify the presence or absence of indaziflam in the studied soils, the bioassay technique has satisfactory efficiency. Chromatographic assay is necessary when quantifying the concentration of this herbicide in the soil.

RESUMO Herbicidas aplicados em pré-emergência, como o indaziflam, têm eficiência agronômica quando disponíveis na solução do solo, principalmente na camada superficial (0-10 cm), região de maior concentração do banco de sementes das plantas daninhas. Contudo, as informações acerca da sorção do indaziflam em solos brasileiros ainda são escassas, pois a maioria dos estudos disponíveis na literatura foram conduzidos em solos de regiões temperadas. O objetivo desse estudo foi estimar a sorção do indaziflam, utilizando a técnica da cromatografia líquida de alta eficiência (CLAE) e do bioensaio em um Latossolo Vermelho-Amarelo e Cambissolo nos valores de pH 5,1 e 6,1. No ensaio biológico foi utilizado o Sorghum bicolor como planta indicadora. Os dados quantitativos do indaziflam foram obtidos por CLAE e os coeficientes de sorção e dessorção foram determinados em solos utilizando as isotermas de Freundlich. A elevação do valor de pH dos dois solos de 5,1 para 6,1, proporcionou diminuição da C50 e dos valores do coeficiente de sorção. A dessorção, parâmetro estimado apenas pela CLAE, apresentou comportamento inverso ao da sorção, ou seja, na condição de maior sorção foi observada a menor dessorção. A elevação do pH dos solos estudados diminui a sorção do indaziflam, influenciando as recomendações desse herbicida, tanto do ponto de vista agronômico quanto ambiental. Quando se pretende verificar a presença ou ausência do indaziflam no solo a técnica do bioensaio possui eficiência satisfatória. Na quantificação da concentração desse herbicida no solo é necessária à realização do ensaio cromatográfico.

RESUMO São escassas as informações sobre o efeito de herbicidas sobre a qualidade sementes de feijão -caupi. Objetivou-se avaliar o efeito de dessecantes químicos na pré-colheita sobre a antecipação da colheita e qualidade fisiológica das sementes de feijão-caupi Cv BRS Tumucumaque, antes e após o armazenamento. No experimento 1, adotou-se o delineamento de blocos casualizados, com quatro repetições. Os tratamentos foram: sete herbicidas (carfentrazone-ethyl, saflufenacil, glyphosate, paraquat, flumioxazin, amonio -glufosinate e diquat) e um tratamento controle. Avaliou-se a antecipação de colheita, teor de água, germinação e vigor das sementes. As sementes foram armazenadas por seis meses em sala climatizada e ambiente não controlado e avaliadas quanto ao o teor de água, germinação e vigor, compondo o experimento 2, que foi disposto em esquema fatorial 7x2+1, com quatro repetições. O primeiro fator correspondeu a sete herbicidas, o segundo a dois ambientes de armazenamento, mais um tratamento controle. Observou -se um período de 3 a 9 dias de antecipação da colheita em relação a testemunha. O amônio-glufosinate afeta negativamente a germinação e o vigor das sementes. Após o armazenamento, menor germinação e vigor foram observados para o herbicida glyphosate. Os herbicidas carfentrazone-ethyl e flumioxazin não afetaram a qualidade fisiológica das sementes de feijão caupi nos períodos pós-colheita e seis meses após o armazenamento. O paraquat e o diquat foram os herbicidas mais eficientes na antecipação da colheita (nove dias). O glyphosate e o amonio -glufosinate foram os herbicidas mais prejudiciais à qualidade fisiológica das sementes. A sala climatizada é o ambiente mais adequado para conservação das sementes.

