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Made available in DSpace on 2021-07-14T10:19:28Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-08-28. Added 1 bitstream(s) on 2021-07-14T11:27:09Z : No. of bitstreams: 1 S0034-737X2020000400263.pdf: 272585 bytes, checksum: 3a7d780572098e3be4252e09fed816ad (MD5) The objective of this work was to evaluate the behavior of Crisphead lettuce as a function of production seasons under different forms of protected environment. Two experiments were carried out in the field at different times: September to December 2017 and June to August 2018, in a randomizaed blocks desing, in a 4 x 7 factorial scheme, the first one being production environments under shade nets: red screen, chromatinet® screen, black screen and full sun, and the second, lettuce cultivars: Winslow, Irene, Balsamo, Rafaela, Iron Wood, Great Lakes and Delícia. The harvest was carried out at forty-two days after transplanting, where the following variables were analyzed: stem length (cm), total production and commercial productivity (t ha-1). The data were submitted to analysis of variance, and a joint analysis was performed to analyze the treatments effect, then the means were compared by the Scott-Knott test, at 5% probability. The microclimate was altered in the shaded beds, which affected the cultivars development. The cultivation in protected environment provides higher productivity of Crisphead lettuce from September to December, at that time the cultivars Balsamo and Delicia were highlighted under chromatinet®. In the period of mild temperatures, a better performance was observed for cv. Balsamo in full sun. Universidade Estadual Paulista, Departamento de Horticultura Universidade do Estado da Bahia, Departamento de Tecnologia e Ciências Sociais Empresa Brasileira de Pesquisa Agropecuária Universidade Estadual Paulista, Departamento de Horticultura

Floating system and management of abiotic factors in the greenhouse achieved the optimal lettuce growth and shortening of production cycle. Aim of the research was to select the combination of cultivar and plant density (stand) which meets the market requirement of lettuce head mass (200- 300 g) and provide the highest yield. Five lettuce cultivars ('Tourbillon', 'Othilia', 'Maritima', 'Caipira', 'Bonaly') and 3 stands (13, 17 and 21 plant m-2) were tested by method of randomized block design with three replications. Lettuce was sown on July 31 and the seedlings were deployed on polystyrene floaters on August 18 (100 plants m-2) and redeployed on August 28 at scheduled stands. Morphometric analysis of lettuce was conducted five times during the growing period and also over the harvest on September 20. During the production cycle the mean air temperature was 22.3 °C, while relative humidity ranged from 39 to 80%. Parameters of nutrient solution were: temperature 22.7 °C, dissolved oxygen 7.8-8.3 mg l-1, pH- value 6.1 and EC-value 1.3-1.7 dS m-1. Relative growth rate was higher at the start of growing period, i.e., the younger plants were grown faster. Adequate lettuce head weight (276 and 321 g) was recorded by stands of 17 and 13 plants m- 2. The highest marketable yield was achieved by combinations: 17 × 'Bonaly' and 13 × 'Tourbilon' (4.07 and 4.17 kg m-2, respectively). Combinations 'Bonaly', 'Othilie', 'Tourbilon' and 'Maritima' with stand of 17 plants m-2 can be recommended since they provided satisfactory head weight for sales per piece and thus a higher income per unit area compared to other combinations.

