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Root-knot nematodes (RKNs), Meloidogyne spp., are considered, worldwide, as one of the main pathogens of solanaceous crops, including pepper (Capsicum spp.). Restrictions on the use of standard nematicides have motivated the development and use of resistant cultivars and rootstocks. Three genes in pepper, called Me1, Me3 and N, confer resistance to the three main RKN species (Meloidogyne incognita, Meloidogyne javanica and Meloidogyne arenaria). However, their effectiveness seems to be limited because nematode populations that have overcome the resistance have been found, leading to a search for new sources of resistance and strategies to preserve their effectiveness. In two greenhouses and over a 7-month growing period, we evaluated the resistance to M. incognita and the agronomic behaviour as rootstocks of nine pepper (Capsicum annuum) accessions – HDA330 (Me1 carrier), Serrano Criollo de Morelos, (Me3 carrier), Yolo Wonder (partially resistant) and another six accessions of unknown resistance originating from cultivars well adapted to the local growing conditions. The resistance conferred by the Me1 gene was more robust than that conferred by Me3. Resistance to M. incognita was found in four new accessions: P13, CTL, CT5, and P14. In P13, the level of resistance was similar to that of HDA330. The resistant accessions showed better agronomic behaviour than the susceptible accessions, which was most noticeable towards the final of the growing period. Some accessions constitute a potential resource for use in the genetic breeding of RKN-resistant rootstocks.

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Biodisinfection using fresh sheep manure in August is effective in controlling Phytophthora root rot in greenhouses in southeast Spain, but this is not the case after the beginning of September. The effectiveness of biodisinfection of new amendments has been evaluated beginning in October in sweet pepper greenhouses to control Phytophthora capsici. The amendments used were: T1: wheat husk + fresh sheep manure (FSM), 3.5 kg m−2; T2: sunflower pellets 3.5 kg m−2; T3: FSM: 3.5 kg m−2; T4: Control. Temperatures above 40°C were obtained in some amendments; anoxic conditions were found in all amendments, and also a reduction of the viability of P. capsici oospores with respect to the control, as well as a higher yield. The contribution of fresh sheep manure to the amendments did not lead to an improvement in their effectiveness. Autumn biodisinfection under low temperature conditions using fresh organic amendments that enhance soil anaerobic conditions may be a promising strategy for the control of P. capsici in pepper greenhouses in southeastern Spain.