A pimenta é um fruto do gênero Capsicum, bastante utilizada na culinária como tempero. Objetivou-se com este trabalho verificar o efeito do condicionamento fisiológico em sementes de Capsicum frutescens, e sobre as mudas obtidas das sementes condicionadas. O delineamento experimental foi o inteiramente casualizado em esquema fatorial 2x6, designado por: qualidade fisiológica das sementes (vigor acima e abaixo) e cinco agentes no condicionamento fisiológico (água, nitrato de potássio a 0,2%, nitrato de cálcio a 0,2%, giberelina GA 3 a 200 ppm e antioxidante riboflavina a 25 ppm), e testemunha, com quatro repetições. Para obtenção das sementes com vigor abaixo foi realizado a deterioração a 42 °C por 24 horas. O método de condicionamento fisiológico empregado foi à hidratação entre papéis, pelo período de 20 horas à 25 ºC. Foram avaliados a germinação, o vigor das sementes e a qualidade de mudas. Sementes com vigor acima apresentam melhor expressão do potencial fisiológico em relação às de vigor abaixo. O condicionamento fisiológico propiciou maior velocidade de emergência. Sementes condicionadas produziram mudas com maior fitomassa seca.Palavras-chave: Capsicum frutescens, priming, germinação, emergência, expressão de vigor.Physiological aspect sand quality of pepper seedlings in response to vigor and conditioning seeds Abstract Pepperis a fruit of the genus Capsicum, widely used in cooking as a seasoning. The objective of this study was to evaluate the effect of priming in Capsicum frutescens seeds, and on the seedlings obtained from seeds conditioned. The experimental design was completely randomized in a factorial scheme 2x6, referred to as: seed quality (above and below vigor) and five agents in priming (water, potassium nitrate at 0.2%, calcium nitrate at 0.2%, gibberellin GA 3 at 200 ppm and antioxidant riboflavin at 25 ppm), and the control; with four replications. To obtain of seeds with smaller vigor minus the deterioration was performed at 42 °C for 24 hours. The employee priming method was to hydration between roles, by 20 hours at 25 ° C period. Germination and seed vigor were evaluated, as well as the emergence and seedling quality. Seeds with above vigor have better expression of the physiological potential in relation to the below vigor. The priming presented higher emergence rate. Primed seeds produced seedlings with higher dry matter.Key words: Capsicum frutescens, priming, germination, emergency, expression of vigor. INTRODUÇÃOAs pimenteiras (Capsicum spp.) são cultivadas em todas as regiões do Brasil, porém foi mais recentemente que seu cultivo teve maior valorização, devido às demandas externas do mercado consumidor, levando a equiparar o seu consumo ao das demais hortaliças (Nascimento et al., 2006).A grande maioria das hortaliças é propagada por sementes e quanto maior o potencial fisiológico destas, maiores as chances de se obterem mudas de qualidade elevada. O máximo potencial fisiológico de sementes se dá no momento da maturação fisiológica, logo após se iniciam diversos processos morfoló...

