Protected agriculture: Precipitation in spring and summer make up a scenario of high vulnerability in cranberry production in southern Chile
Blueberry production presents productivity gaps, packaged fresh fruit and fruit condition at destination. This is often caused by extreme climatic events that occurred during critical periods of the crop, and which undoubtedly limit competitiveness in this important area of production.
Flowering rainfall y in harvest period they are the causes of greater losses of productivity and condition of fruit in destination. In this regard, studies conducted by INIA have determined that spring rains have a direct relationship with the productivity of the crop. Depending on the distribution and frequency of flowering precipitation - the most vulnerable period - there are significant drops in yield.
According to Abel Gonzalez, specialist of INIA-Carillanca, the precipitations majors to 75 mm in full state of flowering cause strong falls in the number of yolks curdled, with falls of yield of until a 45%, respect to a normal year.
Table 1: Distribution and accumulation of precipitation (mm) in harvest period, in three regions of southern Chile. Season 2013-14.
Source: Elaboration based on information registered by www.agromet.inia.cl
On the other hand, in summer there are high probabilities of precipitation (Figure 1). Thus, depending on the number and intensity of rainfall, it has been possible to evaluate that up to an 40% of the total fruit of an orchard is destined to IQF after 4 events greater than 10 millimeters of precipitation. Another negative aspect attributable to summer rainfall is the influence of these on the frequency of harvest. When a rain event occurs, the harvesting must stop until the fruit is dried by the sun, producing collaterally on maturity and softening of the fruits harvested in a rainy summer. In addition to the above, the fruit packed for fresh in years with high rainfall at harvest presents problems of condition at destination expressed mainly in the presence of the mycelium of Botrytis cinerea, softening and dehydration.
Figure 1. Number and intensity of effective rainfall (> 10 mm) for three productive regions in harvest period in southern Chile. Seasons 2011-2012 to 2016-2017.
"The interaction of all the aforementioned events undoubtedly influences and limits the obtaining of a fruit with good quality at destination, and there is no postharvest technology that can solve a problem generated during the pre-harvest," says Portal Frutícola, Bruno Defilippi, specialist of the Postharvest Unit of INIA.
Why crop protection?
The level of climatic risk in agricultural activity is the result of the interaction between the components of threat and vulnerability. It has undoubtedly been evident that rainfall is one of the main threats that limit the competitiveness of the blueberry industry.
"Indeed, the crop is vulnerable not only in summer during the harvest stage, as was normally thought, but according to the studies carried out, said period is longer and extends from full flowering onwards.", Indicates González.
"Therefore, in the face of the evidence, it is necessary to adopt protection measures that minimize the vulnerability of the crop and thereby make the business more competitive."He adds.
In this scenario, it is pertinent that, at the industry level, the configuration of varieties in each orchard is analyzed from different angles. Even more when currently in the southern zone of the country, more than 80% of the surface is constituted by varieties of long flowering, therefore of high vulnerability. In this sense, it is necessary to consider in the current validation studies of new varieties of blueberries, which include the clear and precise determination of the phenological behavior of the variety in each agroclimatic zone. Having said the above, it is possible to deduce that it is fundamental for a new variety to be able to express the genetic potential, it must be adapted to the climatic conditions of southern Chile, not only in terms of thermal parameters.
In this way, a variety of high productive level, will express all its potential, to the extent that shows late blooms and whose extension of the period does not exceed 30 days. The foregoing, moreover, is consistent with the idea of looking for varieties whose concentrated harvests allow a labor productivity, since they contain more fruit for each harvest.
In parallel, it is necessary to evaluate the relevance of using crop protection technologies, and thereby reduce the climatic risks typical of southern Chile, or another area with similar climatic restrictions. The work teams of the INIA Carillanca Fruit Platform and the Post-harvest Unit of INIA La Platina, are developing a project whose main objective is to determine the impact on productivity, packaged fruit (quality at harvest) and the storage potential in postharvest ( postharvest quality), of the use of two types of coverage (RAFIA and LDPE) of protection to the effect of extreme environmental conditions, which occurred during critical periods during flowering and fruit development, such as rainfall, frost and excessive temperature, considering three production areas.
A second project financed by Corfo, as indicated Bruno Defilippi, and developed in conjunction with the University of Concepción, Asoex (Committee of Blueberries) and FDF, aims to define a technological package of management in replacement varieties produced under a coverage system. As Dr. Defilippi points out, only by understanding well what, and how the management and climatic variables affect the fruit's yield and quality, will it allow an adequate establishment of these technologies to allow to offer, on the part of producers and exporters, a blueberry of excellent overall quality in aspects of appearance, texture or firmness, and flavor.
These works are being financed by the following CORFO projects:
Protective technologies in blueberry orchards to mitigate climate risks and their impact on yield and postharvest quality of fruit destined for the export market as fresh ".
Technological Program for Export Fruit Production South Central Zone. Technological package of postharvest handling of new blueberry replacement varieties.
Source: Fruit Portal
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