Management of defoliation in Trifolium vesiculosum S. for the production of seeds / [Manejo da desfolha em Trifolium vesiculosum Savi para a produção de sementes]

The present study aims to determine the appropriate defoliation management for the production of seeds and forage in arrowleaf clover via trail analysis. The results obtained demonstrated that defoliation practices have a great influence on the composition of seed yield and germination power. In addition, when the goal is the maximum balance between dry matter production and seed yield, this can be achieved in up to two defoliation practices. These results are confirmed by analyzing the positive association between the weight of a thousand seeds and the seed yield. When the third defoliation practice is performed, it negatively correlates with the weight of a thousand seeds, suggesting that, with the increase in defoliation frequency, there is a lower weight of a thousand seeds, and, therefore, lower seed yield. Therefore, management planning in Trifolium vesiculosum Savi that aims at natural reseeding, maximum yield and seed germination must prioritize one to two defoliation practices, aiming to promote favorable conditions for the perennialization of the species. In this context, the trail analysis proved to be a useful tool as a criterion for obtaining the ideal management aiming at the production of seeds and forage in vesicular clover.(AU)

O presente estudo visa determinar o manejo de desfolha adequado para a produção de sementes e de forragem em trevo-vesiculoso via análise de trilha. Os resultados obtidos demonstraram que as práticas de desfolha possuem grande influência na composição do rendimento de sementes e no poder germinativo. Além disso, quando o objetivo for o máximo equilíbrio entre a produção de matéria seca e o rendimento de sementes, esse pode ser alcançado em até duas práticas de desfolha. Esses resultados são confirmados ao se analisar a associação positiva entre o peso de mil sementes e o rendimento de sementes. Quando realizada a terceira prática de desfolha, esta se correlaciona negativamente com o peso de mil sementes, sugerindo que, com o aumento da frequência de desfolha, ocorre menor peso de mil sementes e, por conseguinte, menor rendimento de sementes. Portanto, o planejamento do manejo em T. vesiculosum Savi que objetive a ressemeadura natural, o máximo rendimento e a germinação de sementes deve priorizar até duas práticas de desfolha, visando promover condições favoráveis para a perenização da espécie. Nesse contexto, a análise de trilha demonstrou ser uma ferramenta útil como critério para obtenção do manejo ideal visando à produção de sementes e de forragem em trevo-vesiculoso.(AU)

Vigor of red clover seeds under salinity stress / Vigor de sementes de trevo vermelho submetidas a estresse salino

The accelerated aging test is a considerably important method for measuring the physiological potential of seeds. This study sought to apply the accelerated aging test to determine the vigor of red clover seeds of the Quiniquelli and Estanzuela 116 cultivars under water and salinity stress conditions. Accordingly, the seeds were aged for 12, 24, 36, 48, and 72 hours at 42 °C in water and a saturated salt solution (40% NaCl) and then assessed by the accelerated aging test. The lengths of 15 normal seedlings from each of the four replicates for both cultivars were measured, and the seedlings dry mass (48 h/60 °C) was determined. After aging 12, 24, and 36 hours in a saturated salt solution, vigor was above the average of 84.5% for both cultivars. In the test conducted with water, 36 hours were enough to stress the seeds. The accelerated aging time that best represented the vigor of the seeds of the Quiniquelli and Estanzuela 116 cultivars was 48 hours at 42 °C in the saturated NaCl solution, thus being the most suitable for red clover seeds.

O teste de envelhecimento acelerado é de grande importância para expressar o potencial fisiológico das sementes. O objetivo do trabalho foi determinar o vigor de sementes de trevo vermelho das cultivares Quiniquelli e Estanzuela 116 pelo teste do envelhecimento acelerado sob estresse hídrico e salino.  Para tal, as sementes foram expostas a solução hídrica e salina com NaCl (40%) nos tempos de 12, 24, 36, 48 e 72 h a 42 °C e, em seguida, avaliadas pelo teste de envelhecimento acelerado. Foram medidos os comprimentos de 15 plântulas normais de cada uma das quatro repetições de ambas as cultivares e determinada a massa seca das plântulas (48 h /60 °C). Após 12, 24 e 36 h de envelhecimento em solução salina o vigor foi superior à média de 84,5% para ambas cultivares. No teste conduzido com água, o tempo de 36 h foi suficiente para estressar as sementes. O tempo de envelhecimento acelerado que melhor caracterizou o vigor de sementes das cultivares Quiniquelli e Estanzuela 116 foi o de 48 h sob temperatura de 42 °C com o uso de solução saturada de NaCl, sendo o mais indicado para as sementes de trevo vermelho.

