The state of São Paulo, Brazil, renowned for its agricultural productivity, is currently confronting substantial obstacles in its watermelon cultivation. Elevated temperatures combined with a scarcity of rainfall have precipitated a series of challenges, notably in the Marília/Oscar Bressane region. Growers in this area have reported increased incidences of viruses and infestations by whiteflies, pests that thrive under such climatic conditions. Additionally, the excessive heat has resulted in sunburned fruit skins, diminishing both the aesthetic appeal and commercial value of the watermelons. Consequently, the initial harvests are anticipated to yield below-average productivity.
In contrast, regions like Presidente Prudente and Itápolis have experienced these viral issues less frequently, suggesting that the impact of climatic stressors can vary significantly across different locales. The first watermelon harvest commenced in early March and is expected to intensify by month’s end, with a secondary, shorter harvest concluding in late April.
These climatic challenges are not isolated to São Paulo. The Brazilian semi-arid region, a major watermelon producer, frequently grapples with drought periods that directly affect crop yields, especially since rainfed agriculture predominates among small and medium producers. Research indicates that drought conditions can significantly impair photosynthetic efficiency in watermelon plants, with reductions of up to 60% in CO₂ assimilation observed under certain stress conditions. However, it’s noteworthy that short-term drought stress does not drastically affect fruit productivity, underscoring the crop’s resilience to brief periods of water scarcity.
The current climatic adversities in São Paulo underscore the critical need for adaptive agricultural practices. Implementing integrated pest management strategies, optimizing irrigation systems, and selecting drought-resistant cultivars are essential steps to mitigate the adverse effects of climate variability on watermelon production. Such measures will be pivotal in sustaining both the quality and yield of crops in the face of environmental challenges.
