Without Brix, Your Crop Has No Value and Is More Susceptible to Pests
Fatma Abd Alazez
Horticulture and Pomology Research, Agricultural Data Collection, Curriculum Development, Analysis Data, Provide Research-based Recommendations, Create Educational Material, Sale Support, and Prepare Marketing material.
What is Brix?
Brix is known as a measure of sugar content, expressed as a percentage of the total solution. It was named after Adolf Brix, a mathematician and engineer who invented an instrument to measure sugar content in beer. However, plant tissues don’t just contain sugar—they also have other compounds like amino acids, organic acids, minerals, and vitamins that can affect the Brix reading. That's why the term Brix has been expanded to include Total Soluble Solids (T.S.S.), where sugar is usually the dominant component. Therefore, Brix is often used as an indicator of fruit sweetness: the higher the Brix value, the sweeter the fruit.
The Brix level in fruit is typically higher than in leaves, with fruit reaching up to 20%, while leaves rarely exceed 20%. This increase in Brix in fruit reflects the plant's goal of boosting sugar levels in the fruit, which contain seeds and aid in the spread and survival of the species. Brix values aren’t constant—they rise as the fruit develops and start to decline as it ages.
Benefits of Measuring Brix:
1.???? Quality: If a plant is rich in sugars and other beneficial components like acids, minerals, vitamins, oils, and resins, it indicates that the crop is of high quality.
2.???? Overall Plant Health: A high Brix value reflects that the plant is nutrient-rich, meaning it's efficiently carrying out photosynthesis and absorption.
3.???? Shelf Life: Fruits and vegetables with higher Brix values last longer; enzymes and vitamins may decline over time, but the mineral content remains stable.
4.???? Determining Ripeness and Harvest Time: Brix can be used to determine crop ripeness and the best time for harvest. It's especially useful for non-climacteric fruits like citrus, grapes, and cherries, while for climacteric fruits, it’s better to rely on other ripeness indicators, particularly dry matter content.
5.???? Pest Resistance: Plants with high sugar levels are less susceptible to pests and diseases. Insects are often attracted to plants with low Brix, while avoiding healthy, sugar-rich plants. For example, spider mites don't favor plants rich in sugar and minerals. If they do attack, the sugar in the plant ferments into alcohol, which the mites can't digest, leading to their natural death. This creates natural pest resistance without using toxic chemicals. Additionally, a high sugar concentration causes osmotic pressure that draws water out of the insect's body, leading to its dehydration. Healthy plants also have strong cell walls, making it harder for insects to penetrate.
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Brix Levels and Pests:
Some research suggests that plants with a Brix value of 12 or higher do not face significant issues with insect pests, while plants with lower values may be more vulnerable. Different pests tolerate different Brix levels, and there’s a chart that shows Brix levels and the types of pests that prefer certain values. The four groups are:
1.???? Grasshopper Group: This includes long-horned grasshoppers (Tettigoniidae) and crickets. These insects target plants with Brix levels of 10 to 12, with lower infestation in plants with a Brix below 10.
2.???? Chewing Group: This includes beetles (Coleoptera) and butterflies and moths (Lepidoptera). Infestation decreases at Brix levels of 9 to 11. Below this range, the plant is more vulnerable to this type of pest.
3.???? Sucking Group: This includes leafhoppers (Cicadellidae), froghoppers (Cercopoidea), planthoppers (Fulgoromorpha), stink bugs (Pentatomidae), and thrips (Thysanoptera). Infestation decreases when Brix levels are between 7 and 9. Below this range, the plant is more susceptible to this type of pest.
4.???? Aphid Group: Insects in this group prefer low Brix values, below 6 to 8, as they cannot handle high sugar levels.
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How to Measure Brix:
Brix can be measured using a refractometer, which relies on measuring the refractive index.
Dr. Carrie Remy has also created a table showing the appropriate Brix levels for different fruits and vegetables, which you can check out in the images.