ABSTRACT Information about the effect of herbicides on cowpea seed quality is scarce. The objective of this work was to evaluate the effect of using chemical desiccants at pre-harvest on the anticipation of harvest and physiological quality of cowpea seeds of the cultivar BRS-Tumucumaque, before and after storage. Two experiments were conducted: experiment 1 was conducted under a randomized block design, with four replications; the treatments consisted of seven herbicides (carfentrazone-ethyl, saflufenacil, glyphosate, paraquat, flumioxazin, glufosinate-ammonium, and diquat) and a control treatment; anticipation of harvest, and seed water content, germination, and vigor were evaluated. The seeds were stored for six months in controlled environment and not-controlled environment rooms and evaluated for water content, germination, and vigor in Experiment 2, which was conducted in a 7^2+1 factorial arrangement, with four replications; the first factor consisted of the seven herbicides, the second factor was the two storage environments, plus a control treatment. The results showed 3 to 9 days of anticipation of harvest relative to the control. The glufosinate -ammonium herbicide negatively affected seed germination and vigor. The glyphosate herbicide decreased seed germination and vigor after storage. The physiological quality of cowpea seeds at the post -harvest period and after six months of storage was not affected by the carfentrazone-ethyl and flumioxazin herbicides. Paraquat and diquat were the most efficient herbicides for the anticipation of harvest (nine days). Glyphosate and glufosinate -ammonium were the most harmful herbicides to seed physiological quality. The controlled environment room was the most adequate environment for seed conservation.

ABSTRACT The purpose of this study was to assess the effect of different herbicide treatments on moisture removal and calorific power of biomass sorghum for co-generation of electric energy through burning. The experiment was conducted in randomized complete block design with four replicates per treatment and a 6x4 factorial scheme (six herbicide treatments x four intervals between spraying and harvesting). The herbicide treatments were: two different doses of glyphosate (1.92 kg a.i. ha-1 and 3.84 Kg a.i. ha-1), paraquat (0.4 Kg a.i. ha-1), a commercial mixture of paraquat + diuron (0.6 + 0.3 Kg a.i. ha-1), glufosinate-ammonium (0.8 Kg a.i. ha-1) and control (unsprayed). The intervals between spraying and harvesting assessed were 7, 14, 21 and 28 days after desiccation (DAD). It was assessed: the number of leaves per plant, moisture content of leaves, panicles, culm and whole ground plants and Superior Calorific Power (SCP). The herbicides paraquat and paraquat + diuron promotes defoliation, after 14 DAD. Glyphosate, paraquat, paraquat + diuron and glufosinate-ammonium reduce leaf and panicle moisture, despite only glyphosate reduces moisture in the culm. The herbicides do not affect the SCP of biomass sorghum. Therefore, the herbicides, especially glyphosate, have high potential for pre-harvest desiccation in biomass sorghum.

RESUMO O objetivo do presente trabalho foi avaliar o efeito de coberturas do solo sobre a incidência e severidade da podridão cinzenta do caule em feijão-caupi. Foram conduzidos dois ensaios em esquema fatorial 5 x 2 x 2, com cinco coberturas de solo (Brachiaria brizantha (Braquiária), Pennisetum glaucum (Milheto), Crotalaria spectabilis (Crotalária), filme de polietileno e solo sem cobertura), duas formas de utilização do solo (esterilizado e não esterilizado) e duas condições de infestação do solo (infestado e não infestado com Macrophomina phaseolina). No primeiro experimento, as plantas de cobertura foram cultivadas em vasos e dessecadas com glifosato, para posterior plantio do caupi. O segundo consistiu do novo plantio do caupi nos mesmos vasos. A avaliação da incidência e severidade da doença foi realizada aos 60 dias após o plantio. Determinou-se a massa seca do feijão em estufa e o monitoramento da temperatura do solo com dataloggers Campbell CR 1000. Os tratamentos com cobertura vegetal reduziram o aquecimento e a amplitude térmica em relação ao solo sem cobertura. O filme de polietileno proporcionou incremento nos referidos índices. No primeiro cultivo, o P. glaucum proporcionou a maior produção de massa da matéria seca do feijão-caupi. A massa de matéria seca das plantas de feijão-caupi foi maior em solo não esterilizado. O solo não esterilizado e infestado com M. phaseolina causou maior incidência da doença. Em solo não esterilizado, B. brizantha foi a cobertura que proporcionou maior incidência da doença.

