Roots Reserve Analysis
Deciduous species, in their first stages of development during the season, are supported by various reserve nutrients accumulated during the preceding cycle. All nutrients, including nitrogen, phosphorous, and potassium, are absorbed by plants in various ionic forms.
AGQ Labs provides you the necessary technical tools to contribute to better planning of the crop’s productive period. The lab reports are followed-up with an interpretation of the results by our Agronomy team. These recommendations will vary according to the levels obtained in the results of Arginine, Starch, Phosphorus, and Potassium.
The goal is to verify Nitrogen reserves and their availability to be metabolized. The nitrogen required for initial growth (first sprouting stage) comes from the nitrogen stored as a reserve. In the vine, there is a preferential form of storage that is expressed as Arginine concentration in roots.
The purpose is to determine the carbohydrate reserves. The starch concentration in the roots gives us a clear reference of the accumulated energy (energy potential) that the plant has in its initial growth in order to be able to absorb mineral elements that require energy expenditure, such as potassium. Carbohydrates are divided into three groups:
- Structural carbohydrates: celluloses, hemicelluloses, etc.
- Simple molecules: glucose, fructose, etc.
- Carbohydrate reserve: Starch, which is insoluble, must be split in order to be used. This is stored in the roots to be split into simple molecules or structural carbohydrates, and in this process, they bind with minerals to form Arginine.
The objective is to know the amount of Phosphorus available during initial root growth. A low accumulation of phosphorus in the roots at the end of the dormancy can be associated with decayed vines or branches. Initial signs of decay associated with phosphorus deficiency are due to the lack of energetic metabolism of the plant.
A large percentage of potassium is concentrated in the fruits, and potassium demand would be covered by what can be accumulated in the aerial part of the plants, which is accomplished when potassium levels are at normal levels in the aerial part. This is not always achieved, due to the insufficient monitoring of the plants and deficient programs that end early in the cycle. It has also been described that better budding and production have been obtained when the potassium levels in the roots range between 0.35% and 0.45%.
Suggested sampling periods for a proper Roots Reserve Analysis are as follows:
- Pre-pruning: sample extraction between 10 and 2 days prior to pruning to measure reserves. The decision to begin nitrogen fertilization will be based on this data.
- Post-harvest: after the harvest is finished to measure the wear of the crop.