The survey comprised the following crops: flowering potted plants, cut flowers, seedlings and summer flowers, decorative plants, lettuce, herbs, tomatoes and cucumbers. The survey, which was a full census with a duty to respond, included 328 greenhouse holdings.
Biological control agents were applied at least once in 45 per cent of the areas with ornamental plants and in 89 per cent of the areas with edible crops. Of the ornamental plants, flowering potted plants had the highest proportion of the area with the use of biological agents. Here, 73 per cent were treated with biological agents at least once, while 57 per cent of the area with decorative plants, 46 per cent of the cut flowers and 23 per cent of the area with seedlings and summer flowers were treated. Of the edible cultures, cucumber had the highest proportion of biological treatment. Here, almost the entire area was treated with biological control agents at least once. Otherwise, 93 per cent of the tomato area, 88 per cent of the herbal area and 41 per cent of the lettuce area were treated with various beneficial organisms.
Biological treatment where the main pest was thrips accounted for the largest share of the accumulated area (total area of all repeats) in cut flowers, seedlings and summer flowers, flowering potted plants and decorative plants with 74, 41, 36 and 35 per cent respectively. Aphid treatments accounted for the largest share of lettuce and herbs, both of which accounted for 45 per cent of the accumulated area. On tomato areas, on the other hand, treatments against whitefly accounted for the largest share of the accumulated area with 45 per cent, while for cucumbers spider mites accounted for the largest share with 33 per cent.
The extent of chemical pesticide usage varied by type of crop. Chemical pesticides were used at least once in 79 per cent of the areas with ornamental plants and in 29 per cent of the areas with edible plants. Chemical pesticides were used at least once on 90 per cent of the area with flowering potted plants, while it was used on 84, 71 and 67 per cent of the area with decorative plants, seedlings and summer flowers and cut flowers, respectively. On areas with lettuce, 49 per cent of the area was treated chemically, while 41 per cent of the cucumber area was treated at least once. 21 percent of the tomato area and only 4 percent of the area with herbs were chemically treated at least once.
Chemical pesticides are divided into the main groups of herbicides, fungicides, insecticides and growth regulators. Herbicides are used to a negligible degree in greenhouse cultures. Growth regulators are used in ornamental plants to change their appearance. For all types of ornamental plants taken as a whole, the growth regulators accounted for 59 per cent of the accumulated area (total area of all repetitions of treatments), insecticides 28 per cent and fungicides 13 per cent. For vegetable areas, pesticides accounted for the largest share with 56 per cent, while fungicides accounted for 44 per cent of the total area of all repetitions of chemical treatments.