Cauliflower (Brassica oleracea var. botrytis L.) requires large amounts of nitrogen (N) fertilizer to produce high yields. The intercropping of cauliflower with a leguminous species may help farmers to reduce N fertilizer rates, production costs and environmental pollution. Moreover, the recycling of crop residues can contribute to the nutritional support of subsequent crops in a rotation. In this study, cauliflower was cultivated in year one either alone or intercropped with annual clover (Trifolium resupinatum L.), using four N fertilization rates: 0, 75, 150, and 300 kg N ha−1 (referred to as N0, N1, N2, and N3 respectively). Following crop residue incorporation in year two, iceberg lettuce (Lactuca sativa var. capitata (L.) Janchen) was cropped on the same field without the supply of N fertilizer to assess the effect of cauliflower and clover residues as well as of residual N fertilizer rates on the growth and N uptake of lettuce. The presence of clover did not affect the marketable yields of the intercropped cauliflower, which were similar to the cauliflower sole-cropped. The N1 and N2 fertilizer rates maximized both growth and N uptake of the intercropped cauliflower, while with the N3, crop development was limited. In the N0 plot, the legume competed for N and depressed growth and N absorption of cauliflower. The sole-cropped cauliflower was, on the contrary, unaffected by the N fertilizer rates. The iceberg lettuce cultivated in succession benefited from the presence of clover in plots N1 and N2. When succeeded to the sole-cropped cauliflower, however, the iceberg lettuce produced less biomass and absorbed less N. Results from this study suggest that the intercropping system cauliflower-clover can be a sustainable tool to optimize N input and reduce N fertilizer requirements for the successive crop.

This study aims to evaluate the effect of protecting floating row covers on the behavior of environmental variables and the yield of a crop of lettuce. For it was sowed during two seasons autumn-winter cultivar of butterhead lettuce type (Lactuca sativa var. capitata) in germination trays of 128 cells with subsequent transplantation field performed at 37 (cycle 1) and 49 (cycle 2) days after sowing. The treatments were: 1)- Crop protected with floating row cover (MT); 2)- Control unprotected (T) in an experimental design in split plots with 3 repetitions. The plantation frame used was 0.35 m between rows and 0.25 m between plants and irrigation was made by a drip system. The effect of floating row cover on the transmissivity of photosynthetically active radiation (PAR), temperature and relative humidity, crop yield, heat summation in degree.days-1 from trasplant to harvest (ºC.ddt-1) and efficiency of use of radiation (EUR) was evaluated. The results showed an average transmissivity of 63.1% RFA, temperature increase of minimum, average and maximum air 1.1; 2.0 and 3.1 °C respectively, and 4.3% relative humidity. The fresh weight yield (t ha-1) showed statistically significant differences between treatments, being 38.2 (MT); 15.5 (T) for cycle 1 and 33.8 (MT) and 14.7 (T) for cycle 2. The heat summation and EUR was higher in the treatment with floating row cover. Crop protection allows greater earlier maturity with significant performance improvements. El presente trabajo tuvo como objetivo evaluar el efecto de la protección de la manta térmica sobre el comportamiento de variables ambientales y el rendimiento de un cultivo de lechuga. Para ello, se sembró durante dos temporadas otoño-invernales un cultivar de lechuga tipo mantecosa (Lactuca sativa var. capitata) en bandejas de germinación de 128 celdas, con posterior trasplante en campo, realizado a los 37 días (ciclo 1) y 49 días (ciclo 2) después de la siembra. Los tratamientos fueron: 1) Cultivo protegido con manta térmica (MT); 2) Testigo no protegido (T) en un diseño experimental en parcelas divididas con tres repeticiones. El marco de plantación utilizado fue de 0,35 m entre hileras y 0,25 m entre plantas. El riego se efectuó mediante un sistema de goteo. Se evaluó el efecto de la manta térmica sobre la trasmisividad de la radiación fotosintéticamente activa (RFA), temperatura y humedad relativa del aire, rendimiento del cultivo, suma térmica en grados.día-1 desde el trasplante hasta la cosecha (ºC.ddt-1). Los resultados mostraron en el tratamiento MT una trasmisividad promedio de la RFA de 0,69 (ciclo 1) y 0,73 Mj.m-2.día-1 (ciclo 2), incremento de la temperatura del aire mínima, media y máxima en 1,1; 2,0 y 3,1 ºC, respectivamente, y de la humedad relativa. El rendimiento en peso fresco (t ha-1) presentó diferencias estadísticas significativas entre los tratamientos, siendo de: 37,7 (MT); 15,5 (T) para el ciclo 1 y 33,8 (MT) y 14,7 (T) para el ciclo 2. La suma térmica fue mayor en el tratamiento con manta térmica. La protección del cultivo permitió una mayor precocidad con mejoras significativas en el rendimiento.

