The influence of leaf traits and deficit irrigation on insect communities in mature green tomato production

Drought affects many agriculturally important areas, hampering the cultivation of water intensive crops such as tomatoes. Unlike processing tomatoes, deficit irrigation of fresh market tomatoes is not currently practiced. Deficit irrigation could have negative trade‐offs for yield and pest populations by changing plant nutritional values and the microenvironment. The present study compared crop response and insect populations at two field locations: an on‐farm trial with 0%, 15% and 30% water deficit treatments, and a research station trial with 0%, 10%, 20% and 30% water deficit treatments. At the on‐farm trial, water deficits of 30% affected fruit yield, leaf relative water content (RWC) and leaf δ¹³C, whereas, in the research station trial, water deficits only affected leaf RWC. Treatments did not change the abundance of any insect groups. Sap‐feeding insects such as silverleaf whitefly (Bemisia tabaci) increased with plant traits indicating hydration such as canopy temperature depression (CTD) and RWC. Furthermore, CTD influenced the composition of insect communities. Sap‐feeding insect abundance may vary with traits indicating hydration because of turgor pressure required for feeding, as well as a more suitable microenvironment.