Abstract The production of vegetable crops has been characterized as a highly intensive activity in the use of soil, water, inputs and labor in semi-arid regions, being practiced mostly by small family farmers as a way of subsistence, or in the small-scale commercialization of surplus production. Among the agricultural practices that have been successfully used by vegetable producers are intercrop systems that, when implemented with adequate management, present gains in productivity, nutritional, economic, and environmental value. The aim of this study was to estimate the optimal plot sizes of plantings of carrot (Daucus carota L.) intercropped with arugula (Eruca sativa L.) in bi-cultivation in three spatial arrangements, as well as to determine bio-agroeconomic revenues from associations between these vegetable crops in a semi-arid region. Estimates of optimal sizes of experimental plots in intercropping systems, provided by the methods of bootstrap resampling and of sampling intensity (10%), were four, four and three basic units, respectively, for the spatial arrangements 2R:2C, 3R:3C, and 4R: 4C, between rows of arugula (R) intercropped with carrot (C), and by the Hatheway method, all spatial arrangements were of four basic units. The best bio-agroeconomic performance of carrot intercropped with arugula in bi-cultivation was obtained in the spatial arrangement 2R:2C.

ABSTRACT Melon is one of the most important vegetable crops in the world. With short cycle in a system of phased planting, phytosanitary control is compromised, and a great volume of agricultural chemicals is used to control vegetable leafminer. Genetic control is an ideal alternative to avoid the damage caused by this insect. Thus, the aim of this study was to evaluate Cucumis accessions in regard to resistance to leafminer and correlate the variables analyzed. Fifty-four accessions and four commercial hybrids of melon were tested. The study was divided into two experiments: with and with no choice. The following characteristics were evaluated: with choice, in field - subjective score based on the infestation and the number of mines per leaf; and with no choice, in cage - number of mines per leaf, chlorophyll content, and leaf colorimetry. The results showed variability among the accessions and some genotypes showed favorable results for resistance in both experiments. There was correlation between the two variables in the experiment in the field. The accessions CNPH 11-282, CNPH 06-1047, and CNPH 11-1077 are the most recommended for future breeding programs with aim on introgression of resistance to vegetable leafminer in melon.

Os objetivos deste estudo foram determinar a importância das componentes simples e complexa da interação genótipo × ambiente e avaliar a adaptabilidade e estabilidade de híbridos de melão Gália. Nove híbridos foram testados em doze ambientes do Estado do Rio Grande Norte no período de 2000 a2001. Os experimentos foram conduzidos em blocos completos casualizados com três repetições. Os métodos estatísticos de Toler e Burrows, Wricke e AMMI (Additive Main effect and Multiplicative Interaction) foram usados para estudar a adaptabilidade e estabilidade. A componente complexa é responsável pela maior parte da interação genótipo × ambiente para a produtividade e teor de sólidos solúveis dos frutos. Os ambientes associados com Mossoró e Assu são os mais adequados para a avaliação de melão híbrido. O híbrido DRG1537 é o mais promissor para o cultivo no Complexo Agro-industrial Mossoró-Assu, devido à sua estabilidade, alta produtividade e alto teor de sólidos solúveis.

The objectives of this study were to determine the importance of simple and complex components of the interaction genotype × environment and to evaluate the adaptability and stability of Gália melon hybrids. Nine hybrids were tested in twelve environments of Rio Grande Norte State from 2000 to 2001. The experiments were carried out in a randomized complete block design with three replications. The statistical methods of Toler and Burrows, Wricke and AMMI (Additive Main effect and Multiplicative Interaction) were used to study the adaptability and stability. The complex component is responsible for most of the genotype × environment interaction for the yield and content of solids soluble of fruits. The environments associated with Mossoró and Assu municipalities are the most suitable to evaluate melon hybrids in the state. The hybrid DRG 1537 was the most likely to be grown in the Agro-industrial Complex Mossoró-Assu due to its stability, high productivity and high content of soluble solids.

Avaliou-se a qualidade comercial de híbridos de melão amarelo cv. Gold Mine e Gold Pride, submetidos a diferentes épocas de colheita. Os frutos foram colhidos no pólo agrícola de MossoróAssu (RN), e armazenados a 11±1ºC e 90±5% UR, durante 28 dias. Utilizou-se o delineamento inteiramente casualizado em esquema fatorial 5 x 5, com cinco repetições e um fruto por parcela. O primeiro fator constou das épocas de colheita (0 sem retardamento, 2; 4; 6 e 8 dias de retardamento da colheita) e o segundo, do tempo de armazenamento (0; 7; 14; 21 e 28 dias). Avaliou-se a firmeza da polpa (N), perda de massa (%), aparência externa e interna e conteúdo de sólidos solúveis totais (%). A firmeza da polpa e a aparência interna foram fortemente influenciadas pelo retardamento da colheita, proporcionando frutos com colapso interno e menor resistência da polpa. O retardamento da colheita influenciou significativamente a perda de massa apenas para o híbrido Gold Mine, observando-se a partir do 21º dia, maiores perdas de massa para os frutos colhidos com 4 e 6 dias de atraso na colheita. O retardamento no período de colheita induziu maior suscetibilidade a danos por frio em ambos os híbridos e aumento no teor de sólidos solúveis apenas para híbrido Gold Pride.

