Cultivation of tomato [Lycopersicon esculentum] in a sloped greenhouse by a fertigation system suitable for use on sloping land

To produce tomato in summer and autumn seasons in hilly and mountain areas steadily, we developed a sloped greenhouse and a fertigation system suitable for use on sloping land. We installed and tested the greenhouse and the fertigation system in three tomato-growing farms in Mikamo, Tokushima (about 300-370 m above sea level, 4-20 deg C inclination). Cost of materials of the greenhouse and the fertigation system were 3,000,000 yen and 500,000 yen per 1000 square m, respectively. Between 2002 and 2005, we compared tomato cultivation using a sloped greenhouse and fertigation system to cultivation under the conventional rain shelters. The number of times using insecticides under the greenhouse with an insect screen were lower than that under the conventional rain shelters. There was no consistent tendency in the number of times germicides were applied in the greenhouse compared to that under conventional rain shelters. Tomato yields from greenhouse cultivation with fertigation system for all years and all three growers were higher than those under the conventional rain shelters. Compared to the greenhouses, tomato yields under the conventional rain shelter demonstrated sharp fluctuations because of damage due to typhoon or plant diseases. We considered that installing a sloped greenhouse and fertigation system increased the tomato yield and income of the grower, although the initial costs were more expensive than those of installing conventional rain shelters.