Abstract:
Garlic (Allium sativum L.) is the second most important and widely grown Allium crop in many
regions of Ethiopia. However, the average bulb yield is low compared to the crop's potential yield
due to several factors including lack of improved varieties, the occurrence of diseases and insect
pests, lack of improved post-harvest technologies, poor agronomic and cultural practices and
inappropriate use of fertilizer rates. Among these, inappropriate applications of macro- and
micronutrient fertilizers are the major agronomic practices that tremendously reduce the yield of
the crop. Using proper types and rates of fertilizer is one of the measures to increase the crop
productivity in the region. Hence, a field experiment was conducted to evaluate the effects of
blended NPS and zinc fertilizer rates on the growth, yield, and quality of garlic during irrigation
time of 2022/23. The treatments consisted of factorial combinations of four rates of NPS fertilizer
(0, 121, 242 and 363 kg ha-1) and four levels of Zn (0, 0.3, 0.6 and 0.9%). The experiment was
laid down in a randomized complete block design with three replications using the garlic cultivar
‘Qundi’. Data on different phenological, growth, bulb yield and quality-related variables were collected
and analyzed using R- software. The analysis of variance showed that most of the studied parameters
were significantly affected by the interaction of the two factors. Accordingly, the study revealed
that the combined application rates of 242 kg ha-1 NPS and 0.6% zinc resulted in the widest neck
diameter (1.52cm), longest bulb length (4.98cm), widest bulb diameter (4.44 cm), longest clove
length (2.61 cm), widest clove diameter (1.59cm), highest average bulb weight (44.63g), highest
average clove weight (5.93 g), highest total bulb yield (14.89g), highest harvest index (87.41%),
and highest percent dry matter content (43.18%). The average bulb weight, percent dry matter
content and total bulb yield due to 242 kg ha-1 of NPS and 0.6% of zinc fertilizer application was
increased by15.17, 24.12 and 39.94%, respectively, as compared to 242 kg ha-1 NPS without zinc
application. In addition, the highest net benefit (Birr 1,606,330 ha-1) with an acceptable marginal
rate of return (116.61%) was recorded from 242 kg ha-1 of NPS with 0.6% Zn rate application as
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compared to the other treatments. Thus, it can be concluded that the combined application of
NPS at a rate of 242 kg ha-1 and Zn at 0.6% rate could be recommended to enhance total bulb
yield and quality of garlic in the study area and other similar agro-ecologies.
