The provincial Ha Tinh there are more than 7,000 ha of citrus trees, of which orange and pomelo trees account for nearly 90%. The most cultivated area for pomelo trees is in Phuc Trach, Huong Trach and Huong Do communes (Huong Khe district), while the orange area is mainly concentrated in Vu Quang district up to 2,500ha, Thuong Loc commune (Cam Loc district) is 240 ha.

Land for planting oranges and pomelo This area belongs to the group of red and yellow feralit soil and an area of ​​basalt soil formed on hilly or mountainous terrain interspersed with high mountains, very hot summer climate, on average 380C, cold winters and rainfall. Large, suitable for grapefruit, orange trees.

However, in the agronomy of pomelo and oranges, there are many limitations due to the unscientific use of fertilizers, farmers rarely invest in organic fertilizers, use too much acidic chemical fertilizers such as supe, phosphorus, nitrogen, etc. or types of fast-soluble NPK containing acid root for fertilization, intercropping legumes for land investment is limited, and in the rainy season, soil is very large.

As a perennial tree, pomelos and oranges in Ha Tinh lack nutrition and sour environment, thus reducing productivity, appearing harmful pests and diseases. Before 2010, the brand name of Phuc Thach pomelo and oranges in the market was faint. The area of ​​orange cultivation has narrowed, the gardeners’ income has decreased sharply … in order to restore the brand, regain productivity and quality, Ha Tinh province has focused on investing in building a fertilization process according to the VietGAP standards.

Understanding local needs and shortcomings in the use of fertilizers by farmers, Van Dien Fused Phosphate Joint Stock Company cooperates with Ha Tinh Gardening Association to deploy many models. using Van Dien fertilizer for pomelos, oranges and safe vegetables on the table in Huong Khe, Vu Quang, Duc Tho …

Trial on Van Dien fertilizer in pomelo production areas of Phuc Trach, Cam Khe May, Thuong Loc, Cam Bu Huong Son.

The experiment was conducted in a closed crop year 2010 on 1.5 ha of 15 year old grapefruit in Phuc Trach, together with 2.0 ha of 10 year old oranges in Khe May and Huong Son by using completely Van Dien fertilizer including Fused phosphate fertilizer and NPK multi-factor fertilizer is used specifically for citrus. Van Dien fertilizer divided fertilizer 4 times a year:

• Stage 1: Applying after harvesting, using 1.5 – 2.0 kg / root of Van Dien fused phosphate + multi-element of NPK 5.10.3, from 2- 4 kg + 15 kg of decomposed organic fertilizer /origin.

Phase 2: Applying flowers with the amount of fertilizer from 1.0 -1.5 kg / root of ĐYT NPK 12.5.10.

Stage 3: Applying after fruiting from 2.0 to 3.0 kg / root of health care NPK 12.8.12

• Phase 4 fertilizing 50 days before harvesting fruit from 1.5 -3.0 kg / root ĐYT NPK 12.7.20.

Grapefruit fertilized with Van Dien is more prominent than the control along with other NPK fertilizers in that: Bright green leaves, shiny leaf surface, thick leaves, smooth bark and branches, 50% reduction of harmful pests and diseases. high fruiting, fruit uniformity, concentrated ripening, beautiful peel color, less fruit drop, yield 1.8 times higher than control, sweet and fragrant quality characteristic of Phuc Trach grapefruit and famous Buu before. After only 10 years, farmers have liked the effectiveness of Van Dien Fertilizer

Mr. Nguyen Xuan Tinh – Chairman of the Gardening Association of Ha Tinh province said, “Since the introduction of Van Dien fertilizer, orange trees, grapefruit trees here are fully supplemented with nutrients, healthy plants, good growth and development. With high yield and quality, up to now, Ha Tinh province has thousands of hectares of citrus trees fertilized with Van Dien fertilizer ”.

Mr. Hoang Van Giam, Phuc Trach commune, Huong Khe district, said: “My family has 200 grapefruit roots 10 years old, in the last 6 years, I completely use Van Dien fertilizer, every year grapefruit has good season to sell. After fertilizing a healthy grapefruit tree, wrong flowering, large fruiting, uniformly large fruit, less drop, reducing pests, yield, high quality, Van Dien fertilizer contains much more nutrients than other types. Fertilizer is currently on the market, in Phuc Trach most people use Van Dien fertilizer.

Ms. Pham Thi Lanh, who has 500 oranges and is 13 years old, commented: “Van Dien fertilizer with good quality, competitive price, convenient supply, easy to use, high efficiency, great profit. More than 7 cases of oranges in the family completely use Van Dien fertilizer, the most difference is the color of the leaves, the shade is visible from a distance, dark green, after heavy rains, the trees are very few to drop fruit, the stools are good and durable. , good quality, high productivity, high quality, easy to consume, especially less using plant protection drugs, safe for users, protecting the environment ”.

