Betânia Brum

Estimativa da área foliar de meloeiro em estádios fenológicos por fotos digitais

This experiment was aimed at evaluating the precision of digital photos in estimating the leaf area of watermelon plants and to find mathematical models that estimates leaf area as a function of leaf linear measurements at different growth stages. All odd leaves of eight plants were photographed after being established on the field using a digital camera that resulted in 4,188 photos in which length and width were measured using a Sigma Scan Pro v. 5.0 Jandel Scientific software. In order to estimate the precision of the digital photos method, a sample consisting of 40 leaves was taken and leaf area measured using the standard leaf disks and the photo method. A 0.99 correlation coefficient was detected between the two methods. Therefore digital photos can be used to estimate leaf area of watermelon plants and estimation of leaf area per growth stage presents higher precision. The larger variability in leaf area was observed during reproductive growth. Maximum leaf width is the measure that best estimates leaf area.

Crescimento, duração do ciclo e produção de inflorescências de crisântemo multiflora sob diferentes números de despontes e tamanhos de vasos

The objective of this research was to evaluate the vegetative and reproductive behavior as well as the length of growing stage of two chrysanthemum cultivars under protected environment and submitted to different number of prunings and pot sizes. The experiment was conducted from April 30 until December 12, 2003 in a greenhouse located at the University of Santa Maria, RS, Brazil. Three pot sizes were used: 11, 15 and 20. The variance analysis for plant height and stem diameter was conducted under a bifactorial scheme: number of prunings (1a up to 31a week), for each combination of cultivar and pot size. Regarding the inflorescence production, they were considered as treatments the numbers of prunings for each pot size and chrysanthemum cultivar. The means were compared using the Tukey Test (a=5%). Plant height, stem diameter and number of inflorescences increased as the number of prunings and pot size increased, however, stem diameter decreased on both cultivars. The cultivar Veria Dark was less responsive than cultivar Papiro. In order to produce good quality plants, there is a necessity to increase the number of prunings as pot size increases. To cultivate would see them Dark and Papiro had presented good performance in the region of Santa Maria, RS, mainly with the use of four lappings of the tops of corn for the vases number 11 and five for the vases number 15 and 20, being the cycle of culture of 21 weeks in the vase number 11 and 25 weeks, in the vase number 15 and 20.

Cronograma de amostragem de plantas de alface hidropônica para ajuste de curvas de crescimento

The fitting of growth curves for lettuce plants requires many samplings within o time interval, while can restrict the number of studied treatments. With the aim o determine sampling chronogram hidroponic lettuce for the fitting of growth curves until maturation of seeds. Two greenhouse trials were carried out in spring an autumn, at UFSM experimental area, Santa Maria, RS. Different sampling interval were simulated using the fitting of a daily model. The optimum sampling interval were determined by comparing daily sampling model with simulated sampling model by F test. Simulations were carried between out for the following variables: total leaf, root and leaf area phytomass. Based on trials carried out during spring it is recommended sampling in intervals of three (total), eight (leaf), 20 (roots) and nine (leaf area) days and for carried out in autumn the sampling interval should be of two, 11, 12 and 11 days.

Área foliar e número de flores de nastúrcio sob duas densidades de plantio

ABSTRACT Leaf area and flower number of nasturtium in two plantdensities Two experiments were conducted in a plastic greenhouses inSanta Maria, Rio Grande do Sul State, Brazil, to estimate thenasturtium ( Tropaeolum majus L.) leaf area through non destructivemethods, as well as to study the leaf area and flower number variationin time, in two planting densities. In the first experiment, leaf areawas assessed using 50 leaves harvested out of ten plants throughdigital image. This calculated value was then compared to leaf areaestimation obtained using leaf disks. In addition, leaf area wascorrelated to the following leaf diagonals: main rib, perpendicularto the main rib, and two transversal measures to the main rib. Adetermination coefficient (r 2 ) of 0,94 (p<0,05) was obtained for leafarea calculated through digital images and leaf disks. The leaf areaformula 0,8906x 2 , where x corresponds to the measure on the mainrib, presented the largest determination coefficient (r 2 = 0,99; p<0,05)among the four tested diagonals. In the second experiment, two plantdensities were tested: 0.60 x 0.50 m and 0.30 x 0.25 respectivelybetween plants and rows. For each plant density, leaf area wasestimated using the equation adjusted for the length of the main rib.Main rib was measured in all leaves larger than 5 cm of four plants.Logistics models were adjusted for leaf area and flower numbervariation in time. Flowers were harvested in 1 m