The importance of boron in citrus plantations

Brazil is the world's largest citrus producer and exporter of concentrated orange juice, according to the National Association of Citrus Juice Exporters (CitrusBR). And oranges, like other citrus fruits, play an important role in health, as they are rich in vitamin C. The World Health Organization (WHO), for example, recommends a minimum consumption of 45 mg/day of this vitamin, number which can be achieved by ingesting an orange.

The Brazilian population seems to have seen the benefits of vitamin C coming from citrus, and this has guaranteed producers a greater flow of fruit production. This achievement is only possible thanks to the high productivity of the crop - the correct balance of the number of fruits on the tree, with ideal size and weight -, but which begins with balanced plant nutrition, with all the essential macro and micro nutrients to help the build a healthy tree structure that can withstand this load, thus ensuring that they reach productive potential, and meet market demands.

For citrus plants to complete their life cycle, performing metabolic and structural functions of great relevance for plant development, boron is a very important element. The presence of the nutrient must also be involved in germination and cell growth, which is why plants well nourished with boron have a lower rate of floral abortion and, consequently, greater fruit production. Using an adequate supply has a positive effect on juice yield, increases sugar content and improves flavor, in other words, everything the consumer is looking for in a product in this category.

Therefore, it is clear to observe plantations that suffer from boron deficiency, as citrus can present abnormalities in growth, development and reproduction. The absence of boron generates the possibility of weakening the plantation, fruits with reduced size, wrinkled, with little juice and the likelihood of albedo collapse, which is nothing more than the loss of cohesion between the layers below the skin.

As a solution to the problem of sudden citrus death, to maintain high productivity, some farmers use rootstock citrumelo swingle, as it has shown greater resistance to this disease. This rootstock has a greater need for boron than the others to express its full productive potential, and the dose applied must be at least 3 kg per hectare year in adult plants on rootstock. citrumelo swingle while for the others 2 kg is sufficient, remembering that excess on these rootstocks can harm the plantation.

Given these recommendations, it is clear that the correct management of nutrients is essential for superior quality production, favoring the profitability not only of the producer, but of the entire production chain.

Bruno Dittrich is an agronomist and agronomic specialist in citrus at Yara Brasil.