M. EI-Sherif
Introduction
Nematology in Egypt
Nematological problems
Control measures
Infrastructure and training
Support for nematology
Conclusions and recommendations
The area of agricultural land in Egypt is confined to the Nile Valley and delta, with a few oases and some arable land in Sinai. The total cultivated area is 7.2 million feddans (1 feddan = 0.42 ha), representing only 3 percent of the total land area. The entire crop area is irrigated, except for some rain-fed areas on the Mediterranean coast. Over the past four decades, an area of 900 000 feddans of newly reclaimed land has been added to the agricultural area. The landholdings are fragmented, with the average size of farm units being 2.5 feddans. The total area cropped annually is about 11.5 million feddans, which represents a cropping ratio of about 2:1. Egypt has an arid climate with an annual average rainfall ranging from 60 to 190 mm along the Mediterranean coast to 25 to 60 mm in the Nile delta, and less than 25 mm in upper Egypt and adjacent areas. The climate is generally very uniform with good sunshine. In addition, the Nile is an exceptional source of water, and soil near the Nile is generally of excellent quality.
Egypt's total agricultural crop production has increased by more than 20 percent in the past decade. During the same period, the rate of population growth has increased at a slightly higher rate than the increase in crop production. The most important crops grown in Egypt are discussed briefly below.
Cereals. Rice is one of the major field crops, grown on nearly 500 000 feddans, and is considered the second most important export crop after cotton. Wheat is the major winter cereal grain crop and the third major crop in terms of area planted (about 600 000 feddans). Maize is the second most important crop (750 000 feddans), but at least 50 percent of its production is used for livestock and poultry feed.
Fibre crops. Cotton has traditionally been the most important fibre crop in Egypt and the leading agricultural export crop.
Sugar crops. Sugar cane is the main sugar crop in upper Egypt. About 90 percent of the yield is used for sugar extraction. Sugar beet also grows in large areas in the Nile delta, and contributes to the sugar industry in Egypt.
Food legumes. These include a number of bean crops that are used for human consumption, such as broad beans and soybeans.
Forage crops. Egyptian clover, berseem, is the major winter forage crop cultivated in the Nile Valley and delta. It is the most widely grown field crop and occupies an area which totals 1.2 million feddans.
Fruits. Citrus, primarily oranges that represent 85 percent of total citrus production, makes up 50 percent of total fruit production. The fruit-planted area has expanded over the last three decades to reach about 200 000 feddans. Other subtropical fruits are also grown in Egypt, including grapes, stone fruits and pome fruits.
Vegetables. Tomatoes are grown in three seasons - winter, summer and autumn - on about 3 percent of Egypt's total planted area. Losses in tomato crops have been large as a result of tomato leaf curl virus, early and late blight, and nematodes. Potatoes are the second most important vegetable after tomatoes, both in terms of cash value and total tonnage produced.
One of the major obstacles facing the production of more food for Egypt's fast-growing population is the damage caused by pests. The wide distribution, extensive host range and involvement with other micro-organisms in disease complexes put nematodes on top of the list of plant pests affecting agricultural production in the country.
The Ministry of Agriculture (MOA) is encouraging farmers to control nematodes in vegetable crops, citrus, grapes, cotton and soybeans and to follow the recommendations of the Ministerial Higher Committee for Pest Management. Nematicidal field trials are made every year under the supervision of MOA and in cooperation with many faculties of agriculture for the assessment of crop losses and to provide new recommendations for nematode control. Nematicides constitute a high percentage of the total pesticides imported annually.
Training of agricultural engineers involved in the field of plant protection and pest control has lately become the concern of MOA. A two-week training course in the different plant protection disciplines (insects, nematodes, mites, diseases, weeds) is held annually at Cairo University. The Nematology Research Centre (NRC) is entrusted with the nematology part of the course. Agricultural engineers as well as teachers at agricultural technical high schools attend this training course.
MOA, through its experiment stations and Institute of Plant Pathology and the NRC of Cairo University, provides the service of examining soil samples for nematodes, issues the necessary recommendations for control measures, and follows up nematicidal applications.
