Aquatic rooted plants. Roots in the fall from the fallen above ground stem nodes sprouting, the formation of new plants, short internodes, like roots out of the leaves, and from the new roots of the stem nodes to the surrounding stolons, and then continue to sprout seedlings, the upper leaves in winter freezing withered, the base of the stem and leaves rely on the aquatic layer of overwintering, and then continue to sprout reproduction, the plant height of 70-80 cm; two pinnately compound leaves, leaves elongated, alternate, the stem is angular, the upper part of the white-green, the lower part of the white; Umbels, small, white flowers; non-fruitful or empty seeds. Sex like cool, avoid heat and drought, below 25 ℃, the mother stem began to sprout growth, 15 ~ 20 ℃ fastest growth, 5 ℃ or less to stop growing, can withstand -10 ℃ low temperature; to live in the river gorge, paddy fields next to the soft soil, deep fertile soil, rich in organic matter fertilizer water retention force of clay soil is appropriate; long sunshine is conducive to the growth of stolon growth and flowering and fruiting, short sunshine is conducive to the root out of the leaf growth.

1 Variety selection

It is advisable to choose disease resistance, high quality, good yielding local varieties, recommended selection of Yu Qi watercress, Suzhou round leaf, Changshu watercress, Liyang white celery, Danyang watercress, Lujiang high peduncle and other varieties.

2 Environmental requirements

Harmless watercress origin environment should be in line with the national standard GB/T18407.1 ~ 2001 "agricultural quality and safety of pollution-free vegetable origin environmental requirements" provisions. At the same time, it is required to have sufficient water sources, flat terrain, convenient drainage and irrigation and good water retention.

3 Soil Preparation

The depth of plowing should be 25-30cm, and it is required to remove weeds and rake the mud surface. All around and in the middle of the field should be opened wide and deep are 15cm perimeter ditch and ditch, ditch spacing is suitable for 2 ~ 3 m. Base fertilizer application requirements in line with the agricultural industry standard NY/T394 ~ 2000 "Green Food Fertilizer Guidelines for the use of the requirements of 4.2 and 5.2, after the transformation of the soil fertility indicators should not be lower than the agricultural industry standard NY/T391 ~ 2000 "green food origin environmental technical conditions" in the 4.6 stipulated in the "green food environment". The index of soil fertility after transformation should not be lower than the index of Class II soil fertility (paddy field) stipulated in 4.6 of "Green Food Producing Environment Technical Conditions" of the agricultural industry standard NY/T391～2000. Fertilizer use and soil fertility indexes should not be lower than the basic requirements of Grade A green food production. Recommended fertilizer index is 3000kg of rotted stable fertilizer, 60kg of diammonium phosphate and 180kg of compound microbial fertilizer per 667 square meters.

4 Seed stem preparation

It is preferable to collect the seed stems from the dedicated seed field, and the seed plants for the collection of seed stems should be with the typical traits of varieties, with healthy growth, and without pests or light pests. Seed stem stem thickness should be 1.0cm, should not be greater than 1.5cm or less than 0.5cm. Early maturing varieties are generally required to germinate, it is appropriate to collect seed stems 15 days before planting; late maturing varieties are generally not germinated, it is appropriate to collect seed stems 1 to 2 days before planting.

5 seed stem germination

5.1 Bundling and stacking

It is appropriate to the base of the seed stems, remove debris, bundled into a diameter of 30cm round bundles, and cut off the seed stems on the buds or only small axillary buds on the top. Stacking place is suitable for near water sources in the shade or covered with black shade net under the trellis. Before stacking a layer of 10cm thick straw, stacking will be bundled seed stems cross yard, yard height and diameter should not exceed 2.0m, stacked and then covered with a layer of 5-10cm thick straw.

5.2 Germination management

It is advisable to water 1 time in the morning and 1 time in the evening every day to maintain the temperature in the heap at 20-25℃; every 5-7 days, turn the heap 1 time in the morning when it is cool to wash away the rotten leaves and debris, mobilize the position, and re-stack. Germination indicators to the seed stem more than 50% of the axillary buds sprouting, and bud length of 2 ~ 3cm is appropriate.

