scholarly journals Osmotic treatment, growth regulator and rooter in Tabebuia roseoalba (RIDL.) Sandwith seeds for direct sowing

2020 ◽  
Vol 42 ◽  
Author(s):  
Alexandre Carneiro da Silva ◽  
Maiara Pilar Palmeira da Silva ◽  
Rayssa Zamith ◽  
Gustavo Galetti ◽  
Fatima Conceição Márquez Piña-Rodrigues

Abstract: Direct seeding is a technology that reduces the costs of forest restoration projects and favors species which are difficult to establish for seedlings. The seeds osmotic treatment to accelerate and standardize germination and induce tolerance to environmental stresses may favor seedling establishment in field through direct sowing and contribute to the greater efficiency of this technique. With the purpose of favor seed germination and seedling establishment under direct seeding conditions in the field, Tabebuia roseoalba osmoprimed seeds in polyethylene glycol (PEG) solution and unconditioned seeds were treated with isolated and/or combined solutions of plant growth regulators (PGR) and rooting (RTG). These seeds were submitted to germination test and evaluated for percentage germination rate, germination speed index and normal seedlings, and to seedling emergence test by direct field seeding. RTG had a toxic effect on T. roseoalba seeds. Osmoconditioning induced stress tolerance by RTG during germination and on seedling establishment. PGR treatment favors seedling emergence in field conditions and alleviates the toxicity effect caused by RTG. These treatments have great potential for use in direct sowing of T. roseoalba seeds.

Nativa ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 438-441
Author(s):  
Rubens Marques Rondon Neto ◽  
Fabrício Pereira de Jesus ◽  
Lucas Alves da Silva

Este estudo teve o objetivo de avaliar a estratégia de uso de sementes pré-germinadas de pata-de-vaca (Bauhinia ungulata L.) na semeadura direta para restauração florestal. Os tratamentos testados foram: T1= Plantio de mudas em tubetes (Testemunha); T2 = Semeadura direta sem pré-germinação; T3 = Semeadura direta com pré-germinação; T4 = Semeadura direta sem pré-germinação e hidrogel; e T5 = Semeadura direta com pré-germinação e hidrogel. O experimento foi instalado em blocos ao acaso com quatro repetições de 10 mudas ou pontos de sementes semeadas. Aos 100 e 210 dias de instalação do experimento foram feitas as seguintes avaliações: taxa de sobrevivência (Ts); altura total (Ht); diâmetro do colo (Dc); e número de folhas (Nf). A Ts e o crescimento morfológico de B. ungulata regeneradas pelo plantio de mudas não foram superadas pelas estratégias de semeaduras diretas utilizadas, mas a técnica demostrou ser promissora para futuros testes com outras espécies arbustivas e arbóreas de interesse à restauração florestal. Palavras-chave: área degradada; regeneração florestal; regeneração artificial.   Direct seeding of pata-de-vaca (Bauhinia ungulata L.) with pre-germinated seeds for forest restoration   ABSTRACT: This study aimed to evaluate the seed use strategy of using pre-germinated seeds of Bauhinia ungulata L. in direct sowing for forest restoration. The treatments tested were: T1 = Planting seedlings in tubes (Witness); T2 = Direct sowing without pre-germination; T3 = Direct sowing with pre-germination; T4 = Direct sowing without pre-germination and hydrogel; and T5 = Direct sowing with pre-germination and hydrogel. The experiment was installed in randomized blocks with four replications of 10 seedlings or points of seed sown. At 100 and 210 days after installation of the experiment, the following assessments were made: survival rate (Ts); total height (Ht); diameter (Dc); and number of leaves (Nf). The Ts and the morphological growth of B. ungulata regenerated by planting seedlings were not overcome by the direct seeding strategies used, but the technique proved to be promising for future tests with other shrub and tree species of interest to forest restoration. Keywords: degraded area; forest regeneration; artificial regeneration.