ABSTRACT. Palisade grass is a forage plant that is widely used in pasture cropping in the Brazilian savannah. The aim of this experiment was to evaluate palisade grass (Brachiaria brizantha cv. MG-5) seeds subjected to priming and stress at high humidity and temperature (before and after conditioning). The experimental design was completely randomized in a 2x5 factorial arrangement. Seeds were exposed to stress under high humidity and temperature (before and after conditioning) and five priming treatments [Water (Control), potassium nitrate (KNO 3 ) at 0.2%, calcium nitrate Ca(NO 3 ) 2 at 0.2%, gibberellin (GA 3 ) at 0.2% and glucose at 10%] with four replications. Two experiments were performed: Experiment I -seed with chemical scarification using H 2 SO 4 and Experiment II -without scarification. The stress on the seed was applied using artificial aging at 41°C for 96 hours. Seed priming was accomplished by immersion at 25°C for 2 hours. Thereafter, the seeds were oven-dried at 35°C until they regained hygroscopic equilibrium. Seed germination and vigor were evaluated. Priming using KNO 3 and Ca(NO 3 ) 2 produced seeds with high tolerance to stress under high temperature, and this process is efficient to overcome dormancy.Keywords: palisade grass, seed deterioration, expression of vigor, nitrate.Condicionamento fisiológico e stress sob alta umidade e temperatura na qualidade fisiológica de sementes de Brachiaria brizantha cv. MG-5 RESUMO. Nas pastagens do cerrado brasileiro a braquiária é uma forrageira amplamente utilizada. O objetivo da presente pesquisa foi avaliar o desempenho de sementes de Brachiaria brizantha cv. MG-5 mediante condicionamento fisiológico e stress a alta umidade e temperatura (antes e após o condicionamento). O delineamento experimental utilizado foi o inteiramente casualizado em esquema fatorial 2x5, constituído por exposição das sementes ao stress a alta umidade e temperatura (anterior e posterior ao condicionamento) e cinco tratamentos com condicionamento fisiológico [água, nitrato de potássio (KNO 3 ) 0,2%, nitrato de cálcio Ca(NO 3 ) 2 0,2%, giberelina (GA 3 ) 0,2% e glicose 10%], com quatro repetições. Foram realizados dois experimentos (Experimento I -em sementes com presença de escarificação química com H 2 SO 4 e Experimento II -ausência de escarificação). O stress nas sementes foi proporcionado através do envelhecimento artificial (96h a 41ºC). O condicionamento foi realizado através da hidratação das sementes por imersão direta a 25ºC (2h). Posteriormente as sementes foram secas em estufas a 35ºC até retomada da umidade de equilíbrio higroscópico. Avaliaram-se a germinação e vigor das sementes. O condicionamento fisiológico com KNO 3 e Ca(NO 3 ) 2 propiciam sementes com maior tolerância ao stress a alta umidade e temperatura, sendo eficiente na superação de dormência.Palavras-chave: braquiária, deterioração de sementes, expressão de vigor, nitrato.

Different type of greenhouse and substrata on pepper productionPepper production has great commercial value for ornamental and food use. This makes it necessary to improve cultivation techniques, such as environmental control and low cost substrata. Therefore, this study aimed to evaluate the emergence parameters and growth of seedlings in tray, as well as plant growth and production in pots of pepper cvs. Tupã Bode Vermelha and Boyra Habanero Vermelha and ornamental pepper cultivars Etna and Pirâmide, in three different types of greenhouse and six types of substrata. Three greenhouses were evaluated: 1) a greenhouse with low-density transparent polyethylene film and reflective aluminized screen under the film; 2) sombrite ® mono black filament with 50% shade; and 3) aluminet ® , reflective aluminized screen. In these environments we tested six substrata a) ½ cattle manure (E) and ½ humus (H); b) ½E and ½ vermiculite (V); c) ½E and ½ cassava's leaves (R); d) ⅓E+⅓H+⅓V; e) ⅓E+⅓H+⅓R and f) ¼E+¼H +¼V+¼R. Since no replication of cultivation was carried out, each environment was considered as one experiment. The use of substrata ½E+½R; ⅓E+⅓H+⅓R and ⅓E+⅓H+⅓V allowed greater stem diameter, plant height and Dickson quality index in seedling stage of cultivars Etna, Pirâmide, Tupã and Boyra. The number of fruit was higher with the use of the substrata ½E+½R and ⅓E+⅓H+⅓V. The most suitable environment for pepper production is the greenhouse for all cultivars, followed by sombrite ® (especially for cultivars Tupã and Boyra) and aluminet ® (Pirâmide).

Priming is an alternative to improve the performance of seeds that have germination problems, such as Urochloa brizantha seeds. This study aimed at evaluating the appropriate hydration period and chemical agents used for priming, via direct immersion, in the physiological quality and carbohydrate content of U. brizantha seeds. The experimental design was completely randomized, in a 3 x 4 factorial arrangement, with four replicates of each treatment, consisting of lower, median and higher hydration periods, in the phase II of the absorption curve, and agents used for priming: water, gibberellin, sucrose and antioxidant (riboflavin). Germination and vigor tests were carried out, as well as carbohydrate contents determination, in the seeds. It was observed that seeds hydrated in the lower period show higher physiological potential. Priming with gibberellin provides a greater seedling emergence, and with sucrose higher carbohydrate contents.

