Effects Of Plant Nutrient Solutions On Fruit Quality And Storage Of Longan

In order to boost growth, improve quality and defer postharvest senescence of longan fruit, Ca, B, Ca+B, K, K+Ca and K+B plant nutrient solutions and water (CK) were sprayed on leaves and fruits three times during the developmental stage of aril. Development, quality, storage of longan fruit were studied chiefly; Content of N, P, K, Ca, Mg and B mineral nutrition in leaves and mature fruits were also analyzed; At the same time, sugar content in leaves and tissues of fruit were investigated during the developmental stage of aril. The results were showed as fol lowed:1.Ca treatment had distinctly improved longan fruit quality in 2003, but there was not significantly impact in 2004. B and Ca+B treatments had obviously increased size, weight of fruit and flesh and sugar content of fruit in 2003 and 2004, but the effect of Ca+B treatment was less than B treatment. K, K+Ca and K+B treatment had also significantly improved size, weight of fruit and flesh and sugar content of longan fruit in 2004. The effect of K+Ca and K+B on quality of fruit were better than K treatment, and the effect of K+B treatment was not significant different from B treatment.2. There was a close relationship between fruit quality at harvest and storage. Fruit weight lose rate was negativelycorrelated with content of K, Ca and B in fruit, thickness of pericarp and soluble solid of flesh. Intact fruit ration was positively correlated with content of K, Ca and B in fruit, thickness of pericarp and content of soluble solid in flesh. Ca, B and Ca+B treatments had significantly decreased fruit weight lose rate, inhibited dropping speed of soluble solids, sugar, acidity and ascorbic acid of flesh in storage, increased intact fruit ratio. The effect of K+B treatment was greater than K and K+Ca treatment.3. Correlationship of K> Ca and B nutrition to other mineral nutrition in longan leaves were as followings: The contents of K was positively correlated to the contents of N, P, Mg and B; the contents of Ca was negatively correlated to N, P, K and B; The contents of B was positively correlated to N, P and Mg. Ca treatment increased content of Ca and P in leaves in initial fruit developing stage, but it decreased N, K, Mg and B contents of leaves in whole fruit developing stage. B treatment had significantly increased B content; its effect on increment of N, Pt K and Mg was less than B of leaves and fruit. But it decreased Ca content in leaves after spraying nutrient solutions second time. Ca+B treatment had significantly increased content of Ca and B, and also increased content of N, P, K and Mg leaves in some extent. Moreover, Ca+B treatment significantly enhanced content of Ca and B in fruit, and improved N, P, K and Mg in flesh and seed.K treatment increased content of N, P, K, Ca, Mg and B in leaves and fruits, reduced Ca content in seed. K+Ca treatment obviously improved content of K, Ca in leaves and fruits, caused some changes of N, P, Mg and B in leaves and fruits. K+B treatment significantly increased content of K, Bin fruit and improved N, P, K, Ca, Mg and B nutrition in leaves N, P and Ca in fruit,decreased Mg in seed.4. The treatments of plant nutrient solution promoted transporting the sugar of leaves into aril and seed. Besides, the sugar content in fruit had significant correlation to content of sugar in leaves and fruit development. The correlation between sugar content of aril and leaves was negative, while the sugar content in fruit had positive correlation to weight of flesh and dry matter in fruit. Ca treatment promoted transporting the sugar in leaves into aril and seed during fruit development, but inhibited accumulation of sugar in aril and seed after spraying nutrient solutions second time. At the same time, Ca treatment promoted development of fruit, restrained the growth of fruit after spraying nutrient solutions second time. B and Ca+B treatment had significantly promoting the sugar of leaves into aril and seed, increased dry matter of fruit. However, effect of Ca+B treatment on sugar transporting was smal ler than B treatment.K, K+...