Good to Know Technique
Processing tomato ripening: how to increase Brix and color
Foliar fertilization to promote uniform ripening, yield, and tomato quality.
22/07/2026
Summary:
In processing tomatoes, ripening and coloration directly affect Brix degree, quality, and crop value. Targeted nutrient management can favor sugar accumulation, dry matter content, and berry uniformity. This in-depth analysis examines the physiological processes and a technical foliar strategy with ETIXAMIN™ BIO-K and ILSAKOLORADO™.
Processing tomato ripening: related critical issues
In processing tomatoes, the final stage of the crop cycle is a decisive phase for expressing yield and quality. Suboptimal ripening management can generate high variability, both in berry uniformity and sugar content (°Brix).
At the root of these agronomic challenges is often an imbalance between vegetative activity and the reproductive phase. When the plant continues to produce new vegetation in late stages, fruits compete with vegetative apices for assimilates, slowing berry filling and ripening. This physiological imbalance directly affects the production outcome:
- Increase in rejects
Non-uniform ripening leads to a significant proportion of berries still green or improperly colored at harvest, which are penalized or excluded during delivery. - Reduced delivered quality
Suboptimal sugar translocation limits the accumulation of soluble solids in fruits, resulting in lower Brix values and reduced industrial value. - Lower harvest efficiency
Uneven ripening makes it more difficult to identify the optimal harvest timing, increasing qualitative losses and reducing field operational efficiency.
Physiology of ripening: sugar accumulation and lycopene synthesis
In the pre-harvest phase, the tomato plant enters a physiological stage in which it must progressively shift its metabolic activity from vegetative growth to fruit accumulation. Sugars are produced in the leaves through photosynthesis, but their contribution to Brix depends on the plant’s ability to transfer them to the berries. This process occurs through the phloem and is regulated by osmotic gradients, plant water status, and metabolic efficiency.
At the same time, pigment synthesis is activated in the fruits. The transition from green to red is linked to the accumulation of lycopene, a carotenoid whose formation depends on enzymatic activity and the availability of energy substrates. Ripening and coloration are therefore closely connected processes: both require a metabolically active, balanced plant capable of consistently supplying the fruits.
Limiting factors for ripening and coloration
Under field conditions, these processes are often slowed or become less efficient due to several factors:
- Prolonged high temperatures (>30–32°C) can reduce or inhibit lycopene synthesis, leading to incomplete or uneven coloration.
- Nutritional imbalances—especially excess nitrogen in late stages—maintain the plant in vegetative activity, reducing assimilate flow to fruits.
- Water management also has a direct impact. High water inputs near harvest dilute soluble solids and sustain vegetative vigor, while sudden stress can interrupt sugar translocation.
The result is non-uniform ripening, with berries showing marked differences in color, sugar content, and maturity level.
Nitrogen management: controlling vigor in late stages
Nitrogen nutrition is one of the main factors influencing the balance between vegetative growth and ripening. When nitrogen remains available in high amounts during late stages, the plant continues producing new tissues. This behavior increases internal competition for assimilates and reduces the share of sugars allocated to fruits. Limiting nitrogen availability in the final phase allows the plant to redirect resources to the berries, supporting filling and dry matter accumulation.
Role of potassium: supporting translocation and accumulation
Unlike nitrogen, potassium plays a central role during ripening. It directly affects mechanisms regulating sugar transport:
- contributes to phloem transport regulation
- regulates osmotic gradients
- supports cellular water balance
Adequate potassium availability therefore enables more efficient assimilate translocation toward fruits, with direct effects on Brix degree and berry firmness. In deficiency or imbalance conditions, this process slows down and fruits contain less dry matter.
Irrigation management: balance between accumulation and dilution
Water management directly impacts ripening processes. Excess water in late stages dilutes fruit sugars and maintains vegetative growth, delaying ripening. Conversely, a gradual and controlled reduction in water supply—known as regulated water stress—can promote soluble solids concentration without inducing plant decline, with positive effects on Brix. A balanced irrigation strategy is therefore essential to guide the plant toward ripening, avoiding both excess and sudden shortages.