The first published research article relating to plant-parasitic nematodes in Egypt was in 1901, when Prayer described a nematode disease of banana which caused root galling. Now at least 20 plant-parasitic nematode genera are reported to occur in all the agricultural lands of Egypt. Four genera of these plant-parasitic nematodes have been identified and classified as important pathogens that can cause severe damage to some important crops in the country: Meloidogyne spp., Rotylenchulus spp., Tylenchulus spp. and Pratylenchus spp. Of these the root-knot nematodes (Meloidogyne spp.) have been recognized as a major pest causing substantial reductions in the yield of almost all vegetables, including tomatoes, fruit-trees including peaches and grapevines, and field crops including cotton and sunflower. The actual damage caused by these nematodes is difficult to assess at the national level. It was estimated, however, in individual fields and experimental plots to be around 25 percent. Complete crop losses were also reported for tomato crops when the soil population of the nematodes was very large, especially in the summer crop and in sandy soils. The reniform nematode, Rotylenchulus reniformis, is next to the root-knot nematodes in inflicting significant crop losses in many vegetable and field crops. The disease caused by this nematode is particularly severe on the heavy soil of the Nile Valley and delta. Cotton, soybean, tomato, cowpea, beans and jasmine are among the hosts of this nematode.
The citrus nematode (Tylenchulus semipenetrans) is an important and destructive pest of citrus trees in Egypt. It has been detected in at least 60 percent of the citrus-growing areas in Egypt. In addition to citrus, this nematode also infects grapes and olives and affects their production. The lesion nematodes (Pratylenchus spp.) are considered economically important nematodes causing disease in Egyptian clover, legume crops and banana trees. They are widely distributed in the light soils of the Nile Valley and delta as well as in the newly reclaimed desert areas. The cyst-forming nematode has recently become an important pest in Egyptian agriculture. Heterodera zea and H. cajani are of common occurrence in maize and legume crops. Their actual damage has not been assessed. Other nematode species are present in almost all cultivated lands in the country, some of them such as the stunt nematode (Tylenchorhynchus spp.) and the lance nematode (Hoploliamus spp.) seem to cause some noticeable damage to crops, but none of them has been of great importance to the economy of the country. Association between dagger nematodes (Xiphinema spp.) and some virus diseases reported in Egyptian vineyards has not yet been confirmed.
Root-knot in Egypt is the major problem in greenhouse cultures and commercial nurseries, where high-value crops are grown in relatively small areas. Therefore, the use of nematicidal applications is economic. This does not apply to small farmers with small landholdings (less than 1 feddan), and to many university graduates who are assigned 5 feddans each in newly reclaimed desert areas; nematicides are simply not within their economic reach This category of landholders therefore has no economic way of combating the nematode damage that is always present.
Rotation is not usually a practical control measure because of the intensive use of the land and the government pricing policy for some crops. However, in newly reclaimed areas heavily infected with root-knot nematodes, farmers, by experience, substitute tomato summer crops with a non-host crop. The use of nematode-resistant or -tolerant varieties and rootstocks is always recommended in tomato, soybean, peach and citrus.
Legislative measures do exist but are not always put into effect. Inspection of soil and seedling roots in private and government nurseries for root-knot and citrus nematodes is not seriously undertaken. Quarantine measures should be enforced to prevent the transport of any infected plant parts, infected soil, or organic manures to newly reclaimed areas.
Results of some research work carried out by the NRC show the possibility of using some biological agents (bacteria or fungi) as well as soil solarization in controlling root-knot nematodes. It is hoped that such biological control may be integrated into the nematode control programmes.
There are three sectors in which nematological research, teaching and extension fall. These sectors are: Egyptian universities, the Agricultural Research Centre of the Ministry of Agriculture (ARC/MOA), and the National Research Centre of the Academy of Scientific Research and Technology. The 12 universities in Egypt include 14 faculties of agriculture in which nematology is taught to undergraduate and postgraduate students. Most students enrolled for postgraduate studies come from the Plant Pathology and Plant Protection Institutes of the ARC, as well as from the universities themselves.
There are several trained nematologists in Egypt (71 with Ph.D. degrees) distributed among the universities and the Agricultural Research Centre and the National Research Centre as follows: Cairo University (Giza) 16; Cairo University (Fayoum) 2; Ain Shams University 2; Assiut University 2; Tanta University (Kafr El-Sheikh) 2; Mansoura University 2; Zagazig University (Zagazig) 3; Zagazig University (Moshtohor) 1; Menia University 1; Menofia University 3; Suez Canal University 2; Al-Azhar University 3; Helwan University 1; Alexandria University 4; Agricultural Research Centre 13; Desert Institute 2; National Research Centre 12.
