Control Methods for Lotus Root Rot and Analysis of Planting Costs and Returns

Lotus root is also known as mi, Rongyu node, Yu Linglong, jade shoot, jade arm dragon, jade lotus root, Guangpang, rain grass, and Linglong wrist. It prefers warmth, is not tolerant of shade, and should not lack water or be exposed to strong wind. It is mainly cultivated in marshy land. So how do you control lotus root rot? What are the current planting costs and returns?

How do you control lotus root rot?

Symptoms:

This is a fungal disease that mainly infects the underground stem of lotus root, causing it to turn brown and rot, and leading to withering of the aboveground parts. Early symptoms on the underground stem are not obvious; later, irregular brown spots appear on the diseased stem, lotus whip, and roots, and when the diseased stem is cut open, the vascular bundles in the center are browned. The leaves of affected plants become lighter in color, then water-soaked wilting appears at the leaf margins, and finally the entire leaf curls and dies. The pathogen overwinters as mycelium in seed lotus roots or in the soil. Infected seed lotus roots and field plots are the main primary infection sources of this disease.

Control measures:

1. In old lotus root areas, promptly dispose of crop residues. Except for fields where seed lotus roots are retained, after harvest, promptly cut down the remaining lotus stems and burn them in a centralized manner. After harvest, the lotus root field can be planted with one season of winter crops. For plots not planted with overwintering crops and plots without a water source, deep plowing and sun-drying of the soil should be carried out in winter. Where water sources are good, the field can be flooded in winter; it is very difficult for the pathogen to overwinter in flooded fields in winter.

2. Lime treatment: before the first plowing, evenly broadcast 100-150 kg of quicklime and 25-30 kg of calcium cyanamide per mu, then plow deeply into the soil. This not only provides fertilizer but also helps adjust soil pH and disinfect the soil, effectively killing many pathogenic bacteria.

3. Choose disease-free fields for seed production, which can avoid seed lotus roots carrying the pathogen and reduce the primary infection source.

4. Disinfect seed lotus roots: after the seed lotus roots are dug up, soak them for about 10 hours in a 1000-fold solution of 33.5% copper quinolinate plus an 800-fold solution of 70% thiophanate-methyl wettable powder, then remove them, let them dry, and plant. The above agents can also be sprayed on the seed lotus roots, followed by covering with plastic film and sealing for 24 hours for airtight seed disinfection; after drying, plant them.

5. Crop rotation: alternating paddy and dryland cropping every other year is preferable, and continuous cropping generally should not exceed 3 years. Paddy-dryland rotation can purify the soil, reduce pathogen accumulation, regulate soil nutrients, improve soil structure, and enhance disease resistance.

6. Apply sufficient fully decomposed organic fertilizer and topdress in a timely manner. Topdressing should combine nitrogen, phosphorus, and potassium fertilizers, and should also supplement trace fertilizers such as molybdenum, zinc, and boron.

7. In the early stage of disease onset, promptly pull out diseased plants. Per mu, mix 500 g of 50% carbendazim plus 75% chlorothalonil wettable powder with 50 kg of fine soil, mix well, compost for 3-4 hours, and broadcast it in shallow-water lotus root fields. At the same time, spray the leaves with a 1000-fold solution of 50% prochloraz, once every 7-10 days, for 2-3 consecutive applications. Alternatively, in mid-June, drain the lotus root field, drench the soil around the lotus root crowns with a 600-fold solution of dexon, refill with water the next day, and apply once every 5-7 days for 4 consecutive applications.

What are the planting costs and returns of lotus root?

The investment in planting lotus root can be large or small. Generally, land rent is about 1200 yuan per mu, fertilizer and pesticides about 600 yuan per mu, lotus root seed about 1600 yuan per mu, labor for cultivation, harvesting, and fertilization about 1600 yuan per mu, and other costs such as water and electricity about 200 yuan per mu. The investment in lotus root planting is about 5200 yuan per mu. At the same time, loach, ricefield eel, and other species can be raised in the lotus root field. Taking loach as an example, stocking 100 jin of loach fry per mu requires about 1500 yuan in cost. Therefore, the investment cost of planting lotus root is 6700 yuan per mu.

Profit per mu:

1. Vegetable lotus root: yield is 6600 jin of vegetable lotus root per mu, marketable rate 80%, wholesale price 1.6 yuan per jin, that is, 6600*0.8*1.6=8448 yuan.

2. Seed lotus root: yield is 6600 jin of seed lotus root per mu, finished product rate 80%, wholesale price 2.6 yuan per jin, that is, 6600*0.8*2.6=13728 yuan.

3. Loach: stocked at 100 jin per mu in June, harvested at 200 jin per mu in November, wholesale price 18 yuan per jin, that is, 100*18=1800 yuan.

4. Profit: the total income of lotus root per mu is 23976 yuan. Subtracting the cost of 6700 yuan, the net profit is about 17276 yuan.

Prospect analysis:

1. The entire lotus root plant is valuable; its roots, stems, leaves, flowers, and fruits all have economic value. In addition to the lotus root and lotus seeds being used as food, the rhizome, lotus leaves, lotus plumule, and so on can also be used in dishes, beverages, and health products. Lotus root generally contains 10%-20% starch and 1%-2% protein, while the starch and protein contents in lotus seeds are as high as 40%-50% and 19%-22% respectively, and both contain multiple vitamins. They are excellent aquatic vegetables and side-food delicacies and can be eaten raw, cooked, processed into canned goods, made into candied fruit, and made into lotus root powder. The products are relatively storage- and transport-tolerant and have broad market outlets at home and abroad, making them important commodities for earning foreign exchange through export. Lotus root is also a commonly used medicine in traditional Chinese medicine; lotus root nodes, lotus roots, lotus plumule, petals, stamens, lotus leaves, and so on can all be used as medicine.

2. Lotus root is distributed very widely in China and is rich in resources. It can be found from the black soil of the Northeast to Hainan Island, and from the coast of the East China Sea to the Tibetan Plateau. The main cultivation areas are in the Cheng River basin and the Huanghuai basin, with the largest planting areas in Hubei, Jiangsu, Anhui, and other provinces. With the development and utilization of lake beach resources in vast water towns, the adjustment of the rural industrial structure, and further opening to the outside world, China's lotus root production and sales will surely achieve new development and improvement.