Biological control agents in the integrated nematode management of potato in Egypt

Background

Potato represents Egypt’s largest vegetable export crop. Many plant-parasitic nematodes (PPNs) are globally inflicting damage to potato plants. In Egypt, their economic significance considerably varies according to PPN distribution, population levels, and pathogenicity.

Main body

This review article highlights the biology, ecology, and economic value of the PPN control viewpoint. The integration of biological control agents (BCAs), as sound and safe potato production practice, with other phytosanitary measures to manage PPNs is presented for sustainable agriculture. A few cases of BCA integration with such other options as synergistic/additive PPN management measures to upgrade crop yields are reviewed. Yet, various attributes of BCAs should better be grasped so that they can fit in at the emerging and/or existing integrated management strategies of potato pests.

Conclusion

A few inexpensive biocontrol products, for PPNs control on potato, versus their corresponding costly chemical nematicides are gathered and listed for consideration. Hence, raising awareness of farmers for making these biologicals familiar and easy to use will promote their wider application while offering safe and increased potato yield.

The effect of storage time and temperature on the population dynamics and vitality of Meloidogyne chitwoodi in potato tubers

The population densities of Meloidogyne chitwoodi in potato tubers stored at 4, 8 and 12°C after 0, 60, 120, 180 and 240 days of storage were assessed. Compared to day 0, storage temperatures of 4 and 8°C reduced population densities to 9 and 35%, respectively, after 240 days of storage, while nematode numbers in tubers stored at 12°C increased 2.5 times. The maximum hatching rate of nematodes from tubers stored at 8 and 12°C increased linearly with storage time. At 4°C it remained constant. The time required for the hatching process to reach the maximum number of second-stage juveniles (J2) decreased with increasing storage temperature. Recovered juveniles of M. chitwoodi from tubers after 180 and 240 days of storage at all three temperatures were still infective and able to multiply on ‘Desiree’ with estimates of the maximum multiplication rate (a) and the maximum population density (M) of 63.6 and 70.8 J2 (g dry soil)−1, respectively.

Tuber and root resistance of potato genotypes against Meloidogyne chitwoodi in the presence of Avena strigosa, related to tuber quality

Relative tuber infestation and quality of two Meloidogyne chitwoodi resistant potato genotypes, AR04-4096 and 2011M1, were compared in glasshouse experiments at initial population density () = 16 second-stage juveniles (g dry soil)−1 in the presence and absence of the bristle oat, Avena strigosa. When A. strigosa was added, ( final population) on both AR04-4096 and 2011M1 increased 130×, increased 1.9 and 3.7×, respectively, while × fresh root weight (FRW)−1 was the same. Nematode hatch from peel of AR04-4096, without A. strigosa, was delayed by 3 weeks but relative hatching rate was increased. Although the RStuber (RS = Relative Susceptibility) of both AR04-4096 and 2011M1 were lower than 1%, in the presence of A. strigosa tuber quality of 2011M1 dropped below the marketable level, while that of AR04-4096 was hardly affected. We conclude that: i) is influenced by root mass; ii) root quality influences nematode hatch; iii) tuber quality is not an estimator for tuber resistance, and the reverse; iv) root resistance is equal to tuber resistance.