ABSTRACT Beetroot, when cultivated in hot regions such as the Brazilian semi-arid, is subjected to various stressful environmental factors that can negatively impact its productivity and quality. Silicon is an element known for its ability to mitigate damage caused by both abiotic and biotic stressors and is recognized as a productivity and quality enhancer in agricultural crops. Therefore, this study aimed to evaluate the effects of silicon application on the agronomic performance of the beet crop. The experimental design used was a randomized block design in a 5 x 2 factorial arrangement with four replications, comprising five silicon doses (0.0; 0.9; 1.8; 2.7, and 3.6 kg ha-1) and two table beet cultivars (Fortuna and Maravilha). The assessed variables included plant height, number of leaves per plant, polar and equatorial diameter of the tuberous root, tuberous root, shoot and total dry matter mass, commercial, non-commercial, and total productivity, as well as quality assessment of the root with determinations of pH, vitamin C, titratable acidity, and total soluble sugars. A silicon dose of 2.56 kg ha-1 promoted optimal root development in the Fortuna cultivar; however, silicon application at all tested doses reduced the levels of soluble sugars, while a dose of 3.6 kg ha-1 increased total titratable acidity. In contrast, silicon did not infl uence root development in the Maravilha cultivar, but an application of 3.13 kg ha-1 increased the total soluble sugar content by 86.13%. Beetroot semiarid, semiarid semi arid, arid semi-arid crops Therefore crop replications 0.0 00 0 (0.0 0.9 09 9 1.8 18 1 8 27 7 2.7 36 3 6 3. ha1 ha Maravilha. . Maravilha) height mass commercial noncommercial, noncommercial non non-commercial pH C acidity sugars 256 56 2.5 ha- cultivar however contrast 313 13 3.1 8613 86 86.13% 0. (0. 1. 2. 25 31 861 86.13 (0 86.1 ( 86.

ABSTRACT No study has investigated the fertilization of beet with manganese (Mn) in the Brazilian semi-arid region. In this study, we evaluated the agronomic performance of manganese fertigated beet in Mossoró, Rio Grande do Norte. The experiments were conducted at Fazenda Experimental Rafael Fernandes in 2019 and 2021, and the study had a complete randomized block design with five treatments (0, 3, 6, 9, and 12 kg ha-1 Mn) and four replications. The Mn content increased in foliar diagnosis with fertilization. The accumulation of dry mass and the number of leaves did not differ significantly as a function of the dose. The highest total (21.59 t ha-1) and commercial (20.55 t ha-1) yields of tuberous roots were obtained with 6 kg ha-1 Mn. The adverse effects of excess Mn were expressed in the lower total and commercial productivity of beet fertilized with more than 6 kg ha-1 Mn. The accumulation of Mn in the tuberous roots was not affected by fertilization. In the leaves and the whole plant, the maximum accumulation occurred when 12 kg ha-1 Mn was applied. Although Mn did not influence the content of soluble solids, the pH of the tuberous roots of plants fertilized with 6 kg ha-1 Mn decreased, and the dose with the highest total and commercial productivity had a lower content of soluble sugars. Our findings suggest that treatment with 6 kg ha-1 Mn is optimum for the beet crop. (Mn semiarid semi arid region Mossoró Norte 201 2021 0, 0 (0 3 9 1 ha1 ha ha- replications 21.59 2159 21 59 (21.5 20.55 2055 20 55 (20.5 plant applied solids decreased sugars crop 202 ( 21.5 215 2 5 (21. 20.5 205 (20. 21. (21 20. (20 (2

