Response of Garlic (<i>Allium sativum</i> L.) on Intra Row Spacing and NPS Ratio for Growth, Yield Components and Yield at Bench-Sheko Zone, South Western Ethiopia

The objective of this study is to identify the optimum Nitrogen, Phosphorus and sulfur and plant density for maximum production of garlic crop in the study area. Garlic is an important condiment and cash crop in Ethiopia. Low yield and productivity of the crop are the major characteristics of the crop in the country. The field experiment was composed of three intra raw spacing and four labels of NPS ratio, three levels of intra-row spacing with 5 cm, 10 cm and 15 cm laid out in a Randomized Complete Block Design replicated three times. Data pertaining growth, yield and yield-related parameters were collected and analyzed using SAS version 9.3. The result of the study revealed that almost all of the variables considered were significantly affected by the interaction between NPS ratio and intra-row spacing. As a result,, bulb length (4.71 cm), bulb diameter (3.7 cm), bulb weight (59.0 g), clove number per bulb (29.00), dry matter (37.13 %), marketable bulb yield (kg ha-1) (6715.87 kg ha-1), unmarketable bulb yield (kg ha-1) (607.67 kg ha-1), total bulb yield per hectare (kg ha-1) (7313.97 kg ha-1) and harvest index (57.93 %). The highest marginal rate of return of garlic (873.75 %) was obtained from the treatment combination of 19: 38: 7 labels of NPS ratio with wider intra row spacing (15 cm). The minimum marginal rate of return (-7,160.1 %) was recorded from the treatment combination of 0: 0: 0 labels of NPS ratio with medium intra row spacing (10 cm). The correlation analysis indicated that the relationship between marketable yield and all variables except unmarketable bulb yield and total bulb yield (where negative and significant) was positive and highly significant (P<0.001). According to the findings of this study, it can be concluded that applying 19: 38: 7 labels of NPS ratio combined with the wider intra row spacing (15 cm) helps to produce higher product in the study area. Because it was helps to produce higher marginal rate of return. Therefore, it is better to use 19: 38: 7 labels of NPS ratio combined with the wider intra row spacing (15 cm) for producing higher garlic product in the study area. But, since the current study was limited to a single season at a single location and varieties, it should be repeated across locations, seasons and varieties for comprehensive recommendation.