Impact of the orientation of seed placement and depth of its sowing on germination: A review

Seed orientation and its impacts on germination and seedling establishment mainly depend on the type of germination (hypogeal (or) epigeal), seed size and shape. Higher germination per cent is noticed when seeds are sown in the horizontal position. Planting seeds in a downward position can lead to a variety of physiological, chemical and morphological changes in seedlings. Consequences are usually manifested as noticeable modifications in their development. Vigorous seeds have strong, resilient seedlings due to their well-balanced metabolism and coordinated subcellular activity, making them well-suited for tough environments. Proper plumule and radicle growth require additional hormones and energy to ensure seedling survival. Four necessary factors must be considered while deciding the sowing depth viz., soil moisture, optimum soil temperature, soil aeration and atmospheric humidity required for seed germination, emergence and seedling growth. Variations are observed in germination behaviour and seedling growth for different sowing depths. The necessary factors are very much important for efficient nursery seedlings production. This review looks at the effects of seed depth and orientation on the germination and growth of important agricultural, horticultural and silvicultural crops

Effect of ageing on in vitro true seed and in vivo drupe germination and its dormancy mechanism in teak (Tectona grandis Linn.f)

The germination percentage of teak seed is generally very poor due to its higher percentage of empty seed and poor seed viability. The viable seeds exhibit protracted germination behaviour due to their inherent seed dormancy and other physiochemical characteristics. Hence establishing a teak nursery for largescale plantation activities is a challenging task. This study was undertaken to study the effect of ageing on in vitro true seed and in vivo drupe germination and its dormancy mechanism in teak. Fresh, one-year and two-year stored drupes were used to represent different levels of ageing. Under in vivo conditions, poor drupe germination was observed in fresh drupes (3%) and germination percentage was increased when the drupes were subjected to ageing for one year (17%) or two years (32%). When true seeds separated from fresh drupes and germinated under in vitro conditions, enhanced germination (58.3%) was observed. Biochemical analysis showed that indole-3- acetic acid, indole butyric acid, abscisic acid and coumarin are not present in fresh, one year and two-year-old true seeds. The gibberellic acid was increased with an increase in ageing, but the GA3 did not influence the germination percent under in vitro conditions. Scanning electron microscope (SEM) image of fresh teak true seed showed that embryo tip was shrivelled, whereas one and two-year-old true seed embryo tip bulged; this was confirmed that one and two-year-old true seed embryos were matured and satisfied the after-ripening requirement. Nursery studies revealed that one and two-year-old drupes recorded the highest germination compared to fresh drupes.                

Grammar Content Knowledge of Tamil Language Among Secondary School Teachers

The study aims to identify the level of knowledge of grammar content among Tamil language teachers at the secondary school level in aspects of phonology, morphology, syntax and morphophonemic. This study uses a quantitative research survey in the form of a descriptive design carried out in Selangor. A total of 160 Tamil language teachers in secondary schools in the state of Selangor were selected as a random sample. Questionnaires were used as instruments in this study. The data obtained were analyzed using SPSS software version 22.0. The findings of the study showed that secondary school Tamil teachers had a moderately high perception of the Tamil grammatical content of Form Four (M = 3.23, SP =.697). The study also found that the level of knowledge of Tamil grammar content was moderately low (M = 2.98, SP =.334) by following phonology (M = 3.26, SP =.560), morphology (M = 3.14, SP =.589), syntax (M = 2.85, SP =.716), and morphophonemic (M = 2.67, SP =.585). The implication obtained through this study is that the Ministry of Education Malaysia (MOE) is proposing to emphasize the importance of aspects of Tamil grammar, namely phonology, morphology, syntax, and morphophonemic. As a result of this, teachers who teach Tamil will be able to realize the importance of mastering the content of Tamil grammar

Determination of methane and carbon dioxide fluxes during the rice maturity period in Taiwan by combining profile and eddy covariance measurements

A field campaign was undertaken over a rice paddy in Central Taiwan to investigate the flux of CH4 through the flux-gradient method. During the campaign period, the average observed concentrations of CH4 during the campaign period at the lower height (22.2 m above ground level, agl) and upper height (27.5 m agl) were around 2.04 ppm and 2.01 ppm, respectively. It was noticed that the profile concentration of CH4 was lower during day time when compared to night time. However, the flux of CH4 was observed to be higher during the day time than during night hours. In order to understand the relationship between the influences of meteorological variables on the flux of CH4, six meteorological variables were studied. It was observed that soil heat flux has a linear positive correlation with the flux of CH4. During the study period, the maturity stage of rice paddy, the rice paddy ecosystem was behaving as sources of CH4 and CO2. Over a 100-year time frame, the global warming potential (GWP) fluxes of CH4 and CO2 observed at this study site were 0.16 and 0.71 μmol CO2 equivalents m−2 s−1, respectively. The total GWP flux (CH4 and CO2) was 0.86 μmol CO2 equivalents m−2 s−1 in which CH4 and CO2 contribute 18% and 82%, respectively