Field trial with root-knot nematodes
A Good Experimental Practice-compliant trial was performed between
September 2019 and February 2020 in a naturally nematode-infested
greenhouse in Ispica (Sicily, Italy; coordinates 36.723783°N
14.968736°E) by SATA s.r.l (Quargernata, Italy). Treatments were
arranged in a randomized complete block design with four 22
m2 plots per treatment (22 tomato plants per plot,S. lycopersicum ‘Ciringuito F1’, planted September
9th 2019). The pre-trial nematode population was
assessed as in Hallmann & Viaene (2013). PA was applied using a
handheld sprayer (300 µM PA, 0.1% (v/v) DMSO and 0.1% (v/v) Tween 20)
three times: eight and one days before transplanting and two weeks after
transplanting. The nematicide Cedroz (Eastman), containing geraniol (121
g l-1) and thymol (41 g l-1), was
used as a reference treatment and was applied per the manufacturer’s
guidelines (9 l ha-1 total, 6 fortnightly
applications). Starting in October 2019, four (intermediate assessments)
or ten (final assessment) tomato plants per plot were uprooted and
evaluated for vigor, phytotoxicity and galling severity on the Zeck
scale (Zeck 1971). Yield was evaluated by picking and weighing ripe
fruits weekly between December 2019 and February 2019.