Plant nematode problems and their control in the Near East region. (FAO Plant Production and Protection Paper - 144) (1997): Part II: Country reports: Outlook on plant nematodes and their control in Cyprus: Introduction

Plant nematode problems and their control in the Near East region. (FAO Plant Production and Protection Paper - 144) (1997)

Part II: Country reports

Outlook on plant nematodes and their control in Cyprus

		(introduction...)
		Introduction
		Important parasitic nematodes and their control
		Nematode control and side-effects
		Research and facilities
		Advisory work on nematology and training
		Conclusions and recommendations
		Bibliography

Introduction

Agriculture in Cyprus is still considered to be one of the most important sectors of the economy, mainly because of its contribution to gross domestic product. The production and value of the main crops in 1990 are shown in Table 10. The island, with an area of 9 500 km², is basically an agricultural country, its agricultural exports being the most important source of national income. The annual mean precipitation is around 470 mm while the yearly average air temperature is approximately 19°C.

Between 1960 and 1989 the Government of Cyprus initiated several projects for water storage in dam reservoirs and increased their capacity from 6 million m³ before 1960 to 300 million m³ at the outset of the republic in 1960 (Ministry of Finance, 1991). It is also worth noting that the population engaged in agriculture is 35 400, or approximately 15 percent of the total economically active population.

Threats to crop production

Agricultural production in Cyprus is very often affected by adverse conditions. Some of these are unavoidable and farmers can do very little to prevent their effects on crop yields. However, there are cases where the farmer, if advised properly, has the ability to use modem techniques and cultural practices to prevent crop failure.

Pests and diseases often threaten agricultural production. The severity of attack depends on the kind of crop grown, but mostly on the crop sequence that is followed by growers. Nematodes are among the parasites that attack numerous economically important plants reducing their yield potential substantially. Many people call this large group of tiny parasitic worms, which destroys the root system of plants by penetrating into the roots, the hidden enemy. In many cases the role of these tiny microorganisms can easily be overlooked unless someone is very familiar with them. It is well known that plant nematodes can thrive in warm climates of tropical and subtropical countries. This does not mean that temperate regions are excluded from nematode damage. A classical example of this is the potato-cyst nematode which seriously attacks potato crops in the northern hemisphere.

TABLE 10
Production and value of production of main crops (1990)

Crop	Production (million tonnes)	Value of production at producers prices (US$ million)
Potato	185000	59.6
Citrus	203 000	37.8
Grapes	160000	30.8
Cereals, olives	121 080	41.0
Vegetables	4930	63.4
Fresh fruits	28400	26.4
Other	-	22.4
Total		281.4

Severity of problem

In Cyprus, annual soil temperatures at the depth of the root zone (10 cm) range from 10°C in winter to around 30°C in summer (Fig. 10). This indicates that most nematode genera are active and can develop freely almost throughout the year. Most nematode damage, however, occurs from late spring to mid-autumn (April to November).

Yield losses caused by parasitic nematodes cannot easily be assessed unless a thorough and systematic study is carried out for each crop. However, an attempt was made to assess damage of sampled crops caused by several pathogenic nematodes, as determined by visual observations in the field (Table 11).

The figures in Table 11 are only estimates. It is logical, however, to assume that national crop damage caused by root-knot (Meloidogyne spp.) and citrus nematode (Tylenchulus semipenetrans) is considerable, compared with non-infested fields. These two nematodes are at present considered to be the most destructive. It is anticipated that for citrus and vegetables the national loss in yield caused by the citrus and root-knot nematodes reaches around US$8 million per year, while for potato and bananas, as a result of the effective control measures practised by farmers, the losses are much smaller (US$1 million). Information on yield losses concerning other crops, such as cereals, vetch, broad bean, deciduous trees and vines is not, as yet, available.