STANDARDIZATION OF PLANTING TIME OF TURNIP CV. PURPLE TOP WHITE GLOBE ROOT CROP FOR SEED PRODUCTION

The healthy seed of turnip cv. Purple Top White Globe was sown on seven planting times at
weekly intervals from III week of July to I week of September viz. P1: Jul 20, P2: Jul 27, P3: Aug
04, P4: Aug 11, P5: Aug 18, P6: Aug 25 and P7: Sep 03 during two consecutive years 2008 and
2009 in a randomized Block Design with three replications every year at a spacing of 30x10 cm
having plot size of 2.00x1.20 m with a population of 80 plants per plot. The roots from the plots
of all the planting times were uprooted by the mid of November when the sub zero temperature
ceases the growth of the crop and then after selection roots were stored in trenches for
overwintering till melting of snow in March-April for further planting of seed crop. The observations
were recorded on a) normal roots (%) viz. i) true to type roots (%) and ii) off-type roots (%); b)
abnormal roots (%) viz. i) oversized/ cracked roots (%) and ii) undersized roots (%). Significant
differences were observed for all the traits studied during both the years. The turnip crop sown
in the second week of August produced significantly higher percentage of mature normal roots
(69.28%) by the mid of November. The every advance or delay in sowing resulted in continuous
increase in percentage of abnormal roots viz. oversized/ cracked roots and undersized roots.
The reduction in percentage of mature normal roots was more drastic due to delay in sowing
than advance sowing.