ABSTRACT
It has been established that climate change has a direct impact on water availability, an essential resource for agricultural development. As a result, controlling, mitigating, and adapting to water deficit requires the advancement of research on promising wild flora species. As recent studies have shown, wild relatives of certain cultivars are tolerant to adverse factors, enabling the development of sustainable and resilient agriculture. The present study evaluated the morpho-physiology and productivity of tomato scions grafted on wild Solanaceae (Datura stramonium, Solanum sisymbriifolium, Solanum quitoense, and Cyphomandra betacea) grown under water deficit conditions (100% ETc - high level, 75% ETc - moderate level, 50% ETc - medium level, and 25% ETc - low level). The results showed that tomato plants grafted on Datura stramonium rootstocks performed better morpho-physiologically under deficit irrigation. The improved osmoregulation caused by a higher relative water content (98.49%) allowed the scion to be more tolerant to water stress. In addition, these scions showed high water potential during their phenological stages (vegetative -0.47 MPa, flowering -0.59 MPa, and production -0.64 MPa), as well as improved photosynthetic efficiency. The overall tolerance of the scion resulted in better yield (8.14 kg/plant) with higher number of commercially valuable fruits. The D. stramonium rootstock allowed better management and use of irrigation water, increasing productivity (54.95 kg/m3); that is, it is presented as a species with potential for establishing tomato production areas in scenarios of water scarcity or cultivation under deficit irrigation.
ABSTRACT
Growing a melon crop during the rainfall period has been a great challenge for producers from the north eastern Brazil due to crop sanitary problems. This work was aimed at evaluating the effects of soil coverages and irrigation depth on yield and quality of yellow melon (hybrid Goldex) during the rainfall period. The experiment was carried out at Fazenda Santa Júlia Agro-Comercial Exportadora de Frutos Tropicais Ltda, Mossoró-RN, Northeastern Brazil, during the period of April to July 2003. The experimental design was a randomized complete blocks with four replications. The treatments were the combinations of five soil coverages (soil with no coverage and coverages with polyethylene films - black, silvery, yellow, and brown) with three irrigation depth (100%, 86% and 72% of the standard lamina, this equivalent to 238.44mm). The traits evaluated were number, mean weight and yield of marketable (internal and external markets), refuse and total fruits, pulp firmness and thickness, fruit shape index, and soluble solids content. Interaction between soil coverage types and irrigation depth was significant with regard to total fruit yield. The greatest marketable fruit yields and soluble solids contents were obtained with the use of polyethylene soil coverages. The numbers of marketable, refuse and total fruits, as well as the yields of marketable and refuse fruits were not significantly affected by the irrigation depth.
O plantio de melão no período chuvoso tem sido um dos grandes desafios para os produtores da região do Nordeste brasileiro devido a problemas fitossanitários. Objetivou-se, neste trabalho, avaliar os efeitos de cobertura do solo e de lâminas de irrigação na produção e na qualidade do melão amarelo híbrido "Goldex", no período chuvoso. O experimento foi desenvolvido na Fazenda Santa Júlia Agrocomercial Exportadora de Frutos Tropicais Ltda, no município de Mossoró-RN, no período de abril a julho de 2003. O delineamento experimental utilizado foi o de blocos completos casualizados, com quatro repetições. Os tratamentos resultaram da combinação de cinco tipos de coberturas do solo (solo descoberto e coberturas do solo com plástico preto, prateado, amarelo e marrom) com três lâminas de irrigação (100%, 86% e 72% da lâmina padrão, esta equivalente a 238,4mm por ciclo). As características avaliadas foram número, massa média e produtividade de frutos comercializáveis (mercados interno e externo), refugos e totais, firmeza e espessura de polpa, relação de formato e teor de sólidos solúveis totais. Houve interação significativa entre os tipos de coberturas do solo e as lâminas de irrigação para a produtividade total. A maior produtividade de frutos comercializáveis e de conteúdo de sólidos solúveis totais foi registrada nas coberturas do solo com plástico. Os números de frutos comercializáveis, refugos e totais, bem como a produtividade de frutos comercializáveis e refugos, não foram afetados significativamente pelas lâminas de irrigação.
ABSTRACT
Growing a melon crop during the rainfall period has been a great challenge for producers from the north eastern Brazil due to crop sanitary problems. This work was aimed at evaluating the effects of soil coverages and irrigation depth on yield and quality of yellow melon (hybrid Goldex) during the rainfall period. The experiment was carried out at Fazenda Santa Júlia Agro-Comercial Exportadora de Frutos Tropicais Ltda, Mossoró-RN, Northeastern Brazil, during the period of April to July 2003. The experimental design was a randomized complete blocks with four replications. The treatments were the combinations of five soil coverages (soil with no coverage and coverages with polyethylene films - black, silvery, yellow, and brown) with three irrigation depth (100%, 86% and 72% of the standard lamina, this equivalent to 238.44mm). The traits evaluated were number, mean weight and yield of marketable (internal and external markets), refuse and total fruits, pulp firmness and thickness, fruit shape index, and soluble solids content. Interaction between soil coverage types and irrigation depth was significant with regard to total fruit yield. The greatest marketable fruit yields and soluble solids contents were obtained with the use of polyethylene soil coverages. The numbers of marketable, refuse and total fruits, as well as the yields of marketable and refuse fruits were not significantly affected by the irrigation depth.
O plantio de melão no período chuvoso tem sido um dos grandes desafios para os produtores da região do Nordeste brasileiro devido a problemas fitossanitários. Objetivou-se, neste trabalho, avaliar os efeitos de cobertura do solo e de lâminas de irrigação na produção e na qualidade do melão amarelo híbrido "Goldex", no período chuvoso. O experimento foi desenvolvido na Fazenda Santa Júlia Agrocomercial Exportadora de Frutos Tropicais Ltda, no município de Mossoró-RN, no período de abril a julho de 2003. O delineamento experimental utilizado foi o de blocos completos casualizados, com quatro repetições. Os tratamentos resultaram da combinação de cinco tipos de coberturas do solo (solo descoberto e coberturas do solo com plástico preto, prateado, amarelo e marrom) com três lâminas de irrigação (100%, 86% e 72% da lâmina padrão, esta equivalente a 238,4mm por ciclo). As características avaliadas foram número, massa média e produtividade de frutos comercializáveis (mercados interno e externo), refugos e totais, firmeza e espessura de polpa, relação de formato e teor de sólidos solúveis totais. Houve interação significativa entre os tipos de coberturas do solo e as lâminas de irrigação para a produtividade total. A maior produtividade de frutos comercializáveis e de conteúdo de sólidos solúveis totais foi registrada nas coberturas do solo com plástico. Os números de frutos comercializáveis, refugos e totais, bem como a produtividade de frutos comercializáveis e refugos, não foram afetados significativamente pelas lâminas de irrigação.