Sunflower (Helianthus annuus L.) is one of the most cultivated oil crops in the world. Given its high dependence on water availability, its cultivation in the Mediterranean area is severely threatened by climate change: very hot and dry weather conditions currently occurring in the Mediterranean area have a negative impact on sunflower yield. Many studies have pointed to earlier sowing dates as a promising strategy to prevent summer drought stress causing sunflower yield losses, but the literature on winter sowing dates is scarce. The aim of this research was to quantify the interplay between sowing date (winter time included) and water regime to sustain sunflower cultivation in the Mediterranean area. A field experiment and a modeling study were carried out to evaluate the effects of different sowing dates (00SD: ‘conventional sowing date’ in March/April and ‘earlier sowing dates’ in December-January-February, depending on years) under two different water regimes (irrigated vs. rainfed) on quantitative traits of high oleic cultivars of sunflower. Field experiments revealed that sowing in late February - mid March was the most effective strategy in terms of achene productivity. Achene production by sunflower was also simulated using EPIC under a baseline climatic scenario and for 4 hypothetical sowing dates (D1: 10th January, D2: 10th February, D3: 10th March, D4: 10th April) and different irrigation strategies. The most effective sowing date was D3 under rainfed conditions, confirming the results of the field study. Irrigation from 20 days before anthesis up to flowering significantly improved achene yield for the early sowing dates (D1 and D2), which almost reached their respective yield potentials. This confirms that an earlier sowing date could be a viable management strategy in Mediterranean areas with little water availability.

向日葵 ( Helianthus annuusL.) 是世界上种植最多的油料作物之一。鉴于其对水资源的高度依赖，其在地中海地区的种植受到气候变化的严重威胁：地中海地区目前发生的非常炎热和干燥的天气条件对向日葵产量产生了负面影响。许多研究指出，早播日期是防止夏季干旱胁迫导致向日葵产量损失的有希望的策略，但有关冬季播种日期的文献很少。这项研究的目的是量化播种日期（包括冬季时间）和水情之间的相互作用，以维持地中海地区的向日葵种植。进行了田间试验和建模研究以评估不同播种日期（00SD：对比雨养）对向日葵高油酸品种数量性状的影响。田间试验表明，就瘦果产量而言，2月下旬至3月中旬播种是最有效的策略。还使用 EPIC 在基线气候情景和 4 个假设播种日期（D1：1 月 10 日，D2：2 月 10 日，D3：3 月 10 日，D4：4 月 10 日）和不同的灌溉策略模拟了向日葵的瘦果产量。在雨养条件下，最有效的播种日期是 D3，这证实了田间研究的结果。从开花前20天到开花的灌溉显着提高了早播日期（D1和D2）的瘦果产量，几乎达到了各自的产量潜力。