Evaluation of C/N Ratio and SPAD value in Perlis Harumanis mango (Mangifera indica) leaves at vegetative growth

Abstract

Harumanis mango leaves is a usually green, flat lateral structure that protrudes from a plant's stem to collect sunlight for photosynthesis, and the site where transpiration takes place. Leaves are an a bsolutely essential part of any vascular plant for the processes of transpiration and photosynthesis. After carbon, hydrogen and oxygen, nitrogen (N) is one of the essential elements in plants due to its key role in chlorophyll production, which is fundamental for the photosynthesis process. In addition, nitrogen is part of various enzymatic proteins that catalyse and regulate plant-growth processes. Besides, carbohydrate is also an important element in affecting the attributes for flowering e vent in mango trees. However, there was lack scientific report about the relationship between SPAD reading, nitrogen concentration level and C/N ratio that are required in Haerumanis mango leaves at vegetative growth. This project aims to study the evaluation of C/N ratio and SPAD measurement in Harumanis mango leaves at vegetative growth and it is carried out for 8 weeks before it achieve the flowering stage. In this research, the experiment is conducted on Harumanis mango leaves to examine the quantity of nitrogen and carbohydrate by using Kjedahl method and Anthrone method. While, SPAD meter is used to examine the chlorophyll content in Harumanis leaves which is closely related to nitrogen status of the leaves. The SPAD value from week 1 to week 4 was increased from 41.12 units to 48.54 units where Harumanis leaves entered the maturity stages. Next, the value of SPAD were slowly decreased from week 5 (47.96 unit) to week 8 (46.58) when they entered the dormancy period stages where the plants did not shows any respond. The value of C/N ratio and SPAD value is highly correlated to each other because they helped each other to develop the plant growth. In a conclusion, the development of the leaves depends on the nutrients that contain in the leaves.