Seasonality of coffee vegetative growth

Understand the seasonal characteristics of the vegetative growth of coffee helps to optimize crop management, as well as such as planning the crop fertilization program. That's why the importance of understanding this process and its particularities in the main producing regions.

Temperature and water stress are characterized as the climatic factors that most affect the development of the coffee tree. Temperatures below 13ºC and deficit accentuated water conditions affect several components involved in the process photosynthetic, as they lead to a reduction in stomatal conductance, net photosynthesis, the photochemical efficiency of photosystems, the electron transport in thylakoid membranes, enzymatic activity, as well as carbon metabolism, also altering the composition and structure of photosynthetic pigment complexes, lipid and fatty acid classes with different intensities between genotypes and species.

Highs air temperatures can cause denaturation and aggregation of proteins, increased production of reactive oxygen species, ethylene synthesis and evaporative demand, which may cause stomatal closure and reduced of CO2 supply, with a consequent decrease in photosynthesis liquid. In turn, when in conditions of higher CO2 concentration, these metabolic damage is mitigated due to the “fertilization” effect caused to the plant, due to the increase in photosynthetic rates and production of photoassimilates.

To understand The seasonal characteristics of coffee vegetative growth help to optimization of crop management, mainly in pruning, irrigation, as well as planning the crop fertilization program. Furthermore, it must be considered that the success of Crop production is conditioned to good growth and development of the plant, since grain production occurs in new buds and the emission of buds depends on the elongation of plagiotropic and orthotropic branches. In that context, the seasonal behavior of the C. canephora in the three main regions producers (Espírito Santo, Bahia and Rondônia) and in Rio de Janeiro, as well as regional and management particularities.

Spirit Santo: evaluation of different genotypes

O work was carried out in the municipality of Nova Venécia, Espírito Santo, evaluating plagiotropic and orthotropic branches of 14 genotypes. However, they will be Two genotypes are presented, one representative (behavior similar to that of majority) and another that corresponds to the exception (different behavior). The work was published in full in the Journal of Agricultural Science, vol. 5, no. 8, p. 108-116, 2013.

The results suggest that the rate of growth of the orthotropic and plagiotropic branches of C. canephora are divergent between genotypes and present seasonal variation throughout the year, mainly influenced due to variations in air temperature. At minimum air temperatures below 17,2ºC, the growth rate of branches is greatly reduced for most studied genotypes (Figure 1A), with the exception of the V8 genotype (Figure 1B) which maintained a high growth rate before and after the temperature drop in mid-August.

These results suggest different mechanisms of adaptation between genotypes to low temperature. Therefore, the majority of Conilon coffee genotypes grown in the North of Espírito Santo demand greater amount of nutrients for growth between mid-September and second week of May.

Bahia: irrigated and non-irrigated coffee tree

The work was carried out in the municipality of Itabela, Bahia, to evaluate plagiotropic and orthotropic branches of the genotype called “02” by Emcapa, irrigated and non-irrigated. Only the behavior of orthotropic branches. The work was published in full in Acta Scientiarum, v. 38, no. 4, p. 535-545, 2016.

In general, the work allowed us to affirm that irrigation provides increased productivity of Conilon coffee in the Atlantic region of Bahia, even in years with rainfall greater than 1200 mm. The growth rate of the orthotropic (Figure 2) and plagiotropic branches is superior in plants irrigated compared to non-irrigated. Maximum growth rates occur in spring.

Unlike what happens in Espírito Santo and Rio de Janeiro, the growth rate of Conilon coffee branches is not limited by temperature average air minimum. The greatest nutritional demand for vegetative growth occurs from September to January.

Amazon:coffee tree fertilized and unfertilized

The research was carried out in the municipality of Rolim de Moura, Rondônia, evaluating plagiotropic and orthotropic branches of fertilized and unfertilized plants. The work was published in full in Coffee Science, vol. 12, no. 2, p. 50 - 59, 2017.

The research allowed us to verify that the Mineral fertilization provides higher branch growth rates plagiotropic (Figure 3) of coffee trees in certain periods, under conditions studied. There are seasonal variations in vegetative growth throughout the throughout the year in the South Western Amazon, with maximum growth between mid- September to early April, when there is greater rainfall and the average maximum temperatures below 33ºC. Therefore, fertilization, associated vegetative growth must be prioritized during this period, due to greater nutritional requirement of the plant to maintain growth rates and to grain production, which occur concomitantly in this period.

River de Janeiro: Different ages of branches

The fourth region presented refers to work carried out in Campos dos Goytacazes, Rio de Janeiro, to evaluate plagiotropic branches of different ages and orthotropic branches. The work was published in full in Coffee Science, v. 12, n. 2, p. 50 - 59, 2017.

The growth rate varies throughout of the year (Figure 4). A higher rate was observed when the average minimum air temperature was above 17ºC and the average maximum temperature below 31,5ºC. Below 17ºC the growth rate of branches decreased significantly. The seasonal pattern of branch growth is similar, however, plagiotropic branches of different ages present rates of different growth rates in the same period of the year. Thus, studies on the Seasonal vegetative growth of branches should be based on groups of branches with different ages.

BOX - The coffee

The genus Coffea is represented by at least 125 species, of which C. arabica (Arabica coffee) and C. canephora (Conilon or Robusta coffee) correspond to the production of 99% of what is one of the most valuable products of the global economy, coffee . In 2016, more than 150 million bags were harvested worldwide, of which 95 million were C. arabica and 56 million were C. canephora. It is characterized as a product with great social and economic importance, as it generates 175 billion dollars, being produced by more than 25 million families.

Brazil is the world leader in coffee production and exports, totaling 51,4 million bags processed in 2016, of which 43,38 million were Arabica and 7,99 million Conilon/Robusta. For many years, Conilon coffee has been the main raw material for soluble coffee. In recent years it has been increasingly added to Arabica coffee to accentuate the flavor of the drink or even consumed pure. As a result, there is a significant increase in the search for improvements in production to add quality to the product, and such improvements are linked to crop management, processing and coffee preparation.

Article published in issue 223 of Cultivar Grandes Culturas, December 2017/January 2018.