The effects of nematicide rotation on banana (Musa AAA cv. Williams) root weight, root nematode control, and crop yield
were compared in a commercial banana plantation in Ecuador, testing six treatments in a randomized complete block design
with six replicates. Treatments consisted of two, three and four differing nematicide cycles per year plus the untreated control.
Regarding the untreated plants and averaging the 24 root nematode samplings after treatment application, the nematicide
application reduced significantly R. similis (P<0.0001) between 20 and 49%, Helicotylenchus spp. (P<0.0001) between 31 and
51%, and total nematode population (P<0.0001) between 29 and 49%. Accordingly, in the treated plants, there was an increase
between 16 and 21% in living root weight (P=0.0003), and its percentage (P<0.0001) reached between 74.5 and 81.7% in
the follower suckers. In addition, the death of roots by nematodes decreased (P=0.0009) between 20 and 46%. At harvest,
nematicide application increased bunch weight (P=0.0002; P=0.0467), ratio (P=0.0003 at 12 months), ratooning (P<0.0001;
P<0.0001) and the number of boxes of 18.14 kg (P<0.0001; P=0.0005) per hectare per year at 12 and 24 months after treatment
application, respectively. Plants treated with nematicides increased yield between 671 and 1,158 (12.2-21 t) and between 545
and 1,046 (9.9 - 19.0 t) boxes of 18.14 kg per hectare per year, which resulted in a net (deducted the nematicide cost and
packing of the additional boxes) profit between US $3,266 -$5,750 and between US $2,587 and $5144 per hectare per year at
12 and 24 months after treatment application, respectively.