EFFECT OF BLENDED NPS AND BORON FERTILIZER RATES ON GROWTH, YIELD AND QUALITY OF CARROT (Daucus carota L.) AT DEBRE BERHAN, CENTRAL HIGHLAND OF ETHIOPIA

Abstract

Carrot (Daucus carota L.) is an important root vegetable cultivated widely in the world as well as in Ethiopia in particular. However, the total root yield is low at the international, national and regional levels as compared to its potential, due to various factors including lack of improved varieties, low soil fertility, inappropriate application rates and type of fertilizers, lack of enhanced agronomic and cultural practices, occurrence of diseases and insect pests and lack of improved post-harvest technologies. Among these, inappropriate application of macro and micronutrient fertilizers is the bottleneck of agronomic practices that caused tremendous yield reduction. Therefore, a field experiment was conducted at demonstration and research site of Debre Berhan University during the main cropping season of 2022/23 to evaluate the effects of different rates of blended NPS and boron fertilizers on growth, yield, and quality of carrot. The treatments consisted of factorial combinations of four rates of NPS fertilizer (0, 75, 150 and 225 kg ha-1) and four levels of B (0, 250, 500 and 750ppm). The experiment was laid down in a randomized complete block design with three replications using the ‘Nantes’ carrot variety as a test crop. Accordingly, the combined application of 150 kg ha-1 of NPS and 500ppm boron application rates resulted in the widest root diameter (2.45cm), highest root dry weight (19.34g), highest marketable root yield (56.28 t ha-1), highest total root yield (58.68 t ha-1) and highest dry matter content (45.7%). In addition, this treatment resulted in the highest net benefit (Birr 1248724 ha-1) with an acceptable marginal rate of return (1879.22 %).In conclusion, the combined application of NPS at 150 kg ha-1 and B at 500ppm rates could be recommended to increase the production of carrot in terms of yield and quality in the study area and other similar agro- ecologies. However, additional study is needed in different seasons and locations to give full recommendation since the study was conducted in a single season and location.