ABSTRACT The objective of the present study was to evaluate the effect of soil covers on the incidence and severity of charcoal rot in cowpea. Two trials were conducted in 5 x 2 x 2 factorial arrangement, with five soil covers (Brachiaria brizantha, (Brachiaria) Pennisetum glaucum, (Millet) Crotalaria spectabilis, (Crotalaria), polyethylene film and bare soil), two ways of using the soil (sterilized and unsterilized) and two infestation conditions (soil infested with Macrophomina phaseolina and not infested). In the first trial, the cover plants were grown in pots and desiccated with glyphosate for subsequent planting of cowpea. The second trial consisted of new planting of cowpea in the same pots. Evaluation of the incidence and severity of the disease was carried out at 60 days after planting. The dry mass of cowpea in a stove was determined and the soil temperature was monitored with data loggers Campbell CR 1000. The treatments with vegetal cover reduced heating and thermal amplitude relative to bare soil. The polyethylene film provided an increase in the respective rates. In the first cultivation, P. glaucum provided the greatest cowpea dry matter production. The dry matter mass of cowpea was higher in unsterilized soil. The unsterilized soil infested with M. phaseolina caused higher incidence of the disease. In unsterilized soil, B. brizantha was the cover that provided the highest incidence of the disease.

RESUMO O objetivo do trabalho foi avaliar as respostas fisiológicas em feijão-caupi sob efeito de estresse hídrico e reidratação nos sistemas de plantio direto (PD) e convencional (PC). Foram avaliados dois sistemas de plantio (direto e convencional) e três condições hídricas (sem estresse, estresse moderado e estresse severo). Foram determinados: área foliar, matéria seca total, fotossíntese, condutância estomática, transpiração, concentração interna de CO2 e potencial hídrico foliar. O estresse hídrico afetou todas as variáveis avaliadas, com exceção do potencial hídrico foliar. Houve recuperação de todas as variáveis após reidratação em ambos níveis de estresse. O fechamento estomático é um importante mecanismo de tolerância à seca, sendo que o feijão-caupi pode ser considerado uma espécie conservadora, i.e. que prioriza a manutenção do status hídrico em detrimento da produção fotossintética. Os sistemas de plantio não afetaram as taxas fotossintéticas. O sistema de plantio direto promove maior acúmulo de biomassa e maior área foliar.

ABSTRACT The goal of this work was to evaluate the physiological responses of cowpea under water stress and rehydration in conventional and no-tillage systems. We evaluated two crop systems (conventional and no tillage) and three water conditions (no stress, moderate stress and severe stress). The following were determined: leaf area, total dry matter, photosynthetic rate, stomatal conductance, transpiration rate, internal CO2 concentration and leaf water potential. Water stress affected all variables evaluated, with the exception of leaf water potential. Cowpea recovered with respect to all variables after rehydration at both stress levels. Stomatal closure is an important drought tolerance mechanism, and cowpea can be considered a conservative species (i.e., one that prioritizes water status maintenance rather than photosynthetic rate). Planting systems did not affect photosynthetic rate. The tillage system promoted greater accumulation of biomass and higher leaf area.

RESUMO A ocorrência de doenças radiculares representa uma das principais causas de perda de rendimento na cultura do melão, com destaque para patógenos causadores das podridões de raízes e colos, como os fungos Fusarium solani, Macrophomina phaseolina e Rhizoctonia solani, observados no meloeiro tanto de forma isolada quanto associada. A utilização de material vegetal e restos de culturas, além de melhorar as propriedades físicas do solo e favorecer a atividade microbiana neste ambiente, pode interferir negativamente sobre a população de patógenos. Portanto, o objetivo deste trabalho foi verificar o efeito da utilização do Feijão-de-porco [Canavalia ensiformis (L.) DC] no manejo da podridão radicular do meloeiro (Cucumis melo L.) causada pelos patógenos F. solani, M. phaseolina e R. solani, quando sozinhos ou associados. O experimento foi realizado em casa de vegetação no delineamento de blocos casualizados, com esquema fatorial 8 x 4, sendo 8 tipos de fungos/associações e 4 formas de manejo, com 4 repetições. As características avaliadas foram: incidência de podridão radicular das plantas de melão no final do ciclo, prevalência dos patógenos e a massa da matéria seca do meloeiro. O feijão-de-porco em cobertura proporciona menor incidência de podridão radicular no meloeiro quando Fusarium solani está sozinho. Macrophomina phaseolina é o fungo que prevalece na maioria das associações nas quais está presente. Aumento na massa da matéria seca do meloeiro foi observado quando aplicado o mulch (filme de polietileno preto) nos tratamentos com associação de F. solani + R. solani e no solo não infestado.