In order to evaluate the quality of seedlings obtained in germination trays with different volumes of cells and their influence on the yield for a crop of lettuce for two production cycles autumn- winter, seeded cultivar type buttery (Lactuca sativa var. capitata) in a completely randomized design. The treatments were: 24 cm3/cell (128 cell/tray); 13 cm3/cell (200 cell/tray) y 7 cm3/cell (288 cell/tray). Leaf number, root length, seedling height, fresh and dry weight of shoot and roots were evaluated until the time of transplantation in field made at 37 and 49 days after planting for each production cycle. The results showed significant differences with a greater number of leaves, root length, seedling height, fresh and dry weight of the aerial parts and roots of seedlings obtained in 24 cm3 cells followed by 13 cm3 and finally 7 cm3. The quality of the lettuce seedlings is related to the volume of the cell plug trays, yielding subsequently better yields. Con el objetivo de evaluar la calidad de plántulas obtenidas en bandejas de germinación de diferente volumen de celdas y su influencia sobre el rendimiento de un cultivo de lechuga durante dos ciclos de producción otoño-invernal, se sembró un cultivar tipo mantecosa (Lactuca sativa var. capitata) en un diseño completamente aleatorio. Los tratamientos fueron: 24 cm3/celda (128 celdas/bandeja); 13 cm3/celda (200 celdas/bandeja) y 7 cm3/celda (288 celdas/bandeja). Se evaluó número de hojas, longitud de raíces, altura de plántula, peso fresco y seco de la parte aérea y raíces hasta el momento del trasplante en campo efectuado a los 37 y 49 días después de la siembra para cada ciclo de producción. Los resultados mostraron diferencias significativas con un mayor número de hojas, longitud de raíces, altura de plántula, peso fresco y seco de la parte aérea y raíces para las plántulas obtenidas en celdas de 24 cm3 seguidas de las 13 cm3 y finalmente las de 7 cm3. La calidad de las plántulas de lechuga está relacionada con el volumen de celda de las bandejas de germinación, obteniéndose posteriormente mejores rendimientos.

Field experiments using ‘melt-blown’ biodegradable nonwovens were carried out on the ‘Melodion’ butterhead lettuce (Lactuca sativa var. capitata L.) cultivar for early harvest. All biodegradable nonwovens were manufactured in the Institute of Biopolymers and Chemical Fibres and POLMATEX CENARO in Łódź, Poland. Lettuce seeds were sown into boxes in a greenhouse at the beginning of March, and transplants were planted into the field at the beginning of April. Biodegradable nonwovens - aromatic polyester IBWCH 75 g m-2, polybutylene succinate Bionolle 100 g m-2 and standard polypropylene PP Agro 20 g m-2 - were stretched over the lettuce in the field. The covers were kept on until 4-5 days before harvest. Plots without covers were defined as the control. Ascorbic acid, soluble sugar, dry matter, nitrates, chlorophyll a, chlorophyll b and carotenoid contents were recorded in the leaves. All biodegradable nonwovens showed a positive effect on yielding in comparison to the control in 2009. In the second year of the experiment, there were no significant differences between covers with regard to the yield. Dry matter and soluble sugar content in both years of the experiment was diversified. Nonwovens used as covers in 2009 significantly increased the content of nitrates in comparison to the control. In the second year, the highest level of nitrates was demonstrated in the control object. It is worth underlining that the maximum allowed limit of nitrate content in lettuce (4000 mg kg f.w.) was not exceed. The kind of cover had no significant effect on the level of chlorophyll a in 2009 or chlorophyll b and carotenoids in 2009 and 2010 in the lettuce

Lettuce is one of several cool-season crops that Indiana growers produce to meet market demands for local produce early and late in the season. It is grown in the field as well as in unheated and heated structures. Growers who responded to a survey in 2013 indicated that important characteristics for lettuce varieties include slow bolting, good eating quality, and disease resistance. Numerous varieties are available and it is important to identify which perform well in Indiana. We report here characteristics of 38 lettuce cultivars grown in an unreplicated field trial at the Pinney-Purdue Agricultural Center in Wanatah, Indiana.