Vigor of red clover seeds under salinity stress / Vigor de sementes de trevo vermelho submetidas a estresse salino

The accelerated aging test is a considerably important method for measuring the physiological potential of seeds. This study sought to apply the accelerated aging test to determine the vigor of red clover seeds of the Quiniquelli and Estanzuela 116 cultivars under water and salinity stress conditions. Accordingly, the seeds were aged for 12, 24, 36, 48, and 72 hours at 42 °C in water and a saturated salt solution (40% NaCl) and then assessed by the accelerated aging test. The lengths of 15 normal seedlings from each of the four replicates for both cultivars were measured, and the seedlings dry mass (48 h/60 °C) was determined. After aging 12, 24, and 36 hours in a saturated salt solution, vigor was above the average of 84.5% for both cultivars. In the test conducted with water, 36 hours were enough to stress the seeds. The accelerated aging time that best represented the vigor of the seeds of the Quiniquelli and Estanzuela 116 cultivars was 48 hours at 42 °C in the saturated NaCl solution, thus being the most suitable for red clover seeds.(AU)

O teste de envelhecimento acelerado é de grande importância para expressar o potencial fisiológico das sementes. O objetivo do trabalho foi determinar o vigor de sementes de trevo vermelho das cultivares Quiniquelli e Estanzuela 116 pelo teste do envelhecimento acelerado sob estresse hídrico e salino.  Para tal, as sementes foram expostas a solução hídrica e salina com NaCl (40%) nos tempos de 12, 24, 36, 48 e 72 h a 42 °C e, em seguida, avaliadas pelo teste de envelhecimento acelerado. Foram medidos os comprimentos de 15 plântulas normais de cada uma das quatro repetições de ambas as cultivares e determinada a massa seca das plântulas (48 h /60 °C). Após 12, 24 e 36 h de envelhecimento em solução salina o vigor foi superior à média de 84,5% para ambas cultivares. No teste conduzido com água, o tempo de 36 h foi suficiente para estressar as sementes. O tempo de envelhecimento acelerado que melhor caracterizou o vigor de sementes das cultivares Quiniquelli e Estanzuela 116 foi o de 48 h sob temperatura de 42 °C com o uso de solução saturada de NaCl, sendo o mais indicado para as sementes de trevo vermelho.(AU)

Expression of seed vigor and initial growth of red clover under fungicide influence / Expressão do vigor de sementes e crescimento inicial de trevo vermelho sob influência de fungicida

The objective of this study was to evaluate the expression of seeds vigor and physiological performance of initial growth of red clover plants under the influence of fungicide doses of carboxin + thiram. Three lots of seeds were used (high; medium and low vigor) treated with 0; 150; 250 fungicide doses and 350 mL i.a./100 kg of seeds. Germination, first count, emergence, speed index of seedling emergence, length and dry matter of shoot and root, leaf area and shoot/root ratio were evaluated. The experimental design was completely randomized in a factorial 3 x 4 (three lots - high, medium and low vigor x four fungicide doses of carboxin + thiram). Data were submitted to analysis of variance and if significant at 5% probability, adjusted for orthogonal polynomials. It was possible to observe that there were significant differences for the means of the variables germination, first germination count, emergency, emergency speed index, shoot length, root length, aerial part dry mass, root dry mass, leaf area, leaf area ratio and shoot and root ratio. The fungicide doses of 150 to 350 mL i.a./100 kg of seeds result in greater seedling emergence, higher leaf area ratio and increased shoot/root ratio in plants from lots of medium vigor seeds.The fungicide consisted of carboxin + thiram enhances the expression of seed vigor and physiological performance of seedlings growth derived from lots of medium vigor seeds.

