Rogério Antônio Bellé

Estimating leaf appearance rate and phyllochron in safflower (Carthamus tinctorius L.)

Safflower may be an interesting option for the flower market, either as fresh or dried cut flower. Estimating the leaf appearance rate and the phyllochron (the time interval between the appearance of successive leaves) is important for calculating the number of emerged leaves (NL) on the plant, which is an excellent measure of plant development. The objective of this study was to estimate the leaf appearance rate and the phyllochron in safflower (Carthamus tinctorius L.). An experiment was conducted in Santa Maria, RS, Brazil, inside an 8 x 15m plastic greenhouse. Sowing was on 03 October 2003 and emergence was on 08 October 2003. The experimental design was a randomized complete block design with three replications. The main stem NL was measured twice a week from 24 October 2003 to 15 November 2003 in four plants per replication. Daily growing degree days above a base temperature (5°C) and accumulated thermal time (TT) were calculated. The NL was linearly regressed against TT. The angular coefficient of the linear regression is the LAR (leaves/ °C day) and the phyllochron (°C days/leaf) was estimated by the inverse of the angular coefficient of the linear regression. The LAR was 0.0467 ± 0.0203 leaves/ °C day and the phyllochron was 25.5 ± 14.6°C days/leaf.

Populações de plantas e estratégias de manejo de irrigação na cultura da soja

Este trabalho teve por objetivo verificar o efeito do manejo da irrigacao e da populacao de plantas sobre o rendimento de graos em soja semeada apos a epoca recomenda. O experimento foi conduzido de janeiro a maio de 2005 na Universidade Federal de Santa Maria. O delineamento experimental utilizado foi blocos ao acaso com parcelas subdivididas e quatro repeticoes. Nas parcelas principais foram distribuidos tres manejos de irrigacao: 1) nao-irrigado; 2) irrigado todo o ciclo; e 3) irrigado nos periodos criticos. Nas subparcelas foram distribuidas duas populacoes de plantas (250.000 e 400.000 plantas ha-1). Para as plantas irrigadas todo o ciclo ou somente nos periodos criticos, o rendimento de graos nao diferiu entre as populacoes testadas. O rendimento de graos das plantas nao-irrigadas teve um incremento de 21% com o aumento da populacao de plantas para 400.000 plantas ha-1.

Crescimento, desenvolvimento e retardamento da senescência foliar em girassol de vaso (Helianthus annuus L.): fontes e doses de nitrogênio

Sunflower is the fourth oil grain crop grown worldwide and some genotypes are used with ornamental purpose as cut and pot-grown flower. The objective of this study was to evaluate the effect of different sources and rates of nitrogen on some growth and developmental parameters, and on the delay of leaf senescence in pot-grown sunflower. An experiment was carried out inside a greenhouse in Santa Maria, RS, Brazil. Treatments were: urea, ammonium nitrate and calcium nitrate at rates of 0, 50, 100 and 150mg L-1 of N in the fertigation solution, with two weekly applications. The experiment was a two-factorial (sources and rates of N) in a completely randomized design with six replications. Each replication was a number 15 pot (1.5L, 15cm height) with one plant/pot. The variables analyzed were: final leaf number, final plant height, percentage of senescent leaves at selling stage and at the end of vase life, total leaf area per plant, phyllochron, and the thermal time from emergency to visible bud and from emergency to selling stage. The N source influences leaf area of pot-grown sunflower, with urea being recommend for higher leaf growth. The rate of around 100mg L-1 of N applied twice a week through fertigation promoted desirable characteristics for commercialization such as earliness and delay of leaf senescence.

Efeito do tamanho de fruto e do método de extração na qualidade fisiológica de sementes de porongo

Bottie gourd - Lagenaria siceraria (Mol.) Standl - the fruits harvested from a farm localed in Restinga Seca county, were used to evaluate seeds in the Seed Laboratory of the Federal University of Santa Maria. The effect of fruit size on seed physiological quality was studied using seeds from ten large, medium and small bottle gourd fruits. Fruits were characterized by the length, the diameter. the shell thickness, and by the number of seeds. The seeds were characterized by the length, the width, the thickness, and the weight of 1000 seeds. Water fermentation during 24, 48, 72, 96, and 120 hours and dipping in HCl solution by 10, 20, and 30% during 30 minutes were used to compare methods of extracting seeds from medium bottle gourd fruits stored for 60 days. The manual extraction of seeds was considered as the control treatment. The physiological quality of the seeds was evaluated by the germination and the first counting test and averaging time of germination parameters. Results indicated that the size of botlle gourd fruit can be characterized either by the length or the width. Lighter seeds with smaller width and thickness were extracted from smaller fruits. The treatment with HCl solution specially on 20 and 30% concentration was not efficient for the extracting bottle gourd seeds because the cleaning process was more difficult and qffected negatively seed germination and the vigor. The results show that as the size of the fruits increase the number and weight of seeds also increase without changing the ability to produce normal seedlings. The cleaning process of bottle gourd seeds in HCl solution reduces their vigor. The best period of fermentation of seeds was observed in water at 25°C for 72 hours, however, the period from 48 to 96 hours improved their physiological quality and also facilitated the cleaning process. The bottle gourd seeds germinate in environment with 43.4% of humidity and resonable air temperature, humidity and aeration.

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.