The commercial quality of yellow melon 'Gold Mine' and 'Gold Pride' hybrids at different harvest times was examined. The fruits were harvested in the MossoróAssu agricultural pole, Rio Grande do Norte State, Brazil, being kept under 11±1ºC and 90±5% relative humidity, during 28 days. A 5 x 5 factorial scheme in a completely randomized design was used with five replications and one fruit per plot. The first factor was recorded at harvest time (0; 2; 4; 6 and 8 days retardation of the harvest) and the second at the storage periods (0; 7; 14; 21 and 28 days). We evaluated the flesh firmness (N), weight loss (%), internal and external appearances and soluble solids content (%). The flesh firmness and the internal appearance were strongly influenced by the harvest delay, providing fruits with internal disorder and smaller flesh resistance. The harvest delay influenced significantly the weight loss of the Gold Mine hybrid with larger weight losses occurring after 21 days of storage in treatments where the harvest was delayed 4 and 6 days. The harvest delay induced larger susceptibility to chilling injury in both hybrids and increased the soluble solids content in the hybrid Gold Pride.

Objetivou-se avaliar a conservação pós-colheita de frutos de melão tipo cantaloupe (Cucumis melo L var. Cantaloupensis ), genótipo Nun 3984, colhido nos estádios de maturação II ( frutos imaturos em início de descoloração e pedúnculo totalmente preso) e IV (frutos com pedúnculo totalmente rachado), em seis períodos de armazenamento: 0; 5; 10;15; 20 e 25 dias. Os frutos foram provenientes do Agropolo Mossoró-Assu (RN), cujo clima é caracterizado como quente e seco, com temperaturas máxima e mínima de 33ºC e 29ºC, respectivamente. O armazenamento foi realizado a 20ºC e 50% UR. Utilizou-se um fatorial 2 x 6 (dois estádios de maturação e seis períodos de armazenamento), em delineamento inteiramente casualizado, com três repetições, sendo utilizados dois frutos por parcela. Os frutos foram avaliados individualmente quanto à firmeza da polpa, perda de peso, teor de sólidos solúveis, aparências externa e interna. Houve efeito significativo da interação entre os fatores estudados apenas para variável firmeza da polpa. A firmeza da polpa foi de 30,07 N e 18,75 N por ocasião da colheita e 5,32 N e 3,50 N aos 25 dias de armazenamento, respectivamente, para os estádios II e IV de maturação. O teor de sólidos solúveis apresentado por esse genótipo (7% a 9%), nos estádios II e IV de maturação respectivamente, não estabelece um padrão mínimo para a aceitação no mercado externo. A perda de peso atingiu valores médios de 6,26% e 6,67% aos 20 e 25 dias de armazenamento, respectivamente. Os frutos chegaram aos 20 dias de armazenamento com nota média 3,1 (deterioração mediana) e 4,0 (deterioração leve) para as aparências interna e externa, respectivamente, nos dois estádios de maturação, sendo portanto, considerados próprios para o consumo, por terem notas acima de 3,0

This work aimed to evaluate the postharvest shelf life of cantaloupe melons type (Cucumis melo L. var Cantaloupensis), genotype Nun 3984, harvested in two maturation stages (Stage II and IV). The fruits were harvested in the agricultural region of Mossoró-Assu, Rio Grande do Norte State, Brazil. The region is characterized by hot dry summers with maximum and minimum temperatures of 33ºC and 29ºC, respectively. Storage of fruits took place at a temperature of 20ºC and relative humidity of 50 %. The fruits were checked individually at five-day intervals. A 2 x 6 factorial completely randomized design with three replications was used (two fruits per plot). The factorial consisted of two maturation stages (II and IV) and six storage periods (0; 5; 10; 15; 20 and 25 days). During this period the pulp firmness, weight loss, soluble solids content, external and internal appearances were evaluated. There was a significant interaction among the studied factors and pulp firmness. The pulp firmness was of 30.07 N and 18.75 N at the harvest date and 5.32 N and 3.50 N after 25 days of storage, respectively, for stages of maturation II and IV. The soluble solids content presented for this genotype (7% to 9%) was not enough for the external market. The weight loss was of 6.26% and 6.67% at 20 and 25 days of storage, respectively. The fruits reached at 20 days of storage the grade 3.1 (average deterioration) and 4.0 (little deterioration) for external and internal appearances, respectively, in the two maturation stages. They were therefore considered marketable.