In the Buu orange growing area in Son Mai, Son Thuy, Son Truong communes with more than 1,000 hectares, Mr. Ngo Xuan Hoa, Son Mai commune, cultivating 300 orange trees, shared: “The family has tested many fertilizers for orange trees, but Only Van Dien fertilizer is suitable and easy to use fertilizer. Van Dien fertilizer is more than other fertilizers, it is full of 13 types of nutrients to meet the needs of orange trees, so plants are healthy, less pests, high yield and quality ”.

Van Dien fertilizer helps plants to be healthy, less pests, high yield and quality

Bringing Van Dien Fertilizer back to people growing safe vegetables in Ha Tinh.

Recently, the demand for safe vegetables of consumers is very large, small farming methods, heavy using chemical fertilizers and pesticides have been replaced by more scientific farming methods. according to VietGAP standards, cultivating safe vegetables, clean vegetables, organic vegetables. The vegetable growing land in Ha Tinh is mostly on alluvial soils that are poor, humus and acidic, pH

Want immediate effect

Dr. Nguyen Ba Phu, Department of Crop Production (Faculty of Agriculture, Can Tho University) said that in recent years, many gardeners renovate mixed gardens and a movement to establish specialty gardens in some localities is emerging.

Efficiency and profits increase if farmers know to invest in the right direction and apply the right care techniques. Currently in the Mekong Delta, the provinces of Soc Trang, Hau Giang, An Giang and Can Tho city … organize many training programs on cultivation techniques, cultivation of specialty orchards in the direction of sustainability.

Local agricultural officers together with farmers implement the model of economical watering of durian gardens in Cho Lach district, Ben Tre province. Photo: HD

Although understanding and understanding techniques to build specialized gardens in a sustainable direction, some gardeners still have not changed their practice in a new way.

The farming methods, applying new technical advances, training the majority of farmers agree, and think in the right direction. If you do, the garden will be “solid”, sustainable and completely applicable.

However, there are still some gardeners who believe that applying methodical techniques, the tree will take long to produce high-yield fruits, it takes time, because the psychological pressure of “eating in the same place”, wants to follow the tree to produce fruit. profit quickly, high profit even only 3-5 years.

Therefore, when realizing that the market for fruit varieties is attracting products for one or two consecutive years with high prices, they rush to find seeds to buy and plant for them. Some people are even ready to cut down orchards that are giving fruit if after only one or two seasons the fruit price falls and it is difficult to sell.

For example, some gardeners planting persimmon tangerines (also known as tangerines) in Lai Vung district (Dong Thap) admitted: Since 2 years ago, there were signs of pests and diseases “raiding” many orchards.

However, some gardeners still accept to pour billions of capital into tangerine gardens, even dig soil up, buy land from the fields and pour it in to hope to gain silver in the tangerine season.

However, due to the wrong care and prevention of pests and diseases, the disease has worsened and the garden gradually deteriorates. Some farmers often spread word of mouth to each other about prevention and treatment.

Pink mandarin trees have two quite common diseases, for each root rot disease, they buy Ridomil to control plant diseases, and mealybugs buy Nokaph (medicine to treat nematodes and pests in the soil), even in gardens that are not diseased. also bought for prevention before, every 2 months and considered as “miracle”.

As a result, as now seen, many pink tangerine orchards get worse and worse, they have to ask for help from scientific staff to find the right gardening method.

The orchard selects citrus trees in Cho Lach district, Ben Tre. Photo: HD

Currently, Soc Trang province organizes a training program on the model of building a special-purpose orchard specializing in citrus trees for farmers. Thereby improving knowledge, updating farming techniques, applying new technologies in fruit production. This model is applied by growers quite popularly in the fruit export cooperatives.

It is an open way to improve garden economic efficiency. The local government acts as a bridge to create a link between agricultural cooperatives – businesses – scientists. In which the role of scientist will guide farming techniques for cooperatives farmers.

Technical solutions for sustainable fruit production in the Mekong Delta

Dr. Nguyen Ba Phu proposed a number of technical solutions for planting and taking care of fruit trees in the Mekong Delta.

Select and improve soil: Soil has a pH of 6-7. The soil must be loose and airy, able to hold moisture and drain well, the arable layer is thick (at least 0.5 m) and stable.

Seedlings from good, selected seedlings, preferably from the best clones. There is an appropriate propagation method, free of diseases (special attention is paid to green leaf yellowing disease and Tristeza on citrus trees).

About the planting type, should be planted in rows. Rows in the wind direction (Northeast – Southwest). Spacing between thin rows, on thick rows.

