• International Journal of Industrial Entomology and Biomaterials
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• v.6 no.1
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• pp.15-19
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• 2003

The study evaluated the influence of feeding different maturity leaves i.e., tender, medium, coarse and mixed leaves of three different maturity during late larval stages of new bivoltine race $(CSR_{3} {\times} CSR_{6})$. The data were compared with shoot feeding and control batches in which conventional feeding method was followed. The most of the larval and cocoon characters were recorded significantly higher in tender leaves fed batches followed by T4 batch (2 times tender and 1 time coarse leaves). Lowest melting percentage (1.494%) was recorded in T4 and highest (4.69%) was recorded in coarse leaf (T3) fed batches. Significantly higher post cocoon parameters viz., average filament length, non-breakable filament length, renditta and raw silk percentage were recorded in tender loaves fed batches.

• Journal of the Korean Society of Tobacco Science
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• v.6 no.1
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• pp.73-78
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• 1984

The changes of contents of organic acids in flue-cured tobacco leaves depending on stalk position and maturity viz immature, mature and overmature were studied in 1982-83. Among them, particularly, the leaves harvested at mature stage have the lowest amounts of oxalic and citric acids in smoking or cutter leaves but the acid contents has increased during the overmature. The linolenic acid content tended to be lower with increase of maturity.

• Journal of the Korean Wood Science and Technology
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• v.52 no.5
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• pp.450-458
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• 2024

Litsea elliptica, a Southeast Asian tree with a rich history of medicinal applications, is attracting increasing research attention. This study investigated the effects of leaf maturity and solvent selection on the extraction of bioactive compounds from L. elliptica leaves, specifically with regard to their antioxidant activity. 2,2'-Azino-bis(3-ethylbenzothiazoline)-6-sulfonic acid (ABTS) method was employed to quantify the free radical scavenging capacity of L. elliptica leaf extracts prepared using three different solvents (n-hexane, ethyl acetate, and ethanol) at three different leaf stages (tender, immature, and mature). These results highlight the significant effects of leaf maturity and solvent selection on the extraction of phenolic compounds and flavonoids from L. elliptica leaves. Ethanol is the most effective solvent for the extraction of bioactive compounds, particularly from mature leaves. The ethanol extraction of tender leaves demonstrated potential for optimizing the antioxidant content. Further research is necessary to investigate the specific factors influencing the observed differences in antioxidant activity between leaves of varying ages and the potential impacts of other bioactive compounds present in the leaves.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.12
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• pp.43-48
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• 1972

The present experiments were carried out to find out the proper concentration of CEPA(2-chloroethy-lphosphonic acid) for the purpose of accelerating the leaf maturity and of reducing the nicotine content of tobacco. Varried levels of CEPA were sprayed Yellow Special A right after topping. The effects of each level CEPA treatment on leaf ripening and total alkaloid contents were periodically observed. The results are summarized as follows; 1. The higher the CEPA concentration was, the more the leaf maturity was accelerated. During the period from six to 11 days after treatment, the differences of leaf maturity among levels were prominent. 2. Treatment with CEPA only on the upper surface of the tobacco leaf, accelerated the maturity of that particular part treated, but not apparently the other parts of leaf. 3. The higher the CEPA concentration was, the more the accumulation of the total alkaloid was reduced. The reduction of alkaloid accumulation was evident after acceleration of leaf maturity. 4. Distinctive acceleration of leaf maturity was observed in the fully developed lower leaves, while reduction of alkaloid accumulation in the growing upper leaves. The degree of total alkaloid content reduced in the ripened leaves, however, were similer to all the leaves at different positions. 5. Yields of tobacco leaves were not significantly affected by CEPA treatment. 6. In the present experiments, it may be concluded that CEPA2, 000ppm is the most applicable level for accelerating leaf maturity and decreasing total alkaloid content. In the view point of the practical use, however, the applicable level is assumed to be properly choosed between 500 to 2, 000ppm, depending on the situations. 7. The mechanism of accelerating maturity and reducing alkaloid accumulation of tobacco leaves by CEPA, is further to be explored.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.32 no.3
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• pp.347-352
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• 1987

This studies were carried out to investigate the effects of nitrogen fertilizer rates and methods of its application on maturity of leaves, total nitrogen and total alkaloids concentration in burley tobacco leaves. Nitrogen rate ranged from 17.5 to 40.5kg/10a and applied through basic fertilization and sidedressing. The filling capacity of cured leaves was decreased with increasing levels of nitrogen fertilizer. As the rate of nitrogen fertilization was increased or sidedressing, the maturity of leaves was delayed and total alkaloids and total nitrogen concentration were increased. Total alkaloids concentration in leaves was gradually increased, especially more in upper leaves from 60 to no days after tratnsplanting, but total nitrogen concentration was decreased.

• Journal of the Korean Society of Tobacco Science
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• v.4 no.1
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• pp.37-42
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• 1982

Korean local and introduced varieties were classified by the cluster analysis of correlation and taxonomic distance based on nineteen growth characters. 1. Thirty six varieties can be classified into three groups(I, II, III) by WVGM (weighted variable group method) 2. Major characters for classifying cultivars were days to flowering, number of leaves, leaf length, stem diameter and width of midrib: the five characters seemed to be useful in monothetic classification. 3. Korean varieties were similar to oriental, and japanese varieties to taiwan. 4. WVGM was more accurate and meaningful than classification by WPGM (weighted paired group method) and reticulate diagram of correlation. 5. Characteristics of each group: Group I closely related to many leaves, late of maturity and broad leaf type, Group II related to medium leaves, late of maturity and narrow leaf type, Croup 19 related to few leaves, early of maturity and medium leaf type respectively.