Na tržištu su prisutni brojni novi i poboljšani kultivari salate namijenjeni za proizvodnju na otvorenom. Međusobno se razlikuju u morfološkim i biološkim svojstvima (dužina vegetacije, brzina prorašćivanja cvjetne stabljike, otpornosti na bolesti, prilagodba proizvodnim uvjetima). Na pokušalištu Zavoda za povrćarstvo u proljetno-ljetnom roku uzgoja postavljen je jednofaktorijalni pokus sa četiri kultivara salate (Metamis, Salakis, Vanity, Venegia) u četiri ponavljanja. U jednokratnoj berbi, 14. srpnja, utvrđen je broj tržnih i netržnih biljaka te su mjereni promjer, visina i masa rozete salate. Prema promatranim svojstvima, za proizvodnju na otvorenom mogu se preporučiti kultivari Salakis i Vanity.

Bu araştırmada öğütülmüş cibrenin içine inorganik (jips, perlit, zeolit) ve organik materyaller ( odun kömürü, nemlendirici granül polimer) ve ana ve iz elementler katılarak, kuru cibrenin nemlendirilmesi kolay, besin elementlerince zengin, yeni ve uygun bir ortam haline getirilmesine çalışılmıştır. Fide denemesi sonuçlarına göre gövde çapı ve gerçek yaprak sayısı esas alındığında en iyi ortamların perlit, torf ve 8 no’lu (1 g/L nemlendirici granül polimer + 10 g/L jips + %15 kırılmış odun kömürü + %25 perlit + %60 öğütülmüş cibre+ana ve iz elementler) ortamlar olduğu bulunmuştur. Dikim dönemi sonuçlarına göre soğuk serada kış döneminde topraktan sonra en uygun dikim ortamı pazarlanabilir bitki ağırlığı yönünden 9 no’lu konu (1 g/L nemlendirici granül polimer + 10 g/L jips + %15 kırılmış odun kömürü + %25 zeolit + %60 öğütülmüş cibre +ana ve iz elementler) olduğu görülmüştür. In this research inorganic (gypsum, perlite, zeolite) and organic ( chracoal, granulated wetting agent) materials and main and trace elements were added to dry ground grape marc to make it easily wettable, nutrient-enriched and new and more suitable medium. According to the results of seedling propagation experiment, perlite, peat and treatment number 8 (1 g/L granulated wetting agent + 10 g/L gypsum + %15 chracoal + %25 perlite + %60 ground grape marc + main and trace elements) were found as the most suitable medium for seedling stem diameter and number of true leaves. According to the results of the main growing period, following soil the most suitable medium for marketable yield by weight was treatment number 9 (1 g/L granulated wetting agent + 10 g/ gypsum + %15 chracoal + %25 zeolite + %60 ground grape marc + main and trace elements) in a cold glasshouse in winter growing period.

The experiment was carried out during 2008-2009, using the method of water cultures. The biological material was head lettuce var. ‘Nochowska’. The first experimental factor was concentration of sodium chloride in the medium: the control, 68 and 136 mÌ NaCl, whereas the second factor was the level of fertilization with potassium: + 20%K, the control (without additional fertilization with potassium). The control was a full Hoagland’s medium (pH 5.5). A significant decrease in the intensity of CO2 was observed in plants grown in the medium of 136 mÌ NaCl concentration, with no additional nutrition with potassium. An increase in salinity, in the hydroponic growing media enriched with 20% of potassium, did not cause a decrease in photosynthesis. A decrease in the intensity of transpiration and an increase in the index of water use effectiveness in photosynthesis were recorded along with an increase in the NaCl concentration in plants additionally nourished with potassium.The addition of 20% of potassium caused, independently of the level of salinity of the media, an increase in the content of all the forms of chlorophyll in the leaves of the studied plant.