Preparation of growing tissue and planting: All the soil above and below the base of the tissue (0.3 m) is soil mixed with organic fertilizer (5 – 10 kg) and fused phosphate fertilizer (0.5 – 1 kg). The tissue diameter should be about 1 – 1.2 m. The tissue height should be about 0.3 – 0.4 m. When placing plants, pay attention to the surface of the pot to be level with the tissue surface and tighten the soil around the pot.

Applying the process of pruning properly, creating canopy will help fruit trees for good design and quality. Photo: HD.

Trimming, creating canopy: Apply right in the stage of silk, from a young tree. Trees for fruits outside the canopy (citrus, mango, longan …) need to create a canopy with hemispherical shape or open heart, according to the principle of 1 branch leaving 2-3 branches (equally good, sparse, balanced).

Cutting time: Old leaves, just before or after fertilizing, combine bud control at the same time. For fruit trees on the main branch (durian, jackfruit …), create a crown shaped tree (pine canopy), keeping a main stem, growing straight.

Choose to keep level 1 branches (branches growing from the main body) with criteria for good branches, horizontal growth, evenly distributed, 20-30 cm apart. Can bend level 1 branches, creating the shape of a spiral staircase. Pay attention to keep level 1 branches during the fruit harvest.

Hygienic pruning should be carried out throughout the planting period, especially after harvest.

Cut off branches reaching high and shade (control canopy), pests, dry branches, branches that are not capable of bearing fruit … Keep appropriate canopy. Always leave a space between the two rows to help the garden clear. Keep a reasonable height of the garden for easy care and intensive farming.

Fertilize: Plants need to be provided with 13 essential nutrients: Macronutrients (N, P and K); intermediate (Ca, Mg and S); trace elements (Fe, Cu, Zn, Mn, B, Mo and Cl). In the Mekong Delta, fertilizers containing S should be limited, since most of the soil contains S in high levels.

Lime: should use limestone (CaO) “phi”, fertilizing in the beginning of the rainy season, fertilizing with soil pH. If the pH is above 6.5, there is no need for liming; pH from 5.5 to 6.5, applying 500 kg of limestone / ha; pH from 4.5 to 5.5, apply 1,000 kg of limestone / ha; pH from 3.5 to 4.5, apply 2,000 kg of limestone / ha.

Organic fertilizer: Chewable and properly composted. During the incubation process, it is necessary to pay attention to the appropriate humidity (about 70 – 80%) and to mix the compost pile. Applying in the dry season, the amount of fertilizer is 10-20 tons / ha. Do not use together lime and organic fertilizers.

Inorganic fertilizers: Need to determine the type and amount of fertilizer depending on the needs of the plant. Plants have different nutritional requirements depending on the stage of growth and each stage of fruit development.

In the period of silk (trees without fruit), fertilizers (N – P2O5 – K2O): 30 – 20 – 10 or 30 – 10 – 10. The amount of fertilizer is from 50-100 g / time. Fertilizer time when leaves are old, should not be applied when the leaves are young. Need to fertilize according to the canopy, burial or watering.

Reasonable vegetation should be maintained in orchards. Photo: LHV

It is advisable to combine cultivating and improving lettuce with fused phosphate, organic fertilizer and sedimentation. Micronutrients can be added by spraying leaves at silk leaves, combined with pruning measures, helping plants to sprout simultaneously. The type and amount of manure can be decreased depending on the type of tree, soil area, density and yield of the previous crop.

Note: Apply according to the canopy (active root zone). The manure must be buried in the soil (using a hoe or machine to mix the fertilizer).

Fused phosphate fertilizers (Ninh Binh, Van Dien, Lam Thao) should be used, especially on low pH soils in the Mekong Delta. In addition to containing phosphorus, molten phosphate also contains Ca, Mg, Si and some trace elements.

Grass management: Should let the grass in the garden, weeding clean the part close to the base, around should only cut, leave the grass stump about 3 – 5 cm.

Water management and irrigation techniques: Water systems in garden ditches must be well ventilated and downstream. Regularly change the water in garden ditches.

Keep the water level in the ditch about 0.6 m from the trench surface during the dry season and 0.8 m. In the rainy season, limit watering to the leaves. Do not water after 3pm. Best in the morning. Maintain a suitable soil moisture of 70 – 80%.

Pest management: Adopt integrated pest management (IPM), make full use of farming practices. Apply biological methods. Using agricultural medicine is the last resort and must adhere to the 4 correct principle.

How to exploit fruit and flower processing: should exploit fruit concentratedly. Should not “pass” fruit (many sizes of fruit) on the tree. Depending on the natural conditions, choose the appropriate time to process the flowering so that the fruit has good quality, high yield, less pests and strong plants. Keep a reasonable number of fruits (pruning) depending on the growth situation (leaf set) of the tree.

It is possible to combine the use of soil “cropping” method (about 30 cm deep) to both treat flowering and improve soil porosity and ventilation.