Quantification of yield gaps and understanding their causes in sunflower ( L.) is a key requirement for developing management strategies to take advantage of the productive potential of this crop in Argentina. The term yield gap (Yg) refers to the difference between water-limited potential yield (Yw) and actual yield (Ya). This study quantified sunflower Yg across its full range of cropping regions of Argentina and used the results to identify potential causal factors. This study, structured around component climate zones, proceeds in two steps. In the first, Yg is calculated by three methods according different Yw estimators: (i) yield simulations using CROPGRO-Sunflower model; (ii) top yields of comparative yield trials; and (iii) top yields of farmer's paddocks. Corresponding Ya values were estimated from national statistics. In the second, an independent database was established from the Regression trees were used to explore associations between technological variables and estimated Yg. National sunflower Yg remained consistent across the different Yw estimation methods: 34 % via simulated yields, 40 % using comparative yield trials, and 34 % based on farmer's paddock yields. Tillage system, phosphorus fertilization, and the adoption of herbicide- resistant and high oleic cultivars were key factors in explaining the smaller sunflower Yg in Argentina. Argentina has the potential to substantially increase its sunflower grain production, and key factors to increase current production were identified in this work. Increased sunflower production could boost Argentina's exports, contributing significantly to its economy. The identified factors pave the way for designing practices that help farmers bridge the yield gap.

中文翻译：

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阿根廷向日葵产量差距及其原因


量化向日葵 (L.) 的产量差距并了解其原因是制定管理策略以充分利用阿根廷向日葵作物生产潜力的关键要求。术语产量差距（Yg）是指水限制潜在产量（Yw）与实际产量（Ya）之间的差异。这项研究对阿根廷整个种植区的向日葵 Yg 进行了量化，并利用结果确定了潜在的致病因素。这项研究围绕组成气候区进行，分两个步骤进行。首先，根据不同的 Yw 估计量，通过三种方法计算 Yg：（i）使用 CROPGRO-Sunflower 模型进行产量模拟； (ii) 比较产量试验的最高产量； (iii) 农民围场的最高产量。相应的 Ya 值是根据国家统计数据估算的。第二步，从回归树中建立了一个独立的数据库，用于探索技术变量和估计的 Yg 之间的关联。全国向日葵 Yg 在不同的 Yw 估算方法中保持一致：34% 通过模拟产量，40% 使用比较产量试验，34% 基于农民围场产量。耕作制度、施磷肥以及采用抗除草剂和高油酸品种是解释阿根廷向日葵 Yg 较小的关键因素。阿根廷有潜力大幅增加其向日葵谷物产量，这项工作确定了增加当前产量的关键因素。向日葵产量的增加可以促进阿根廷的出口，为其经济做出重大贡献。已确定的因素为设计帮助农民缩小产量差距的做法铺平了道路。