Evaluation of broccoli (Brassica oleracea var. italica) response to nitrogen fertilizer under two different shaded conditions
1 Faculty of Agriculture, University of Guyana, Berbice Campus, Tain, Corentyne, Guyana.
2 Institute for Marine and Riverine Ecologies and Economies, University of Guyana, Berbice Campus, John’s Science Centre, Corentyne, Berbice, Guyana.
Research Article
Open Access Research Journal of Science and Technology, 2025, 14(02), 008-017.
Article DOI: 10.53022/oarjst.2025.14.2.0087
Publication history:
Received on 23 May 2025; revised on 05 July 2025; accepted on 07 July 2025
Abstract:
Broccoli (Brassica oleracea var. italica) is a cruciferous vegetable gaining popularity for its taste and health benefits. This flowering head vegetable, related to cabbage and cauliflower, is a rich source of vitamins, minerals, and fiber. This versatile vegetable can be enjoyed raw, cooked, or roasted, making it a delicious and nutritious addition to any diet. Broccoli production is on the rise in Guyana and this project seeks to investigate the various effects that nitrogen fertilizer and shade has on the vegetative growth and yield of broccoli. Commencing, the broccoli seedlings were germinated and all the plots were prepared. Plot management was done where weed and pest and disease management was done. A soil test revealed the pH to be between 6-6.5 and the salinity to be 0.75-0.9 decisemens per centimeter. The drip irrigation system was also set up to supply the plants with adequate water. During the management of this research, prophylactic measures were implemented with the use of Caprid and Carbenazim to control insects and fungi respectively. The Split Plot Experimental Design was used where the main plots were the conventional shade house and the tunnel house and the sub plots were the five (5) different rates of nitrogen fertilizer (0, 75, 120, 180 and 225 kg N/ha). Urea was used as the nitrogen fertilizer. This study investigated the effects of nitrogen fertilizer and shade on the vegetative growth (average leaf length in centimeters and plant height in centimeters) and yield (number of curds per plant and total weight of curds per plant per treatment in grams). The data were collected and analyzed after which the results were thoroughly discussed. The results revealed that both nitrogen and shade had significant effects on the vegetative growth and yield of broccoli. Increasing the nitrogen application rate increased the vegetative growth as well as the yield of the broccoli. The tunnel house offering more light and better humidity and temperature control saw significantly greater result compared to the conventional shade house. Shade had significant differences in all the parameters of interest whilst nitrogen application rate had significant differences in all the parameters expect number of curds per plant. Tunnel houses, with their controlled environment promoting optimal light, temperature, and humidity, is significantly more favorable for broccoli growth compared to traditional methods. Additionally, while the study suggests that maximum yield was attained at 225 kg N/ha which is the highest rate, future research can be done to find the rate at which maximum yield is attained.
Keywords:
Broccoli; Nitrogen Fertilizer; Shade House; Tunnel House; Yield; Growth; Guyana
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