RESUMO Não há na literatura recomendações de adubação com manganês (Mn) para beterraba estabelecidas no semiárido brasileiro. Objetivou-se avaliar o desempenho agronômico de beterraba fertirrigada manganês em Mossoró, RN. Foram desenvolvidos experimentos na Fazenda Experimental Rafael Fernandes nos anos de 2019 e 2021, delineados em blocos casualizados completos com cinco tratamentos (0, 3,0, 6,0, 9,0 e 12,0 kg ha-1 de Mn) e quatro repetições. Houve aumento no teor de Mn na diagnose foliar com a adubação. O acúmulo de massa seca e o número de folhas não diferiram estatisticamente em função das doses. A maior produtividade total (21,59 t ha-1) e comercial (20,55 t ha-1) de raiz tuberosa foi obtida com 6,0 kg ha-1 de Mn. O efeito deletério do excesso de Mn foi expresso na menor produtividade total e comercial de beterraba adubada com mais que 6,0 kg ha-1 de Mn. O Mn acumulado na raiz tuberosa não foi influenciado pela adubação. Nas folhas e na planta inteira, o acúmulo máximo ocorreu na dose 12,0 kg ha-1 de Mn. O Mn não influenciou no conteúdo de sólidos solúveis, mas reduziu o pH e, a raiz tuberosa das plantas adubadas com 6,0 kg ha-1 de Mn, dose com maior produtividade total e comercial, tiveram menor teor de açúcares solúveis. Recomenda-se adubação com 6,0 kg ha-1 de Mn para a cultura da beterraba. (Mn brasileiro Objetivouse Objetivou se Mossoró RN 201 2021 0, 0 (0 30 3 3,0 60 6 90 9 9, 120 12 12, ha1 ha 1 ha- repetições doses 21,59 2159 21 59 (21,5 20,55 2055 20 55 (20,5 6, inteira solúveis Recomendase Recomenda 202 ( 3, 21,5 215 2 5 (21, 20,5 205 (20, 21, (21 20, (20 (2

ABSTRACT. The management of weeds in melon is hindered by the slow initial growth of the crop, favouring weed infestation and reducing production. During the years 2016 and 2017, weed interference periods were evaluated in two melon hybrids, yellow and frog skin, to determine the time of weed control in the crop. Four-parameter logistic regression was used to determine the critical weed control period (CPWC). The weed species with the highest occurrences in 2016 were Merremia aegyptia, Senna obtusifolia, and Urochloa plantaginea. In 2017, there was a predominance of M. aegyptia, indicating the possibility of successive cultivation, favouring the predominance of species with growth habits similar to melons. The increase in the period of living with weeds reduced the productivity and quality of melon fruits. Coexistence with weeds throughout the cycle reduced productivity by about 50%. The CPWC was 15 to 58 and 10 to 45 for frog skin and 12 to 52 and 4 to 50 days for yellow melon in 2016 and 2017, respectively, considering a productivity loss of 5%. These results underscore the importance of adopting strategies that allow melons to grow free from the presence of weeds, especially before they are fully established in the growing area.

ABSTRACT Phosphorus (P) is an important nutrient for obtaining high yields and has been the one that most often limits production. The objective of this study was to evaluate the agronomic performance of onion cultivars as a function of phosphate fertilization. The experiments were installed at the Rafael Fernandes Experimental Farm, of the Federal Rural University of the Semi-Arid Region, Mossoró-RN, Brazil, from July to October 2016 and from June to October 2017. The design used was randomized blocks, in a 2 x 6 factorial scheme, with four replicates. The treatments consisted of the combination of two onion cultivars (IPA11 and Rio das Antas) and six P doses (0, 60, 120, 180, 240 and 300 kg ha-1 P2O5). The economical doses of P, associated with the maximum marketable yields of onion were estimated at 212.45 and 207.65 kg ha-1 of P2O5, respectively for the cultivars IPA 11 and Rio das Antas. In general, the cultivar Rio das Antas was more productive than IPA 11, in the two growing periods.