ABSTRACT The occurrence of root diseases represent one of the major causes of yield loss in melon crop, especially considering pathogens that cause root and stem rot, such as the fungi Fusarium solani, Macrophomina phaseolina and Rhizoctonia solani, observed in muskmelon either alone or in association. The use of plant materials and crop residues, besides improving the soil physical properties and favoring the microbial activity in this environment, negatively interferes in the population of pathogens. Therefore, the aim of this study was to verify the effect of using jack beans [Canavalia ensiformis (L.) DC] in the management of root rot of muskmelon (Cucumis melo L.) caused by the pathogens F. solani, M. phaseolina and R. solani either alone or in association. The experiment was carried out in a greenhouse in randomized block design, with 8 x 4 factorial arrangement, 8 types of fungi/associations and 4 management systems, and 4 replicates. The evaluated characteristics were: incidence of root rot in melon plants at the end of the cycle, prevalence of pathogens and dry weight of muskmelon. Jack beans in coverage provides lower incidence of root rot in muskmelon when Fusarium solani is alone. Macrophomina phaseolina is the fungus that prevails in most associations in which it is present. Increased dry weight of muskmelon was observed when mulch (the black polyethylene film) was applied in the treatments with F. solani + R. solani association and in non-infested soil.

RESUMO Com o objetivo de avaliar a sobrevivência de Macrophomina phaseolina em solo submetido a diferentes coberturas, conduziu-se dois experimentos em casa de vegetação, no delineamento inteiramente casualizado, em esquema fatorial 5 x 2, com cinco coberturas (Brachiaria brizantha, Pennisetum glaucum, Crotalaria spectabilis, solo coberto com filme de polietileno e solo sem cobertura) e solo esterilizado e não esterilizado. No primeiro experimento, as plantas foram cultivadas em vasos e dessecadas, para posterior plantio do feijão-caupi e no segundo, a semeadura da cultura foi realizada em sucessão ao primeiro cultivo. Nos dois experimentos foram colocadas em cada vaso a 10 cm de profundidade, no dia do plantio da cultura, quatro bolsas de tecido contendo, cada uma, 10 gramas de inóculo de M. phaseolina, das quais, duas foram retiradas aos 30 dias após o plantio e duas no final do ciclo da cultura, para posterior plaqueamento e determinação da sobrevivência. Realizou-se também o monitoramento das temperaturas máximas e mínimas diárias do solo. Os tratamentos com solo coberto com material vegetal apresentaram menor elevação da temperatura em relação ao solo coberto com filme de polietileno e sem cobertura, que elevaram a temperatura em até 5,9 e 3,9 ºC, respectivamente, em relação ao solo coberto com palhada de P. glaucum. O solo coberto com filme de polietileno e sem cobertura apresentaram maiores taxas de sobrevivência de M. phaseolina e o solo coberto com palhada de P. glaucum a menor taxa. Maior sobrevivência foi observada no solo não esterilizado.

ABSTRACT Aiming to evaluate the survival of Macrophomina phaseolina subjected to different soil covers, two experiments were conducted in a greenhouse, in a completely randomized design, 5 x 2 factorial arrangement, with five covers (Brachiaria brizantha, Pennisetum glaucum, Crotalaria spectabilis, polyethylene film and bare soil) and sterilized and unsterilized soil. In the first experiment, the plants were grown in pots and desiccated for subsequent planting of the cowpea, while in the second experiment the culture was sown after the first cultivation. In both experiments, each pot received, at 10cm depth, on the day of planting, four fabric bags containing 10 grams of M. phaseolina inoculum each, of which two were removed at 30 days after planting and the other two were removed at the end of the culture cycle for subsequent plating and determination of the survival. Daily maximum and minimum soil temperatures were also monitored. The treatments of soil covered with straw mulch had lower temperature rise in relation to soil covered with polyethylene film and without cover, which raised the temperature up to 5.9 and 3.9 °C, respectively, relative to the soil covered with P. glaucum straw. The soil covered with polyethylene film and the soil without cover had higher M. phaseolina survival rates, while the soil covered with P. glaucum straw had the lowest rate. Increased survival was observed in the unsterilized soil.

