Effects Of Bagging On The Growth And Qualities Of Muskmelon Fruit In Protected Field

Bagging as an important method to produce green fruit and advance commodity value of fruit is widely used in fruit production, but the report of application on muskmelon is scarce. Different breeds, such as yellow thick-skin melon (Jinyu), white thick-skin melon (L2) and netted melon (L1) and seven different color plastic bags and two different paper bags were used as materials. I took these experiments in northern greenhouses in order to study the effect of bagging on growth and quality of Muskmelon, including effect on microenvironment in bags, type of bags most suitable for Muskmelon, the formation rule of indexes of growth and nutrition, effect on debagging time of Muskmelon, effect on skin structure of Muskmelon, and so on. These investigations of this study can provide scientific basis for applying of bagging on muskmelon. The main results are as fellows:1. Light intensity in each bags was declined comparing with CK. The paper bag's effect was much more obvious than the plastic bags, but the black-plastic bag is the worst in light transmittance. Bagging with all the texture bags could increase the temperature and the moisture in the bags in runny days, and the effect of CO₂ is not obvious.2.Bagging can reduce the browning spot and fruit scar caused by farm working, can protect from pesticide and pests' feces, can made the skin clean and glossy, and so improve remarkably the appearance quality.3. Effect on growth. Single-fruit weight of bagged Jinyu is more than CK expect green-plastic bag, and average weight of all the bagging treats increases by 12.73% compared with CK. Bagged L1 and L2 increase single-fruit weight than CK, while increasing amount reach to 4.87% and 12.5%.Bagging increases the firmness, decreases the flesh thickness, and the effect of index is not obvious.4. Effect on nutritional quality. Bagging can increase the content of fructose, acid and TSS. Apart from the L1 bagged with black-plastic bag, all the bagging treats increase the content of total sugar. Bagging can make VC content higer than CK except Jinyu bagged with colorless-plastic bag, L1 bagged with sulfuric acid paper bag and L2 bagged with black-plastic bag. Apart from L2 bagged with pulp paper bag and black-plastic bag, all the bagging treats increase the content of free amino acid. Apart from black-plastic bag and red-plastic bag increase the sucrose in Jinyu, and colorless-plastic bag and sulfuric acid paper bag increase the sucrose in L2, bagging on muskmelon makes the sucrose content lower than CK.5.There are so many white cracks turned to black on bagged netted melon, cutting down the appearance quality, in addition L1 has had great quality itself, so I thick L1 don't need bagging. In all, Jinyu comparatively fit for pulp paper bag, and L2 comparatively fit for sulfuric acid paper bag.6. Dynamic study on growth and nutritional index using bagged L2 as experiment material. In the growing process, single-fruit weight of both bagged and non-bagged melon is increasing continuously, while fruit shape index is decreasing. Single-fruit weight of bagging melon is always higher than non-bagging. Effect of bagging on fruit shape index is not obvious.Contents of fructose, soluble protein, soluble sugar, acid and sucrose of bagged melon are increasing slowly in the whole growth period. Fructose, soluble protein, soluble sugar and acid content in bagged melons is higher than CK, while sucrose content in bagged melon is lower.7. Study on debagging time shows that: compared with the bagged melons, melons which are removed bags in advance have a lower nutrition index content including VC, soluble sugar, total sugar, acid, soluble protein, but usually higher than that of CK. So, I hold that during the bagging culture of muskmelon, we shouldn't remove the bags in advance.8. Bagging has changed the arrangement mode of epidermal cells on melon. It can make the epidermal cells arrange more orderly. Bagging can made the histiocyte under the epidermal cells volume bigger, arrangement looser and layer number less.