O objetivo deste trabalho foi avaliar a expressão do vigor de sementes e o desempenho fisiológico de crescimento inicial de plantas de trevo vermelho submetidas à influência de doses de fungicida à base de carboxin + thiram. Foram utilizados três lotes de sementes (alto; médio e baixo vigor) tratadas com as doses de fungicida 0; 150; 250 e 350 mL i.a./100 kg de sementes. Foram avaliados a germinação, primeira contagem, emergência, índice de velocidade de emergência de plântulas, comprimento e matéria seca de parte aérea e de raiz, área foliar, razão de parte aérea e raiz. O delineamento experimental utilizado foi inteiramente casualizado, em esquema fatorial 3 x 4 (três lotes - alto, médio e baixo vigor x quatro doses fungicidas de carboxin + tiram). Os dados foram submetidos à análise de variância e se significativos a 5% de probabilidade, foram ajustados para polinômios ortogonais. De acordo com os resultados foi possível observar que houve diferença significativa para as médias das variáveis germinação, primeira contagem de germinação, emergência, índice de velocidade de emergência, comprimento de parte aérea, comprimento de raiz, massa seca de parte aérea, massa seca de raiz, área foliar, razão de área foliar e razão de parte aérea e raiz. As doses de fungicida 150 a 350 mL i.a./100 kg de sementes resultam na maior emergência de plântulas, superior razão de área foliar e incremento na razão parte aérea e raiz em plântulas originadas de sementes de lotes com médio vigor. O fungicida a base de carboxin + thiram realça a expressão do vigor de sementes e o desempenho fisiológico de crescimento de plântulas originadas de lotes de sementes de médio vigor.

Expression of seed vigor and initial growth of red clover under fungicide influence / Expressão do vigor de sementes e crescimento inicial de trevo vermelho sob influência de fungicida

The objective of this study was to evaluate the expression of seeds vigor and physiological performance of initial growth of red clover plants under the influence of fungicide doses of carboxin + thiram. Three lots of seeds were used (high; medium and low vigor) treated with 0; 150; 250 fungicide doses and 350 mL i.a./100 kg of seeds. Germination, first count, emergence, speed index of seedling emergence, length and dry matter of shoot and root, leaf area and shoot/root ratio were evaluated. The experimental design was completely randomized in a factorial 3 x 4 (three lots - high, medium and low vigor x four fungicide doses of carboxin + thiram). Data were submitted to analysis of variance and if significant at 5% probability, adjusted for orthogonal polynomials. It was possible to observe that there were significant differences for the means of the variables germination, first germination count, emergency, emergency speed index, shoot length, root length, aerial part dry mass, root dry mass, leaf area, leaf area ratio and shoot and root ratio. The fungicide doses of 150 to 350 mL i.a./100 kg of seeds result in greater seedling emergence, higher leaf area ratio and increased shoot/root ratio in plants from lots of medium vigor seeds.The fungicide consisted of carboxin + thiram enhances the expression of seed vigor and physiological performance of seedlings growth derived from lots of medium vigor seeds.(AU)

O objetivo deste trabalho foi avaliar a expressão do vigor de sementes e o desempenho fisiológico de crescimento inicial de plantas de trevo vermelho submetidas à influência de doses de fungicida à base de carboxin + thiram. Foram utilizados três lotes de sementes (alto; médio e baixo vigor) tratadas com as doses de fungicida 0; 150; 250 e 350 mL i.a./100 kg de sementes. Foram avaliados a germinação, primeira contagem, emergência, índice de velocidade de emergência de plântulas, comprimento e matéria seca de parte aérea e de raiz, área foliar, razão de parte aérea e raiz. O delineamento experimental utilizado foi inteiramente casualizado, em esquema fatorial 3 x 4 (três lotes - alto, médio e baixo vigor x quatro doses fungicidas de carboxin + tiram). Os dados foram submetidos à análise de variância e se significativos a 5% de probabilidade, foram ajustados para polinômios ortogonais. De acordo com os resultados foi possível observar que houve diferença significativa para as médias das variáveis germinação, primeira contagem de germinação, emergência, índice de velocidade de emergência, comprimento de parte aérea, comprimento de raiz, massa seca de parte aérea, massa seca de raiz, área foliar, razão de área foliar e razão de parte aérea e raiz. As doses de fungicida 150 a 350 mL i.a./100 kg de sementes resultam na maior emergência de plântulas, superior razão de área foliar e incremento na razão parte aérea e raiz em plântulas originadas de sementes de lotes com médio vigor. O fungicida a base de carboxin + thiram realça a expressão do vigor de sementes e o desempenho fisiológico de crescimento de plântulas originadas de lotes de sementes de médio vigor.(AU)

