傾斜ハウスおよび傾斜地対応型養液供給システムによる夏秋トマトの実証栽培(栽培管理・作型)  [in Japanese] Cultivation of Tomato in a Sloped Greenhouse by a Fertigation System Suitable for Use on Sloping Land(Crop Production & Cropping Type)  [in Japanese]

中山間傾斜地における夏秋トマトの安定生産のために開発した傾斜ハウスおよび傾斜地用養液供給システムを,徳島県三加茂町K地区(標高300〜600m,傾斜度4〜25°),山腹型傾斜畑地域の3戸のトマト生産者に導入し,その効果を検討した.傾斜ハウスの資材費は10a当たり300万円程度,傾斜地対応型養液供給システムの資材費は10a当たり50万円であり,養液栽培を行う場合はさらに66万円程度必要であった.2002〜2005年に傾斜ハウスおよび養液供給システムを利用した栽培(ハウス養液栽培)と慣行の簡易雨よけ栽培とを比較した.ハウス養液栽培では,慣行雨よけ栽培では設置が困難な防虫ネットおよび非散布型製剤の利用により,殺虫剤の使用回数を減らすことができた.殺菌剤の使用回数は,ハウス養液栽培と慣行雨よけ栽培との間で明確な差はみられなかった.トマト果実の収量は,すべての生産者および栽培年において,ハウス養液栽培の方が慣行雨よけ栽培に比べて著しく多かった.雨よけ栽培では,収量が少ないだけでなく,台風や病虫害の影響を大きく受けて収量が変動しやすいことが推察された.以上より,傾斜ハウスおよび養液供給システムは,安価な簡易雨よけ施設に比べるとコストはかかるものの,収量の増加と安定生産によって農家収入も増加することから,導入効果は大きいと判断される.

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 300-370m above sea level, 4-20°inclination). Cost of materials of the greenhouse and the fertigation system were \3,000,000 and \500,000 per 1000m^2, 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.