SANTOS FGB; NEGREIROS MZ; MEDEIROS JF; LOPES WAR; SOARES AM; NUNES GHS; FREITAS FCL. 2014. Growth and yield of Cantaloupe melon ‘Acclaim’ in protected cultivation using agrotextile. Horticultura Brasileira 32: 55-62. Growth and yield of Cantaloupe melon ‘Acclaim’ in protected cultivation using agrotextile Francisco GB Santos1; Maria Z Negreiros2; José F Medeiros2; Welder AR Lopes2; Alinne M Soares2; Glauber HS Nunes2; Francisco CL Freitas2 1IFCE, Campus Crato, Rod CE 292 km 06, Bairro Gisélia Pinheiro, 63115-500 Crato-CE; [email protected]; 2UFERSA, Depto. Ciências Vegetais, BR 110 km 47, Presidente Costa e Silva, 59625-900 Mossoró-RN; [email protected]; [email protected]; [email protected]; [email protected]; [email protected]; [email protected] ABSTRACT RESUMO In Rio Grande do Norte, the melon growers have been using Crescimento e produtividade de melão Cantaloupe ‘Acclaim’ the row cover on the roof of the plants to start flowering in order em cultivo protegido utilizando agrotêxtil to reduce the population of insect pests that cause severe losses, No Rio Grande do Norte, os produtores de melão utilizam agro- rising production costs, especially with the application of defensive. têxtil na cobertura das plantas até o início da floração, para reduzir Thus, it is important to know the best time to remove the row cover a população de pragas que causam sérios prejuízos à cultura. Desta because, due to its use, it is assumed that there are changes in the forma, é importante saber o momento da retirada do agrotêxtil porque, physiological response of plants. In order to evaluate the growth decorrente de seu uso, presume-se que ocorram alterações fisiológicas and yield of the melon plants ‘Acclaim’ cultivated under protection nas plantas. Com o objetivo de avaliar o crescimento e produtividade agrotextile (TNT) for different periods, a trial was conducted at the de plantas de melão Cantaloupe ‘Acclaim’ cultivadas sob proteção Universidade Federal Rural do Semi-árido, Mossoró, Rio Grande com agrotêxtil (TNT), realizou-se um experimento na Universidade do Norte state. The experimental design was a randomized complete Federal Rural do Semi-árido em Mossoró-RN. O delineamento foi de block, with four replications, in a splitplot, the plots were the plant blocos casualizados completos, com quatro repetições, dispostos em protection periods (0, 18, 21, 24, 27 and 30 days after transplanting, parcelas subdivididas, tendo nas parcelas os períodos de proteção de DAT), and splitplots, times of sampling the plants (13, 20, 27, 34, plantas [0, 18, 21, 24, 27 e 30 dias após o transplantio (DAT)], e nas 41, 48 and 55 DAT). We evaluated the dry matter accumulation in subparcelas, as épocas de amostragens das plantas (13, 20, 27, 34, 41, leaves (LDMA), branches (BDMA), flowers (FDMA), fruits (FrdMA) 48 e 55 DAT). Foram avaliados o acúmulo de massa seca nas folhas and total (TDMA), assimilate partitioning, leaf area index (LAI), (AMSFO), ramos (AMSR), flores (AMSF), frutos (AMSFR) e total leaf weight ratio (LWR), absolute growth rate (AGR) and relative (AMST), partição de assimilados, índice de área foliar (IAF), razão (RGR), net assimilation rate (NAR), total (PTOT) and marketable de peso foliar (RPF), taxa de crescimento absoluto (TCA) e relativo productivity (PCOM). The treatments with plant protection did not -1 (TCR), taxa assimilatória líquida (TAL), produtividade total (PTOT) affect the TDMA which peaked at 295.12 g plant at 53 DAT, with e comercial (PCOM). Os tratamentos com agrotêxtil não afetaram the fruits behaving like sink preferred plant, accounting for 72.25% o AMST que atingiu o máximo de 295,12 g planta-1, aos 53 DAT, of the dry mass accumulated. The LAI and the AGR grew by 55 and com os frutos se comportando como dreno preferencial da planta, 42 DAT (1.95 and 18.518 g/plant/day), respectively, while the LWR sendo responsáveis por 72,25% da massa seca acumulada. O IAF e and RGR decreased over the cycle, with peaks of 0.911 and 0.242 a TCA apresentaram crescimento até 55 e 42 DAT (1,95 e 18,518 g/ g/g/day, at 13 and 20 DAT, respectively. The PTOT and PCOM were planta/dia) respectivamente, enquanto a RPF e a TCR decresceram not affected by periods of plant protection, with averages of 29.30 -1 ao longo do ciclo, com máximos de 0,911 e 0,242 g/g/dia, aos 13 e and 22.25 t ha , respectively, indicating that it is possible to manage 20 DAT, respectivamente. A PTOT e PCOM não foram afetadas pelos the row cover in order to remove it later, that reduces costs and crop períodos de proteção das plantas, com médias de 29,30 e 22,25 t ha-1, protection without significant loss in productivity. respectivamente, indicando que é possível, manejar o agrotêxtil de modo a retirá-lo tardiamente, o que reduz custos com defensivos e sem prejuízos