ABSTRACT Garlic is a vegetable that has a high economic importance for Brazil. However, despite increases in garlic bulb production in the last years, Brazil is still dependent on imported garlic to meet the national demand. Thus, proper management practices and the use of virus-free clove-seeds are promising alternatives to ensure a high productivity and profitability. Thus, the objective of this work was to evaluate production characteristics and profitability of conventional and virus-free garlic crops as a function of different clove-seed sizes and plant spacings. Two experiments were conducted simultaneously, using virus-free and conventional garlic plants in Portalegre, state of Rio Grande do Norte, Brazil, in a randomized block experimental design, with four replications. The treatments were arranged in split-plot, with the clove-seed size (large and small) in the plots, and the spacing between plants (7.5, 10.0, 12.5, and 15.0 cm) in the subplots. The combination between the use of virus-free clove-seeds, large clove-seed size, and spacing of 12.5 cm between plants resulted in the highest commercial bulb yield and net income, R$ (BRL) 85,151.00 ha-1. The use of large clove-seeds and spacing of 7.5 cm between plants are recommended for conventional garlic crops. However years demand Thus virusfree virus free cloveseeds clove seeds cloveseed seed spacings simultaneously Portalegre Norte design replications splitplot, splitplot split plot, plot split-plot small plots 7.5, 75 7 5 (7.5 100 10 0 10.0 125 12 150 15 15. subplots cloveseeds, seeds, 12. income R BRL (BRL 8515100 85 151 00 85,151.0 ha1. ha1 ha 1. 1 ha-1 7. (7. 10. 851510 8 85,151. ha- (7 85151 85,151 ( 8515 85,15 851 85,1 85,

RESUMO O alho é uma hortaliça de grande importância econômica para o Brasil. No entanto, apesar da produtividade do alho brasileiro ter aumentado nos últimos anos, ainda há uma dependência do alho importado para atender a demanda interna. Dessa forma, práticas de manejo e o uso de alho-semente livre de vírus, tornam -se uma alternativa promissora para garantir maiores produtividades e rentabilidade. Assim, o objetivo deste trabalho foi avaliar características de produção e rentabilidade do cultivo de alho convencional e livre de vírus em função do tamanho de bulbilho-semente e espaçamento entre plantas. Dois experimentos foram conduzidos simultaneamente, utilizando alho livre de vírus e convencional, em Portalegre-RN. O delineamento experimental foi o de blocos casualizados, com quatro repetições. Os tratamentos foram dispostos em parcelas subdivididas, sendo as parcelas representadas pelo tamanho dos bulbilhos: grande e pequenos. As subparcelas foram compostas por quatro espaçamentos entre plantas: 7,5; 10,0; 12,5 e 15,0 cm. A combinação entre o alhosemente livre de vírus, bulbilho de tamanho grande e espaçamento de 12,5 cm entre plantas resultou em maior produtividade comercial e receita líquida (R$ 85.151,00 ha-1). Para o alho convencional, sugere-se a utilização de bulbilhos grandes com espaçamento de 7,5 cm entre plantas. Brasil entanto anos interna forma semente se Assim bulbilhosemente simultaneamente PortalegreRN. PortalegreRN Portalegre RN. RN Portalegre-RN casualizados repetições subdivididas pequenos 75 7 5 10,0 100 10 0 125 12 12, 150 15 15, R$ R (R 8515100 85 151 00 85.151,0 ha1. ha1 ha 1 . ha-1) sugerese sugere 7, 10, 851510 8 85.151, ha-1 85151 85.151 ha- 8515 85.15 851 85.1 85.

ABSTRACT In regions with high temperatures, carrot cultivation is impracticable, as high temperatures tend to reduce yield and quality of the product. However, with the advent of summer cultivars, carrot cultivation in these regions has become viable. The aim of this work was to evaluate the performance of ten carrot cultivars in different planting seasons. The experiments were carried out at the Rafael Fernandes Experimental Farm of the Federal Rural Semiarid University (UFERSA). The experiments were carried out in May, June, July and August of 2017. The experimental design was a randomized block with ten treatments and four repetitions. The characteristics that were evaluated were the root classification (long, average and short roots); commercial, non-commercial and total yield; dry plant weight and root fresh weight. Both the planting season and the cultivar played important roles in agronomic performance throughout the experimental period. In May and June, the highest average yields and plant growth were obtained (43 and 45 t ha-1 yield, respectively). Hybrid cultivars showed better performance than open-pollinated cultivars in terms of yield. The Brasília, BRS Planalto, and Kuronan varieties showed poor performance in all the evaluated characteristics.

