CULTURAL PRACTICES SITE PREPARATION
The sweet potato is usually grown outdoors. After removal of the previous crop stubble by plowing and harrow work, and after the addition of soil fertilizers and insecticides, the land was available in hills or ridges. It is necessary to leave the field perfectly soft for easy plant vegetation and thickening of the tubers. These are usually
triangular ridges 90 cm wide and 35 cm in height and line spacing of 95 cm. When the ridges are prepared are made a small hole at the top. PLANTATION
a) Time of planting. According
growing area, times may vary, but generally occurs during the months of April and June. In warmer climates can be chosen any time, provided during the dry season, providing abundant irrigation.
b) Setting of planting.
The distance between lines is usually 95 cm. The separation of plants within the line is between 30 and 40 cm, representing a density ranging from 35,000 to 26,300 plants / ha. The distance between plants varies depending on the force and the earliness of the variety to cultivate. At larger distances are obtained larger tubers.
c) Plantation.
is done by bucket for planting tips and cuttings (pieces of branches about 30-35 cm and equipped with three or four buds at least). It uses a cane handle around 2.25 m, at whose end is placed a cylindrical tin. Using this instrument provides water to the hole while the cutting is planted. This makes the part buried in the muddy hole is arched, which makes rooting. The cuttings will be planted so that two or three knots are buried and will vary depending on the vigor of the variety chosen. The higher the number of nodes in the ground, the greater the number of fruits (crops), because they originate from root buds that emit located at each node.
OTHER WORK
a) Replenishment of yore.
is done between 7-10 days from planting. It is recommended when failures exceed 15%.
b) ridging. At 40-50 days of planting have made an earthing is advisable to allow combat weeds.
c) weeding. It takes place during the early stages of crop treatments using screens, targeting weeds with diquat, paraquat, etc. They can also be used in pre-plant herbicide chlorthal, naptalam, etc.
d) Control of air overdevelopment. By pinching and removal of foliage at the top, to avoid negative effects on tuberization.
ALTERNATIVE CROP
are many rotations that can be made by combining the cultivation of sweet potatoes during the summer, with many vegetable species that develop during the winter months. The choice of either rotation, where the sweet potato from once a year, once every two, three or more years, depending mainly on economic conditions (demand, labor, farm size, etc..). The most commonly used alternative is to keep sweet potatoes in the rotation early and precede potatoes with onions, tomatoes, etc. In many tropical countries is above the sweet rice. PAID
a subscriber is usually done before planting or is supplemented from the manure and mineral fertilizer it receives from the previous crop. The sweet potato is demanding in potassium, low in nitrogen and organic nitrogen and phosphorus as discrete. 1:2:3 balances
recommended dose of 270 kg of nutrients per hectare. This corresponds to 500 Kg / ha of 9-18-27 complex or to the following formulation with straight fertilizers: ammonium sulphate
21%: 220 kg.
lime superphosphate 18%: 500 kg.
potassium sulfate 50%: 280 kg. IRRIGATION
The potato needs moist soil, especially when making the planting of cuttings or points, to encourage rooting, in the early stages of cultivation, and in general to throughout the cycle. Excessive moisture can cause loss of production quantity and quality. Sweet potato is a plant is moderately drought tolerant, although it responds productively to irrigation Gaul.
Regarding the number of irrigation will be sufficient three or four in the four or five months that the crop, but if the weather or the season will be very dry until eight or nine irrigations applied every fortnight. The area is used for irrigation, filling the grooves in which the parcel is divided. PEST
or doradilla wireworms (Agriotes lineatus).
this beetle larvae excavate galleries and holes in the tuber, appreciably reducing the commercial value thereof. His control is done proactively, during site preparation and before establishing the crop, insecticides, granular preparations to spread on the ground and wrap with the work. Active substances most used are lindane, parathion, carbofuran, chlorpyrifos, diazinon, and phoxim fonofos. Doughnut
black (Spodoptera litoralis).
The larvae of this lepidopteran noctuid evening climb to the top of the plant and eat the leaves. The damage occurs by the end of cultivation, located mainly focuses on the edges and slopes. For control treatments are recommended as baits for the day. Used about 100 kg of bait per hectare, usually in two treatments, one in July and another in August. You can also use sprays of chlorpyrifos, trichlorfon, retraclorvinfos, cypermethrin, deltamethrin, etc.
DISEASES
Virus.
A sweet potato virus diseases will affect mainly the following: Mosaic
sweet potato. Produces dwarfism, mosaic and leaf deformation and little or no tuber. Virus
internal shortening of the sweet potato (Internal Cork). Corky tissue deformation occurs inside the tuber, with chlorotic spots on leaves, light green venation, etc. Spotted
complex sweet potato. Produces dwarfing, yellowing of the veins of young leaves, yellow spots on older leaves, internodes and small tubers. It is transmitted by whiteflies and whitefly Bemisia tabaci snuff.
Sweet Potato Vein Mosaic Virus (SPVMV). Puff produces leaves, curly, mottled, etc. affected plants grow poorly and develop short and leaves remain small.
Fusarium oxysporum.
vascular disease that causes progressive yellowing of leaves and later develop a black rot the roots. Should be prevented by disinfection of soil, distance of the alternatives, etc. Mummified
sweet potato. Raised
Monilichaetes infuscans by the fungus produces reddish blotches and sometimes cracking of the crust. When it appears in the magazine, produces desiccation and mummification of tubers. Must be combated by treatment with TBZ, benomyl, etc., Disinfecting the propagating material and using resistant varieties.
Blackrot of sweet potato. Anomaly
own nursery and storage caused by the fungus Cerastomella fimbriata, which produces small dark brown spots. resistant varieties should be used, disinfect the tubers used for multiplication, etc.
COLLECTION AND CONSERVATION
Five or six months after planting can begin to collect the potatoes, usually during the months of October and November. A fortnight before necessary do a job of cutting the branches. When the potato is mature, the leaves turn yellow. The manual collection is letting the roots dry out in the field, although large areas of mechanized harvesting is common.
Average yields vary between 20 and 30 tons / ha and average production per foot for 2 to 4 tubers with weights ranging between 200-400 grams each.
For the conservation of sweet potato tubers are arranged in layers in a ventilated room at 11-15 º C and a humidity of 80-85%. Conservation at temperatures below 12 º C can cause wrinkling of the roots, enmarronecimiento meat, hollow small surface and side cryptogamic attacks. BIBLIOGRAPHY
ALSINA, L. 1980. Special Horticulture. Volume I. Ed Sintes, SA Barcelona.
MAROTO, JV 1995. J. Immunol. Ed Mundi-Prensa. Madrid. 611 pp.
RODRÍGUEZ, G. 1984. The potato and its cultivation. Ministry of Agriculture, Fisheries and Food. Madrid. 95 pp.
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