Abstract:
Beet (Beta vulgaris) is a cool-season vegetable grown in Kalpitiya. The area consists of sandy Regosol
soil and due to the high permeability, and high evaporation rates the agricultural lands in this region
require frequent heavy irrigation. Consequently, the crops need to be applied with high fertilizer
doses frequently to compensate for the leachate with irrigation water. It causes a gradual
accumulation of nitrogen in groundwater that has already reached alarming levels causing health
concerns. Cultivation of crops adaptable to low nitrogen levels is a long-term sustainable approach
to overcome this problem. Hence, the present study was conducted to screen three commercially
grown beet varieties for their adaptability to low nitrogen supplements under in vitro conditions. A
factorial experiment was conducted in a completely randomized design with three varieties (Chariot,
Ruby Queen and Red Ace) and four Nitrogen levels supplemented through altered concentrations of
NH4NO3 [875 (control), 656.25, 437.5 and 218.75 mg/L] in the MS Medium using 30 seedlings.
Seedling characteristics including the number of leaves, number of roots, shoot dry weight root dry
weight were recorded at the end of 30 days of subculturing the two leaved seedlings onto the media
containing four nitrogen levels. The data were subjected to Analysis of Variance using R statistical
package. An interaction effect was not observed in the tested parameters. A significant difference
was not observed among the four nitrogen levels for the number of roots, shoot and root dry weight
in all three varieties whereas the number of leaves was affected by the nitrogen level in all three
varieties. In Chariot, a significant increase was observed in the number of leaves in the media
containing 656.25 and 437.5 mg/L compared to the lowest level 218.75 mg/L. However, the lowest
level was comparable to the control whereas in Ruby Queen and Red Ace a significant reduction was
observed at the lowest level compared to the control. Therefore, the variety Chariot was identified
as the most potential variety that is adaptable for cultivating soils with reduced nitrogen, compared
to the other two varieties tested. Further study is required to estimate the actual performance of the
identified varieties under in vivo conditions.