Author(s):  
Ying Ki Law ◽  
Calvin Lee ◽  
Chun Chiu Pang ◽  
Billy Hau ◽  
Jin Wu

Landslides are common in tropical and subtropical regions with hilly terrains and heavy rainstorms, which cause significant economic, ecological, and social impacts. Natural forest succession is usually slow on landslide scars due to poor soil structure and the lack of seeds of woody plant seeds, and often comes with a higher risk of repeated landslide. Ecological forest restoration has recently been suggested as an effective alternative to restore the exposed landslide scars, however, a comprehensive study to identify effective landslide restoration strategies remains lacking, particularly associated with seed treatment methods and species selection. Here we evaluated the effectiveness of different seed coating treatments of both pioneer and later successional tree species of different seed sizes on seed germination in a one-year study on three landslides in Hong Kong. Our results show that bare seeds had germination rates of 17 to 67% across all selected species (n=7). Biochar-dominant seed coating formulation boosted an additional 9.33 (SE= 0.04) in seed germination rate, while the clay-dominant seed coating formulation did not show significant effect on germination. Our results also show that medium and large-seeded non-pioneer species have significantly higher germination rates than pioneer species. These results collectively suggest that direct seeding using a biochar seed coat is a manageable and useful method to enhance tree seed germination—an essential first step to restore the forests after landslide disturbances in Hong Kong, with potential to be extended to other humid tropical and subtropical forests.


1994 ◽  
Vol 70 (2) ◽  
pp. 151-158 ◽  
Author(s):  
R. L. Fleming ◽  
D. S. Mossa

A series of spot seeding experiments was set out on coarse-textured upland sites in northwestern Ontario to investigate how black spruce (Picea mariana [Mill.] B.S.P.) seedling establishment and growth could be improved by site selection and seedbed preparation. Virtually all germination occurred within the first growing season. Annual seedling mortality rates were greatest during the first year, then declined steadily and stabilized at low levels (<10%) after the third year. The highest fifth-year establishment ratios (seedlings/viable seed sown) were found on seedbeds derived from materials near the mineral soil/humus interface. On wetter sites (i.e., higher Soil Moisture Regimes) the best seedbeds occurred closer to the soil surface. Mean fifth year establishment ratios for the best seedbeds were 0.032 on moderately fresh to fresh sites, 0.146 on very fresh to moderately moist sites, and 0.082 on moist to very moist sites. On adjacent lowland sites, slow-growing, compact Sphagnum mosses had a mean establishment ratio of 0.179. Mean fifth-year seedling heights on upland sites ranged from 12 to 14 cm, and were not strongly correlated with site or seedbed type. Key words: direct seeding, black spruce, seedbed, seedling establishment, site type and germination


2013 ◽  
Vol 31 (4) ◽  
pp. 823-832 ◽  
Author(s):  
A. Derakhshan ◽  
J. Gherekhloo

Specific knowledge about the dormancy, germination, and emergence patterns of weed species aids the development of integrated management strategies. Laboratory studies were conducted to determine the effect of several environmental factors on seed germination and seedling emergence of Cyperus difformis. Germination of freshly harvested seeds was inhibited by darkness; however, when seeds were subsequently transferred to complete light they germinated readily. Our results showed that 2 wk of cold stratification overcome the light requirement for germination. Seeds of C. difformis were able to germinate over a broad range of temperatures (25/15, 30/20, 35/25, and 40/30 ºC day/night). The response of germination rate to temperature was described as a non-linear function. Based on model outputs, the base, the optimum and the ceiling temperatures were estimated as 14.81, 37.72 and 45 ºC, respectively. A temperature of 120 ºC for a 5 min was required to inhibit 50% of maximum germination. The osmotic potential and salinity required for 50% inhibition of maximum germination were -0.47 MPa and 135.57 mM, respectively. High percentage of seed germination (89%) was observed at pH=6 and decreased to 12% at alkaline medium (pH 9) pH. Seeds sown on the soil surface gave the greatest percentage of seedling emergence, and no seedlings emerged from seeds buried in soil at depths of 1 cm.