Nutrition and biostimulation: supporting physiological processes
In real field conditions, maintaining optimal balance through irrigation and base fertilization alone is not always feasible. For this reason, foliar applications can serve as a useful tool to support plant physiology during sensitive stages.
The objective is not only to supply nutrients, but to improve:
- assimilate translocation efficiency
- metabolic continuity under stress conditions
- the plant’s ability to complete ripening processes
Within this framework lies the ILSA strategy, involving targeted applications during veraison and ripening stages to support a more uniform and higher-quality result.
ILSA foliar strategy: acting where the plant needs it most
In such a dynamic scenario, foliar fertilization can become a particularly useful technical tool, as it allows direct intervention on plant physiology at key ripening stages. The approach is not simply nutritional supply, but modulation of metabolic processes according to crop needs: improving assimilate translocation, supporting metabolism under stress, and enhancing final fruit quality.
The strategy is structured around two closely linked stages:
- veraison, preparing the plant for ripening
- the subsequent phase, focusing on fruit quality and coloration
ETIXAMIN™ BIO-K: potassium-based fertilizer to support metabolic transition
ETIXAMIN™ BIO-K is a nutritional solution based on amino acids and potassium, formulated to support plant metabolism during the transition from vegetative growth to ripening. When applied at veraison in processing tomatoes, it can promote:
- metabolic activity under stress conditions
- photosynthetic efficiency
- sugar translocation toward fruits
The product is designed to support the plant during a delicate stage, favoring better assimilate allocation and preparing the crop for ripening.
ILSAKOLORADO™: foliar biopromoter designed to enhance coloration and sugar accumulation
ILSAKOLORADO™ is a bioactivator specifically developed for the ripening phase, formulated to stimulate berry coloration processes and final fruit quality.
Applied a few days before harvest, it can help improve:
- pigment synthesis (lycopene)
- dry matter accumulation
- ripening uniformity
Application at this stage can support the expression of the crop’s qualitative potential, potentially contributing to a more homogeneous increase in color and Brix degree.
Agronomic and economic benefits of the strategy
Proper ripening management can enable several advantages:
Agronomic perspective:
- greater berry uniformity
- improved coloration
- reduction of green fruits
Economic perspective:
- increased Brix degree
- reduced rejects
- optimized harvesting operations
These aspects can contribute to increasing Gross Marketable Production per hectare.
ILSA nutrition: a physiological approach to the crop
The strategy based on ETIXAMIN™ BIO-K and ILSAKOLORADO™ is designed to manage plant physiology during critical stages, with the aim of directing the plant toward ripening, supporting metabolism, and helping growers enhance berry quality.
FAQ – Frequently asked questions
How to increase Brix in processing tomatoes?
Promoting sugar translocation from leaves to fruits and properly managing irrigation and nutrition—especially potassium—can be beneficial. During veraison, foliar applications with ETIXAMIN™ BIO-K, thanks to its amino acid and potassium content, can support metabolic activity and may help improve assimilate transfer efficiency toward the berries.
The most suitable stage is veraison, when accumulation and coloration processes begin. At this stage, ETIXAMIN™ BIO-K can support metabolic transition, followed by ILSAKOLORADO™ in later stages to accompany ripening and final fruit quality.
Color heterogeneity is often linked to physiological imbalances: excessive vegetative vigor, unbalanced nutrition, or unfavorable environmental conditions. When the plant cannot efficiently complete ripening, lycopene synthesis becomes irregular. Targeted applications with ILSAKOLORADO™ in final stages can help improve coloration uniformity.
Yes, it can be, because it allows direct and timely intervention on plant physiological processes. In particular, ETIXAMIN™ BIO-K at veraison and ILSAKOLORADO™ at advanced ripening can support assimilate translocation and coloration and dry matter accumulation processes, respectively.
Higher Brix may enable greater product valorization in the processing industry, as well as reduced rejects related to immature or non-uniform fruits. Targeted nutritional strategies, including foliar applications at key ripening stages, can contribute to improving these parameters and overall crop profitability.
The information provided herein is for general informational purposes only. Actual results may vary depending on agronomic conditions, application timing, soil type, climate, crop variety, and other local factors. Product use should conform to label directions and applicable local regulations.
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