Managing Citrus Total Soluble Solids (TSS)
The TSS content of the fruit is usually obtained from assessing the 0Brix of the fruit.
The TSS or sugar content measures and includes the carbohydrates, organic acids, proteins, fats and minerals of the fruit.
It represents from 10-20% of the fruit's fresh weight and increases as fruit matures to produce a less acidic, sweeter fruit. It is important that the grower aims to produce an acceptable balance of TSS and fruit acidity (see TSS/Acid ratio).
Crop Nutrition and Citrus TSS
Potassium and nitrogen have a relatively minor effect on TSS. However, boron, iron, manganese and zinc all increase TSS. Molybdenum, on the other hand, will induce a reduction in TSS.
Boron
Boron increases the levels of sugars in the fruit. In these trials - particularly on sweet orange - there was almost a 50% increase in TSS from use of a 0.6% application.
Iron
Use of iron effectively increases the level of sugars in the fruit. Trials show increases where iron is deficient across Pineapple oranges, Washington navels, and Balady mandarins.
Manganese and zinc
Manganese - often in association with zinc - increases TSS contents of the fruit. It can also help improve the ascorbic acid content of the fruit. As a result, manganese has little influence on the TSS/Acid ratio and this combination of improved sugars and acidity content produces more desirable fruit for the consumer.
Recommended Yara Fertilizers for Citrus
| Leaf Analysis All Citrus Fruits | |||||
| Deficient | Marginal | Adequate | High | Toxic or Excessive | |
| N (%) | <2.2 | 2.2 - 2.3 | 2.4 - 2.6 | ||
| P (%) | <0.09 | 0.09 - 0.11 | 0.12 - 0.16 | 0.17 - 0.25 | >0.25 |
| K (%) | <0.04 | 0.04 - 0.69 | 0.7 - 1.5 | 1.6 - 2.3 | >2.3 |
| S (%) | <0.14 | 0.14 - 0.2 | 0.21 - 0.4 | 0.41 - 0.5 | >0.5 |
| Ca (%) | <1.6 | 1.6 - 2.9 | 3.0 - 6.0 | >7.0 | |
| Mg (%) | <0.16 | 0.16 - 0.25 | 0.26 - 0.6 | 0.7 - 1.2 | >1.2 |
| Na (%) | <0.16 | 0.17 - 0.25 | >0.25 | ||
| Cl (%) | <0.3 | 0.4 - 0.7 | >0.7 | ||
| Cu (mg/kg) | <3 | 3.0 - 5.0 | 6.0 - 10.0 | 11.0 - 15.0 | >15.0 |
| Zn (mg/kg) | <16 | 16 - 24 | 25 - 80 | 90 - 300 | >300 |
| Mn (mg/kg) | <16 | 16 - 24 | 25 - 80 | 90 - 300 | >300 |
| Fe (mg/kg) | <36 | 36 - 60 | 61 - 120 | 121 - 200 | >200 |
| B (mg/kg) | <21 | 21 - 30 | 31 - 100 | 101 - 260 | >260 |
| Mo (mg/kg) | <0.06 | 0.06 - 0.09 | 0.1 - 3.0 | 3.0 - 100 | >100 |
| Samples taken from 5 - 7 month old, healthy leaves, from the middle of non-fruiting, spring extension growth. | Ref: Plant Analysis An Interpretation Manual - Second Edition by Reuter and Robinson | ||||
YaraVita®
Ensure that leaf/fruit samples have sufficient boron, iron, manganese and zinc to maintain a high TSS content in the fruit and use YaraVita® foliar products to correct any imbalances.
See more about YaraVita® products.
YaraVita MANGAZIN
YaraVita Mangazin is a highly concentrated flowable formulation containing manganese and zinc in significantly higher concentrations than most liquid solutions and liquid chelates.
The fluid formulation makes it easy to measure, pour and mix the product in the spray tank, while giving the highest nutrient content.
The product is specifically formulated to provide maximum crop safety. This helps to ensure that application will not cause damage to the crop which can reduce it's market value.
The purity of raw materials selected for this product makes it safe for application to the crop and helps ensure that the harvested produce will not be rejected at any point in the supply chain.
A controlled particle size gives quick uptake and long lasting effect. This reduces the need for repeat applications saving both time and money.
A broad tankmixability makes it easy to co-apply the products with agrochemicals, saving both time and money. Just as important, free access to Tankmix information online or via smart phones makes it quick and easy to check whether products can be co-applied.
YaraVita POWERBOR Ca
YaraVita Powerbor Ca is a highly concentrated flowable product containing significant levels of calcium, boron and zinc.
The fluid formulation makes it easy to measure, pour and mix the product in the spray tank, while giving the highest nutrient content.
The product is specifically formulated to provide maximum crop safety. This helps to ensure that application will not cause damage to the crop which can reduce it's market value.
The purity of raw materials selected for this product makes it safe for application to the crop and helps ensure that the harvested produce will not be rejected at any point in the supply chain.
A controlled particle size gives quick uptake and long lasting effect. This reduces the need for repeat applications saving both time and money.
A broad tankmixability makes it easy to co-apply the products with agrochemicals, saving both time and money. Just as important, free access to Tankmix information online or via smart phones makes it quick and easy to check whether products can be co-applied.
