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Grafting can be an ally in the vegetable’s soilless cultivation, being the objective of this work evaluate the growth and production, as well as to define the thermal sum and trophic limit of grafted and non-grafted tomato plants cultivated in substrate. The experiments were conducted in a protected environment in the city of Jaguari-RS, in two growing seasons in the years 2019 and 2020. Italian and Gaucho tomato cultivars were used, the rootstock was chosen for giving vigor and longevity to the plants. Yield data were obtained through weekly fruit harvesting, growth data through periodic collections of whole plants and the total biomass obtained at the end of the experiments. Grafted plants show greater vegetative growth regardless of the crop season; however, non-grafted plants are more productive in a growing cycle with restricted light and low temperatures. Grafted plants require a greater thermal sum to complete their phenological stages. The trophic limit for grafted and non-grafted plants of Italian and Gaucho tomato cultivars is 4.8 MJ/m2/day.

O objetivo deste trabalho foi avaliar os efeitos da luz e da temperatura sobre a germinação das sementes e o comprimento e produção de massa seca das plântulas de calêndula (Calendula officinalis L.). As sementes foram colocadas para germinar a temperaturas constantes de 15; 20; 25; 30 e 35ºC, na presença e na ausência de luz. O delineamento experimental utilizado foi inteiramente casualizado com quatro repetições. Constatou-se que a percentagem de germinação das sementes é maior à temperatura de 20ºC, e que temperaturas de 30 e 35ºC são prejudiciais à germinação, e afetam significativamente o comprimento das plântulas e a sua produção de massa seca. The effects of light and temperature were evaluated on seed germination and on the length and dry matter of marigold seedlings (Calendula officinalis L.). The seeds were placed to germinate at constant temperatures of 15; 20; 25; 30 and 35ºC, in the presence and absence of light. The experimental design used was of complete randomized plots with four replications. The percentage of seed germination was higher at 20ºC, and temperatures of 30 and 35ºC were harmful to germination and affected significantly the length of seedlings and their dry matter production.

The control potato late blight needs a great number of fungicide sprayings. These increase the costs of cropping and cause undesirable environmental impacts. The use of forecast systems to predict disease has the potential of reducing fungicide applications without reducing yield. The objective of this study was to evaluate the performance of Blitecast and Prophy systems as a reference model for predicting late blight potato and support decision of spray fungicides. Experiments were carried out during Spring 2004 and Autumn 2005, in Santa Maria, RS, Brazil. Meteorological data were measured in the center of the experimental area at 0.10 and 1.50 m above soil surface. Different accumulated severity values (VS) were calculated with 'Blitecast' (VS = 18, 24, 30, 36 and 42) and 'Prophy' (VS = 15, 20, 25, 30 and 35) forecast systems. These values were used to perform. Two additional treatments were the weekly sprays and without fungicides. The experimental design was a completely randomized, with four replications. Each plot had four rows plants with 5 m length. Late blight severity was evaluated in each three to five days. The fungicide spraying schedule based on Blitecast system with 18 accumulated severity values increased tuber yield at least 42.6 % compared to the control without fungicides treatment. It also reduced the number of sprayings by 25% during wet periods and 70% during dry periods compared to weekly sprayings. The efficiency of controlling late blight was similar to the weekly sprayings treatment in the treatments Bli18 e Pro15. The Prophy model predicted higher number of fungicide sprayings than the Blitecast system and did not improve disease control.

O objetivo deste trabalho foi estimar o filocrono em plantas de calêndula (Calendula officinalis L.) cultivadas em diferentes épocas de semeaduras. Realizaram-se três épocas de semeaduras: 06/04/2005, 23/06/2005 e 03/10/2006, no interior de uma estufa plástica com área de 240m2, instalada no campus da Universidade Federal de Santa Maria, UFSM. A semeadura foi realizada em vasos plásticos com capacidade volumétrica para cinco litros. O delineamento experimental foi inteiramente casualizado com 320 vasos em cada época, sendo distribuído em quatro fileiras de 80 vasos cada. Em uma planta de oito vasos de cada quatro fileiras, fez-se a contagem, semanalmente, do número de folhas emergidas da haste principal e na primeira haste lateral. Os dados do número de folhas foram correlacionados com a soma térmica diária acumulada, considerando-se uma temperatura base de 8°C. Constatou-se que o filocrono variou com a época de semeadura, sendo o menor valor igual 15,9°C dia folha-1, obtido na 2ª época de semeadura e o maior, igual a 24,5°C dia folha-1, na 1ª época na haste principal e 48,9°C dia folha-1 na semeadura de outubro na primeira haste lateral. The objective of this study was to estimate the phyllochron in calendula (Calendula officinalis L.) grown in different sowing dates. Three sowing dates (06/04/2005, 23/06/2005 and 03/10/2006) were performed inside a 240m2 plastic greenhouse at the Campus of the Federal University of Santa Maria, RS, Brazil. Sowing was in five liter plastic pots. The experimental design was a completely randomized with 320 pots on each sowing date and rows with 80 pots. The number of leaves in the main stem and oi the first lateral branch was counted on a weekly basis in one plant of eight pots. The number of leaves data was regressed against accumulated thermal time, assuming a base temperature of 8oC. The main stem phyllochron varied with sowing date, with the lowest value (15.9°C day leaf -1) obtained on the second sowing date, and the greatest value (24.5°C day leaf -1) obtained on the first sowing date. The greatest phyllochron on the first order lateral branch was 48.9°C day leaf -1 in the October sowing date.