ABSTRACT Microorganisms have a fundamental importance in agricultural ecosystems and may be influenced by several factors, including soil management. The aim of this study was to evaluate the effects of cropping systems and soil covers on the microbial community in soil cultivated with muskmelon (Cucumis melo L.). The experiment was conducted in a randomized complete block design with four replications. The treatments were arranged in a split plot design with cropping systems (no-tillage and conventional tillage systems) assigned to the whole plot treatments, while a group of seven soil covers (sunn hemp; millet; sunn hemp + millet; corn + brachiaria; spontaneous vegetation; bare soil; and spontaneous vegetation + polyethylene film) defined the subplot treatments. Total bacteria, sporulating bacteria, fluorescent Pseudomonas sp., and total fungi were quantified at six different times (in fallow soil, at planting of green manures in the soil, when transplanting muskmelon seedlings, and 20, 40, and 60 days after transplanting [DAT]). To determine the quantity of microorganisms, the plate count method was used, with a specific culture medium for the groups. The cultivation of sunn hemp associated with no-tillage at transplanting of muskmelon showed a greater quantity of colony forming units (CFUs) of total bacteria compared to the conventional tillage system. In most treatments, conventional tillage showed greater amounts of sporulating bacteria in relation to no-tillage at the time of transplanting muskmelon and at 40 DAT. The tillage systems and soil cover did not change the total amount of fungi and fluorescent Pseudomonas sp.

Objetivou-se avaliar o efeito dos sistemas de plantio direto e convencional e as estratégias de manejo de plantas daninhas na eficiência do uso da água pela cultura do pimentão. O experimento foi conduzido na Universidade Federal Rural do Semi-Árido, em Mossoró-RN, utilizando o esquema de parcelas subdivididas, no delineamento experimental em blocos casualizados, com quatro repetições. Os sistemas de plantio foram avaliados nas parcelas, e nas subparcelas três estratégias de manejo de plantas daninhas (cobertura do solo com filme de polietileno, capinado e sem capinas). Avaliou-se a densidade e massa seca das plantas daninhas, a produtividade comercial, total e o consumo diário de água. Verificou-se que o sistema de plantio direto reduziu a densidade e a massa seca das plantas daninhas em relação ao plantio convencional e a interferência destas reduziu a produtividade comercial em ambos os sistemas de cultivo. O tratamento com capinas nos sistema de plantio direto, apesar do maior consumo de água, apresentou produtividade e eficiência no uso da água superior aos tratamentos com filme de polietileno nos sistemas de plantio direto e convencional e o capinado no plantio convencional.

This study aimed to evaluate the effect of no-tillage and conventional planting systems, and of weed-management strategies on water-usage efficiency in capsicum crops. The experiment was carried out at the Universidade Federal Rural do Semi-Árido in Mossoró, Rio Grande do Norte, using a split-plot layout in a randomized block design with four replications. The tillage systems were evaluated in the plots, and three weed-management strategies evaluated in the subplots (soil cover with polyethylene film, and with and without weeds). The density and dry mass of the weeds, the commercial and total productivity, and the daily water consumption were all evaluated. It was found that the no-tillage system reduced the density and dry mass of the weeds in comparison to conventional systems, and the interference of these plants reduced commercial productivity under both planting systems. The strategy of weeds under a no-tillage system, despite a higher water consumption, showed a productivity and efficiency of water usage superior to those of the strategies of polyethylene film both under no-tillage and conventional systems, and of weeds under a conventional tillage system.

