In recent years, as peopleกฏs living standard improved, fresh fruits had become an absolutely necessary item in our life. The planted area of fruit trees has been increasing rapidly, and fruit output has increased sharply. However, the high-quality fruit only accounts for about 30% of the overall fruit product; around 20% of the fruit product is of low grade. From the perspective of marketing, high-quality fruit sells well and low-quality fruit is unmarketable, which is the reason why itกฏs hard to sell fruits in some area and for some breed of fruit trees of our country. Thus itกฏs inevitable to replace quantity with quality, and itกฏs very important to change the concept of fruit planting and improve the quality of fruit. Well then, how should we improve the quality of fruit? We interviewed Mr. Chen Dong, the fruit tree expert in provincial academy of agricultural sciences.
Mr. Chen Dong said that the quality of fruit is a comprehensive concept, mainly referring to the appearance, taste and nutrition of fruit, which are important factors that affect the commercial value of fruit. In real life, the fruits are required to have pretty appearance, and their inner quality is also highly regarded. The health-care effect of fruits is especially regarded by consumers in recent years.
As a whole, the quality trait of fruits can be summed up in two categories: sensory trait and biochemical trait. Sensory trait is the trait of fruits that can be known by people through vision, smell, touch and taste, such as the fruitsกฏ size, shape, color, polish, flaw (plant disease and insect pests, mechanical damage and physiological handicap), hardness, crispness, the amount of dregs and juices, taste (sour, sweet, bitter, acerb), smell, etc. Biochemical trait is the amount and ingredients of nutrients and health-care substances contained in fruits, mainly including water, carbohydrate (sugar and starch), organic acid (citric acid and malic acid), protein, grease, pigment, mineral substance, enzyme, as well as flavor and aroma substances.
Generally speaking, we mush choose fine breed and feasible breeding condition to produce high-quality fruits. Besides, the following methods could be used to improve the quality of fruits: Setting up the orchard with high standard
Dig deeply in fix planting. The size of fix planting pit on sloping field should be 80cm กม 80cm กม 80cm. If the soil stratum is thin, the size could be enlarged properly. In dense planting orchard or plain ground, dig fix planting channels, 80cm deep and 80cm wide. Firstly, fill the channel bottom with 20-30cm-thick straw stems and weeds, then fill 500-1000 kg/mu organic fertilizer and 50 kg/mu calcium superphosphate layer by layer, mixing the fertilizer and soil evenly. After backfill, the soil should be about 20cm higher then the ground. Water it thoroughly to sink the soil.
Pay attention to the load of the fruit trees. Flower thinning and fruit thinning should be carried out strictly to maintain a proper leaf-fruit ratio. This way, the fruits will grow big and be in good color, and the sugar content will be high.
Balanced fertilization should be advocated. Organic fertilizer should be applied more, and inorganic fertilizer should be applied properly. Fall manuring should be applied heavily, and phosphor and kalium fertilizer should be added. Top application should be carried out at proper times. Small trees are mainly applied nitrogenous fertilizer and appropriately added phosphor and kalium fertilizer. The fertilizer should be applied frequently, a little at a time. For first fruiting trees, nitrogen should be controlled, phosphor should be increased and kalium should be added. Nitrogenous, phosphor and kalium should be compounded to apply for fruiting trees. If nitrogenous fertilizer is over applied, or quick result nitrogenous fertilizer is applied before the fruits ripe, the color of the fruits will be affected, and the sugar content will be reduced. Phosphor fertilizer and kalium fertilizer is good for the accumulation of sugar and formation of protein, and can improve the color of the fruit. In the orchards where organic fertilizer is applied sufficiently, the output and quality of fruits is evidently increased when phosphor fertilizer and kalium fertilizer are applied accordingly. The nutrients in organic fertilizer are relatively comprehensive. Therefore, the sugar content and taste of fruits will be increased and improved by adding organic fertilizer, and the color of fruits will be fine.
Digging deeply and improving the soil: Every autumn when applying basal fertilizer, dig deeply and enlarge the pit. Dig circular or parallel channel out of the fix planting pit or channel. The channel is 50cm deep and 30-50cm wide. Itกฏll be better to dig shallow near the tree, and gradually deeper outward. If it is the nectarine orchard with sticky heavy soil and shallow soil stratum, the channel could be somewhat deeper. Deep-dig the whole garden 3-4 years after planting.