Isoflavone production in hairy root cultures and plantlets of Trifolium pratense.

OBJECTIVES: The aim of this study was to develop a Trifolium pratense hairy root (HR) production protocol and select HR lines with high isoflavone yield following elicitor treatments. RESULTS: We obtained 13 independent HR lines, producing approximately three times more isoflavonoids than seedlings (3.3 mg/g dry weight) and in which 27 isoflavonoids were detected. Each HR line had its own isoflavonoid profile. These lines produced as major components daidzein, genistein, formononetin and biochanin A. Sucrose, salicylic acid (SA), yeast extract (YE) and flagellin 22 (flg22) were tested as elicitors. Using SA 140 mg/L, allowed the maximum isoflavonoid production in plantlets (11.9 mg/g dry weight) but reduced root growth, possibly as a result of its toxicity. The highest isoflavone production in HR (27.9 mg/g dry weight) was obtained using sucrose 60 g/L, for 3.5 days. CONCLUSION: This work reports the high production of various isoflavonoids with T. pratense elicited HR cultures.

Development and reprotuction of Spodoptera eridania on natural hosts and artificial diet / Desenvolvimento e reprodução de Spodoptera eridania em hospedeiros naturais e dieta artificial

Abstract The development and reproductive potential of Spodoptera eridania (Stoll, 1782) (Lepidoptera, Noctuidae) was compared on natural and artificial diets. Its biology was determined under laboratory conditions, providing an artificial diet, leaves of white clover and the peach cultivar 'Chimarrita' and fruits and leaves of the apple cultivar 'Gala'. Larvae of S. eridania could not complete their biological cycle when fed on apple fruits or peach leaves. The artificial diet provided the shortest development time, with a cycle of 28.5±0.14 days from egg to adult and 37.3% total viability. Apple leaves led to a longer development time from egg to adult (62.8±1.22 days) and lower total viability (23%) and white clover provided the highest total viability (54.3%). The results showed that S. eridania can use white clover and apple leaves to develop normally in apple orchards. The reduction of food sources such as white clover used by the larvae results in infestation and damage to fruits from "test bites".

Resumo O desenvolvimento e o potencial reprodutivo de Spodoptera eridania (Stoll, 1782) (Lepidoptera, Noctuidae) foi comparado em dietas naturais e artificial. A biologia de S. eridania foi determinada em condições de laboratório, comparando-se uma dieta artificial com folhas de trevo branco e de pêssego da cultivar 'Chimarrita' e frutos e folhas de maçã da cultivar 'Gala'. As larvas de S. eridania não puderam completar seu ciclo biológico quando alimentadas com frutas de maçã ou folhas de pêssego. A dieta artificial proporcionou o menor tempo de desenvolvimento, com um ciclo completo de 28,5 ± 0,14 dias de ovo a adulto e 37,3% de viabilidade total. As folhas de maçã levaram maior tempo de desenvolvimento de ovo a adulto (62,8 ± 1,22 dias) e menor viabilidade total (23%). O trevo branco apresentou a maior viabilidade total (54,3%). Os resultados mostraram que S. eridania pode usar trevo branco e folhas de maçã para se desenvolver normalmente em pomares de maçã. A redução de fontes alimentares, como o trevo branco usado pelas larvas, resulta em infestação e danos aos frutos através das "mordidas de prova".

