Quality of peach fruit in relation to carbon supply

Evolution of growth and of some physiological and biochemical criteria in peach fruit (cv Suncrest) were investigated in relation to carbon supply: normal cultural conditions (30 leaves per fruit, T30) or very poor supply (6 leaves per fruit, T6). While T30 fruits had a typical and normal growth, T6 fruits grew very slowly to reach a lower weight (75 g) than T30 fruits (180 g). In T6 fruits autocatalytic production of ethylene was delayed (two weeks later) and remained much lower; glucose, fructose and especially sucrose accumulated more slowly; the metabolism of malate and citrate anions was modified. So T6 fruits were less sweet and more acid than T30 fruits, corresponding to a poor organoleptic quality. Trees suffering from nutritional stress cannot produce fruits with good quality.