ABSTRACT In regions with high temperatures, carrot cultivation is difficult because high temperatures tend to reduce the size and pigmentation of the root and, consequently, the yield and quality of the product. However, with the advent of summer cultivars, the cultivation of quality carrots under high temperatures has been viable. The aim of this work was to evaluate the postharvest quality of ten carrot cultivars as a function of different planting dates. The experiments were carried out on the Rafael Fernandes Experimental Farm of the Universidade Federal Rural do Semi-Árido (UFERSA). Four experiments were carried out in May, June, July and August 2017. The experimental design was a randomized block with ten treatments and four replications. The following was evaluated: white halo percentage, soluble solids content, total soluble sugars, total titratable acidity, soluble solids/titratable acidity ratio and beta-carotene content. The interaction between the carrot cultivars and planting date had a significant influence on the postharvest quality of carrot roots. The hybrid cultivars had an overall better post-harvest quality. The carrots sown in July had better quality traits; however, they were more affected by the “white halo” disorder.

RESUMO O alho é uma hortaliça que possui grande importância econômica mundial, podendo ser consumido de forma in natura ou industrializado. Mesmo assim, poucos trabalhos envolvendo a análise da qualidade pós-colheita são encontrados. Desta forma, é necessário estabelecer práticas e métodos de cultivo que visem à obtenção não só do aumento da produtividade, mas também, de um produto de melhor qualidade pós-colheita. O objetivo deste estudo foi avaliar a qualidade de bulbos de alho nobre convencional e livre de vírus em função do tamanho do bulbilho e do espaçamento entre plantas. Dois experimentos foram conduzidos simultaneamente, utilizando alho livre de vírus e convencional, em Portalegre-RN. O delineamento experimental adotado, em ambos os experimentos, foi de blocos casualizados, com quatro repetições. Os tratamentos foram dispostos em parcelas subdivididas, sendo as parcelas representadas pelo tamanho dos bulbilhos: grande e pequeno. As subparcelas foram compostas por quatro espaçamentos entre plantas: 7,5; 10,0; 12,5 e 15,0 cm. O uso de bulbilho grande proporcionou maior diâmetro de bulbo e acidez titulável. Os teores de sólidos solúveis, açúcares solúveis totais, relação SS/AT e sólidos totais diminuíram com o aumento dos espaçamentos entre plantas, independente da sanidade e tamanho de bulbilho utilizado. O alho livre de vírus e os espaçamentos entre 12,5 e 15,0 cm promoveram maior diâmetro de bulbos, acidez titulável, pungência e índice industrial, possibilitando a produção de bulbos com melhor qualidade e com boas perspectivas para a industrialização.

ABSTRACT Garlic has a worldwide economic importance; this vegetable can be consumed fresh or processed by food industries. However, few studies evaluate its postharvest quality. It is necessary to establish cultural practices and methods that focus not only on increase of yield, but on obtaining a product with better postharvest quality. The objective of this work was to evaluate the bulb quality of conventional garlic and virus-free garlic as a function of seed clove size and space between plants. Two experiments were conducted simultaneously in Portalegre, Rio Grande do Norte, Brazil. A randomized block experimental design with four replications was used in both experiments. The treatments were arranged in split-plots, with the seed clove size (large and small) in the plots, and the plant spacings (7.5, 10.0, 12.5, and 15.0 cm between plants) in the subplots. The use of large seed cloves resulted in higher bulb diameter and titratable acidity (TA). Soluble solids (SS), total soluble sugars, SS to TA ratio, and total solids decreased as the space between plants was increased, regardless of the seed health and seed clove size. Virus-free garlic seed cloves planted with spacing of 12.5 and 15.0 cm resulted in higher bulb diameter, TA, pungency, and industrial index, i.e., they produced better quality bulbs with good prospects for industrialization.