6 field planting

6.1 Planting materials and time

Early maturing varieties can be germinated seed stems, late August to early September to choose cloudy or sunny days in the afternoon when the cooler planting; late maturing varieties can be ungerminated seed stems, late September to early October planting. Each 667 square meters of seed stem dosage of 200 ~ 250kg.

6.2 planting method

Can be used in row sowing method and sowing method. When sowing seeds, it is appropriate to sow the field around the first row, and then sow the middle. It is appropriate to sow around the tips of the seed stems inward, and the middle of the rows may not take into account the direction. The row spacing is 6cm, and the seed stems are placed one after another. When sowing, it is appropriate to sow two circles around the first row, the tip of the seed stem inward, row spacing 6cm, to the middle of the line again sowing, sowing should be uniform.

7 Field management

7.1 Water depth regulation

15 days after planting, it is appropriate to keep water in the field ditch so that the bed is fully wet without water layer, in case of rain should be drained in a timely manner; 15-20 days after planting, it is appropriate to drain the field for 1-2 days, so that the soil is slightly dry or the surface of the cracks appear; after the field, it is appropriate to irrigate the field 3-5cm deep.

7.2 Fertilizer

Fertilizer should comply with the agricultural industry standard NY/T394 ~ 2000 "Green Food Fertilizer Use Guidelines" in 4.2 and 5.2 requirements. General fertilizer 3 times, the first fertilizer should be applied in the field after shelving, every 667 square meters of 20% ~ 25% of the rotted manure water solution of 2000kg; later in turn after an interval of 15 ~ 20 days for the second and third fertilizer, each time every 667 square meters of 20% ~ 25% of the rotted manure water solution of 2500kg.

7.3 homogenization

That is, the seedlings from the seedling The seedlings are transplanted from the dense place to the sparse or lack of seedlings. It is advisable to even out the seedlings when they are 15cm high, so that the distance between the holes is 10-12cm, and there are 2-3 plants in each hole.

7.4 Deep-planting softening

It is appropriate to carry out in mid to late October, that is, when the plant height is 35-40cm. It is required to uproot the plants and replant them after straightening the roots. Each hole should be planted 20 ~ 30 plants, 15 ~ 20cm deep, hole spacing should be 15cm. softening period should stop fertilizer, water level requirements with the lowering of the temperature and gradually deepen to the plant growth point exposed to the water surface of the appropriate 3cm.

8 Pest control

It is appropriate to focus on the control of major pests and diseases, such as watercress spotted wilt, watercress rust and aphids. Agricultural measures and physical measures should be prioritized, and the use of pesticides should be in accordance with the agricultural industry standard NY/T393 "Green Food Pesticide Use Guidelines". Weeds should be manually pulled out in combination with field operations.

Watercress spotted wilt disease should be selected with disease-resistant varieties, pay attention to nitrogen, phosphorus, potassium fertilizer with the application, to prevent nitrogen fertilizer bias. At the beginning of the disease, it is appropriate to use 50% carbendazim wettable powder 500 times liquid and 50% diclofenac manganese zinc wettable powder 600 times liquid to spray 1 time each, with an interval of 7 days, the safety interval should not be less than 10 days.

Watercress rust should choose disease-resistant varieties. At the early stage of the disease, it is appropriate to use 25% powder rust 1000 times of wettable powder and 50% Dyson Manganese zinc 600 times of wettable powder alternately sprayed 1 time, during the interval of 7 days, the safety interval should not be less than 10 days.

Aphids are appropriate to use a short period of time to irrigate deep water to submerge the plant to diffuse the aphids. In the early stage of the infestation, it is appropriate to use 40% of Lego emulsion 1000 times and 50% of the aphid mist wettable powder 1000 times alternately spray 1 time, the interval between 7 days, the safety interval should not be less than 10 days.

9 Harvest

Deeply planted softening 20 days after the harvest can begin, it is appropriate to harvest in batches, can continue to harvest until early April of the following year. The target yield for this protocol is 4500kg per 667 square meters.