Drought and Heat Harm Brazil’s Harvest

Tacy CalliesBrazil

Lack of rain withered this commercial citrus orchard in Jales (north São Paulo state). The photo was taken in October 2020.

By Maurício Mendes

There is a saying among those who have been in the industry for a long time: “There is no citrus harvest like the other.” Growers are facing production challenges in the current harvest season in Brazil.

The first signs of a decrease in the season’s fruit crop were given by last year’s (August to September 2019) bloom. This was a period with limited rainfall and high temperatures that caused fruitlet drop. Fruits grew up to 2 to 3 centimeters in diameter but were then overturned by excessive heat. In some regions, trees bloomed again in December 2019, which was not enough to compensate for previous losses. 

The period from May to October 2020 without rainfall was one of the most extensive droughts ever recorded in the Brazilian citrus belt. In addition to the extended drought, heat waves caused considerable weight and fruit-quality impairment.

Overall fruit losses were greatest in the northern part of São Paulo state and in Triângulo Mineiro (an area in the west of Minas Gerais state) — the driest and hottest regions of the citrus belt.

The first crop forecast released by Fundecitrus in September 2020 was for production of 287.8 million boxes of oranges, 25 percent lower than in the previous crop season (2019–2020). This forecast was revised in December to 269 million boxes of oranges, indicating another 6.4 percent loss.

The hot, dry climate caused extremely withered orchards. With irrigation only available in approximately 27 percent of the citrus belt, many growers could not fully irrigate trees.

Because of uneven flowering from August 2019 to January 2020, trees will bear a large proportion of ripe fruits grown after the normal flowering period (August to September 2019), mixed with unripe fruits grown later. This characteristic will certainly hinder the next harvest, increasing picking costs. Furthermore, the mixture of such fruits from different flowering periods during harvest will impair the quality of juice produced, especially due to the high amounts of limonin in the orange peel. In the northern region of the citrus belt, fruits are ripening fast, which will cause increases much higher than normal in the soluble sugar to acidity ratio.

Citrus orchards in the southernmost regions of the citrus belt bloomed during the spring, between late August and September 2020. However, irregular rainfall and high temperatures (Table 1) just after are concerning growers about the size of the crop. Some orange varieties, mostly the early ones, exhibit good fruit set. On the other hand, Pera and Valencia, medium and late varieties, are not exhibiting similar fruit set.

Moreover, orchards in the northernmost regions exhibited a late bloom (November 2020), after resuming rainfall in the last days of October 2020. However, high temperatures in summer will likely cause severe fruit drop that will also affect crop size.

Experience demonstrates that fruit harvest after irregular climate conditions, as was the case this year, is usually not good. However, we will have to wait a little bit more to see what we can expect from the next crop season.

Maurício Mendes is a citrus grower, citrus consultant and member of GCONCI (Citrus Consultants Group), which provides direct technical assistance to more than 40 million citrus trees in the Brazilian citrus belt.