RESUMO O aumento na densidade de plantas aliado à utilização de híbridos no cultivo da cebola tem proporcionado ganhos significativos na produtividade desta cultura, com impacto direto na quantidade de macronutrientes absorvidos. Objetivou-se avaliar a produtividade e qualidade de duas cultivares de cebola sob sistema adensado em função de doses de potássio fornecidas via fertirrigação em Mossoró/RN. Adotou-se o delineamento em blocos casualizados, em esquema fatorial 2 x 7, com quatro repetições. Os tratamentos constituíram-se de duas cultivares (IPA 11 e Rio das Antas) e sete doses de potássio (0, 70, 140, 210, 280, 350 e 420 kg ha-1 de K2O), fornecidas via fertirrigação. As doses de potássio que proporcionaram as máximas produtividades total e comercial de bulbos foram de 215 e 216 kg ha-1 de K2O, respectivamente. Os sólidos solúveis e o percentual de bulbos das classes 2, 3 e 4 não foram influenciados pela adubação potássica. Houve redução do percentual de bulbos não comerciais com o aumento das doses de potássio. A dose de máxima eficiência econômica foi de 210,6 kg ha-1 de K2O, responsável por uma produtividade comercial de 61,8 t ha-1.

ABSTRACT The increase in plant density, combined with the use of hybrids in onion cultivation, has provided significant gains in yield, with a direct impact on the amount of absorbed macronutrients. The present work aimed to evaluate the yield and quality of two onion cultivars under a densified system as a function of potassium doses supplied via fertirrigation. A randomized complete block design was used in a 2 x 7 factorial scheme with four replications. The treatments consisted of two cultivars (IPA 11 and Rio das Antas) and seven potassium doses (0, 70, 140, 210, 280, 350 and 420 kg ha-1 K2O), provided by fertigation. The potassium doses that provided maximum total and commercial yields were 215 and 216 kg ha-1 of K2O, respectively. The soluble solids and the percentage of bulbs of classes 2, 3 and 4 were not influenced by potassium fertilization. There was a reduction in the percentage of non-commercial bulbs with the increase of potassium doses. The dose with maximum economical efficiency was 210.6 kg ha-1 of K2O, responsible for a commercial yield of 61.8 t ha-1.

RESUMO O gergelim é uma cultura de elevada complexidade morfofisiológica, com grande variabilidade no hábito de crescimento. A análise quantitativa do crescimento é uma ferramenta acessível e precisa para avaliar o desenvolvimento vegetal e a contribuição de diferentes processos fisiológicos sobre o seu desempenho. Nesse sentido, objetivou-se avaliar o crescimento de cultivares de gergelim em duas épocas de cultivo nas condições de Mossoró-RN. Foram instalados dois experimentos na Horta Didática da UFERSA. O delineamento experimental em cada época foi em blocos casualizados completos, com quatro repetições. Os tratamentos foram dispostos em parcelas subdivididas, onde as parcelas foram representadas pelas cultivares de gergelim: CNPA G2, CNPA G3 e CNPA G4 e as subparcelas consistiram das épocas de coletas (21; 35; 49; 63; 77; 91 e 105 DAS). O crescimento das cultivares de gergelim é lento no início do ciclo vegetativo da cultura, se intensificando no início do florescimento (após os 35 DAS). Entre os índices fisiológicos estudados, a cultivar CNPA G4 apresenta ser mais eficiente em relação ao crescimento, podendo ser variado dependendo da época de cultivo.

ABSTRACT Sesame is a plant with high morphological and physiological complexity, with great variability in growth habit. Quantitative growth analysis is an accessible and accurate tool for evaluating plant development and the contribution of different physiological processes to plant performance. In view of this, the purpose of this study was to evaluate the growth of sesame cultivars in two cropping seasons in the conditions of Mossoró-RN. Two experiments were conducted in Horta Didactics of UFERSA. The experimental delineation in each time was a randomized complete block design with four replications. The treatments were arranged in split plots where each experimental plot contained different sesame cultivars, CNPA G2, CNPA G3 and CNPA G4, and the subplots represented seven collection times, 21, 35, 49, 63, 77, 91 and 105 days after sowing (DAS). The growth of the sesame cultivars was slow at the beginning of the crop cycle, intensifying at the beginning of flowering (after 35 DAS). Among the physiological indexes studied, CNPA G4 cultivar was more efficient in relation to growth and varied depending on the cropping season.

