Young researcher: Salome Arewa

Salome Arewa won the ISHS Young Minds Award for the best oral presentation at the XVIII International Symposium on Processing Tomato, which was held in Monterey for her paper entitled: “Optimizing Transplanting Windows to Reduce Tuta absoluta Losses in Commercial Processing Tomato Production in Northern Nigeria“.

In sub-Saharan Africa, the processing industry faces severe disruptions due to the invasive tomato pinworm (Tuta absoluta), a pest whose development accelerates under high temperatures. To establish practical scheduling interventions, this study evaluated how different transplanting periods interact with pest arrival, final output, and fruit quality parameters. Field data were gathered during the 2024–2025 dry season across 31 large-scale commercial blocks in Kaduna State, Nigeria, evaluating three distinct planting intervals: early (November 5–21), mid (November 23–December 7), and late (December 9–19).

Climatic tracking via an on-site sensor suite revealed an increasingly hostile microclimate as the season progressed, with weekly ambient averages climbing to 30.9°C and the vapor pressure deficit reaching a maximum of 3.50 kPa. This intense environmental aridity heavily compressed the pest’s lifecycle, leading to devastating agricultural consequences for delayed crops. The timing of the initial transplanting exerted an exceptionally strong influence on crop performance (p < 0.001). Fields established during the early window achieved an outstanding mean yield of 42.8 t ha⁻¹. In contrast, late-transplanted fields suffered a catastrophic 82.5% collapse, dropping to a meager 7.5 t ha⁻¹.

The specific developmental stage of the crop at the moment of pest colonization proved critical to final productivity. Infestations occurring at the highly vulnerable bloom stage caused severe flower drop, limiting final volumes to just 12.6 t ha⁻¹, whereas fields infested post-ripening maintained a high baseline of 45.2 t ha⁻¹. Spatial tracking also revealed a notable edge effect, with field borders exhibiting significantly lower output (32.8 t ha⁻¹) than the central core zones (48.8 t ha⁻¹). Meanwhile, raw material processing quality remained highly stable, as soluble solids (°Brix) did not fluctuate across the temporal windows.

Ultimately, these findings demonstrate that optimizing the initial planting date serves as a powerful, cost-free cultural barrier. By completing field establishment before late November, commercial producers can effectively shield the sensitive reproductive phase from peak pest pressure, ensuring raw material volume stability for industrial processing without sacrificing fruit quality.

The contents of Salome’s presentation will be published alongside other research work presented during the symposium in a special edition of Acta Horticulturae.