• Korean Journal Plant Pathology
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• v.13 no.4
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• pp.215-218
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• 1997

The environmental factors affecting maturity of pseudothecia overwintered in iufected leaves by Mycosphaserella nawae was investigated. The pseudothecia in the overwinteringinfected leaves were matured at the end of April when the average temperature was $14^{\circ}C$ and precipitation was enough. Pseudothecia initiation was preceded by the fungal biomass development in a given host. The maturity of the pseudothecia from the leaves defoliated in early October was earlier and higher than those defoliated in November of the previous year. Pseudothecia development was also positively affected by low temperature. The maturity time, as determined by percentage of matured pseudothecia out of prematured ones, was also 20 days earlier, and the rate of maturity was higher for the leaves overwintered in door, than for those kept in greenhouse. We have providedevidence that the conidia play a significant role in the epidemiology of this pathogen. Many pseudothecia were developed in the leaves infected by artificially inoculated conidia and maturation rate of the pseudothecia was not different from that of the typical symptom by ascospores infection of Mycosphaerella nawae.

• Journal of Plant Biology
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• v.17 no.1
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• pp.15-21
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• 1974

The most commonly grown economical and flue-cured tobacco cultivar Yellow Special A was used in pot-culture tests in order to study Ethrel (2-chloroethyl phosponic acid) effects on accelerating maturity of tobacco leaves in relation to the most adequate level of the chemical useful for field growing, nitrogen level in soil for the most pronounced response, and the most suitable spray period during the growth stages of pre-, post- and topping periods. The following conclusions, thus, were obtained from the present studies; 1. 500ppm Ethrel spray was reconfirmed to be adequate in the practical applications, although the extent of yellow-ripening of tobacco leaves was increased as the Ethrel level increased. The highest leevel treated resulted in causing chemically damaged lesions on leaves and early defoliation. 2. Ethrel-treated leaves showed deeper yellowish tinge to them than those without treatment, while different levels of the chemcial had less influence on the tinge. 3. An adequate level of nitrogen supply to plants favored the Ethrel response, whereas either very low or high level of nitrogen in the soil lowered the chemical effect on accelerating the yellow-ripening. When carbohydrates versus total nitrogen ratio became relatively high, the condition brought out some outstanding Ethrel effects. 4. Chlorophyll level of leaves increased as soil applications of nitrogen level increased, and that also increased carotenoid level of the tobacco leaves. Ethrel-treated leaves showed deeper orange tinge than those without treatment, while the highest level of nitrogen application showed the deepest orange tinge to tobacco leaves. 5. Pre-topping treatment (12 days before topping and flowering) resulted in almost no Ethrel response, and that treatment right on the day of topping, showed response of yellow-leaf ripening at nearly bottom-half leaves of a tobacco plant. The post-topping treatment (12 days after topping) made plants showing full response of Ethrel from bottom to the top leaves of tobacco plant in accelerating the leaf maturity. 6. The extent of Ethrel responses on accelerating yellow-ripening of tobacco leaves was discussed for the modifying influences brought about by certain environmental factors. Discussions were also made about the possible practical applications (particularly for pre-rice planting) and quality difference that may be caused by such growth environments.

• Journal of the Korean Society of Tobacco Science
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• v.18 no.1
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• pp.5-11
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• 1996

Field experiment was conducted to get the basic information about the difference in color and plastid pigments at the different stage of harvest of flue-cured tobacco cultivated in paddy field, and compared to upland ones. All tested crops were primed in lots of 3 to 4 at each priming, beginning at the bottom of the plant. Leaf pigments and chromatic values of tobacco leaves were determined in samples collected at weekly intervals, and according to analyses obtained from 4 stalk positions. By the degree of maturity, leaves harvested were separated with visual characters into four classes of immature, mature, ripe and mellow. regardless of stalk position, chlorophyll contents was higher in the order of immature > mature > ripe > mellow, respectively. In fresh leaves, chlorophyll levels was higher with ascending stalk position. chlorophyll a and b in cured leaves were less than 10% of the amount present at harvest, and it was estimated that maturity condition also influenced the rates of degradation of plastid pigments. Fully mature leaves of upland diverted from paddy field showed slightly higher in chlorophyll contents than in those of upland tobacco ones but somewhat lowered in $L^*$ and $b^*$ values, and there was no difference in $a^*$ value.

• Korean Journal of Food Science and Technology
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• v.53 no.2
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• pp.133-138
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• 2021

In this study, the leaves of aronia (Aronia melanocarpa) across different stages of maturity were collected and their chlorophyll content, antioxidant content, and activity were analyzed. The leaves of the selected aronia cultivars ('Viking', 'McKenzie', and 'Kingstar K1') were harvested in June (young-stage leaf) and in August (old-stage leaf). The antioxidant content and activity of all three aronia cultivar leaves were significantly higher in the young-stage leaves than in the old-stage leaves. The main polyphenols in aronia leaves were catechol and chlorogenic acid, which tended to decrease as maturation progressed. As a result, the young-stage aronia leaves contained more abundant flavonoids, phenolic compounds, and polyphenols with higher antioxidant activity than those in the old-stage leaves. Overall, our findings indicate that aronia leaves contain potential bioactive compounds that could be used to develop functional food ingredients.