A staging system for development of gladiola (Gladiolus × grandiflorus) that relies on simple, visual, non-destructive criteria is proposed. Four field trials were conducted during the spring 2010, autumn/winter 2011 and winter 2011 at Santa Maria, RS, Brazil, with different gladiola cultivars, in order to observe the developmental stages of the above-ground parts and their dry matter. The developmental cycle, which starts at dormant corm and ends with plant senescence, is divided into four developmental phases: dormancy phase, sprouting phase (from filiform roots appearance to sheaths appearance), vegetative phase (from emergence of the first leaf tip to emergence of the final leaf tip on the stem) and reproductive phase (from heading to plant senescence). The developmental stages that were identified during the dormancy phase and during the sprouting phases are coded as S stages: S0 = dormant corm, S1 = appearance of roots, S2.1 = first sheath, S2.2 = second sheath and S2.3 = third sheath. Vegetative phase is coded as V stages: VE = emergence of the sheaths above ground, V1 = first leaf, V2 = second leaf, Vn = nth leaf and VF = flag leaf. Leaf tip is the marker for V1-VF. The developmental stages during the reproductive phases are coded as R stages: R1 = heading, R2 = blooming, R3 = onset of flowering, R4 = end of anthesis, R5 = end of florets senescence and R6 = plant senescence (leaves and floret axis are brown). Sub-stages have also been assigned between R1 and R2 and between R3 and R4. Illustrations (photographs) of each developmental stage taken from field pot-grown plants are provided and the proposed scale was tested with field observations. These criteria are straight forward and allow for quick determination of development stage. This system can be used by both farmers and for experimental trials.

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Resumo -O objetivo deste trabalho foi determinar as épocas de cultivo, em ambiente subtropical, em que é possível produzir hastes de gladíolo (Gladiolus x grandiflorus) que atendam aos padrões comerciais quantitativos do mercado nacional de flores de corte. Dois experimentos de campo foram realizados, um de agosto de 2011 a julho de 2012 e outro de agosto de 2012 a julho de 2013, com três cultivares do gladíolo e 12 datas de plantio para cada experimento. O comprimento total da haste, o comprimento do pendão e o diâmetro da haste foram avaliados quando as hastes estavam em ponto de colheita, ou seja, quando a cor das pétalas apareceu nos três primeiros floretes na base da haste. Os melhores meses para a produção de hastes de gladíolo são julho, agosto, setembro, fevereiro, março e abril, embora em nenhuma das datas de plantio tenham sido produzidas hastes com parâmetros quantitativos abaixo do padrão mínimo (exceto em períodos com geada, durante o espigamento).Termos de indexação: Gladiolus x grandiflorus, época de cultivo, floricultura, padrão comercial, qualidade.

Cassava [Manihot esculenta (L.) Crantz] plays an important role as staple food in the tropics. The GUMCAS model is a process-based dynamic simulation model for cassava that has been adapted to the Cropping System Model (CSM) framework of DSSAT (DSSAT-CSM). The objective of this study was to calibrate and evaluate the original GUMCAS model, a modified version of the GUMCAS model, and the current cassava model in DSSAT under potential conditions in the subtropical environment of Rio Grande do Sul State, Brazil. The modified original GUMCAS model consisted of three modifications in the code: we included a third independent "clock" in the cassava development for the onset of starch accumulation, we replaced the rate of leaf appearance submodel with the Wang and Engel model, and we modified the leaf senescence submodel. Model calibration was with a field experiment for cultivar Fepagro-RS 13 during the 2011/2012 growing season in Santa Maria, Brazil. Independent data from 16 experiments conducted at four sites in Rio Grande do Sul State were used for testing the performance of the three versions of the cassava model. The original GUMCAS model had the poorest performance, and the modified GUMCAS model slightly improved the predictions of stem and storage root yield compared with the current DSSAT cassava model. The modified GUMCAS model greatly improved the predictions of developmental stages, leaf development, and leaf area growth dynamics compared with the current DSSAT cassava model. Results from this study contribute to our understanding on how a cassava system functions in the subtropics.

IIIDesenvolvimento vegetativo e reprodutivo em gladíolo Vegetative 'Peter Pears', 'Sunset', 'T704', 'Traderhorn', 'Rose Supreme' and 'Jester', and another

