Evaluación agronómica de tomate (licopersicon esculentum m) en invernadero

Agronomía Mesoamericana 01/2001;
Source: DOAJ

ABSTRACT El objetivo del presente trabajo fue determinar la adaptación de genotipos de tomate, bajo condiciones de invernadero. Los genotipos fueron: híbridos: Contessa, Summer Flavor 5000, Summer Flavor 6000, Celebrity, Bonita, Shady Lady, Sunbolt, Sunny, Heat Wave y Olympic; y la variedad FloraDade como testigo. Se evaluaron variables fisiológicas y de rendimiento. Las variables fisiológicas se determinaron en tres evaluaciones en el ciclo del cultivo, en tres horas del día y dos posiciones de hoja en cada evaluación. Se encontraron correlaciones significativas (p≤0,05) entre rendimiento en t/ha, y rendimiento promedio/ planta/corte, frutos/planta/corte y rendimiento/planta, y entre fotosíntesis y uso eficiente del agua. En el análisis de componentes principales, se encontró que los primeros cinco componentes tuvieron un Eigenvalor mayor a uno, explicando los tres primeros un 72% de la varianza total. El primer componente, con un 36% de la variación total, se debió a las ¿características de rendimiento¿, el segundo componente, con un 23% de la variación total, se debió a las ¿características de regulación interna de temperatura¿ y el componente cinco, con un 7,4 % de la variación, a la ¿producción eficiente de fotosintatos¿. El análisis de regresión lineal múltiple fue significativo (p≤0,01). El rendimiento en t/ha, se explica por una ecuación lineal múltiple (r2= 0,98) de cuatro variables

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    ABSTRACT: A greenhouse experiment was conducted to determine the effects of substrate, irrigation scheduling and nutrient solution electrical conductivity (EC) on plant growth and photosynthesis of tomato plants. The plants grown in peat-bags were irrigated by a potential evapotranspiration (PET) dependent irrigation system. The first peat-bag treatment (control) was irrigated when the soil water potential reached −5 kPa. EC was fixed at 2.5 dS m−1. EC of other two peat-bag treatments was varied between 1 and 4 dS m−1 with a soil water potential setpoint (SWPS) of either −5 or −9 kPa. Plants grown in rockwool and by the nutrient film technique (NFT) were treated with EC levels of 2.5, 4.0 and 5.5 dS m−1. EC variation resulted in higher photosynthetic capacity (Pc), quantum use efficiency (QUE) and dry matter production (DMP) under high SWPS compared with the control. The increase in DMP resulted mainly from fruit yield increase. In the treatment of EC variation with low SWPS, Pc and DMP were lower than in treatment of EC variation with high SWPS, but not different from that in the treatment of fixed EC. The high EC treatment of 4.0 dS m−1 decreased DMP in NFT, but did not in rockwool. EC of 5.5 dS m−1 decreased fruit yield but did not affect shoot DMP. However, high EC treatments, especially EC of 4 dS m−1, increased Pc as well as QUE in rockwool and in NFT. DMP and Pc was not positively correlated with each other for EC treatment. However, it is concluded that PET-dependent EC variation increases photosynthetic capacity, plant growth and fruit yield of greenhouse tomato plants.
    Scientia Horticulturae 07/1995; 63(1-2-63):11-20. DOI:10.1016/0304-4238(95)00791-Q · 1.37 Impact Factor
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    ABSTRACT: Photosynthesis of tomato fruit was studied using green fruit from six heritage cultivars of Lycopersicon esculentum Mill. and one of Lycopersicon pimpinellifolium. Chlorophyll concentrations in the green shoulder, pericarp and locular parenchyma of the fruit were determined and the apparent photosynthetic electron transport activity (ETR) and chlorophyll fluorescence quenching characteristics of these tissues and the calyx were compared. In all cultivars, green shoulder formation, apparent as intense pigmentation of the proximal pericarp shoulder, was positively related to the degree of shading of the fruit during development. Appearing as a photosynthetic adaptive trait for increasing the photoautotrophic capacity of fruit grown under low light, the green shoulder contained 17-57% of the total pericarp chlorophyll content. The pericarp below the green shoulder had lower chlorophyll a+b concentrations than in the locular parenchyma. The proportion of light-harvesting chlorophyll to active centre chlorophyll was also lower in the pericarp than in the locular parenchyma as indicated by higher ratios of chlorophyll a/b. At a photon flux density (PFD) of 1200 μmol m-2 s-1, different fruit tissues were found to have different levels of ETR. In 'Yellow Pear', the upper surface of the calyx had an ETR of 154 μmol m-2 s-1, while the lower surface had an ETR of 88 μmol m-2 s-1. On the green shoulder, ETR was 203 μmol m-2 s-1, whereas in the pericarp distal to the green shoulder, ETR was 97 μmol m-2 s-1. In the locular parenchyma, ETR was 66 μmol m-2 s-1. This trend towards a lower ETR in distal and internal fruit tissues appeared to indicate a shift towards a more shade-type photosynthesis. Concomitant with this shift were changes in chlorophyll fluorescence quenching characteristics. Generally when tissues displayed reduced levels of ETR they also displayed a faster decrease in the photochemical quenching coefficient q(P) and a more rapid diversion of absorbed photon energy to non-photochemical pathways which was seen by the rise in the non-photochemical quenching coefficient q(N). However, the response of the locular parenchyma was an exception, under equivalent levels of PFD the q(P) levels in this tissue were much lower than those in the pericarp, but q(N) levels were similar. This finding indicated that the lower ETR of the locular parenchyma was due to a lower capacity to utilize electrons generated from water splitting rather than a greater diversion of absorbed photon energy to nonphotochemical pathways. The levels of photosynthetic activity found in the calyx, green shoulder, pericarp, and locular parenchyma suggest that all of these tissues have significant roles in CO2 scavenging and the provision of carbon assimilates. The potential role of fruit photosynthesis in influencing the fruit acid to sugar ratio and hence fruit quality is discussed.
    Journal of Experimental Botany 05/1999; 50(334). DOI:10.1093/jxb/50.334.707 · 5.53 Impact Factor


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