‘BRS Cainguá’, a blackberry fresh-market cultivar

One of the reasons for the low market demand of blackberries in Brazil is the acid taste of the fresh fruit. The fruits of the newly released cultivar BRS Cainguá taste better and have a very attractive shape.


INTRODUCTION
Small fruits with high anthocyanin content such as blackberries are becoming very popular due to their positive effect on human health. However, one of the factors reducing the market demand of blackberries in Brazil is the acid taste of the fresh fruit.
Blackberry breeding in Brazil was initiated in the late 1970's, in collaboration with the University of Arkansas (USA). In the following years, a boysenberry from Uruguay and pollen and seeds introduced by USDA (Oregon) and the University of Arkansas were included in the program, resulting in the development of the following cultivars: Ébano in 1981 (Raseira and Moore 1981), Negrita (obsolete) in 1983, Tupy and Guarani in 1988, Caingangue in 1992(Raseira and Franzon 2012, BRS Xavante, in 2004(Moore et al. 2004) and BRS Xingu in 2015 (Raseira et al. 2018). All cultivars except Ébano and Xavante have thorny stems. Presently, over 200 selections and about 6000 seedlings are under evaluation, and another few thousand will be included this year.

CULTIVAR CHARACTERISTICS Origin
Cultivar BRS Cainguá was derived from a cross made in 2004, between Selection 2/96 as female parent and cultivar Caingangue as pollen. The origin of Selection 2/96 is unknown. Cultivar Caingangue is a cross between cultivar Cherokee, introduced from the University of Arkansas, and selection Black 1. Black 1 is a selection made in Embrapa from a cross made at the University of Arkansas, in 1975, between Shaffer tree and Brazos (Figure 1).
After scarification and cold vernalization for about three months, the seeds of the above-described cross of 2004 were sown in a greenhouse. In 2006, the seedlings were transplanted to the field and the resulting progenies identified as C 2004-04. During the 2008 growing season, the first plant of this progeny was selected and propagated for further tests, now called Black 212. The flowering and harvest dates were recorded as well as total yield per plant, stem growth habit and plant health. Fruit weight and shape, total soluble solids (TSS) content and fruit quality were also observed (Table 1)

Plants
The stem of BRS Cainguá is erect to semi-erect, with short internodes. It has fewer and smaller thorns than 'Tupy' or 'BRS Xingu'. The plants have low to medium vigor but are very productive. Leaves are light green with small stipules. The plants are not resistant, but less susceptible to rust than 'Tupy'. As the plants are less vigorous than 'Tupy', they can be planted at a higher density.

Fruits
The fruits of cultivar BRS Cainguá are elongated, have a good appearance ( Figure 2) and pleasant taste for the fresh market. The firmness and gloss of the fruits are medium, and the size is larger than of those of 'Tupy' (Table 1). Over a 6-year period, the yield of 'BRS Cainguá' was very similar to that of 'Tupy'.
In 2018, due to a very hot dry season (unirrigated cultivation) with maximum temperatures of 34.5 °C and 36.7 °C, in November and December, respectively, and hotter than 30 °C on several days, the production of all cultivars and