significativos na produtividade. Keywords: Cucumis melo, TNT, growth rate, marketable production. Palavras-chave: Cucumis melo, TNT, taxa de crescimento, produção comercial. (Recebido para publicação em 2 de setembro de 2012; aceito em 14 de outubro de 2013) (Received on September 2, 2012; accepted on October 14, 2013) elon is the vegetable that ha of melon grown in Brazil, in 2011, domestically (Melão, 2011). Mcontributes the most to the the States of Ceará and Rio Grande do In the latest years, noble melon Brazilian trade balance. In 2011, 101 Norte contributed with 11,490 ha, that cultivars, as of the group Cantaloupe, thousand tons of melon was exported means, 85.75%. Approximately 80% of presenting more attractive organoleptic to the European Union, which generated the production in these states is for the features and higher commercial value, revenue of US$ 78 million. Of the 13,400 external market, whereas 20% are sold increased its market share 15-20%, Hortic. bras., v. 32, n. 1, jan. - mar. 2014 55 FGB Santos et al. although more sensitive, requiring The nonwoven fabric (TNT) is made MATERIAL AND METHODS more advanced cultivation techniques from long strands of polypropylene (Damasceno et al., 2012). which are placed in layers and welded The experiment was carried out in the The growth analysis has been largely together at appropriate temperatures Vegetable Garden of the Plant Sciences used to investigate the influence of and, TNT is a very light material (16-25 -2 Department of the Universidade Federal agronomic practices which modify g m ) of adequate strength to be used Rural do Semi-árido in Mossoró, Rio the environment of the crops, in an in agriculture (Dantas, 2010). It has Grande do Norte state, Brazil (5º11’S, attempt to explain differences in growth, the advantage of easy handling; it can 37º20’W, altitude of 18 m), from July because of genetics or resulting from be placed and removed at any stage of 22 to October 5, 2010. The climate environmental changes (Lopes et al., development of the crop, using structure of the region, according to Köppen is 2011). This method evaluates the net as a support or placed as floating row BSwh’, that means, dry and very hot, production of plants derived from the cover directly over the plants (Barros with two climate seasons: a dry season, photosynthetic process, and it is the Júnior et al., 2004). which is usually from June to January result of the performance of assimilatory The use of the row cover conditions and another rainy season from February system during a certain period of changes in the physiological response to May (Carmo Filho et al., 1991) and time, describing the plant morphology of plants by modifying the source: drain soil classified as Eutrophic yellow red in different time intervals between ratios. Thus, it is important to know the Argisols, sandy loam texture. successive samples (Benincasa, 2003). best time to remove the row cover. One The experimental design used was The dry matter accumulation and of the changes is the delay of the fruiting randomized complete blocks, with increase of leaf area, quantified as a by the use of the row cover, because four replications. The treatments were function of time, are used in the estimation while the plants are protected under arranged in split plots, the plots being of several physiological indices related the cover, the flowers are unavailable periods of plant protection with the to performance differences between for pollination performed by the bees. white agricultural textile (0, 18, 21, 24, cultivars and plant communities in Long et al. (2004), working on delay of 27 and 30 DAT), and the split plots, many ecophysiological studies (Lima pollination with the use of the row cover, sampling dates of plants (13, 20, 27, 34, et al., 2007). The distribution of the found that this delay allows the plant to 41, 48 and 55 DAT). invest the available photoassimilates dry mass is the final result of the flow Each experimental unit occupied in vegetative growth, increase in the of the assimilates of the source organs an area of 60 m2 with 8 m wide and 7.5 number of female flowers available for the sink organs, considering that this m long, spaced 2.0x0.3 m, comprising for pollination and later, in subsequent distribution between the sinks of a plant four rows of plants. The useful portion fixation of a higher number of fruits per is primarily regulated by themselves area of the plot was 27.6 m2 (6.9x4 plant, altering the source-sink ratios, (Marcelis, 1996). m), consisting of two central rows, to production and fruit quality. Thus, it Several agronomic practices are evaluate the yield and the two lateral is necessary to evaluate the effects used to manipulate the partitioning rows for growth analysis.