|Budget Amount *help
¥2,200,000 (Direct Cost : ¥2,200,000)
Fiscal Year 1994 : ¥400,000 (Direct Cost : ¥400,000)
Fiscal Year 1993 : ¥1,800,000 (Direct Cost : ¥1,800,000)
In order to clarify uptake rate and amount of mineral elements, especially calcium, by plants, 2 cultivars of tomatoes, 'Momotaro' and 'June Pink', were grown at 4 levels of K/Ca ratio (0.5,1.0,1.5 and 2.0), 4 levels of NH_4-N concetrations (0,0.7,1.3 and 2.0), and the combination of 2 levels of K/Ca ratio (0.5 and 2.0) and 2 levels of NH_4-N concentrations (0, and 2.0me/l) in free drainage rockwool system.
BER occurrence at both cultivars became higher, but Ca uptake rete and GS occurrence became lower, with increasing NH_4-N concentrations and K/Ca ratio in the nutrient solution. Cumulative amount of Ca uptake decreased to one third at 'Momotaro' and one half at 'June Pink' when K/Ca ratio in the nutrient solution increased from 0.5 to 2.0. This suppression of Ca uptake seemed to be induced by lower Ca concentration and also antagonism with potassium. Ca content in laminae decreased to four fifth at both cultivars. Cumulative amount of Ca uptake and Ca content in laminae decreased to seven tenth and one half, respectively, when NH_4-N concentrations in nutrient solution increased from 0 to 2.0 me/l, at both cultivars.
Thus, increasing NH_4-N concentration and K/Ca ratio in nutrient solution made Ca uptake rate, amount of Ca uptake and Ca content in fruit decreased. Less Ca uptake caused BER occurrence. GS occurrence became higher in case of less BER occurrence and higher Ca content in fruits. There is a negative correlation between BER and GS occurrence in each cultivar.