study the relationship between yield and yield components in tobacco (nicotiana tabacum l.) varieties.

this research which aims to survey the relation between tobacco leaf yield and its components is done by using 118 varieties of tobacco in a research farm of guilan tobacco research institute. regarding to five random selections of plants, twenty three traits of each variety were evaluated. correlation between dry matter of leaf yield with plant height, stem diameter, leaf length, leaf width, leaf area index, upper, lower & middle internodes length, days to flowering, green matter of leaf yield, green plant weight, biomass, percentage of dry matter and harvest index was positive and significant and with leaf shape index, flowering period, length of inflorescence and percentage of root note nematode infestation was negative and significant. in stepwise regression analysis the most effective factors on dry matter of leaf yield were particulars of green matter of leaf yield, percentage of dry matter, plant height and leaf area index. according to the results of path analysis the most direct and positive effect on dry matter of leaf yield was related to green matter of leaf yield. in path analysis between green matters of leaf yield with other studied characteristics, the particulars of the green plant weight and leaf length had the most positive direct and indirect effect on green matter of leaf yield. in factor analysis, 7 independent factors explain the variation of 80.54 percent of all data.