Optimization of a phenotyping system in sugarcane to evaluate different strategies against Diatraea saccharalis (Fabricius)

BUDEGUER F.; PERERA M.F; MICHAVILA M.G; RACEDO J.; GASTAMINSZA G.; CUENYA M.I.; CASTAGNARO, ATILIO P.

San Miguel de Tucuman

Congreso; International Sugarcane Congress ISSCT 2019; 2019

ISSCT

Sugarcane borer Diatraea saccharalis (Fabricius) (Lepidoptera: Crambidae) is the most important sugarcane pest in Tucumán, Argentina. Older larvae (L3, L4) bore into the stalks, disrupting the physiological integrity of the plant, facilitating fungi and bacteria colonization which indirectly reduce yield and quality of sugar. The aim of the present work was to optimize a sugarcane plant infestation method with D. saccharalis under controlled conditions to help to evaluate different strategies to manage the pest. Different numbers of neonate larvae were placed in the leaf whorl of sugarcane seedling (2-months-old) of cultivars TUC 95-10, TUC 03-12 and LCP 85-384. On single plants 6-months old of TUC 95-10 10 larvae of several instars were added in the ligule of second and third fully expanded leaves. Trials were conducted under controlled conditions (28-30ºC; 50-70% RH). Each assay was repeated twice with 5-10 replicates per treatment. Several parameters were evaluated on 6-months-old plants: damaged sheath number, number of perforations in the internodes, total tunnel length, and dead heart symptom; whereas on sugarcane seedlings only the last parameter was measured. Dead-heart symptoms were observed on sugarcane seedlings in all treatments with neonate larvae. Sugarcane plants (6-months-old) showed damage in the sheath and stem when infested with L2, L3 and L4 instars, whereas neonate larvae only produced sheath damage since they were unable to pierce and bore the sugarcane stem. Results suggested that different methods could be used to screen different strategies for sugarcane borer management.