Development and reprotuction of Spodoptera eridania on natural hosts and artificial diet.

The development and reproductive potential of Spodoptera eridania (Stoll, 1782) (Lepidoptera, Noctuidae) was compared on natural and artificial diets. Its biology was determined under laboratory conditions, providing an artificial diet, leaves of white clover and the peach cultivar 'Chimarrita' and fruits and leaves of the apple cultivar 'Gala'. Larvae of S. eridania could not complete their biological cycle when fed on apple fruits or peach leaves. The artificial diet provided the shortest development time, with a cycle of 28.5±0.14 days from egg to adult and 37.3% total viability. Apple leaves led to a longer development time from egg to adult (62.8±1.22 days) and lower total viability (23%) and white clover provided the highest total viability (54.3%). The results showed that S. eridania can use white clover and apple leaves to develop normally in apple orchards. The reduction of food sources such as white clover used by the larvae results in infestation and damage to fruits from "test bites".

Derivatives of diterpen labdane-8α,15-diol as photosynthetic inhibitors in spinach chloroplasts and growth plant inhibitors.

In a search of new efficient herbicides of natural origin, four derivatives were prepared from labdane-8α,15-diol (1) and 15-O-acetyl-8α-hydroxy labdane (2) isolated from Croton ciliatoglanduliferus. Their inhibitory activity on photosynthetic electron transport on fresh, broken spinach chloroplasts and on the growth of plants were determined. Derivative 15-O-benzoyl-8α-hydroxy labdane (5) was seven times more active than 2 as reaction Hill inhibitor. Complex of 5 with the adjuvant 2-hydroxypropyl-ß-cyclodextrin (5:HPB) (200 µM) was sprayed on Physalys ixocarpa (green tomato) plants; 48 h later the complex inhibited PS II by transforming the active reaction centers to silent reaction centers or "heat sinks". After 72 h this effect disappeared, probably 5:HPB was metabolized by the plant. Chlorophyll a fluorescence of Trifolium alexandrinum (clover) leaves was affected with 5:HPB at the level of PQ pool reduction. 5:HPB decreases the tomato and clover dry-biomass, without affecting Lolium perenne (grass) plants, suggesting that complex 5 acts as selective herbicide for dicotyledonous plants.

Tricolorin A as a natural herbicide.

Tricolorin A acts as pre- and post-emergence plant growth inhibitor. In pre-emergence it displays broad-spectrum weed control, inhibiting germination of both monocotyledonous (Lolium mutliflorum and Triticum vulgare) and dicotyledonous (Physalis ixocarpa and Trifolium alexandrinum) seeds, being the dicotyledonous seeds the most inhibited. Tricolorin A also inhibited seedling growth, and seed respiration, and since the concentrations required for inhibiting both germination and respiration were similar, we suggest that respiration is one of its targets. Tricolorin A at 60 µM acts as a post- emergence plant growth inhibitor by reducing dry plant biomass by 62%, 37%, 33%, and 22% for L. multiflorum, T. alexandrinum, T. vulgare, and P. ixocarpa, respectively, 18 days after its application. In order to determine the potency of tricolorin A as a plant growth inhibitor, paraquat was used as control; the results indicate that tricolorin A acts as a non-selective post-emergence plant growth inhibitor similar to paraquat, since both reduced the biomass production in P. ixocarpa and T. alexandrinum. Therefore, we suggest that tricolorin A will be a good biodegradable herbicide for weeds.

Agricultural reuse of the digestate from low-cost tubular digesters in rural Andean communities.

