Abstract:
Carrot (Daucus carota L.) is one of the most important root crops grown worldwide and in
Ethiopia. It is a source of nutrition for health benefits, foreign currency and cash for the
smallholder farmer. However, its production and productivity is low due to mainly lack of
improved varieties and unbalanced fertilizer rates among other factors. The Field experiment
was, therefore, conducted to improve the productivity of carrot varieties through blended
fertilizer rates at horticulture Demonstration Site of College of Agriculture and Environmental
Sciences, University of Gondar. The treatment consisted of six rates of blended NPSB fertilizer
(0:0:0:0, 21.3:15.3:2.80:0.04, 42.6:30.6:5.60:0.08, 64:46:8.41:0.12, 85.3:61.2:11.2:0.16 and
106.7:76.7:14.03:0.20 kg ha
-1
),) and two carrot varieties (Haramay-I and Nantes), which was
laid out in a randomized complete block design with three replications. Data were collected on
crop phenology, growth, and root yield parameters and subjected to analysis of variance using
SAS computer software version 9.4. The result revealed that the main effects of both NPSB plus
urea fertilizer rates and varieties had significant effect on all tested parameters, while the
interaction effect was significant on root fresh weight, root length, root dry matter, marketable
and total root yield. The highest aboveground biomass (81.24 t ha
-1
) was recorded from
106.7:76.7:14.03:0.20 NPSB kg ha
-1
of fertilizer rate, while root fresh weight (146.49g plant
-1
),
root length (23.36 cm), root diameter (3.73 cm), and root volume (114.16 ml) were recorded
from 85.3:61.2:11.2:0.16 kg NPSB ha
-1
. Higher aboveground biomass (92.3 t ha
-1
), root diameter
(3.1cm), and root volume (61.3 ml) was obtained from Haramaya I variety. The highest dry
matter (14.83%), marketable (52.26 t ha
-1
) and total (55.36 t ha
-1
) root yields as well as the
highest net benefit (1,169,112.3 ETB birr) with marginal rate of return (11423%) greater than
the minimum requirement (100%) were recorded from the interaction of 85.3:61.2:11.2:0.16 kg
NPSB ha
-1
and Haramaya-I variety. It can tentatively recommended to apply 85.3:61.2:11.2:0.16
kg NPSB ha
-1
and use Haramaya-I variety for the maximum marketable yield and highest net
benefit of carrot in the study area. However, it is needed to repeat similar studies at different
seasons to have stable recommendation