Resumen: El objetivo de este estudio fue evaluar el crecimiento y acumulación de macro y micronutrientes en la planta del melón híbrido Ibérico (Syngenta Seeds). El experimento fue realizado entre enero y abril de 2013 en la hacienda experimental «Rafael Ferdandes» de la Universidade Federal Rural do Semi-Árido, ubicada en Mossoro, Río Grande do Norte, Brasil. El diseño experimental utilizado fue el de bloques al azar con once tratamientos y cuatro repeticiones. Los tratamentos consistieron en colectas a los 0, 7, 14, 21, 28, 35, 42, 49, 56, 63 y 70 días después del transplante. El estudio cuantificó las acumulaciones de materia seca, nitrógeno (N), fósforo (P), potássio (K), cálcio (Ca), magnésio (Mg), zinc (Zn), hierro (Fe), manganeso (Mn) y cobre (Cu) en la parte vegetativa (hojas y tallos), frutas y planta entera. Al final del ciclo los frutos acumularon mayor cantidad de materia seca, correspondiendo al 73,7 % del total. El N, P, K, Fe, Mn, Zn y Cu se acumularon preferencialmente en los frutos, mientras el Ca y Mg lo hicieron en la parte vegetativa. La mayor acumulación de masa seca y nutrientes ocurrió entre 35 y 49 días después del trasplante, con la excepción de calcio, magnesio, cobre y zinc que extendieron su acumulación hasta el final del ciclo. El orden decreciente de acumulación de nutrientes para el melón híbrido ibérico fue: N> K> Ca> P> Mg> Fe> Zn> Mn> Cu.

Summary: The objective of this work was to evaluate the growth and accumulation of plant nutrients in Ibérico hybrid melon (Syngenta Seeds). The experiment was carried out at the «Rafael Ferdandes» experimental farm of the Universidade Federal Rural Semi-Arido in Mossoró, Rio Grande do Norte, Brazil, from January to April 2013. We used a randomized block design with eleven treatments and four replications. The treatments consisted of the sampling periods: 0, 7, 14, 21, 28, 35, 42, 49, 56, 63 and 70 days after transplanting. This study assessed dry matter, nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), zinc (Zn), iron (Fe), manganese (Mn) and copper (Cu), the vegetative part (leaves and stems), fruits, and whole plant. The fruits were the preferred drain of the plant, corresponding to 73.7 % of the dry matter accumulated. The N, P, K, Fe, Mn, Zn and Cu were accumulated preferentially in fruits, while Ca, and Mg accumulated in the vegetative part. The highest accumulation of dry mass and nutrients occurred from 35 to 49 days after transplanting, with the exception of calcium, magnesium, copper and zinc that extended their accumulation until the end of the cycle. The decreasing order of nutrient accumulation for the Ibérico hybrid melon was: N > K > Ca > P > Mg > Fe > Zn > Mn > Cu.

RESUMO Informações sobre a reposta da cebola a diferentes doses de potássio podem contribuir para a otimização do uso de fertilizantes e, consequentemente, tornar a atividade mais rentável e ambientalmente sustentável. Nesse contexto, o objetivo do trabalho foi avaliar os efeitos de doses de potássio na produtividade da cebola. Para isso dois experimentos de campo foram realizados nos períodos de setembro a dezembro de 2012 e abril a julho de 2013 O delineamento experimental foi em blocos casualizados completos com quatro repetições. Os tratamentos corresponderam às doses de potássio (0, 36, 72, 108, 144 e 180 kg ha-1 de K2O). A adubação potássica promoveu aumento do teor de K na folha, produtividade comercial total, com o máximo obtido na dose de 180 kg ha-1 de K2O. As produtividades máximas totais e comerciais foram respectivamente de 54,69 e 54,12 t ha-1 no experimento de setembro a dezembro de 2012 e 47,39 e 46,39 t ha-1 de abril a julho de 2013.