Cultivation and weeding: In the orchards where there is no intercrop, cultivation, weeding and scarification should be carried out after rainfall or watering, 2-3 times each year, 8-12cm deep. Green dressing can be carried out together with cultivation. Donกฏt dig and weed too deep in the plate of small trees. Do it more often instead.
Covering: Haulm, straw, green manure and mulching film can be used as covering materials. Grass mulching in the orchards can improve the soil fertility. It is usually carried out after the basal fertilizer is applied during autumn, or in drought seasons. where the root and stem meet, a 20cm venthole should be set. The thickness is 10-15cm for hay, and 30-40cm for fresh grass, covered by a small amount of fine earth.
Reasonable intercrop or grass planting: In small tree orchards, intercropping or grass planting without cultivation should be advocated. The intercrops are usually shallow-rooted short-culm plants that donกฏt have common plant disease and insect pest with the fruit trees, such as legumes (peanut and soy), vegetables (leaf vegetables and root vegetables), green manures (white clover, alfalfa, common vetch, ryegrass) and some drug plants. Long culm crops, lianas and defertilizing crops should be avoided. Intercrops cannot be planted under the crown of the tree (within the plate of the tree). One kind of crop cannot be planted in sequence.
Reinforce the management of coloring period: When the fruit is gaining color, a silver or silver-gray reflecting film can be laid under the crown of the tree to reflect the sunlight. This way, the lighting condition within and under the crown can be improved. The underside of fruit where sunlight hardly reaches can get some reflected light and have a good color. The fruits on the whole tree would be evenly colored and the high-quality ratio will be increased.
Picking the leaves and turning the fruits: When the fruits are gaining color, pick the leaves that overshadow the fruits so that the fruits can be sunned directly. When the side facing the sun has been evenly colored, turn the fruit slightly and secure it, to make the other side facing the sun. This can solve the problem of bad color in the shade and on the side of the fruit. However, donกฏt pick the leaves too early, or the sugar content of the fruit will decrease, and the flower and bud will not depart sufficiently.
Pruning can create a fine lighting condition for the tree.
Short pruning and thinning out are mainly carried out in winter, so as to foster new fruit-bearing shoot timely, and cut out dense branches, slim and fragile branches and redundant top branches.
In summer, there are some primary pruning measures, such as flower and fruit thinning, bud cutting, twig thinning, branch-pulling, pinching, twig-tweaking, branch-tweaking, ring girdling, etc. The main purpose is to control the contradiction between twigs and fruits, reduce fruit dropping, guarantee sufficient nutrients to support the fruit growing and developing, adjust the tree vigor, and urge the whole tree to be ventilated and sun lighted.
Pay attention to protecting the leaves
Protecting the leaves can help promote photosynthesis, increase the nutrients accumulation and improve the color of the fruits.
Bag the fruits
Bagging can prevent many plant disease and insect pests. The fruit powder on the pericarp will increase, and the fruit will be fresh-colored and nice-shaped. Various physiological barriers such as sunscald and dehiscent fruit will be avoided or alleviated. The mechanical injures that are caused by the friction between the fruits and branches and leaves will be reduced. There will be less pesticide remnants on the fruits, and the security of fruit products will increase. The benefit of planting fruits will increase.
Bagging are usually carried out after fruit thinning, the earlier the better. Pesticide and antiseptic should be sprayed before bagging. Better use special paper bag for fruits. Self-made bags could also be used. There are single- or double-layer bags for different breed of fruits.
Improve the fruit product security
Set the garden in places where the soil, water and air are not polluted; use the fertilizer that is approved to be used in green and nuisance-free food products; strengthen the monitoring of plant disease and insect pests, understand the situation of plant disease and insect pests, and prevent and cure them in time; advocate to use biogalvanic soure pesticide; use high-efficiency, low-toxicity and low-residual pesticide; enforce the safe interval period of pesticide.
Harvest timely and scientifically
Time of harvest: The fruits that are sold fresh should be harvested when they are nearly ripe and have proper color, smell, flavor and taste. Donกฏt pick it too early. Some fruits (such as peach and berries) are not storable, and their harvest must not be too late. Storable fruits can be picked 5-7 days in advance. 10 am or 6 pm is appropriate for harvest. The temperature is too high in the noon to pick fruits.
Way of harvest: Pick in sequence, from the lower place of the tree to the higher, and from the inside to the outside. Pick and place the fruits gently. Prevent the fruits from being hurt by collision, pinch and sting. Keep the fruit powder untouched. Put the fruits in a cool and ventilated place without sunlight to lower the temperature of the fruits. Lay some soft paper in the packaging or container.