Abstract

Among the three countries of the Maghreb, Morocco's farmland is the most exposed to erosion. This applies particularly to the mountain and piedmont areas. To counter the erosion-causing factors, the government's "National Plan for Reforestation and Fight against Erosion" supports the reconstitution of forest areas exploited by the population. The future success of this costly exercise depends on the vigour and resistance of the plants being used. To enhance the latter, a low-cost mycorrhiza inoculation at the nursery level has been undertaken during the first phase of this project. In this second phase, the experimenting will be extended to more nurseries using the drought resistant Pisolithus tinctorius. The main purpose of the project is to reduce reforestation costs through increased nursery productivity. In case of positive results, the employed technique will be recommended for widespread application.

Post-Project Summary

Work during the 5 years of this project included: inoculating seedlings in experimental and pilot nurseries; producing mycorrhized seedlings in the nursery and monitoring their development in the field; and distributing information on the controlled mycorrhization technique. The loss of certain pure cultures from these selected strains made it necessary to call upon the DREF strain bank, and to use both strains of Bisolithus tinctorius and cultures of other symbiotic fungi isolated locally or imported during the first phase of the project. No pure culture was successful in forming mycorrhizae with inoculated pine seedlings. Only natural mycorrhization occurred, and was manifested by the presence on the seedlings of white dichotomic ectomycorrhizae closely resembling those formed by Rhizopogon. Researchers thought that the liquid inoculum, produced without continuous agitation and ground at the end of the incubation phase, was not appropriate to permit the synthesis of mycorrhizae. The acquisition at the end of the project of two stir plates equipped them to test this hypothesis. A species of Rhizopogon with pine ectomycorrhizal fungi in general use worldwide was most abundant in the local collection and was used with success in the experimental nursery in the mycorrhization of Pinus Pinaster var. atlantica seedlings. Rhizopogon was well established in the Ras El Maa tree nursery, where it mycorrhized 100% of Pinus Pinaster var. maghrebiana seedlings at an average rate of 72.87% per seedling. Results were less spectacular in the other nurseries. Three experimental plots were laid out. Annual monitoring took place, including counting survivors and measuring diameter at the stump and the height of the main shoot of each seedling. Differences observed between mycorrhized seedlings and control seedlings have so far been insignificant. Monitoring of the seedlings was planned for 3-4 more years. The project team trained some sixty technicians in three workshops on nursery mycorrhization techniques. The second national seminar on forest seedlings was held March 30 and 31, 1995 at the national school of forest engineering on the theme: "Symbioses in forest trees: whither research, and what does the future hold?" The seminar drew some 80 participants from Morocco and abroad. In all, 19 papers were read at three sessions: Associations of forest trees; Rhizobium; and actinorrhizal trees and shrubs and mycorrhizae of forest species. The findings were further disseminated through the publication in 300 copies of the proceedings of the first day, held on June 3, 1992; and the preparation of a brochure on nursery techniques for the mycorrhization of forest seedlings, intended for forest technicians working in nurseries and published as required. The proceedings of the second day, devoted to forest seedlings, was in preparation when the project ended.

Recipient Institution(s)