Stratification of yerba mate seeds in a commercial nursery and the emergence monitoring

Ilex paraguariensis A.St.-Hil. is a native species in Brazil, Argentina, Bolivia, Paraguay, and Uruguay. Propagation is carried out by seeds that have a low germination rate and morphophysiological dormancy. In order to increase the germination percentage, stratification treatments and emergence monitoring were tested. For this, yerba mate seeds were subjected to stratification treatments: Treatment 1 - seeds between two sand layers; Treatment 2 - seeds between two sand layers and commercial substrate covered with corn straw; Treatment 3 - seeds between two sand layers with the addition of 4.0 g "L" ^"-1"  of slow-release fertilizer (16-8-12 - 6 months); Treatment 4 - seeds between two sand layers covered with corn straw; and a control treatment - seeds without stratification. The stratification period for all treatments was 180 days, and at 120, 150, and 180 days, 100 seeds were removed per repetition from each treatment for emergence tests, with weekly observation for 180-days in a completely randomized design. After that period, the tetrazolium test was performed with the seeds that did not emerge. At 120-days of stratification there was no emergence and at 150-days it was 0.83%. At 180-days, treatment 3 showed the highest percentage - 13.19%. Seeds without stratification do not germinate and after 180-days of emergence the amount of non-viable seeds increased in all treatments. Stratification in sand with slow-release fertilizer favors the emergence of yerba mate seedlings.The propagation of Ilex paraguariensis A.St.-Hil. is carried out by seeds that have a low germination rate and morphophysiological dormancy. In order to increase the germination percentage, stratification treatments and emergence monitoring were tested. For this, yerba mate seeds were subjected to stratification treatments: Treatment 1 - seeds between two sand layers; Treatment 2 - seeds between two sand layers and commercial substrate covered with corn straw; Treatment 3 - seeds between two sand layers with the addition of 4.0 g  of controlled-release fertilizer; Treatment 4 - seeds between two sand layers covered with corn straw; and a control treatment - seeds without stratification. The stratification period for all treatments was 180 days, and at 120, 150, and 180 days, 100 seeds were removed per repetition from each treatment for emergence tests, with weekly observation for 180-days in a completely randomized design. After that period, the tetrazolium test was performed with the seeds that did not emerge. At 120-days of stratification there was no emergence and at 150-days it was 0.83%. At 180-days, treatment 3 showed the highest percentage - 13.19%. Seeds without stratification do not germinate and after 180-days of emergence the amount of non-viable seeds increased in all treatments. Stratification in sand, combined with controlled-release fertilizer favors yerba mate seedlings emergence. After 180-days of emergence in germinator plants at 25°C, there is an increase in non-viable seeds amount. Seeds that did not undergo the stratification process do not germinate and present a higher dormant seeds percentage after 180-days of emergence

Vitis labrusca L. germination: influence of treatments to break dormancy, storage and ripening point of fruits

Grapevine seeds have morphophysiological dormancy, which complicates their germination, an important step in obtaining new plants after crossing during breeding. The objective of this work was to establish the ideal conditions for Vitis labrusca L. ‘Isabella’ seed storage conditions, the method for breaking seed dormancy, ripening of fruits at harvest, need for fungicide application before seed sowing and their germination. The seeds were submitted to three tests with (1 and 2) different treatments to break seed dormancy and storage in two conditions for two different times (Isabella), and (3) seeds from unripe and ripe fruits treated or untreated with fungicide. Germination was monitored two times per week. The percentage of germination (%G), germination mean time (GMT), and germination speed index (GSI) were calculated. Data were submitted to analysis of variance (ANOVA) and means were compared using the LSD-Fisher test (p < 0.05). The 12-month storage at a controlled temperature (25±2°C) provided the best germination results (up to 19.5% of G%). Stratification for 90 or 120 days on wet paper or sand at 5±2°C of seeds from mature fruits is the most suitable for the germination of Isabella seeds (65% to 72% of G%, and 1.73 and 1.95 of GSI for the treatments of stratification on wet sand for 120 days). It is also not necessary to apply fungicide on seeds before sowing, as long as disinfestation with 70% alcohol and sodium hypochlorite 1%, and triple washing with water is done (no statistical difference for seeds from ripe fruits treated or not with fungicide, 58% and 64.7% of %G, and 1.37 and 1.22 of GSI, respectively)

