Late applications in homogenizers: Earlier is not better!

The autumn-winter months begin and, like every year, we evaluate the results of the previous season and plan the next one, a process in which we ask ourselves the question: how is the cold build-up going? When will the Chinese New Year be? And what homogenizer strategy will be optimal? Do I apply only hydrogenated cyanamide or do I use it in tandem with another product? These questions and many others must be answered in order to define an optimal start to the season.

Before mentioning the advantages and benefits of Prostart Plus, it is important to remember the basics and relevance of winter rest in cherry trees and other deciduous fruit trees. As well as the bases that support later applications.

First of all, the recess stage is a phenological stage that plays a physiological role in plants, therefore, it is not an isolated event and both the previous and subsequent stages will define the behavior of the plant and its productivity. In this sense, the 23-24 season is an example of what can happen when there are post-harvests and recess periods and the beginning of sprouting with many limitations (insufficient cold, floods, late rains and accumulation of poor-quality degree days; Figure 1). Therefore, the post-harvest and the adequate choice of our recess exit strategy will determine the potential for productivity and quality.

FIGURE 1

In seasons when the Chinese New Year is “early”, we tend to rush into selecting aggressive strategies, not so effective and highly stressful for our plants.Is it a bad idea to use cyanamide and “tandems” with caustic dormancy breakers? The above is a not so friendly strategy, however, highly suggested in years with low cold accumulation and variety/rootstock combinations that give precocity and are located in early areas. However, although the use of cyanamide and more friendly homogenizers in years of low and inadequate cold accumulation, they may not present differences or arrive (harvest date) from 2 to 4 days with respect to their more aggressive competitors (Very specific for early areas and short cycle varieties), the size and other quality and productivity parameters are lower. While in years with adequate or excellent cold accumulation, the harvest date is exactly the same between both strategies (aggressive vs. friendly products), but the productivity, quality and size parameters are always higher.

What happens when we apply in early stages? 

There is no doubt that the use of cyanamide in conjunction with tandem homogenizing products is important in current agronomic management. However, when observing the application of a tandem of a “caustic” homogenizer plus calcium nitrate 7 days after cyanamide, it shows a “low” penetration of the products (Figure 1). However, when “friendly” products are applied at late times (green tip), the penetration and movement inside the bud is much deeper and more direct in the tissue (Figure 2). The above allows us to intuit that early applications may be inconsistent, depending on the effectiveness of the application and the capacity to damage the bracts and expose the tissue to the environment (forcing activation). On the contrary, late applications and the use of formulations that enter and stimulate the tissue are more effective and can generate more benefits to productivity and quality. However, not all available products have the capacity to be applied at that time.

What do we mean by a more friendly homogenizer? 

Prostart Plus It is the first homogenizing-synchronizing biostimulant on the market and is also the most “friendly”, and whose formulation has a nutritional component (Amine Nitrogen, Calcium, Magnesium, Zinc and Boron) and compounds that promote the natural activity of growth-promoting phytohormones, generating an adequate hormonal relationship in the buds, relieving the stress generated by hydrogenated cyanamide, and stimulating a more homogeneous and synchronous sprouting of vegetative and floral buds. 

Benefits and advantages:

It is the first product of its kind in the national market; hundreds of trials in different variety-rootstock combinations, agroclimatic zones and seasons (more than 20 years; Figure 3); It can be used as a tandem to homogenize, synchronize and advance the precocity of fruits if applied 7 days post cyanamide in tandem with calcium nitrate or another accompanying salt. It is the only product in the segment with the greatest consistency in size and quality (Table 1 and Table 2).

FIGURE 3

TABLES 1 AND 2

Last but not least, we must remember that, although the entry into recess and the accumulation of cold have been optimal, the development at the beginning of spring will be determined by the accumulation of degree days, and, therefore, will be an ally or obstacle for the optimal functioning of homogenizing products.

Figure 1. Cross section of buds applied with hydrogenated cyanamide and “caustic” homogenizer in tandem with calcium nitrate. A: Longitudinal section, front view; B: Longitudinal section, rear view; C: Longitudinal section and penetration zone. 

Figure 2. Histological section of buds in green tip stage with aqueous solution and dye (A) and “friendly” homogenizer with dye (B).

Figure 3. Performance of 7 seasons of Prostart Plus on Royal Dawn cherry. Location Rosario, O´Higgins Region. 

Table 1. Caliber distribution in Santina cherry trees in Rancagua, 2022-2023 season.

Table 2. Leaf area per shoot in Santina cherry trees in the Sagrada Familia locality, 2021-2022 season.