ENERGETICS OF MELOIDOGYNE-INCOGNITA ON RESISTANT AND SUSCEPTIBLE ALYCECLOVER GENOTYPES

To determine the energy cost of a population of Meloidogyne incognita on the root of alyceclover, nematode biomass was estimated and equatio ns in the literature were used to calculate energy budgets. Amounts of energy consumed, respired, or used in production of nematode biomass were calculated. Results suggested that severe infestations of root-kn ot nematodes can remove significant quantities of energy from their ho sts. Over a 36-day period, a population of 2.6 females of M. incognita per root system removed less than 0.4 calories of energy from a resis tant alyceclover plant but over 11 calories were removed by 28 females from a susceptible alyceclover. The calculations indicate that on the resistant alyceclover line, 53% of the energy assimilated by the root -knot population was allocated to respiration, with only 47% allocated to production, whereas on the susceptible line, 65% of the assimilate d energy was allocated to production. Such energy demands by the paras ite could result in significant reductions in yield quantity and quali ty at a field production level.