Avaliação da qualidade de sementes de erva-mate (Ilex paraguariensis A.St.-Hil.) oriundas de diferentes plantas matrizes

Yerba mate seedlings with genetic and physiological quality, high rates of sowing survival and resistance to environmental stresses are necessary for the implantation and establishment of productive plants that will provide quality raw material. However, the production of seedlings, in most cases is carried out from seeds, which are collected from mother-plants with few selection criteria. In this sense, the work aimed to investigate the quality of the seeds of yerba mate after processing by flotation from different mother-plants, by obtaining information about the biometric characterization (longitudinal and transversal measure), water content, a thousand-seed weight, evaluation of the seed integrity and viability through the tetrazolium test. The seeds were collected from 10 mother-plants located in three cities in the yerba-mate region Alto Vale do Taquari – RS state, Brazil. In the integrity assessment, the number of not full (empty and deteriorated) and full (with and without visible embryo) seeds was counted. In the tetrazolium test, the percentage of viable and non-viable seeds was evaluated. The seeds of the different parent plants showed statistical differences for all the variables analyzed. The analysis showed that there are differences related to biometric parameters and water content and, consequently, in the weight of a thousand seeds. Yerba mate shows a varied percentage of empty and deteriorated seeds. The percentage of non-viable seeds is high, which significantly reduces the viability of the seed lot.Mudas de erva-mate com qualidade genética e fisiológica, altos índices de sobrevivência no plantio e resistência a estresses ambientais são necessários para a implantação e estabelecimento de ervais produtivos que irão fornecer matéria-prima de qualidade. No entanto, a produção de mudas, na maioria dos casos, é realizada a partir de sementes, as quais são coletadas de plantas matrizes com poucos critérios de seleção. Nesse sentido, o trabalho teve como objetivo investigar a qualidade das sementes de erva-mate após pré-limpeza por flutuação de diferentes plantas matrizes, por meio da obtenção de informações sobre a caracterização biométrica (medida longitudinal e transversal), teor de água, peso de mil sementes, avaliação da integridade das sementes e viabilidade por meio do teste de tetrazólio. As sementes foram coletadas de 10 plantas matrizes localizadas em três municípios da região ervateira Alto Vale do Taquari – RS, Brasil. Na avaliação da integridade foram contabilizadas a quantidade de sementes não íntegras (vazias e deterioradas) e íntegras (com e sem embrião visível). E no teste de tetrazólio foi avaliada a porcentagem de sementes viáveis e não viáveis. As sementes das diferentes plantas matrizes apresentaram diferenças estatísticas para todas as variáveis analisadas. As análises mostraram que há diferenças relacionadas à biometria e teor de água e, consequentemente, no peso de mil sementes. A erva-mate apresenta percentual variado de sementes vazias e deterioradas. A porcentagem de sementes não viáveis é alta, o que reduz significativamente a viabilidade de um lote de sementes

PRE-TREATMENTS, STRATIFICATION, AND EMERGENCE OF SEEDS OF ILEX PARAGUARIENSIS A.ST.-HIL

The propagation of yerba mate is carried out by seeds. In nature, birds are the main dispersers and the passage of seeds through the digestive system helps in germination. The laboratory simulation of the conditions provided by the passage of seeds in the digestive tract can be a pre-treatment alternative. Thus, the objective of the work was to evaluate the effect of pre-treatments, associating acid environment in the stratification, on the emergence of I. paraguariensis seeds. Two pre-treatments (PT) were tested: acidified aqueous solution (PT1) and a sequence of aqueous solutions (neutral + acid) (PT2). The pretreated seeds were subjected to stratification in sand (T1 and T2), in addition to seeds without pretreatment that were stratified in sand (T3) and stratified in sand and buried (T4). At 90, 135, and 180 days, seeds were removed from the stratification and taken to the laboratory. In addition to these treatments, a control treatment (seeds without pre-treatment and stratification) and pretreated (PT1 and PT2) seeds without stratification (T5 and T6), which were submitted to emergency and followed up weekly for 180 days, were included. After this period, the tetrazolium test was performed on non-emerged seeds. Seeds stratified for 90 days did not emerge, with 135 days there was 0.9% emergence, and the treatment with stratification in sand and buried (T4) had the greatest emergence (4.25%). With 180 days of stratification, an average emergency of 9.6% was obtained and the highest percentage was seen in T2 (pre-treatment followed by stratification), with 33% of emergence