Compatibility and Physical Stability of Mixtures of Pre-Emergent Herbicides with the Insecticide-Nematicide Mocap® for the Control of Weeds, Symphylids and Nematodes in Pineapple (Ananas comosus cv MD-2)

In Costa Rica, pineapple production is affected among other soil pests, by symphylids (Scutegerella spp. Hansiniella spp.) and nematodes (Pratylenchus ssp., Helicotylenchus spp.) that cause production losses. To prevent the presence of soil pests, insecticides-nematicides are applied. In addition, due to the high cost of labor and the reduced yield in manual weeding, it is common to apply pre-emergent herbicide before planting. Ideally, a single application targeting both approaches would be desirable to save water, reduce costs, and maximize labor. The present investigation studied the compatibility and physical stability of solutions that include pre-emergent herbicides (oxyfluorfen, hexazinone, ametrine, diuron) and the insecticide-nematicide Mocap® 72EC. Subsequently, the commercial application of a mixture of oxyfluorfen + Mocap® was carried out to verify if it prevents the initial presence of weeds and pests in the pineapple planting establishment (Ananas comosus cv MD-2). The results showed that the combination of the herbicides with Mocap® 72EC in a volume of 2400 liters per hectare was compatible and keep the spray solution stable in all cases. The field test, with the oxyfluorfen and Mocap® solution, confirmed the biological efficacy of the oxyfluorfen herbicide, where no weeds were found in the evaluation of 10 linear meters of bed 60 days after planting. Similarly, it was confirmed that Mocap® prevented symphylids infestation, finding 0% incidence and a 48% of the total phytoparasitic nematode population reduction (P= 0.0017) at 60 days of planting age, when compared to the untreated control. Therefore, the evaluated pre-emergent herbicides and the insecticide-nematicide Mocap® solutions can be applied given the common occurrence of symphylids, nematodes and weeds in the establishment of pineapple plantations.