Detailed Explanation of Key Points for Standardized Yam Production Technology
I. Environmental Conditions Yam cultivation has relatively strict soil requirements. Generally, loam or sandy loam plots with deep soil layers, loose soil texture, and no tree roots, stones, or rubble within 1 m below the surface should be selected for planting. Clay land can also be planted, but it will reduce the commercial quality of yam and make harvesting difficult. II. Cultivation...
I. Environmental Conditions
Yam cultivation has relatively strict soil requirements. Generally, loam or sandy loam plots with deep soil layers, loose soil texture, and no tree roots, stones, or rubble within 1 m below the surface should be selected for planting. Clay land can also be planted, but it will reduce the commercial quality of yam and make harvesting difficult.
II. Cultivation Techniques
1. Trenching and bed preparation. Yam planting can use manual trenching or mechanical trenching. (1) Manual trenching. Dig manually during the winter slack season, with a trench spacing of 1.4 m, trench width of 35-40 cm, and trench depth of 1 m, placing the excavated raw soil and mature soil separately. Digging trenches before winter can freeze some underground pests to death during overwintering. In early spring of the following year, backfill soil into the trenches as the ground thaws, first filling with raw soil and then with mature soil. When backfilling, do not disturb the soil layers. When filling with mature soil, mix in 4000 kg of fully decomposed organic fertilizer and 50 kg of potassium sulfate compound fertilizer per 1/15 hectare (1 mu), mix thoroughly with the soil, and fill into the trench. When filled to 90%, water to settle it, irrigate enough bottom water, then fill level to form ridges for planting. (2) Mechanical trenching. Before trenching, apply 5000 kg of organic fertilizer and 50 kg of potassium sulfate compound fertilizer per 1/15 hectare, level and harrow finely, and mechanically trench at 85 cm row spacing. After trenching, tread the excavated soil firmly along the ridges, then build up soil into ridges ready for sowing.
2. Cultivating strong buds. Select yam seed tubers weighing 50-75 g, free from rot or shriveling, healthy and plump, and containing a terminal bud. In late March to early April, sun-dry for about 10 days to make the cut surface dry and cracked. When the bud grows to 0.5 cm long, select seed tubers with a blunt-rounded bud base and thick, strong growth. Use a mixed solution of 25% triadimefon 1000x solution plus 50% carbendazim 400x solution plus validamycin 200x solution, soak the seeds for 5 minutes, then remove and air-dry before sowing.
3. Sowing time. Choose clear weather in early April for sowing, no later than mid-April.
4. Planting density and method. (1) Manual trenching: open 2 small trenches 10 cm deep in the exact center of the ridge (that is, double-row planting), with trench spacing of 15 cm. Place the seed tubers flat along the trench in the center, with plant spacing (referring to the distance from bud to bud of two seed tubers) of 10-20 cm, planting 5000 plants per 1/15 hectare. (2) Mechanical trenching. Open a small trench 10 cm deep in the exact center of the ridge (that is, single-row planting). Place the seed tubers flat in the trench in the same way, with plant spacing of 15-17 cm, planting 5000 plants per 1/15 hectare.
Regardless of which method is used, seed fertilizer and pesticide should be applied in the trench before planting. For seed fertilizer, generally apply 4-5 kg each of quick-acting nitrogen fertilizer and potassium fertilizer per 1/15 hectare. To prevent underground pests, roasted soybean cake can be mixed with phoxim emulsifiable concentrate diluted with water, moistened, and scattered into the trench. Mix the applied fertilizer and pesticide with the soil before sowing. Before planting, determine whether to water lightly in the trench based on soil moisture. For mechanical trenching, tread both sides of the ridge firmly to prevent water seepage and trench collapse.
III. Field Management
1. Trellising. A few days after yam emergence, the vines begin to trail, so trellising should be done in time. Generally, an inverted-V trellis shape is used, with a trellis height of more than 1.5 m, horizontal wire pulled across, and fixed with wooden stakes to prevent the bamboo trellis from being blown down by strong winds.
2. Water and fertilizer management. After planting and before trellising, high-quality farmyard manure can be spread again. During the vine-growing stage and the peak rhizome growth stage, continue spreading organic fertilizer. Starting from mid-June, apply potassium sulfate compound fertilizer at 20 kg per 1/15 hectare, once every 15 days, for a total of 3-4 applications. In the later stage, carry out foliar topdressing with 0.3% urea, 0.3% monopotassium phosphate, or spray with Yemianbao or Plant Power 2003 to prevent premature senescence. If the seedlings grow too vigorously, spray with chlormequat to strengthen the seedlings.
3. Pest and disease control. The main diseases of yam are brown spot and anthracnose. In summer, attention should be paid to drainage and moisture removal, enhancing ventilation, and reducing the occurrence of pests and diseases. For diseases, spray 70% thiophanate-methyl 500x solution or 77% copper hydroxide 500x solution 2-3 times. The main insect pest is the yam sawfly, which can be controlled with 2.5% deltamethrin 2000x solution.
IV. Harvesting and Storage
In mid-to-late October, the yam vines gradually die. Harvesting can be done according to market conditions. The yam harvest period is very long; from maturity to March of the following year, it can be dug and sold fresh at any time. If the market price is low, it can be left unharvested and preserved in the planting trench. It can also be harvested and stored in cellars or indoors, as long as it is not damaged by low-temperature freezing. The method is: select yams that are free from rot, free from mechanical damage, and meet the standard. Immediately after digging, wrap them firmly with clay and arrange them layer by layer in a heat-preserving, sterilized cellar or room. This simple storage method can preserve yams for more than 3 months.