Flue-cured Tobacco Varieties Research Articles

たばこ刻のもろさ，膨こう性，平衡水分に与えるグリセリン添加の効果

For the purpose of investigating the effects of addition of glycerol to tobacco laminae on three characteristics of shreds“Y”(fragility, filling capacity and equilibrium moisture content), an experimental plan was set up by using the glycerol addition“G”(0∼6%) and the environmental humidity “h”(43∼80%RH) as two main factors and the shreds length as a subsidiary factor. The tests were carried out with Flue-cured and Burley tobacco varieties. By means of statistical analysis of these experimental data, the relations among“Y”, “G”and“h”were represented with experimental formulae. Moreover, the analysis of multiple regression for fragility and filling capacity was performed with two independent variables of real glycerol content“GR”and moisture content in tobacco shreds.The important results obtained were as follows:(1) When the“G”or the“GR”increased, the equilibrium moisture content of shreds increased, the filling capacity decreased and the fragility of shreds decreased.(2) The addition of glycerol to tobacco had a very large effect on the fragility of shreds, medium on the filling capacity and slight on the equilibrium moisture content.(3) The“GR”in the shorter part obtained by sieving shreds appeared to be larger than that in longer one.

Variations in Flue-cured Tobacco Losses from Different Tobacco Budworm Infestation Levels12

Artificial infestations (1 larva/plant) of wild Heliothis virescens (F.) caused economic yield losses to 2 varieties (Coker 411 and NC 2326) of flue-cured tobacco. Different infestation levels influenced quantitative tobacco losses, but no qualitative differences were apparent. Maximum yield reductions occurred at 20 and 50% infestation levels instead of the expected 100% level with both varieties. The maximum yield loss per larva occurred at the 10 and 20% infestation levels. Larval distribution, possible larval interference, and natural enemies (especially parasitism) were believed to have affected the degree of foliage loss at the various infestation levels.

Possible Causes of Differences in Tobacco Budworm Damage to Flue-Cured Tobacco Varieties1

Differences exist in the amount of damage to flue-cured tobacco varieties caused by Heliothis virescens F. Variation in the disappearance of attacking larvae appears to be the key. Analyses for nicotine, nitrogen, sugar, and starch in developing bud leaves showed that nicotine content early in the growing season may contribute to the differences. Higher trichome counts and resin exudates apparently are related to degree of damage. Seasonal plant growth patterns contribute to these differences.

Waimea, a new flue-cured tobacco variety

Successful cultivation of flue-cured tobacco requires particular soil types and climatic conditions. The only area in New Zealand where these conditions are found is in and around the Motueka Valley, where, on about 6000 acres, half the country's tobacco requirements are grown.

Uptake and distribution of polonium-210 and lead-210 in tobacco plants

Athalye V. V. and Mistry K. B. Uptake and distribution of polonium-210 and lead-210 in tobacco plants. Radiation Botany 12, 421–425, 1972.—The uptake and distribution of polonium-210 and its long-lived precursor lead-210 in two flue-cured tobacco varieties (Nicotiana tabacum L. cv. Delcrest and cv. Virginia gold), were examined in nutrient culture experiments. The accumulation of these radionuclides was greatest in the roots. Over identical durations of growth, the extent of upward transport of 210Po and 210Pb was relatively greater in cv. Virginia gold. The distribution of the radionuclides in aerial tissues followed an acropetal gradient suggesting that 210Po and 210Pb concentrations in leaf tobacco used for cigarette production would be reduced if leaves other than the oldest pairs are harvested.

EFFECTS OF DIETHYL SULPHATE ON SEED GERMINATION AND SEEDLING GROWTH OF NICOTIANA TABACUM

Seeds of three flue-cured tobacco (Nicotiana tabacum L.) varieties, Hicks Broadleaf, Yellow Gold, and Canadel, were soaked for 1, 2, 3 or 5 hours in a saturated solution of diethyl sulphate, a chemical mutagenic agent, to increase variability of plant characteristics. Diethyl sulphate had a detrimental effect on both extent and rate of germination; each decreased with length of soaking period. Seedlings from treated seed grew more slowly than controls.

PHOTOPERIODIC RESPONSE AND ITS EFFECTS ON CERTAIN QUANTITATIVE CHARACTERS IN TOBACCO

The effects of the mammoth gene causing a short-day photoperiodic response in a mutant were studied in 1962 and 1966 in six genetic populations (P1, P2, F1, F2, B1 B2) derived from the cross between Mammoth Delcrest, a short-day mutation of the flue-cured tobacco variety Delcrest, and Praecox, a day-neutral pipe tobacco. The data showed the expected monofactorial segregation of day-neutral against short-day plants, the latter being recessive. Considerable amount of positive heterosis was observed for leaf width. In the inheritance of days-to-flower, in addition to the pair of alleles determining the short-day response, one to two gene groups are indicated, operating probably in an additive fashion. Two and three gene groups are indicated for leaf width and leaf length, respectively. Parameters describing additive gene effects were important for all the character tested but none of the parameters for dominance and digenic epistatic effects were significant. Evidently the segregating major gene for the mammoth character did not excessively influence the relationship of gene effects in the remaining genotype as determined by the generation-mean analysis.