2017 ◽  
Vol 39 (4) ◽  
pp. 374-384
Author(s):  
Cesar Pedro Hartmann Filho ◽  
André Luís Duarte Goneli ◽  
Tathiana Elisa Masetto ◽  
Elton Aparecido Siqueira Martins ◽  
Guilherme Cardoso Oba

Abstract: This study evaluated the physiological potential of soybean seeds harvested during two seasons, on different maturation stages and subjected to different drying temperatures. The seeds were harvested at the maturations stages R7, R7 + 2, R7 + 3, R7 + 5, R7 + 6, R7 + 7, R7 + 10 and R7 + 12 days (55, 50, 45, 40, 35, 30, 25, and 20% of moisture content). For each maturation stage, seeds were divided into three samples: one sample was used to directly evaluate the physiological potential, and the others were dried at 40 °C and 50 °C, until reaching the moisture content of 11.5%. The physiological potential was evaluated through germination test, first germination count of germination, accelerated aging, modified cold, electrical conductivity and seedling emergence. The maximum physiological potential of seeds is achieved at the moisture content of 55%, the point that the dry matter is maximum. The seeds became tolerant to artificial drying approximately at the stage R7 + 7 days (30% of moisture content). Germination and vigor of the soybean seeds reduce as the drying temperature is increased from 40 °C to 50 °C, and this effect is enhanced when the seeds show moisture contents above 30%.


Weed Science ◽  
2017 ◽  
Vol 66 (1) ◽  
pp. 47-56 ◽  
Author(s):  
Ning Zhao ◽  
Qi Li ◽  
Wenlei Guo ◽  
Lele Zhang ◽  
Lu’an Ge ◽  
...  

Shortawn foxtail is an invasive grass weed infesting winter wheat and canola production in China. A better understanding of the germination ecology of shortawn foxtail would help to develop better control strategies for this weed. Experiments were conducted under laboratory conditions to evaluate the effects of various abiotic factors, including temperature, light, pH, osmotic stress, salt concentration, and planting depth, on seed germination and seedling emergence of shortawn foxtail. The results showed that the seed germination rate was greater than 90% over a wide range of constant (5 to 25C) and alternating (15/5 to 35/25C) temperatures. Maximum germination occurred at 20C or 25/15C, and no germination occurred at 35C. Light did not appear to have any effect on seed germination. Shortawn foxtail germination was 27% to 99% over a pH range of 4 to 10, and higher germination was obtained at alkaline pH values ranging from 7 to 10. Seed germination was sensitive to osmotic potential and completely inhibited at an osmotic potential of −0.6 MPa, but it was tolerant to salinity: germination even occurred at 200 mM NaCl (5%). Seedling emergence was highest (98%) when seeds were placed on the soil surface but declined with the increasing burial depth. No seedlings emerged when seeds were buried 6-cm deep. Deep tillage could be an effective measure to limit seed germination from increased burial depth. The results of this study will lead to a better understanding of the requirements for shortawn foxtail germination and emergence and will provide information that could contribute to its control.


1994 ◽  
Vol 24 (1) ◽  
pp. 77-86 ◽  
Author(s):  
Hans Winsa ◽  
Urban Bergsten

Direct seeding of Pinussylvestris L. is a regeneration method, with potential for development considering scarification, microsite preparation, seed invigoration, and seed quality. Three seed lots of different quality concerning seed weight, germination percent, and mean germination time were used on two sites in northern Sweden. Microsite preparation, 2 cm deep pyramidal indentations, of the mineral soil improved seedling emergence on the two sites by 48 and 62%, respectively, compared with seeding without preparation other than removal of the humus layer. Microsite preparation in combination with invigorated seed, i.e., seed incubated at 30% moisture content for 7 days at 15 °C, resulted in seedling emergence of about 85% for the highest and about 50% for the lowest seed quality at both sites. Noninvigorated seed, seeded without microsite preparation, reached about 55% for the highest and 22% at one and 43% at the other for the lowest seed quality. Without microsite preparation there was no, or a negative, effect of seed invigoration on seedling emergence. Seedling survival after the first winter improved significantly with better seed quality. Survival averaged 92 and 72% at the two sites, with frost heaving causing most mortality. Seedlings from invigorated and redried seed survived better than seedlings from untreated seed. Seedlings from the best seed quality had higher values in seedling height, about 35%, shoot length, about 60%, and needle length, about 30%, after two growing seasons than seedlings from lower seed qualities. Invigoration and microsite preparation had no effect on measured growth characteristics.


