Abstract Pests and diseases threaten cacao production worldwide. Agroforestry systems are traditionally seen by farmers as one of the causes of increased pest and disease incidence, in contrast with full-sun monocultures. Cultural management practices—e.g. regular tree pruning, frequent pod harvest, regular removal of infested pods, weed management—have been reported to be crucial for pest and disease management. We performed two experiments for the purpose of assessing the effect of (i) different cacao production systems, and (ii) the frequency of harvest and removal of infested pods on the incidence of pests and diseases and on the cacao yield. The first experiment was performed in a long-term system comparison trial in Bolivia, where data on pest and disease incidence were recorded for three years in five production systems: two monocultures and two agroforestry system under organic and conventional farming, and one successional agroforestry system, i.e. a high tree density multi-strata system. Pest and disease management did not differ between systems and relied on cultural management practices. Overall, the incidence of pests and diseases did not differ between production systems, which indicated they were not the driver of yield differences between them. Across production systems, only 14% of the pods were affected by pests and diseases; 70% of these were affected by frosty pod rot. More than 80% of the pods infected by frosty pod rot were removed before the sporulation phase. In the second experiment, the effects of the frequency of harvest and removal of infected pods—every 15 days versus every 25 days—on pest and disease incidence and yield were tested in four farmers’ fields. Fortnightly harvest and diseased pod removal significantly decreased disease incidence and increased cacao yield, by 25% and 46% respectively. Our results show that cacao agroforestry systems do not increase pest and disease incidence compared with monocultures when good cultural management practices are implemented, which, in turn, can increase the productivity of the cacao plantations.

中文翻译：

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在良好的文化管理实践下，与单一栽培相比，可可农林业系统不会增加病虫害发生率

摘要 病虫害威胁着全世界的可可生产。与全日照单一栽培相比，农林业系统传统上被农民视为病虫害发生率增加的原因之一。据报道，文化管理实践——例如定期修剪树木、频繁收获豆荚、定期清除受侵染的豆荚、杂草管理——对病虫害管理至关重要。我们进行了两个实验，目的是评估 (i) 不同的可可生产系统，以及 (ii) 收获和移除受侵染豆荚的频率对病虫害发生率和可可产量的影响。第一个实验是在玻利维亚的长期系统比较试验中进行的，其中记录了五个生产系统中三年的病虫害发生率数据：有机和常规耕作下的两种单一栽培和两种农林业系统，以及一个连续的农林业系统，即高树木密度的多层次系统。病虫害管理在系统之间没有差异，并依赖于文化管理实践。总体而言，病虫害发生率在生产系统之间没有差异，这表明它们不是造成它们之间产量差异的驱动因素。在整个生产系统中，只有 14% 的豆荚受到病虫害的影响；其中 70% 受到霜状荚腐病的影响。在孢子形成阶段之前，80% 以上的被霜状荚腐病感染的荚被去除。在第二个实验中，在四个农民的田地中测试了收获和移除受感染豆荚的频率（每 15 天和每 25 天）对病虫害发生率和产量的影响。每两周一次收获和去除病荚显着降低了病害发生率并增加了可可产量，分别为 25% 和 46%。我们的结果表明，当实施良好的文化管理实践时，与单一栽培相比，可可农林业系统不会增加病虫害发生率，这反过来又可以提高可可种植园的生产力。