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How to Increase Brix:
1.???? Irrigation: During the fruit ripening period, reducing irrigation can increase sugar content in the fruit. However, this practice requires a lot of expertise because excessive reduction in irrigation can harm the plant.
2.???? Pruning and Ventilation: Proper pruning should be done to allow sunlight to reach all the leaves, enhancing photosynthesis.
3.???? Fertilization:
o?? Avoid using fertilizers with a high salt index, as they negatively affect Brix content by causing osmotic pressure, reducing the plant’s ability to absorb nutrients efficiently.
o?? Avoid overuse of nitrogen fertilizers during this period, as they direct the plant towards forming new vegetative parts like leaves and branches, reducing sugar levels in the fruit.
o?? Reduce nitrate use, as the plant absorbs nitrates and converts them into ammonium, which requires large amounts of carbohydrates for energy.
o?? Increase potassium levels: Potassium should be increased during the ripening stage as it helps transport sugars from leaves to the fruit.
o?? Add iron: Iron helps in forming chlorophyll and enhancing photosynthesis efficiency.
4.???? Temperature: High temperatures increase respiration and burn carbohydrates, affecting Brix content. This effect can be mitigated by monitoring weather conditions and taking measures like irrigation and shading.
5.???? Use of Pesticides: Using insecticides and herbicides can kill beneficial microbes in the soil. Since these substances persist for long periods, attempts to renew microbes by inoculating the soil with them are ineffective, as soil containing these pesticides is toxic.
6.???? Soil Improvement:
o?? Maintain well-structured soil by adding organic compost to improve its structure and enhance its nutrient content and beneficial microbes.
o?? Add organic acids like citric and humic acid to lower the pH level and help in nutrient availability, especially calcium, which enhances water and nutrient absorption by strengthening the plant’s roots and vascular system.
o?? Add seaweed to increase root mass, as it stimulates cell division and aids in greater nutrient absorption, and chelates nutrients, making them available to the plant.
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Monitoring liquids is my passion
5 个月Fatma Abd Alazez Great work. As a seller of refractometers, this article gives me very good arguments why farmers should measure the Brix value regularly. Perhaps one day this concept will prevail worldwide, although many are still not convinced at the moment and are therefore reluctant.
Project Manager at Samoa Coconut Cluster
6 个月Using Brix measurements in Samoa to evaluate plant health I found that with what would be considered low brix levels, I was achieving pest resistance for pests that should have been eating the plants at those levels. For pak choi for example at a 3 brix level the plants were left alone, but below that they got eaten by diamond back moth.
Passionate about healthy soil, healthy food, healthy planet, and healthy people.
6 个月Fatma - Thanks for writing and sharing your article on Brix. I want share the actual story of how the brix chart came to be. Adolf Brix invented the refractometer and used it to check the ripeness of grapes. In the early 1930’s Carey Reams was a student taking a collage chemistry class in Florida. The chemistry lab had just procurrred a refractometer which at the time was a very expensive instrument. Reams had extra time on his hands and used the refractometer to check Brix readings on a lot of produce and crops in his area. He discovered extremely wide variations in crops such as alfalfa and carrots. At first he was puzzeled to find wide variations on the same varieties. By digging deeper he discovered that the farmers using limestone and more phosphate fertilizers had the higher Brix. During this time he also observed that high quality alfalfa will have a solid stem all the way to the crown but low Brix alfalfa will be hollow stemmed. This is what lead Reams to understand that the refractometer was actually an instrument to test for quality. The second discovery was that the environment in soil plays a significant role in helping the plant reach its full potential.
Account Manager, Agriculture Sales, Agronomist (Central California) at Verdesian Life Sciences
6 个月A few years back I wrote some articles on Brix. Importance in most crops including forage crops. Most agronomists including those I worked with had a hard time believing Brix makes better hay with higher feed values. Thanks for the update.
--Organic citrus farmer in the central valley, always looking for innovative solutions organically. Farming is an everyday learning experience and I’m always up for the challenge. High quality citrus is my passion.
6 个月Very good article Thank you