- In the post-harvest, determining processes occur such as floral differentiation, root recovery and accumulation of carbon and nitrogen reserves..
- During this period it is important to avoid stressing the plant so as not to interrupt its fundamental development processes..
The productive potential of an orchard is directly related to the cultural management that ensures the integrity of the plant in the extensive post-harvest period, which also coincides with the period of floral differentiation and with a very important moment which is the accumulation of carbon and nitrogen reserves.
The post-harvest period begins approximately 90 to 120 days after full bloom (DDPF) and is recognized as the root recovery period for most rootstocks. This root recovery is associated with two very important processes, namely, nutrition management and irrigation scheduling.
In general, a large part of cherry nutrition is focused on post-harvest. In vigorous or medium-vigor rootstocks, nitrogen fertilization should be incorporated in post-harvest at around 70 to 80% of the annual amount, as well as with respect to potassium and to complete the demand for other nutrients such as magnesium, often calcium and phosphorus. In this sense, the post-harvest of cherries, in nutritional terms, should not be neglected.
“If we look at the action of the root system in full development, it is adapted and practically coordinated and programmed to grow, absorb and take advantage of everything that is the nutritional component in terms of recovery.” commented Carlos Tapia, Director of Avium.
In terms of irrigation, if the plant is developing its root system, it is directly related to improving, maintaining or perfecting the entire post-harvest irrigation schedule. It is extremely important to address irrigation at this time, from the point of view of soil water distribution. The amount of water being applied is not necessarily sufficient, but that amount has to be related in some way to the efficient distribution of water in the soil.
“The literature speaks of the decrease in post-harvest crop coefficients, but it has been recognized in Chile that post-harvest crop coefficients can often be high, even reaching close to 1.4, considering the efficiency of the different irrigation systems, the plant's capacity to take this water from the soil, the climatic conditions, the development, the vigor condition of the trees, among others. Therefore, we should not only talk about the importance of post-harvest in terms of preventing stress with the use of some agents, such as sunblock, but also as the best way to present soil nutrition, associated with optimal and timely management in this period." Tapia added.
Any abnormality in terms of stress during this period is directly detrimental to the accumulation of reserves and, in parallel, to the formation and development of the flower primordia in the fruit centres that will be involved in the production of the following season. It is therefore essential to avoid this in order not to interrupt these fundamental processes in production.
Post-harvest stress can occur, among other factors, due to an abiotic effect, mainly due to water deficit and/or excess temperature, and a biotic effect caused by a pest or disease. Abiotic stress occurs mainly because plants, generally with a lower vegetative development and/or with a deficit of irrigation, do not have the capacity to make continuous gas exchange to the atmosphere, producing stomatal closure, not capturing CO2 for the generation of sugars and poor formation of flower primordia in the fruit centres, generating loss of fertility and malformations in fruits. It is necessary to consider that the floral induction period (FI) begins approximately 70 days after full flower (DDPF) and the floral differentiation period (FD) begins approximately 100 DDPF, both processes being highly dependent on water and thermal stability in the plant at these times of greatest atmospheric demand.