This research aimed at assessing the properties of guinea pig manure digestate from low-cost tubular digesters for crops fertilization in rural Andean communities. To this end, field trials were carried out to evaluate the effect of the digestate on two common Andean crops: potato (Solanum tuberosum) and forage (Lolium multiflorum and Trifolium pratense L.). The potato yield (20-25 tha(-1)) increased by 27.5% with digestate, by 15.1% with pre-compost and by 10.3% with the mixture, compared to the control. The forage yield (20-21 tha(-1)) increased by 1.4% with digestate - 50% dose, and by 8.8% with digestate - 100% dose and digestate - 150% dose, compared to the control. The results suggest that the digestate is an appropriate substitute of manure pre-compost for potato fertilization. The results with forage indicate that it can be applied in a range of doses, according to the amount produced by the digester. Currently, manure is either used for cooking or as fertilizer. With low-cost tubular digesters implementation, it could be used to feed the digester, using the digestate for crops fertilization and biogas for cooking; improving household living conditions and protecting the environment. Since soil properties in rural Andean communities differ from experimental layouts, the effect of fertilizers should be re-evaluated in-situ in future research studies.

Effect of inoculation with Penicillium albidum, a phosphate-solubilizing fungus, on the growth of Trifolium pratense cropped in a volcanic soil.

Volcanic soils in the south of Chile have an elevated quantity of total P, which is scarcely available due to its high P fixation capacity. One strategy for increasing the availability of P for the vegetables that grow there would be to use phosphate-solubilizing microorganisms. In one assay conducted in a greenhouse on a volcanic soil, the effect of inoculation with Penicillium albidum, a phosphate-solubilizing fungus, was studied on the growth of red clover (Trifolium pratense L). Some chemical and biological properties of the soil were also evaluated. There were three treatments: a) active inoculum [In(+)], b) inactive inoculum (autoclaved) [In(-)] and c) without inoculum [In(0)], each one done in three replicates. The In(+) significantly (P < 0.050) increased the growth of the plants, contributing particularly to root development. The P mobilized to the shoot with In(+) was higher than twofold related to In(0) and In(-) treatments; however, the In(+) plants had similar concentration of shoot P. In the soil, available-P was not statistically different (P < 0.050) among the treatments but phosphatase activity in In(+) was higher (P < 0.050) in comparison to In(0). The results suggest that Penicillium albidum contributed to growth and nutrition of the red clover through the induction of root development and enhancing phosphate mobilization from the soil and into the plant. It is concluded that Penicillium albidum, under greenhouse conditions, in soils deficient in available P can increase the inoculation potential for volcanic soils in Chile. Anyway further studies are required, especially in organic farming where the use of soluble P fertilizer is avoided.

Flavonoids from shoots and roots of Trifolium repens (white clover) grown in presence or absence of the arbuscular mycorrhizal fungus Glomus intraradices.

White clover (Trifolium repens) plants were grown in the presence or absence of the arbuscular mycorrhizal fungus Glomus intraradices. Flavones, 4',5,6,7,8-pentahydroxy-3-methoxyflavone and 5,6,7,8-tetrahydroxy-3-methoxyflavone, as well as two flavones 3,7-dihydroxy-4'-methoxyflavone and 5,6,7,8-tetrahydroxy-4'-methoxyflavone never previously reported in plants, were isolated. The known 3,5,6,7,8-pentahydroxy-4'-methoxyflavone, 2',3',4',5',6'-pentahydroxy-chalcone, 6-hydroxykaempferol, 4',5,6,7,8-pentahydroxyflavone and 3,4'-dimethoxykaempferol were also obtained. Analysis of extracts obtained from roots and shoots revealed that the compositions of the flavonoid mixtures varied with growing conditions. Quercetin, acacetin and rhamnetin accumulated in roots of inoculated plants, whereas they were not detected in non-inoculated plants.

Herbicidal, plant growth inhibitory, and cytotoxic activities of bismuthines containing aromatic heterocycles.

This work presents the herbicidal and plant growth regulatory activities of tertiary bismuthines containing heterocyclic aromatic rings of the general formula (2-C(4)H(3)X)(3)Bi, where X = S (3), O (1), or NMe (2). Toxicity against Artemia salina and herbicidal activity on Lactuca sativa, Trifolium pratense, and Lolium multiflorum were tested. In addition to the effects on mitochondrial respiration obtained from roots of Phaseolus vulgaris, these compounds also demonstrated partial radical scavenging properties against 2,2-diphenyl-1-picrylhydrazyl (DPPH). The furyl substituent is the most important structural requirement for the activity measurements observed in this study.