杂草却能帮助果树结更多的果实，您相信吗？

诸平

Fig. 1 Blaire Kleiman in the field, preparing to count mangos. Credit: Florida International University

Fig. 2 Weeds growing around a mango tree.

据美国佛罗里达国际大学(Florida International University简称FIU) 安吉拉·尼科莱蒂（Angela Nicoletti）2022年2月10日报道，世界上最不受欢迎的植物帮助树木结更多的果实（The world's most unwanted plants help trees make more fruit）。上述照片来自佛罗里达国际大学，布莱尔·克莱曼(Blaire Kleiman)在田里，准备数芒果。

在任何关系中，保持火花不灭都是困难的。果树想要吸引传粉者尤其困难。但是，FIU环境研究所(FIU Institute of Environment)的研究生助教和校友布莱尔·克莱曼等人，发现了一个意想不到的来源——杂草(Weeds)，使这种关系卓有成效。

这些通常不受欢迎的野生植物（Weeds）可能对人类没有特别的吸引力，但它们确实对蜜蜂和蝴蝶等重要的传粉者产生了影响。事实上，杂草的存在对树木和传粉者都有好处，这也意味着美国南佛罗里达最受欢迎的水果之一会更受欢迎。

布莱尔·克莱曼说：“杂草实际上有很多好处。把它们想象成野花，而不是这些需要除掉的可怕、丑陋的东西，可能会有帮助。我说，如果它们没有伤害树木，我们就应该让他们留下来。”

我们称它们为需要授粉的植物，但果树没有传粉者是无法生存的。蜜蜂和其它昆虫已被证明可以提高世界上70%的主要经济重要作物的产量和质量，包括芒果。

但是把蜜蜂带到树上越来越难了。在过去的三十年里，传粉者的数量急剧下降。这可能意味着世界上的芒果要少得多(一个没有人愿意去想象的世界)。

然而，当果树和传粉者走到一起时，相互吸引的游戏才刚刚开始。树木必须保持传粉者的兴趣，这样它们就会逗留在周围，而不会飞到别处去寻找另一棵树。

农民有时依靠食虫植物为生。顾名思义，这些特殊的植物会吸引传粉者，并鼓励它们留在农场。布莱尔·克莱曼想看看杂草是否也能扮演类似的角色，因为有数百种不同种类的开花杂草。

在FIU Suzanne Koptur教授和Krishnaswamy Jayachandran教授的指导下，布莱尔·克莱曼比较了佛罗里达州Homestead当地农场的芒果树。有一块地的树木周围长满了杂草。另一块地经过维护，没有杂草。

传粉者更喜欢有杂草的树木。反过来，这些树也从中受益，产出了更多的芒果。事实上，有杂草的树上有100到236个芒果，而没有杂草的树上只有38到48个芒果。

布莱尔·克莱曼指出，这些发现不仅适用于芒果树，也适用于地球上所有约80%的开花植物，包括果树和所有开花蔬菜，如番茄、豆类、茄子和南瓜。她还希望这些信息可以帮助农民节省时间和金钱，并减少化学杀虫剂的使用。这项研究最近在《昆虫》（Insects）杂志网站上发表——Blaire M. Kleiman, Suzanne Koptur, Krishnaswamy Jayachandran. Weeds Enhance Pollinator Diversity and Fruit Yield in Mango. Insects, 2021, 12(12): 1114. DOI: 10.3390/insects12121114. Published: 13 December 2021. http://dx.doi.org/10.3390/insects12121114.此研究到得了美国农业部Hispanic-Serving机构教育拨款(HSI)计划[U.S. Department of Agriculture’s Hispanic-Serving Institutions Education Grants (HSI) Program]的资助。

上述介绍，仅供参考。欲了解更多信息，敬请注意浏览原文或者相关报道。

一项新的研究表明，种植更多的灌木篱墙和树木可能是帮助英国蜜蜂再次茁壮成长的关键(Planting more hedgerows and trees could hold the key to helping UK bees thrive once again, a new study argues)

Simple Summary

There is an urgent pollinator decline crisis across the globe, with fewer pollinators and yet increasing agricultural reliance on them to produce food and fiber crops for growing populations. Habitat loss and chemical eradication of unwanted plants has limited the floral resources for pollinators, and in farms with only one crop, there are limited resources solely during the flowering season. Weeds, or unwanted vegetation, are often the only remaining floral resource for pollinators, yet they are compulsively removed using chemicals. This article examines how weedy floral resources affect pollinators in a mango farm, Mangifera indica, a pollinator-dependent crop in South Florida, and how fruit yield is affected by either leaving weeds or removing them.

Abstract

Agriculture is dependent on insect pollination, yet in areas of intensive production agriculture, there is often a decline in plant and insect diversity. As native habitats and plants are replaced, often only the weeds or unwanted vegetation persist. This study compared insect diversity on mango, Mangifera indica, a tropical fruit tree dependent on insect pollination, when weeds were present in cultivation versus when they were removed mechanically. The pollinating insects on both weeds and mango trees were examined as well as fruit set and yield in both the weed-free and weedy treatment in South Florida. There were significantly more pollinators and key pollinator families on the weedy mango trees, as well as significantly greater fruit yield in the weedy treatment compared to the weed-free treatment. Utilizing weeds, especially native species, as insectary plants can help ensure sufficient pollination of mango and increase biodiversity across crop monocropping systems.