Vernalização afeta o filocrono em lírio

O experimento foi desenvolvido com o objetivo de estudar o efeito da vernalizacao sobre o filocrono (intervalo de tempo entre o aparecimento de duas folhas sucessivas) em lirio (Lilium longiflorum Thunb.), cv. Snow Queen, no campo experimental do Departamento de Fitotecnia da Universidade Federal de Santa Maria (UFSM), Santa Maria (RS). Os tratamentos constituiram-se de bulbos submetidos a -0,5 oC; 4 oC e 10 oC com periodos de vernalizacao dos bulbos de 2, 4, 6 e 8 semanas. O tratamento testemunha correspondeu a bulbos nao vernalizados. Apos o tratamento de vernalizacao, os bulbos foram plantados no interior de uma estufa plastica em 5 de dezembro de 2002 e observado o desenvolvimento das plantas. O filocrono foi estimado pelo inverso do coeficiente angular da regressao linear entre o numero de folhas e o acumulo termico acima de 1 oC, a partir da emergencia das plantas. Os resultados evidenciaram que o estado de vernalizacao da planta afeta o filocrono em lirio, e plantas nao vernalizadas ou com pouca vernalizacao tem um filocrono mais elevado do que plantas completamente vernalizadas. Quando o tratamento de vernalizacao e maior que 30 dias efetivos de vernalizacao, o valor do filocrono foi em torno de 25 oC dia/folha, valor que pode ser utilizado como referencia quando os bulbos sao vernalizados e utilizados em plantios comerciais.

QUEBRA DE DORMÊNCIA EM SEMENTES DE CROTALARIA

Seed germination of four Crotalaria species were evaluated after physical, chemical and mechanical treatments to overcome impermeability of seed coat. The most efficient methods to break dormancy were: for C. retusa mechanical seed scarfication followed by seed imbibition in boiling water for five minutes; for C. spectabilis seed imbibing in destilated water at room temperature and seed chemical scarification in H2SO4 ; and rinsed in tap water for C. mucronata mechanical seed scarification; for C. grantiana none tested treatments improved dormancy break. The dormancy break efficiency was measured based on percentage of normal seedling.

Safflower grown in different sowing dates and plant densities

The objectives of this study were to test the effects of different plant densities on stem characteristics in two growing seasons: Fall/Winter and Spring/Summer. The plant densities evaluated were 48, 64, 80, 96, 112 and 128plants m-2. The Fall/Winter growing season was from 04/04/2008 to 23/08/2008 and the Spring/Summer growing season was from 03/10/2008 to 23/12/2008. Total and partial plant height did not differ among plant densities in the Fall/Winter growing season. However, in the Spring/Summer growing season total plant height had a quadratic response to increase in plant population whereas the partial height did not vary. In the Fall/Winter cultivation, plants presented larger stems and branches diameter, branches length and total number of nodes main stem and branches diameters, number and length of branches, fresh and dry mass decreased as density increased in the two growing seasons. The capitulums diameter decreased as density increased in the Fall/Winter growing season, but at the Spring/Summer growing season it decreased in the density from 48 to 96plants m-2 and increased in the density from 112 a 128plants m-2.

Ácido giberélico e dia curto interrompido em crisântemo de corte (Dendranthema grandiflora, Tzvelev., "Gompier Chá")

Some chrysanthemums cultivars, as the "Gompier Cha", have problems of small growth during winter crop. The spraying whit gibberellic acid (GA3) and the control photoperiod with interrupted short day can be options for to stimulate growth. Thus, an experiment was carried out with the objective of evaluating the stems quality of cut chrysanthemum "Gompier Cha" response of GA3 and short day (DC) interrupted by long day (DL), during winter time in Rio Grande do Sul. The experiment was conducted at the Universidade Federal de Santa Maria, in 2001, from May to August. The treatments consisted of different gibberellic acid concentration (50, 100, 200, 300, 500 e 500mg L-1) sprayed six, three, two, two and one times, respectively, and short day interrupted (32DL+9DC+12DL+DC until the harvest). The best stem quality was obtained whit GA3 dosages: 100mg L-1 sprayed three times and 200mg L-1 sprayed two times. The short day interrupted used was inefficient to the "Gompier Cha" quality, while the spraying with gibberellic acid improved the length of floral stalks and the plant height during winter time in Rio Grande do Sul.

quALIDADE fISIOLÓGIcA E SANITáRIA DE SEMENTES DE Zinnia elegans Jacq. cOLHIDAS EM DIfERENTES ÉPOcAS 1

RESUMO - O objetivo do trabalho foi o de avaliar a influencia de diferentes epocas de colheita na qualidade fisiologica e sanitaria de sementes de zinia. As sementes zinia foram originadas de plantas semeadas em outubro de 2004, na area experimental do Departamento de Fitotecnia (UFSM). Os capitulos foram coletados manualmente e de acordo com a sua aparencia em sete epocas: 17 de janeiro, 10 de fevereiro, 15 de marco (coleta A), 23 de marco (coleta B), 12 de abril, 10 de maio (coleta A) e 29 de maio (coleta B) do ano de 2005. Aqueles provenientes de coletas em janeiro, fevereiro e maio (A) apresentavam-se verdolengos, os demais tinham aparencia seca. A qualidade fisiologica das sementes foi avaliada pelos testes de germinacao, primeira contagem, classificacao do vigor de plântulas, comprimento e massa fresca de plântulas, emergencia e comprimento de plantas em campo. Foi determinado ainda o grau de umidade das sementes. A qualidade sanitaria, pelo teste do papel filtro, foi avaliada aos sete dias. A epoca de colheita dos capitulos, de acordo com sua aparencia, influencia na qualidade fisiologica e sanitaria de sementes de Zinnia elegans Jacq. Sementes colhidas de capitulos em estadio seco, com menor grau de umidade, foram as que apresentaram melhor qualidade fisiologica. Alem disso, a ocorrencia de patogenos variou conforme a epoca de colheita, sendo que sementes provenientes da colheita de fevereiro apresentaram maior porcentagem de incidencia de Fusarium spp.