ABSTRACT Information about the response of onion to different potassium doses may contribute to optimizing the use of fertilizers and, consequently, make the activity more profitable and environmentally sustainable. In this context, the aim of this study was to evaluate the effects of doses of potassium on onion yields. Two field experiments were carried out in the periods of September to December 2012 and April to July 2013. The experimental design used was completely randomized blocks with four replications. The treatments corresponded to the potassium doses (0, 36, 72, 108, 144 and 180 kg ha-1 of K2O). Potassium fertilization promoted an increase in the content of K in the leaf, commercial and total yield, with the maximum obtained in the dose of 180 kg ha-1 of K2O. The maximum overall and commercial yields were respectively 54.69 and 54.12 t ha-1 in the experiment of September to December 2012 and 47.39 and 46.39 t ha-1 in that of April to July 2013.

RESUMO: A classificação da cebola realizadas com base no diâmetro dos bulbos e a qualidade medida pelos sólidos solúveis, acidez titulável, a pungência em função de doses de nitrogênio foi avaliada em dois experimentos conduzidos no período de dezembro de 2011 a abril de 2012 e de agosto a dezembro de 2012, na Horta do Departamento de Ciências Vegetais da Universidade Federal Rural do Semi-Árida em Mossoró-RN. O delineamento experimental utilizado foi em blocos casualizados completo com seis tratamentos e quatro repetições. Os tratamentos foram constituídos pelas doses de N (0, 34, 67, 101, 134 e 168 kg ha-1 de N). Cada unidade experimental foi constituída por um canteiro de 3,0 x 0,8 m, contento oito fileiras de plantas, espaçada de 0,10 x 0,10 m. Utilizou-se, como área útil, as seis fileiras centrais de plantas do canteiro. A aplicação de 101 e 168 kg ha-1 de N, favoreceram as maiores percentagem de bulbos de cebola classe 3, respectivamente nos plantio de dezembro de 2011 e agosto de 2012. A pungência do bulbo aumentou com o fornecimento de nitrogênio até a dose de 93 kg ha-1, enquanto que, a acidez titulável e os sólidos solúveis reduziram com a aplicação de nitrogênio. O plantio de cebola em agosto de 2012 favoreceu a produção de bulbos de melhor qualidade.

ABSTRACT: The classification of the onion made based on the diameter of the bulbs and the quality measured by soluble solids, titratable acidity, relation soluble solids /acidity e a pungency due to nitrogen and planting times were evaluated in two experiments conducted from december 2011 to April 2012 and August tha december to 2012, horta in the Department of Plant Sciences Universidade Federal Rural do Semi-Árida em Mossoró-RN. The experimental design was a randomized block with four replications. The treatments consisted of N rates: 0, 34, 67, 101, 134 and 168 kg ha -1 N. Each experimental unit consisted of a bed of 3,0 x 0,8 m, satisfaction eight rows of plants spaced 0.10 x 0.10 m. Was used as floor area, the six central rows of plants in the flowerbed. The bulb pungency increased with the supply of nitrogen to the dose of 93 kg ha-1. Acidity and soluble solids reduced with the application of nitrogen. The onion planting in August 2012 favored the production of better quality bulbs.

Desde o ano de 2001, na região do agropolo de Mossoró/Assu-RN, o agrotêxtil é utilizado como proteção de plantas contra pragas da cultura do meloeiro. Este experimento teve como objetivo avaliar a produção e a qualidade de dois híbridos de melão Cantaloupe, em cultivo protegido, temporariamente, com agrotêxtil. O trabalho foi realizado na Horta da Universidade Federal Rural do Semi-Árido (UFERSA), em Mossoró-RN, de julho a outubro de 2010. O delineamento experimental foi de blocos casualizados completos, com quatro repetições, dispostos no esquema de parcelas subdivididas no espaço. As parcelas foram representadas pelo número de dias após o transplante das mudas (DAT), em que as plantas permaneceram sob proteção de agrotêxtil (0; 18; 21; 24; 27 e 30 DAT) e, as subparcelas, por dois híbridos F1 de melão Cantaloupe: 'Acclaim' e 'Caribbean Gold RZ'. Foram avaliadas características de produção e de qualidade. Os tratamentos com proteção temporária com agrotêxtil não afetaram a produtividade total dos dois híbridos; todavia, a firmeza de polpa apresentou aumento crescente, enquanto a acidez total titulável, os açúcares solúveis totais, os sólidos solúveis e o pH apresentaram redução com o aumento do tempo de permanência do agrotêxtil sobre as plantas. O 'Caribbean Gold RZ', em comparação com o 'Acclaim', apresentou maior produtividade comercial para exportação, maior massa média de frutos, mais firmeza de polpa, maior acidez total titulável, maior teor de sólidos solúveis e menor pH.