This study was carried out with the aim of assessing the efficacy of the fluazifop-p-butyl herbicide to control Brachiaria brizantha, cultivar Marandu, in the formation of Tifton 85 grazing. Treatments consisted of five doses of fluazifop-p-butyl herbicide (0.0, 62.5, 125.0, 187.5 and 250.0 g ha-1) plus controls with no herbicide, in a completely randomized layout, with four replications. Each plot consisted of a 10-L capacity pot, with two B. brizantha plants and two Tifton 85 plants. The herbicide application was conducted before the tillage of B. brizantha, when they were about 15 cm high. Visual assessments of control of B. brizantha and intoxication of Tifton 85 plants, at 07, 21 and 45 days after application were carried out. Sixty days after application, plants were harvested at ground level and oven-dried. Regrowth was assessed in the same manner, 60 days after cutting, to determine their dry weight. Control of B. brizantha was noted to be above 50%, from doses of 218.75 g ha-1 at 45 days after application. The fluazifop-p-butylherbicide did not show to be efficient in the control of B. brizantha in the doses assessed and caused intoxication to Tifton 85 plants.

O trabalho objetivou avaliar a qualidade pós-colheita de cenoura 'Brasília' durante o desenvolvimento em monocultivo e consorciada com rabanete 'Crimson Gigante'. A semeadura foi realizada sob canteiros da horta experimental da Universidade Federal Rural do Semi-Árido (UFERSA), localizada no município de Mossoró-RN. A adubação foi efetuada conforme as exigências da cultura. O experimento foi conduzido em delineamento de blocos casualizados, no esquema fatorial 2 x 4 (dois sistemas de cultivo e quatro épocas de colheita) com quatro repetições. As raízes de cenoura foram colhidas nos intervalos de 83; 91; 99 e 107 dias após a semeadura, e em seguida foram transportadas para o Laboratório de Pós-Colheita da UFERSA, onde procederam-se as seguintes análises físicas e físico-químicas das raízes: massa fresca, comprimento, diâmetro, firmeza, sólidos solúveis, potencial hidrogeniônico, acidez titulável e vitamina C. As variáveis estudadas foram submetidos à análise de variância e os níveis do fator qualitativo (sistemas de cultivo) foram comparados pelo teste de Tukey, enquanto para o fator quantitativo (épocas de colheita) procedeu-se o ajuste de modelos de regressão. O sistema de produção consorciado de cenoura e rabanete não propiciou diferença nas características avaliadas. Exceto para o diâmetro das raízes, que foi menor em cultivo consorciado. A época de colheita das raízes influenciou no diâmetro, pH, acidez titulável e vitamina C. Com exceção do pH, as demais características aumentaram com a época de colheita.

The work had for objective to evaluate the quality carrot 'Brasília ' powder-crop during the development in monoculture and intercropped with radish 'Crimson Gigante '. The sowing was accomplished in stonemasons of the experimental vegetable garden of the Universidade Federal Rural do Semi-Árido (UFERSA), in Mossoró-RN. The manuring was made according to the demands of the culture. The experiment was conducted in randomized blocks, in the factorial design 2 x 4 (two cropping systems and four crop times) with four repetitions. The carrot roots were harvested in the intervals of 83, 91, 99 and 107 days after the sowing, and soon afterwards they were transported to the Postharvest Laboratory of UFERSA, where the following analyses were proceeded: fresh mass, length, diameter, firmness, soluble solids, pH, titrabable acidity and vitamin C. The studied variables were submitted the variance analysis, the qualitative factor (cropping systems) were compared by Tukey test and the quantitative factor (crop times) were compared by regression analysis. The associated production system of carrot and radish did not influence the characteristics assessed. Except for the diameter of the roots, that was smaller in associated system. The time of the crop, and of the roots influenced in the diameter, pH, titrabable acidity and vitamin C. Except for the pH, the other characteristics increased with the crop time.

