Influence of sowing dates and sunflower varieties on the development of fungal diseases in Ludewa-Njombe, Tanzania

The study was conducted across three locations in the Ludewa District of Tanzania, namely Nkomang’ombe, Ludewa mjini, and Madope to assess the impact of sowing dates and sunflower varieties on the occurrence of major diseases. A split-plot design within a Randomized Complete Block Design (RCBD) framework was employed, featuring three sowing dates (15th January 2024, 30th January 2024, and 15th February 2024) and three sunflower varieties: Variety one (V1) Local variety (Nyeupe), Variety two (V2) record variety, and Variety three (V3) Hysun 33. The findings revealed that sowing dates had no statistically significant effect on overall crop performance, except for plant stand. Disease incidence and severity were significantly lower when crops were grown in Ludewa mjini and with the use of Variety one (V1) and Variety two (V2). Nkomang’ombe recorded the highest disease severity and incidence. Varieties and locations significantly influenced sunflower performance, except for plant stand across varieties. Additionally, Variety one (V1) outperformed the others in all assessed parameters, including height, plant stand, capitulum size, yield, disease severity, and disease incidence. This study highlights the importance of selecting suitable varieties to improve sunflower seed quality and optimize agricultural production.