The Effect Of Nitrogen Source And Dosage On Growth, Result And Quality Of Red Beetroot (Beta Vulgaris L.)

Abstract

Beet are one of the commodities that are in demand by consumers because they contain nutrients needed by health such as iron, vitamin C, potassium, phosphorus, magnesium, folic acid, fiber and high water content (Ceclu and Nistor, 2020). The increasing demand for beets cannot be fully met due to the yield and quality of beetroots. This is based on the problems faced by farmers, especially in East Java, where some beet farmers choose to cultivate crops other than beetroot commodities. Judging by its growth, red beet plants are quite responsive to nitrogen administration. This is because nitrogen plays a role in plant protein formation through the preparation of amino acids, nucleic acids, nucleotides, coenzymes, phytohormones, cytokinins, and chlorophyll.The materials used were red beet plant seeds of Ayumi variety which were 17 days old. The source of N fertilizer consisted of Urea (46%N), ZA fertilizer (21%N and 24%S), SP-36 fertilizer (36% P2O5), and KCl fertilizer (60% K2O). The study used a Randomized Block Design (RAK) which consisted of two factors, namely two sources of nitrogen fertilizer (N) and a dose of nitrogen fertilizer (P). N1 is the nitrogen source of urea. N2 is the nitrogen source of ZA. P1 is 50% of the recommended dose, P2 is 75% of the recommended dose, P3 is 100% of the recommended dose, P4 is 125% of the recommended dose, P5 is 150% of the recommended dose. Of these two factors, there were 10 combination treatments. This experiment used three replications to obtain an experimental unit of 60 units. A plant can grow and develop properly if all plant needs can be fulfilled optimally. Application of nitrogen fertilizers from different sources and doses is an attempt to increase plant growth and yield. The growth components included number of leaves, leaf area, total chlorophyll, crop growth rate, and net assimilation rate. While the yield components include tuber diameter, fresh weight of tubers planted, fresh weight of tubers per hectare, total dry weight of plants, and betacyanin content in red beet tubers. Based on the influence of the source of N fertilizer at various doses, then the source of fertilization from Urea gave a higher effect on leaf number and leaf area than ZA. At the age of 90 days, the variable number of leaves with a dose of 75% and a dose of 100% resulted in a higher number of leaves 5.48 strands (32%) than the 50% dose. The low number of leaves is a result of the low availability of N for plants.The yield of fresh weight of planted tubers, tuber diameter, and total dry weight of the resulting plant was strongly influenced by the amount of assimilate produced by the plant. The amount of assimilate produced by plants can be described by measuring the total dry weight of the plant. the provision of ZA sources resulted in higher total plant dry weight than urea. This is because crop needs for various nutrients during growth and development are not the same, require different times and are not the same amount.A better crop growth rate was found in the application of 100% N fertilizer for the N source of ZA, while at the N source from urea a better growth rate was found in the 125% N application compared to the 50% and 150% doses. Application of nitrogen fertilizer from ZA sources resulted in better growth and yield than urea. Giving a dose of 100% ZA was able to suppress the need for a dose of urea which was indicated by the higher tuber weight yield than the need for a dose of 125% urea.