Foi objetivo avaliar os efeitos de diferentes espaçamentos de plantio sobre a qualidade de raízes de três cultivares de cenoura nas condições de Mossoró, Rio Grande do Norte. O delineamento experimental utilizado foi em blocos casualizados, em esquema fatorial 6 x 3, com três repetições, sendo o primeiro fator constituído pelos espaçamentos: 20 x 4, 20 x 6, 20 x 8, 15 x 4, 15 x 6 e 15 x 8 cm e o segundo, pelos cultivares: Brasília, Alvorada e Esplanada. As características avaliadas nas raízes de cenoura foram: comprimento da raiz, diâmetro da raiz, comprimento do xilema, diâmetro do xilema, sólidos solúveis (SS), açúcares totais, acidez total (AT), vitamina C, relação SS/AT e pH. Não houve interação significativa entre cultivares e espaçamentos de plantio em qualquer das características avaliadas. Os espaçamentos influenciaram o comprimento e diâmetro da raiz e o comprimento e diâmetro do xilema. O cultivar Alvorada sobressaiuse nos sólidos solúveis, açúcares solúveis totais e relação SS/AT.

This work was carried out from July to September, 2006, at the vegetable garden of UFERSA, in Mossoró, RN, Brazil, to evaluate the effect of different plant spacing on root quality of three cultivars of carrot. The experimental design was a complete randomized blocks, in a 6x3 factorial scheme, with three replications. The studied factors were spacing (20x4, 20x6, 20x8, 15x4, 15x6, and 15x8 cm) and cultivars (Brasília, Alvorada and Esplanada). The evaluated carrot root characteristics were: root length, root diameter, xylem length, xylem diameter, soluble solids content (SS), total sugar content (TS), total acidity, vitamin C, SS/TS ratio, and pH. The factors cultivar and plant spacing did not show interaction for any evaluated characteristic. Plant spacing influenced length and diameter of both root and xylem. Cultivar Alvorada had better performance for soluble solids and total sugar, as well as for SS/TS ratio.

O objetivo deste trabalho foi avaliar o crescimento do pimentão cv. Atlantis sob diferentes arranjos espaciais. Foram avaliados três arranjos de espaçamentos entre fileiras duplas e fileiras simples de plantio (1,5x0,5, 1,6x0,4 e 1,7x0,3 m), e quatro espaçamentos entre plantas nas fileiras (0,2, 0,3, 0,4 e 0,5 m), combinados em esquema fatorial. Utilizou-se o delineamento de blocos ao acaso, com três repetições e parcelas subdivididas no tempo. A avaliação de crescimento foi realizada em nove épocas espaçadas em 14 dias, com a primeira avaliação realizada 14 dias após o transplantio (DAT). Até os 126 DAT, foram avaliados: área foliar (AF); índice de área foliar (IAF); massas secas de folhas (MSF), do caule (MSC), de frutos (MSFr) e do total da parte aérea (MST); taxa de crescimento absoluto (TCA), assimilatória líquida (TAL) e de crescimento relativo (TCR); e as razões de área foliar (RAF) e de massa foliar (RMF). As alterações em AF, TCR, RMF e RAF foram independentes do espaçamento entre fileiras que, no entanto, influenciou MSF, MSC, MSFr e MST, IAF e TCA. O aumento do espaçamento entre plantas reduz o IAF e a RAF e aumenta a AF, MSF, MSC, MSFr, MST, TCA e TAL, mas não influencia a TCR e RMF.

The objective of this work was to evaluate the growth of green pepper cv. Atlantis under different spatial arrangements. Three spacing arrangements between double and simple planting rows (1.5x0.5 m, 1.6x0.4 m and 1.7x0.3 m) and four spacing distances between plants in the rows (0.2, 0.3, 0.4 and 0.5 m) combined in factorial scheme were evaluated. A randomized block design in split-plots divided in time with three replicates was used. The growth assessment was done in nine occasions, 14 days apart, and the first one was performed 14 days after transplanting (DAT). Leaf area (LA), leaf area index (LAI), dry masses of leaves (LDM), stem (SDM), fruit (FrDM) and total shoot (TDM); absolute growth rate (AGR), rates of net assimilation (NAR) and relative growth (RGR); and leaf area (LAR) and leaf mass (LWR) ratios were evaluated until 126 DAT. The changes in LA, RGR, LWR and LAR did not depend on row spacing, but spacing influenced LDM, SDM, FrDM and TDM, LAI and AGR. The increase in spacing reduces LAI and LAR, and increases LA, LDM, SDM, FrDM, TDM, AGR and NAR, but does not influence RGR and LWR.