2018 ◽  
Vol 16 (4) ◽  
pp. 352-358 ◽  
Author(s):  
Junichi Kashiwagi ◽  
Koji Hamada ◽  
Yutaka Jitsuyama

AbstractDirect sowing of rice in a flooded paddy field is a beneficial cultivation practice for water use and labour efficiency, compared to the transplanted cultivation. However, a drastic reduction in seedling emergence under flooded paddy fields is a serious constraint especially when the seeds fell at deeper soil layers. Suitable rice germplasm for the direct sowing in flooded paddy fields could ensure the success of this cultivation practice. Instead of laborious field-based screening systems, a pot-based screening method was adopted for simplicity and efficient evaluation of seedling emergence of a subset of world rice germplasm (n = 75) at different sowing depths. As a result, two rice genotypes, ‘Vary Futsi’ (landrace from Madagascar, non-glutinous, subspecies Indica) and ‘Dahonggu’ (landrace from China, non-glutinous, subspecies Indica), with consistently better seedling emergence were identified from a wide range of rice germplasm. These genotypes could serve as excellent parents for the breeding program in developing new rice cultivars with the improved seedling emergence in flooded paddy fields. There were no significant differences in the seedling emergence rate in flooded paddy conditions among the groups from various agro-geographical regions.


2015 ◽  
Vol 43 (1) ◽  
pp. 153-158 ◽  
Author(s):  
Faruk TOKLU

An experiment was conducted under laboratory and field conditions in order to evaluate the effects of different priming treatments, specifically KNO3 (1%), KCl (2%), KH2PO4 (1%), ZnSO4 (0.05%), PEG-6000 (20%), IBA (100 ppm), Mannitol (4%), GA3 (100 ppm) and distilled water, on seed germination properties and several agro-morphological plant characteristics of red lentil. Seeds not primed were used as a control. GA3 treatment increased shoot length. The control (non-primed seeds) treatment resulted in increased seedling root number and length. Distilled water, ZnSO4 and control treatments increased germination rate and percentage. In the pot experiments, GA3 treatment increased plant height and seedling emergence rate, whereas KCl treatment improved the number of nodules, as well as root and shoot dry weight when compared to the control. ZnSO4 treatment increased yield components and grain yield in field conditions. The results of this study showed that ZnSO4, GA3 and PEG-6000 seed priming treatments may be useful tools due to their positive effects on germination rate, germination percentage, yield component and grain yield of lentil.


Agronomy ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 190
Author(s):  
Lei Chu ◽  
Yiping Gao ◽  
Lingling Chen ◽  
Patrick E. McCullough ◽  
David Jespersen ◽  
...  

White clover (Trifolium repens L.) is cultivated as a forage crop and planted in various landscapes for soil conservation. There are numerous reports of failed white clover stands each year. A good understanding of the seed germination biology of white clover in relation to environmental factors is essential to achieve successful stand establishment. A series of experiments were conducted to investigate the impacts of light, temperature, planting depth, drought, and salt stress on seed germination and the emergence of white clover. White clover is negatively photoblastic, and seed germination averaged 63 and 66% under light and complete dark conditions 4 weeks after planting (WAP), respectively. Temperature affected the seed germination speed and rate. At 1 WAP, seeds incubated at 15 to 25 °C demonstrated a significantly higher germination rate than the low temperatures at 5 and 10 °C; however, the germination rate did not differ among the temperature treatments at 4 WAP. The results suggest that white clover germination decreases with increasing sowing depths, and the seeds should be sown on the soil surface or shallowly buried at a depth ≤1 cm to achieve an optimal emergence. White clover seeds exhibited high sensitivity to drought and salinity stress. The osmotic potential and NaCl concentration required to inhibit 50% seed germination were −0.19 MPa and 62.4 mM, respectively. Overall, these findings provide quantifiable explanations for inconsistent establishment observed in field conditions. The results obtained in this research can be used to develop effective planting strategies and support the successful establishment of white clover stands.


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