Comparison of the geranium (Pelargonium) pathological results of 2016–2017

The geranium (Pelargonium) is part of the Geraniaceae family. Among the genus of the geranium there are annual or perennial herbaceous species, rarely woody (semi-shrubs or shrubs) (Nagy, 1975; Honfi et al., 2011). The most common species is the garden geranium (Pelargonium hortorum) (Szántó et al., 2003). To Europe, the first geranium (Pelargonium triste) was imported by the Dutch around 1600 from South Africa. Today, the cultivated geranium species are of hybrid origin. The bloom depending on the variety and the season lasts 20–40 days. Geranium is an extraneous pollinating plant. In the geranium home country (South Africa), pollen mediated by the birds, while in Hungary the need for artificial pollination when the core recovery. Generally, fertility is poor. The germination strength is 71%. The temperature requirement of the geranium moves within wide limits. Optimum temperature is 16– 18 °C day and night of 12–14 °C vegetative periods. During cuttings it is 20 °C, but it can withstand 25–30 °C during the summer planting. It then blooms with the most intense water supply. The optimum temperature of the hybrid varieties is 18–24 °C (Dobay, 1998). In addition to the optimal light conditions, the geranium develops and blooms favorably. With 25,000 lux illumination both in cultivation and outdoors, there is rapid growth, rich in flowering, rich in branching, stem does not stretch. It does not damage the 50,000 lux light when the required water content is available in the soil (Nagy, 1991). Most of the geranium species live in their natural habitat in a dry, whimsical precipitation distribution area. Relative humidity should not exceed 70–75% in the glasshouse and foil. Particularly in the cool, dark, winter months, night and morning condensation are dangerous. If the temperature reaches the dew point, the water will precipitate on the glass, foil and drop into the plants, leading to the spread of the Botrytis (Glits et al., 1997; Glits and Folk, 2000). Winter irrigate geranium enough for 2–3 weeks. The geranium species live in their original habitat on sandy humus soil. In cultivation, soil is not particularly demanding, just like other ornamental plants. The soils in the pH range of 6.3–7.2 are ideal. Nitrogen, phosphorous and potassium-rich, but excessive N content causes strong vegetative development, hindering flowering. The N deficiency causes short leaves with small leaves. Lime-rich sensitive, it induces chlorosis in plants. In the soil, the salt concentration cannot rise above 0.5% otherwise the lower leaves will be smothered by salt suffocation. Effective defense is frequent, abundant, relieving irrigation. Rooting medium consists of 70–80% peat, 20–30% clay minerals, 10–20% bark + 2.5–3 kg m carbonated lime + 0.5 kg m complex fertilizer (Nagy, 1975). Soil disinfection is inevitable because the source of soil used in propagation and cultivation is very high. In addition to soil-fungi, bacteria and weeds, we find viral infected plant parts in the soil. The soil is disinfected by steaming at high temperatures at 92–95 °C for 4–6 hours (Gerbár, 1992). The aim of the experiment is to determine what fungal diseases occur during the study period and what fungicides we can effectively control.


INTRODUCTION
The geranium (Pelargonium) is part of the Geraniaceae family. Among the genus of the geranium there are annual or perennial herbaceous species, rarely woody (semi-shrubs or shrubs) (Nagy, 1975;Honfi et al., 2011). The most common species is the garden geranium (Pelargonium hortorum) (Szántó et al., 2003). To Europe, the first geranium (Pelargonium triste) was imported by the Dutch around 1600 from South Africa.
Today, the cultivated geranium species are of hybrid origin. The bloom depending on the variety and the season lasts 20-40 days. Geranium is an extraneous pollinating plant. In the geranium home country (South Africa), pollen mediated by the birds, while in Hungary the need for artificial pollination when the core recovery. Generally, fertility is poor. The germination strength is 71%.
The temperature requirement of the geranium moves within wide limits. Optimum temperature is 16-18 °C day and night of 12-14 °C vegetative periods. During cuttings it is 20 °C, but it can withstand 25-30 °C during the summer planting. It then blooms with the most intense water supply. The optimum temperature of the hybrid varieties is 18-24 °C (Dobay, 1998).
In addition to the optimal light conditions, the geranium develops and blooms favorably. With 25,000 lux illumination both in cultivation and outdoors, there is rapid growth, rich in flowering, rich in branching, stem does not stretch. It does not damage the 50,000 lux light when the required water content is available in the soil (Nagy, 1991).
Most of the geranium species live in their natural habitat in a dry, whimsical precipitation distribution area. Relative humidity should not exceed 70-75% in the glasshouse and foil. Particularly in the cool, dark, winter months, night and morning condensation are dangerous. If the temperature reaches the dew point, the water will precipitate on the glass, foil and drop into the plants, leading to the spread of the Botrytis (Glits et al., 1997;Glits and Folk, 2000). Winter irrigate geranium enough for 2-3 weeks.
The geranium species live in their original habitat on sandy humus soil. In cultivation, soil is not particularly demanding, just like other ornamental plants. The soils in the pH range of 6.3-7.2 are ideal. Nitrogen, phosphorous and potassium-rich, but excessive N content causes strong vegetative development, hindering flowering. The N deficiency causes short leaves with small leaves. Lime-rich sensitive, it induces chlorosis in plants. In the soil, the salt concentration cannot rise above 0.5% otherwise the lower leaves will be smothered by salt suffocation. Effective defense is frequent, abundant, relieving irrigation. Rooting medium consists of 70-80% peat, 20-30% clay minerals, 10-20% bark + 2.5-3 kg m -3 carbonated lime + 0.5 kg m -3 complex fertilizer (Nagy, 1975).
Soil disinfection is inevitable because the source of soil used in propagation and cultivation is very high. In addition to soil-fungi, bacteria and weeds, we find viral infected plant parts in the soil. The soil is disinfected by steaming at high temperatures at 92-95 °C for 4-6 hours (Gerbár, 1992).
The aim of the experiment is to determine what fungal diseases occur during the study period and what fungicides we can effectively control.
The study was set up in 1,000-1,000 pieces of geraniums each year. The following pathogens have damaged the geranium stock: Botrytis cinerea, Pythium debaryanum, but rarely occurred Alternaria porri, Phytophthora cryptogea. The fungicides used in the experiment are listed in Table 1.

RESULTS
During the experiment, the greatest damages were caused by botrytis (Botrytis cinerea). In addition, significant damage was caused by the fungal disease Pythium debaryanum, too. The chemical protection was carried out from March to November in both years ( Figure 3). The results are summarized in Table 2 and  Table 3.   The Signum and Amistar Top fungicides were the most effective against Botrytis cinerea. Viral and bacterial diseases did not occur during the period under review.

DISCUSSIONS
Our study was carried out in 2016 and 2017 in a horticulture in Kecskemét, Hungary. During the experiment, the greatest damages was caused by botrytis (Botrytis cinerea). The Signum and Amistar Top fungicides were the most effective against of B. cinerea.
In addition to the use of fungicides, we increased the spatial position of geraniums, early irrigation and frequent ventilation to ensure successful control. By 2017, we were able to reduce the damage caused by pathogens by 4 percent.