All of the 71 nematologists, and more junior nematologists (M.Sc.) and graduate students, have developed a keen interest in forming the Egyptian Society of Nematologists. A steering committee is being formed to help in developing the society.
Large numbers of undergraduate enrolments are usually recorded at the 14 faculties of agriculture. Out of 6 000 students who receive a B.Sc. degree every year, nearly 300 specialize either in plant pathology or economic entomology and study nematology at the undergraduate level. Most universities also provide more opportunities for postgraduate studies in nematology. For example, Cairo University has five Ph.D. and eight M.Sc. candidates.
With the exception of the University of Cairo, nematology laboratory equipment is inadequate for the training of graduate students. Cairo University does have a nematology research centre where some highly sophisticated scientific equipment is made available through United States Agency for International Development (USAID) projects and other foreign funds. This centre is affiliated to the Zoology and Nematology Department of the Faculty of Agriculture. It was established by cooperation between the University of Cairo, the Ministry of Agriculture, and the Supreme Council of Science and Technology, and was opened in 1964. The Centre occupies 1 800 m2 and has an additional area of 2.5 feddans for microplots and greenhouses. Credit should be given to Professor B.A. Oteifa who devoted time and effort to initiate the establishment of the centre, and start a school of nematology in Egypt at that time. As well as the training the centre provides to graduate students, it also provides training for agricultural engineers working in the field of plant protection, and always demonstrates interest and capabilities in extension, although the centre has no direct links with the extension service. Areas of research that have taken place at the centre throughout the past three decades include surveys for nematode infection in major crops (cotton, sugar cane, maize, legumes, vegetables especially tomatoes, watermelons, grapes, fruit-trees including citrus, olives, stone fruits and pome fruits). Moreover, the nematology research programme has generally included work on the biology, pathogenicity, population dynamics and control of plant-parasitic nematodes, as well as a good deal of work on the use of entomogenous nematodes in the biological control of insect pests.
Owing to the limited arable land (5.8 feddans), and equally limited opportunities for expansion, it has become necessary to depend on the development and application of improved technology. It has become essential, therefore, to implement strong and effective programmes of agricultural research, including integrated plant-parasitic nematode management.
Foreign aid research programmes in nematology are limited. The ongoing National Agricultural Research Project (NARP) is financed by USAID. It includes an integrated pest management (IPM) programme on major crops. Through this programme, limited research grants are allocated to a few faculties of agriculture to strengthen their facilities and carry out applied research in this context. Furthermore, a collaborative IPM programme has also started between the Nematology Research Centre of Cairo University and four United States universities: North Carolina State University, the University of Maryland, the University of Georgia and the State University of Florida. Egyptian and American nematologists are collaborating to combat nematodes infecting five major crops; cotton, maize, groundnut, citrus and tomatoes. During the past two decades a few research projects on plant-parasitic nematodes have been financed through USAID programmes: Agriculture Development Systems (ADS), the Egyptian Major Cereals Improvement Project (EMCIP) and PL-480 programmes. The Egyptian Academy of Scientific Research provided partial financial support to a number of research projects for improving food-crop production. Commercial companies working in the field of pesticides have supported some short-term research projects mainly on nematode surveys and control. Other international financial support through foundations and bilateral agreements is contributing to research in nematology for increasing agricultural crop production.
The Nematology Research Centre (NRC), Cairo University, is by far the largest, best-staffed (16 with Ph.D. degrees) and best-equipped nematology research centre in, at least, North Africa. Since its establishment in 1964, the centre has contributed a great deal of research information towards solving some of our national nematode problems in agriculture. Moreover, senior researchers in MOA and abroad who obtained their Ph.D. degrees at the centre still seek advice from our staff and collaborate with them in resolving nematode problems in the country.
The NRC, as a centre, could expand its wide range of nematological services to all the North African countries. It could also offer advanced training for professional, graduate and postdoctoral research fellows. Such technical training programmes would no doubt increase the capabilities of national research systems, and could produce new strategies for nematode management. The centre could also organize meetings and workshops, through which nematologists from North African countries could exchange information that contributes to strengthening their national systems and encourages work towards the objective of nematode management.
The financial support of FAO to the NRC, and its recognition as a focal nematology research and training centre, will certainly help the centre carry out its regional activities. This will definitely contribute, in the long term, to increasing agricultural production in North African countries.