Paricá seeds have dormancy and, even after mechanical scarification, these seeds show slow and uneven germination. Pre-germination treatments can be used to increase seed germination performance. Thus, the aimed to evaluate the physiological potential and initial growth of paricá seeds after pre-germination treatments, using different substances as plant regulators and nutrients, in addition to mechanical scarification. The experimental design was completely randomized, in a 2x7 factorial scheme, consisting of the following pre-germination treatments: mechanical scarification (10% and 50% of the seed coat) and seed pre-soaking [control-water, KNO3 ­0.2%, Ca(NO3)2 0.2%, gibberellin 0.02%, cytokinin 0.02%, and mixture of gibberellin + cytokinin (1:1)] besides a control group without pre-soaking, with four replicates. The study evaluated germination and emergence rates, germination and emergence speed indices, collar diameter, plant height, seedling dry mass, hypocotyl and seedling length, and electrical conductivity. It was observed that pre-soaking the seeds in gibberellin after mechanical scarification at 50% as a pre-germination treatment resulted in seeds with higher vigor expression and greater initial seedling growth.

Seeds of high physiological quality are defined by their superior germination capacity and uniform seedling establishment. Here, it was investigated whether multispectral images combined with machine learning models can efficiently categorize the quality of peanut seedlots. The seed quality from seven lots was assessed traditionally (seed weight, water content, germination, and vigor) and by multispectral images (area, length, width, brightness, chlorophyll fluorescence, anthocyanin, and reflectance: 365 to 970 nm). Seedlings from the seeds of each lot were evaluated for their photosynthetic capacity (fluorescence and chlorophyll index, F0, Fm, and Fv/Fm) and stress indices (anthocyanin and NDVI). Artificial intelligence features (QDA method) applied to the data extracted from the seed images categorized lots with high and low quality. Higher levels of anthocyanin were found in the leaves of seedlings from low quality seeds. Therefore, this information is promising since the initial behavior of the seedlings reflected the quality of the seeds. The existence of new markers that effectively screen peanut seed quality was confirmed. The combination of physical properties (area, length, width, and coat brightness), pigments (chlorophyll fluorescence and anthocyanin), and light reflectance (660, 690, and 780 nm), is highly efficient to identify peanut seedlots with superior quality (98% accuracy).

Seed priming is a practice for improving the expression of seed physiological potential. Such technique consists of synchronizing and reducing the time of seed germination by controlled hydration. The aim of this study was to evaluate the effect of seed-priming with different sugar sources and concentrations on the physiological quality Urochloa brizantha seeds and initial seedling performance. Before treating, seeds were scarified chemically with concentrated sulphuric acid (H2SO4) for 5 minutes to overcome physical dormancy. The experimental design was completely randomized in a 3 x 6 factorial scheme consisting of priming using three sugar sources (glucose, sucrose, and maltose) and six concentrations (zero [water control], 2%, 5%, 10%, 15%, and 20%), with four replicates. The seeds were primed by direct immersion for 2 hours at 25 ºC and, after hydration, they were dried for moisture equilibrium recovery. Seed germination, vigor, viability, and initial seedling growth were evaluated. The results showed that glucose was the source able to promote beneficial effects on the germination of U. brizantha cv. MG-5 seeds. Moreover, the supply of glucose at the concentrations of 2 and 5% for physiological conditioning increased seedling dry phytomass.

The use of computational tools has become notable in seed quality control to assist in confirming seed lots of higher potential. Thus, the aim of this study was to use a computational approach to investigate analysis of morphological parameters that characterize primary root emergence in evaluation of tomato seed vigor. For that purpose, five seed lots were analyzed for germination and vigor (seedling emergence and analysis of seedling images). A parallel analysis of primary root emergence was made using computer-assisted imaging; the images recorded as germination proceeded were processed with the ImageJ® software to obtain aspect ratio and seed area parameters. Vigor differences among tomato seed lots can be identified based on primary root emergence, and computer image processing based on aspect ratio proves to be an efficient procedure to characterize emergence of the primary root in evaluation of tomato seed vigor.