ResumoO objetivo deste trabalho foi avaliar e comparar as variáveis de crescimento, o desenvolvimento e os componentes de produtividade de raízes e hastes de cinco cultivares de mandioca em ambiente subtropical no Rio Grande do Sul, Brasil. O experimento de campo foi conduzido nos anos agrícolas de 2010-2011 e 2011-2012, em Santa Maria, RS, com cinco cultivares de mandioca (Fepagro-RS13, Fepagro-RS14, Estrangeira, Fécula Branca e Cascuda) no delineamento blocos ao acaso com quatro repetições em esquema bifatorial. Foram coletadas variáveis de crescimento e desenvolvimento como área foliar, altura de plantas e número de folhas e componentes de produtividade de raízes e hastes. As cultivares Fepagro-RS13 e Fepagro-RS14 possuem maior IAF com elevada produção de parte aérea e maior altura total comparadas às das cultivares Estrangeira, Fécula Branca e Cascuda por emitirem maior quantidade de ramificações simpodiais. As cultivares Fepagro-RS13 e Fepagro-RS14 possuem elevada produção tanto de parte aérea quanto de raiz, enquanto as cultivares Estrangeira, Cascuda e Fécula Branca possuem maior aptidão para produção de raízes tuberosas em ambiente subtropical no Rio Grande do Sul, Brasil.Palavras-chave: Manihot esculenta Crantz, desenvolvimento, raízes tuberosas, hastes, componentes de produtividade. Performance of cassava cultivars in subtropical environment AbstractThe objective of this study was to evaluate and compare variables of growth, development and yield components of roots and stems of five cassava cultivars in subtropical environment in Rio Grande do Sul, Brazil. A field experiment was conducted in the 2010-2011 and 2011-2012 growing seasons at Santa Maria, RS, with five cassava cultivars, Fepagro -RS 13, Fepagro -RS 13, Fepagro -RS 14, Estrangeira, Fécula Branca and Cascuda in a randomized block design with four replicates and a two factor scheme. Variables of growth and development such as leaf area, plant height and leaf number and yield components of roots and stems were collected. The cultivars Fepagro -RS 13 and Fepagro -RS 14 have the highest LAI, above-ground biomass and height compared to the cultivars Estrangeira, Fécula Branca and Cascuda, because the former have greater sympodial branching. Cultivars Fepagro -RS13 and Fepagro -RS 14 have high production of both above-ground and tuber roots whereas cultivars Estrangeira, Cascuda and Fécula Branca are adapted for tuber roots production in subtropical environment of Rio Grande do Sul, Brazil.

The objective of this study was to determine the cycle duration in days and the quantitative parameters, i.e. stem length, spike length and stem diameter of gladiolus floral stems as a function of the planting date and locations in the Rio Grande do Sul/Brazil. Field experiments were established between 2014-2015 in three locations (Frederico Westphalen, Itaqui and Santa Maria). The experimental design was a complete randomized block, with six gladiolus cultivars in three distinct planting dates at each location as treatments. The shift from vegetative to reproductive stage, the stem length, spike length and stem diameter were evaluated. Data was statistically analyzed by ANOVA and Tukey test. When planted during late July and early August, cultivars of early cycle(‘Purple Flora’, ‘Rose Friendship’ and ‘White Friendship’) and intermediate cycle (‘Green Star’ and ‘Jester’), produced floral stems of gladiolus in the desired patterns besides as well as having a shorter growth cycle than late cultivars (‘Gold Field’), being recommended for commercial cultivation in Southern Brazil.

The objective of this study was to simulate leaf development of cultivated rice genotypes and weedy red rice biotypes in climate change scenarios at Santa Maria, RS, Brazil. A leaf appearance (LAR) model adapted for rice was used to simulate the accumulated leaf number, represented by the Haun Stage, from crop emergence to flag leaf appearance (EM-FL). Three cultivated rice genotypes and two weedy red rice biotypes in six emergence dates were used. The LAR model was run for each emergence date using 100 years of synthetic daily weather data and six climate scenarios, including current, +1, +2, +3, +4 and +5 °C increase in mean air temperature, with symmetric and asymmetric increase in daily minimum and maximum temperature. The increase in air temperature scenarios decreased the duration of the EM-FL phase in the earlier emergence dates (08/20, 09/20, 10/20) whereas in mid (11/20) and late emergence dates (12/20 and 01/20) the longest EM-FL phase was in the symmetric +5 °C scenario and the shortest duration was in the asymmetric +3 and +4 °C scenarios. The timing of the onset of flooding irrigation and nitrogen dressing may be altered if global warming takes place and weedy red rice has a potential to enhance its competitiveness with cultivated rice in future climates.Key words: Oryza sativa, global warming, plant competition, climate change, nitrogen management Desenvolvimento foliar de arroz cultivado e arroz vermelho em cenários de aumento de temperatura RESUMO Objetivou-se com este estudo simular o desenvolvimento foliar de genótipos de arroz cultivados e biótipos invasores de arroz vermelho em cenários de mudança climática em Santa Maria, Rio Grande do Sul, Brasil. Um modelo de aparecimento de folhas foi usado para simular o número de folhas acumuladas, representadas pelo Estádio de Haun, a partir da emergência da cultura até o aparecimento da folha bandeira (EM-FB). Foram utilizados três genótipos de arroz cultivados e dois biótipos de arroz vermelho, em seis épocas de emergência. O modelo foi rodado em cem anos de seis cenários climáticos: atual, +1, +2, +3, +4 e +5 °C, com aumentos simétricos e assimétricos na temperatura mínima e máxima diária do ar. O aumento da temperatura nos cenários ocasiona uma redução da duração da fase EM-FB nas datas de emergência mais cedo (20/08, 20/09, 20/10) enquanto no período intermediário (20/11) e nas datas de emergência tardias (20/12 e 20/01) a maior duração da fase EM-FB foi no cenário simétrico +5 °C e a menor duração foi nos cenários assimétricos de +3 e +4 °C. O momento do início da irrigação por inundação e manejo do nitrogênio em cobertura pode ser alterado com o aquecimento global e o arroz vermelho tem potencial para aumentar sua competitividade com arroz cultivado em climas futuros. Palavras