The rapid expansion of greenhouse crop production in northern Oman in the last 5 years has been mirrored by an equally rapid increase in disease problems associated with the crops produced. Farmers are relying almost exclusively on cucumber production with three or four monocultured crops per year. Although damping-off is the principal disease constraint, flower and fruit rots cause largely unquantified, but significant losses each season. Isolations made from infected fruits indicated that the principal cause of the disease were Fusarium species. Plants were infected systemically with Fusarium being isolated from sections made at nodes throughout the stem. Experimental remedial treatments carried out on commercial farms included foliar applications of fertilizer with and without simultaneous applications of systemic fungicides. The results indicated that fertilizer applications alone did not reduce the incidence of the disease. Fungicide applications alone reduced disease incidence, the reduction in disease was greater when simultaneous applications of foliar fertilizer and fungicides were made. Results from two years suggest fruit losses can be reduced by approximately 30% if an integrated disease and plant nutrition management strategy were adopted. This could be accompanied by an increase in fruit number and fruit weight of approximately 10-15%.

The rapid expansion of greenhouse crop production in northern Oman in the last 5 years has been mirrored by an equally rapid increase in disease problems associated with the crops produced. Farmers are relying almost exclusively on cucumber production with three or four monocultured crops per yea...