1. Introduction
Pineapple, Ananas comosus, is one of Hawaii’s main
agricultural export commodities contributing 100% to total
United States production of pineapple. However, the status
of pineapple as a competitive crop has been degraded over
the past years. Reniform nematode, Rotylenchulus reniformis
(Fig. 1a), is the main plant-parasitic nematode (PPN) of
pineapple that causes a reduced yield. This pathogen reduces
pineapple marketable yield by 26.8-50%. Pineapple lacks host
resistance and adventitious roots do not regenerate after
pruned by PPNs. This nematode problem demands a suitable
nematode management measure. Spirotetramat (Movento®)
(Fig. 1b) is an insecticide that is a lipid biosynthesis inhibitor
with a unique two-way systemic movement in the phloem
and xylem of plants. Spirotetramat inhibits acetyl CoA
carboxylase, a lipid biosynthesis enzyme. Like in insects, lipids
play significant physiological roles such as embryogenesis
and molting in PPNs.
The effect of Spirotetramat (Movento®) against Reniform nematode,
Rotylenchulus reniformis, on pineapple, Ananas comosus
Philip Waisen* and Brent Sipes
College of Tropical Agriculture and Human Resources, Plant and Environmental Protection
Sciences, 3190 Maile Way, Honolulu, Hawaii 96822
Figure 1. a) Female reniform nematode protruding from the
roots b) chemical structure of spirotetramat.
To determine the effect of spirotetramat on the fertility of
Rotylenchulus reniformis on pineapple.
Results & Discussion
Objective
MG3 pineapple crowns were planted in
autoclaved soil in 20-cm-d biodegradable pots in
the greenhouse. Experimental units were
arranged in CRD with spirotetramat levels 0, 88,
100 and 175 g a.i/ha, and 3 replicates.
 The maximum nematode vermiform population
reduction was 64% and achieved with 88 g a.i/ha
spirotetramat with a corresponding reduction in
dry root weight of 14.4% and an increase in shoot
weight of 1.4% compared to the untreated control.
 As the vermiform population decreased the shoot
weight increased (inverse relationship), thus
disease pressure was reduced and plant growth is
enhanced.
Conclusion
 Spirotetramat at 88 g a.i/ha achieved a maximum
reduction of 64% over the 6-month period.
 This study is providing a clear evidence that
spirotetramat affects nematode reproduction.
 We are currently repeating this experiment to
validate the results
Acknowledgment
We thank the Dole Plantation for providing pineapple
crowns.
Materials and Methods
a b
Hypothesis
Spirotetramat is expected to reduce the population of reniform
nematode.
Reniform nematode was reared on cowpea.
4 months later, 3000 reniform nematode
eggs were inoculated to 12-potted pineapple
plants.
1 month post-inoculation, spirotetramat was
appropriately applied using a garden-hand
sprayer to the plants. Irrigation was delayed
for 9 days to avoid washing outspirotetramat
from the foliage.
6 months post-application of spirotetramat,
the experiment was terminated. The roots
were cut off and shoot weights were
measured.
Roots were shaken in 10% Clorox and the
roots were left in the cold room to
Homogenize the moisture. The roots
were then left in the
oven for 3 nights and weighed.
250 cm3 soil was sampled from each
treatment and elutriated to recover
vermiform stages of reniform nematode.
The data were analyzed using SAS and
subjected to analyses of variance (ANOVA).