Row cover has been used as protection against pests in Mossoró/Assu agriculture center in the State of Rio Grande do Norte, since 2001. The objective of this experiment was to analyze the yield and quality of two 'Cantaloupe' melon hybrids grown temporarily with row cover in a greenhouse. This study was carried out in the Garden of the Semi-Arid Rural Federal University (Universidade Federal Rural do Semi-Árido - UFERSA) in Mossoró, State of Rio Grande do Norte, from July to October 2010. The experimental design was a complete randomized block with four replications arranged in a split plot in space design. The plots were the number of days after transplant (DAT) when plants remained under row cover protection (0; 18; 21; 24, 27 and 30 DAT) and the sub plots were two F1 "Cantaloupe" melonhybrids, "Acclaim" and "Caribbean Gold RZ". Yield and quality characteristics were evaluated. The treatments with temporary row cover protection did not affect the total yield of the two hybrids; however, pulp firmness continuously increased whereas total titratable acidity, total soluble sugar, total soluble solids and pH reduced as permanence time of row cover on the plants increased. "Caribbean Gold RZ" yield presented higher commercial productivity for export, higher average fruit weight, higher pulp firmness, higher total titratable acidity and higher content of soluble solids and lower pH than "Acclaim" melons.

Um aspecto importante da produção de sementes é a determinação da maturidade fisiológica e do momento adequado de colheita, visando obter sementes de alta qualidade, minimizando a sua deterioração no campo. Diante disso, esta pesquisa teve por objetivo estudar a influência do estado de maturação dos frutos e dos períodos de repouso pós-colheita na qualidade fisiológica de sementes de pimenta (Capsicum baccatum L.), variedade Dedo-de-Moça, para determinação do ponto adequado para colheita das sementes. Os frutos foram colhidos em quatro estádios de maturação, com base na sua coloração: verde intenso (15 DAA), verde amarelado (25 DAA), verde avermelhado (35 DAA) e vermelho intenso (45 DAA) e submetidos ao armazenamento por 0; 5 e 10 dias para então, proceder à extração das sementes. Foram determinados o peso dos frutos, comprimento, diâmetro e espessura da polpa. A qualidade das sementes foi avaliada pelos testes de germinação, primeira contagem de germinação, emergência de plântulas, grau de umidade, massa seca de 100 sementes, peso de mil sementes e condutividade elétrica. Diante dos resultados, conclui-se que a maturidade fisiológica das sementes de pimenta, variedade Dedo-de-Moça, é indicada pela coloração vermelho intenso dos frutos (45 DAA); o repouso pós-colheita dos frutos por dez dias melhora o potencial fisiológico das sementes.

An important aspect of seed production is the determination of physiological maturity and the appropriate time for harvest, with a view to obtaining high-quality seeds and minimising deterioration in the field. This research therefore aimed to study the influence of the stage of maturation and amount of post-harvest resting of the fruit on the physiological quality of the seeds of the pepper (Capsicum baccatum L.) var. Lady's Finger, to determine the right time for harvesting the seeds. The fruits were harvested at four stages of maturation, based on colouration: deep green (15 DAA), yellow-green (25 DAA), red-green (35 DAA) and deep red (45 DAA), and stored for 0, 5 and 10 days followed by extraction of the seeds. The weight, length, diameter and thickness of the pulp in the fruit were determined. Seed quality was evaluated by germination, germination first count, seedling emergence, moisture content, hundred-seed dry weight, thousand seed weight and electrical conductivity. Given the results, it is concluded that the physiological maturity of the seeds of the Lady's Finger pepper, is indicated by the intense red color of the fruits (45 DAA), and that post-harvest resting of the fruit for ten days improves the physiological potential of the seeds.