Allelochemicals are widely known to have antagonistic effects on the environment by inhibiting the physiological activities of other plants. However, this is the whole characteristic of allelochemicals since their effects are not only limited to inhibiting. In low concentration, allelochemicals could have a promoting effect on other plants especially on the germination and seedling stage. This research was conducted to examine the allelochemical activity of Parthenium hysterophorus L., Eucalyptus creba F. Muell., and Casuarina cunninghana Miq. on Lepidium sativum L. with the sandwich method. The leaves of parthenium, eucalyptus, and casuarina were dried and layered between two 5 mL agar in multi well plates and the sterilized seeds of Lepidium sativum L. were set to germinate on the agar. The results showed that the leaves of parthenium, eucalyptus, and casuarina caused lower germination rate compared to the control treatment but led to the greater shoot and root length of Lepidium sativum.

Abstract. Laboratory management is an important thing where the laboratory is a facility or as a place that can be used to apply a scientific theory. Labor managers usually print documents on A4- size paper and paste them next to laboratory tools. This causes documents to be damaged quickly, can reduce aesthetics, and not suitable for small laboratory tools. The purpose of making this QR- Code sticker, the author was designed to serve laboratory users and may provide digital information and materials to laboratory users to acquire knowledge.The process of making QR-Code was conducted for 2 months, from August to September 2021.QR-Code manufacturing stages were inventory of laboratory tools, inputting documents into Google drive, testing with blackbox methods and attaching QR-Code stickers to laboratory tools. The results obtained of QR-Code stickers are fliyer and QR-Code stickers taped to several soil and agroclimat laboratory tools, it is hoped that the laboratory management system can be improved better

One of the high-quality processed vegetable food ingredients is tofu. Tofu is made from processed soy milk with a thick texture and molded according to the right nutritional amount. White tofu is the most popular of the various forms of tofu available. Today, tofu producers have taken manipulative actions to anticipate production losses by including preservatives in the mix of ingredients used to make tofu. Most of the tofu production centers provide additional ingredients in the form of preservatives such as formalin to reduce losses from damage to the tofu they produce. The presence or absence of formalin in food can be detected using a unique component found in dragon fruit peel called anthocyanins. The methodology applied in this research is a simple and direct one, with primary data collected in the form of testing samples of white tofu collected from numerous traditional markets in the Banten area (up to ten samples). The aim of the research is to identify formalin in white tofu discovered in numerous traditional markets in Banten using natural component extracts, including dragon fruit peel extract. The results stated that there were two positive samples containing formalin and eight negative samples; the presence of formalin in tofu was indicated by a red color on the tissue. Sellers or customers can detect formalin simply by utilizing dragon fruit, allowing them to avoid formin which is harmful to health, with a simple and low-cost method.