Adding diversity to your cropping system can help naturally control insect herbivores 

An increase in plant diversity decreases the need for pesticides. A team of German researchers found that increasing plant biodiversity enhanced natural pest control (Barnes et al. 2020). This could reduce the need for pesticide applications. 

In organic operations, making a conscious effort to increase the kinds  of plants could result in healthier plants with better yields. For example, instead of planting a field of tomatoes only, add basil or oregano in the rows to attract bees and garlic to help repel pests. In addition to providing a healthy and diverse environment, this plant grouping will also add a little zing to your pasta sauce. 

Why diversity works:

  1. Insects eat less: The original study found that in more diverse grassland communities the feeding rate of insects was 44% less  than the feeding rate in a grass monoculture. It is harder for insects to find their preferred plant to snack on in a diverse system. Interestingly, plants in a mixed group contain less nitrogen which makes them less appealing to insects.
  2. Plants grow better surrounded by a mixed group of friends. Diversity increases the total biomass of an area when compared to a monoculture.
  3. Predators thrive in a diverse setting. Both the biomass and the feeding rates of predators such as spiders, beetles and wasps increase.

Read the original research paper here: DOI: 10.1126/sciadv.abb6603

Reference:

Tomatoes ripen on the vine.

Plants communicate at a molecular level

Tomatoes can identify the parasitic vine dodder, Cuscuta spp., as an invader. Dodders do not make chlorophyll so they cannot make their own food. Instead the sneaky plant grafts itself to a tomato or other host plant using special suckers. It steals water, carbohydrates (sugars) and minerals from the host plant. Since dodder can not make its own energy it depends totally on other plants. Dodders do not kill their host but they weaken it. These plant parasites are found in every state.

Researchers found that tomatoes have special receptors in their cell walls that recognize the molecular protein pattern of the dodder (Hegenauer et al. 2020). This triggers the tomato's immune reaction and enables the tomato to fight back against the dodder. This knowledge may help plant breeders select for tomatoes with more resistance to dodder.

Read the research paper and see pictures here: DOI: 10.1038/s41467-020-19147-4

Reference:

Volker H, Slaby P, Körner M, et al. The tomato receptor CuRe1 senses a cell wall protein to identify Cuscuta as a pathogenNature Communications, 2020; 11 (1) DOI: 10.1038/s41467-020-19147-4