Storage of nematode-infected soil, roots and nematode suspensions is important in nematological research. The available storage methods are based on potato cyst nematodes, where cysts with viable eggs can be stored for long periods at 4 degrees C. When dealing with other nematode species, understanding the effect of storage temperature is crucial. This study was designed to investigate the decline rate and survival of four root-knot and a lesion nematode of both temperate and tropical origin, when stored at 4 degrees C in three substrates: water, soil and roots. The starting density (P-i ) for each substrate was determined at t = 0 and survival of all nematode species was estimated at 10-day intervals for 100 days. During storage, population densities of all species declined in all substrates exponentially. A slower decline rate (r(d) = 0.988-0.999) was observed for juveniles of Meloidogyne fallax in water, soil and roots compared to juveniles of M. hapla and Pratylenchus penetrans. Meloidogyne incognita was seriously affected by cold storage with the highest decline rate (r(d) = 0.919-0.977) observed in all substrates. Only data on the root substrate were obtained for M. javanica with a decline rate of (r(d) = 0.977) predicting zero survival at t > 100 days. Notable is the higher fraction of surviving P. penetrans (P-i = 0.238-0.545) in all substrates during the storage period, compared with all other species. Based on the results, it is recommended to process nematode samples in the three substrates as quickly as possible, as underestimation of the actual population densities is likely. Consequences of cold storage in handling and processing of samples from different substrates are discussed.

Meloidogyne hapla is a serious pest of many cultivated plants. In response to the economic significance of the species, efforts are being made to develop a new method to reduce its harmful effects on crops. The aim of the study was to determine the effect of diffusates from seeds of selected species of legumes on the motility of second-stage juveniles and to evaluate the effect of meal from seeds of selected species of legume on the capacity to infect the roots of tomato plants by the J2 stage. The experiment examined the effect of diffusates on the motility of the J2 stage performed in Petri dishes, at temperatures of 10 degrees C, 17 degrees C and 21 degrees C. The evaluation of the J2 stage infectivity was estimated in a pot experiment performed under controlled conditions of 20 +/- 1 degrees C. The pots were filled with sterile substrate mixed with meal from the seeds of selected plants at 1%, 5% and 10% of the substrate weight. The studies carried out in the Petri dishes showed varying effects of the seed diffusates from selected legume plants on the motility of the J2 stage of Meloidogyne hapla . J2 were found to lose their motility within 24 h after immersion in water containing seed diffusates from Melilotus albus , Trifolium pratense T. repens , in the temperature ranges investigated (10 degrees C, 17 degrees C and 21 degrees C). However, in a mixture of seed diffusates and soil filtrate from the root zone of tomato plants, the absence of motility in the second-stage juveniles was observed after 24 h at 17 degrees C and 21 degrees C, with seed diffusates from Lotus corniculatus, Medicago sativa, Medicago x varia, Melilotus officinalis , as well as Onobrychis viciifolia, Ornithopus sativus, Vicia sativa , used in the mixture. Galega officinalis Risa (GoR) seed diffusates were found to have an inhibiting effect on the motility of the J2 stage of M. hapla 24 h following the immersion of the J2 stage in the solution of the soil filtrate containing tomato root diffusates, at 21 degrees C. The J2 stage were not rendered immotile in all the experiment set-ups involving the seeds of V. faba, Lupinus spp., likewise in the control set-ups. In the pots studied, a significant effect of the addition of legume seed meal on the development of M. hapla nematodes and tomato plants was found. The introduction of Lotus corniculatus, Onobrychis viciifolia and Vicia sativa seed meal into the substrate in the proportion of 1%, 5% and 10% resulted in the inhibition of the J2 stage penetration into the roots of tomato plants at temperatures of 17 degrees C and 21 degrees C. With the admixture of the M. sativa and T. repens seed meal, within the temperature range investigated, no nematode infection was observed in the roots, regardless of the seed meal content in the substrate. As regards to the fresh weight, tomato plants grown in a substrate containing 1% and 5% of the V. sativa cv. Jaga seed meal were characterised by significantly higher plant weight values as compared to those grown in the control set -up. The obtained results imply that is advisable to expand the scope of research to include other economically important crops damaged by the northern root-knot nematode.