On-line version ISSN 1668-298X
ODORIZZI, A. S.; AROLFO, V. and BASIGALUP, D. H.. Evaluation of root curculio/weevil damage in alfalfa (Medicago sativa L.) populations with large numbers of lateral roots. Agriscientia [online]. 2011, vol.28, n.2, pp. 119-126. ISSN 1668-298X.
Increasing the number of lateral roots through breeding may be important to reduce the damage caused by the root curculio complex in alfalfa in Argentina. The objective was to evaluate the performance of ten alfalfa experimental populations selected for their large number of lateral roots under four environmental conditions (fall and spring planting with or without irrigation). The evaluated traits were curculio damage (Categories (Cat) 1 = no damage to 5 = very severe damage), dry matter yield (BP), number of secondary roots (NRLR), and diameter of lateral roots (DRLR). Populations s755, s545 and s614 had the highest values for DRLR and NRLR, the least damage from weevil (Cat 2 +3), and the largest variability (mean square) for all the traits. Populations s545 and s616 exhibited the highest DRLR and the lowest NRLR, respectively. Irrigation conditions led to lesser curculio damage, with populations s545, s614 and s617 being the least affected, and populations s461, s755 and s463, the most affected. The highest damage (Cat 4 +5) was observed under rainfed conditions (dryland), with populations s618 and s616 as the most affected by the root curculio complex. Only under these conditions the highest curculio damage was correlated with lowest BP.
Keywords : Alfalfa; Lateral roots; Root weevil damage.