PROGRESSIVE VEINBANDING—A NEW MUTATION IN NICOTIANA TABACUM L.

A new mutation for chlorophyll-deficiency in Nicotiana tabacum L., called progressive veinbanding, was found in the field planting of the flue-cured tobacco variety Hicks Broadleaf. The mutant follows monogenic inheritance of a single recessive gene upon which the normal allele exhibits complete dominance. There was a definite association of the mutant type with the M—chromosome of the sylvestris genome in tests against the monosomic series.

Effects of night temperature on the growth of Nicotiana tabacum

Four varieties of flue-cured tobacco, Nicotiana tabacum L., showed similar responses to night temperatures of 10�, 16�, 22�, and 28�C, with a day temperature of 27�C. Leaf growth rates and leaf production rates were approximately the same at night temperatures of 28� and 22�C, and were successively lower at 16� and 10�C. Dry weight accumulation was greatest at 22�. The node number of flower initiation increased with increasing night temperature over the whole range. There was no evidence of either a shift in the night temperature optimum or a physiological adaptation to low temperature during development.

Effect of Planting Time on Yield and Quality of Flue-Cured Tobacco in Iringa District, Tanzania

SummaryAs part of a project to introduce Virginian-type flue-cured tobacco varieties into a new area, a number of experiments on the effect of time of planting showed that returns declined according to the delay in planting after the start of the rains. This decline was not arrested by differential fertilization, soil fumigation or the use of quicker maturing varieties. The early plantings appeared to have a greater growth potential, which could often be more fully realised under improved cultural techniques. Thus, early plantings gave substantial positive responses to applications of nitrogen which had little effect on, or were detrimental to, later plantings. It is suggested that the responses noted were linked with weather conditions during the first few weeks after planting. The drier and more sunny these were, the better, and the possibility therefore arises of using rainfall probability data, with a minimum of field experimentation, in future problems of this nature.

VARIETAL DIFFERENCES IN PHOSPHORUS LEVEL IN LEAVES OF FLUE-CURED TOBACCO

Six varieties of flue-cured tobacco were tested in the greenhouse in soil for differences in phosphorus level in the leaves, using radiophosphorus. Radioactivity measurement of leaf samples showed significant varietal differences in P32 activity in the leaves. The level of P32 per sq. cm of leaf tissue was higher in Delcrest, Hicks, and Virginia Gold than in White Gold, Jadel, and White Mammoth.

PROCEDURE FOR EVALUATING VARIETIES OF FLUE-CURED TOBACCO FOR PERFORMANCE IN SOIL INFESTED WITH THE BLACK ROOT ROT FUNGUS

Differential reaction of flue-cured tobacco varieties in soil infested with the black root rot organism Thielaviopsis basicola (Berk.) Ferr. was estimated by using data collected on the following characteristics: weight of roots, weight of aerial growth, height of growth, and rated amount of root lesions and aerial growth. The different measurements and scores produce different rankings and in order to set up a single ranking to express the relative performance of varieties, a discriminant function approach was adopted. The objective of this approach was to obtain a linear function which best discriminates among varieties. It is suggested that the discriminant function need be based on only the rated amount of aerial growth and root lesions.

Improvement of flue-cured tobacco by means of ionising radiation

Three commercial varieties of flue-cured tobacco viz., Chatham, Delcrest and Hicks were subjected to neutron irradiation using six different doses ranging from 1×1012 to 5×1013 N/cm2/sec. The N1 generation was grown in the field during 1959–60. Only plants from the lowest two doses viz., 1×1012 and 2.5×1012 N/cm2/sec. survived in the field up to the adult stage. From this material, normal plants with high pollen fertility were selected for testing their performance in replicated trials.

Cytogenetics of neutronic mutants in Nicotiana tabacum

Three commercial varieties of flue-cured tobacco, Chatham, Delcrest and Hicks, were subjected to irradiation by thermal neutrons at six doses. Germination of the treated seeds was good in the lowest two doses, 1×1012 and 2.5×1012 N/cm2/sec. while deterioration started in 5×1012 which was considered to be the threshold dose. The other three doses, 1×1013, 2.5×1013 and 5×1013 proved to be lethal.