Use of Freshly Produced Tubers for Seed

• The potato tuber raised from autumn crop can be utilized can be utilized for spring crop sowing after breaking the dormancy of produce.
• While breaking dormancy, the following points must be taken into account.
• Select the produce for seed purpose by separating the tubers to be used for tubers.
• Keep the produce free from soil adhering on its surface by arranging water washing.
• On account of cold weather during spring sowing, the seed tubers may be cut in to small pieces.
• While giving cuts to tubers, eyes should not be damaged.
• Each tuber can be divided in to 2 - 4 pieces, and take care to cut the longitudinally as there are more eyes on the crown end than at the bottom.
• Each cut piece should have the weight of 30 g.
• Each cut piece should have at least two eyes on its surface.
• Do not sow the cut pieces without breaking dormancy. The autumn crop tubers have about 2 - 3 months dormancy period
• Use Ethylene Chlorohydrin (1 liter for 2 tons of seed tubers) followed by the thio-urea solution (1% or 1 kg of chemical for 1 ton of seed tubers) followed by final treatment with GA (Gibberellic acid 1 ppm for 10 minutes).
• Treat tubers with Ethylene Chlorohydrin (without making into pieces) for 24 hours, @ 1 liter for 2.0 tons of seed under cover or in an enclosed space.
• For effective use of Ethylene Chlorohydrin, digout trenches and put the seed in it and treat with this chemical taking care that these trenches when closed are air proof.

Follow the above treated material with thio urea treatment.

• Dissolve 1 kg thio-urea in 100 liter of water and dip the seed in lots for one hour.
• Solution made once can be utilized for the other lots and seed tubers should be free from soil.
• The same solution can be utilized for 5 - 6 lots without affecting the efficiency of dormancy breaker.
• Prepare separately, 1ppm solution of Gibberellic acid (1 mg in 1000 liter water) and keep the tubers in this solution for 10 minutes
• Cut the seed into small pieces for sowing spring crop of potato.

Germination Capacity

• Maximum germination power will be in 12 months after harvest and then decreased.
• When the tuber is planted before and after the proper age, °eneration is proportionate to the time interval.
• Seed tubers of the longer storage grow more stem than those from short storage, number of stems corresponding to age of the tubers
• Germinating potato tubers at 20 °C resulted in a morbid yield increase over those sprouted at 10 ° C before planting.
• Germinating at 20 ° C in the dark also increased branching of sprouts and no. of stems. Under these conditions gibberellin activity in leaves decreased and that in sprouts increased.
• The low temperature germination increased the gibberellin and auxin activity in leaves.

Seed Sprouting

• Weight of sprouts increases with age of tubers as a result of accelerated sprout growth and an increase in the number of sprouts per tuber
• Age of tuber may be detected by changes in type of sprout growth

1. The one sprout stage
2. The multiple sprout stage
3. The branching stage
4. The small tuber formation stage.

• As number of stem increases, the number of tubers formed also increases and average size of tuber is likely to decrease. Sprouted seed with only 1 or 2 sprout per piece result in a crop with a higher proportion of large potatoes under these situation.
• When all but one sprout were removed before planting, an average of 20.5 tuber per plant were produced, many of saleable size
• When seed pieces were restricted to one stem the no. of tubers was reduced and high proportion of large tubers were formed.
• Removal of the first sprout results in a greater number of sprouts to develop.
• The no. of sprouts increases in proportion to the weight of the seed piece.
• Seed stored under warm conditions soon after harvest produce few sprouts
• Pre germination of tubers results in a greater development of the root system and a higher proportion of root to tops. Early varieties react more in this manner than do late ones.

Method of Planting

The main factors considered for method of planting are

1. - Purpose for which Potatoes are grown
2. - Area to be planted and size of field.
3. - Availability of tractor and Potato planter.
4. - Availability of labor.
5. - Availability of seed size planting.

The plant spacing depends upon the purpose for which the crop is sown i.e. whether for ware / commercial purpose or seed purpose.

• If the crop is sown for seed purpose and large sized seeds are sown at narrow spacing, it will produce large number uniform sized tubers.
• If the large sized potatoes are sown at wider spacing, it will produce large sized and fewer tubers generally, medium sized tubers (3.75 cm diameters) are considered suitable for Potato sowing.
• If large area to be planted, potato planter not only save labor but also ensure timely and accurate sowing at desired depth and spacing.
• In case of small area, sowing with spades prove equally beneficial.
• Moreover, in small fields where heavy machinery does not hold good, manually sowing is preferred.
• On account of the use of potato planter seasonally, small and marginal farmers do not afford to purchase it. However, large farmer do prefer the sowing with planter.
• Availability of labor and as and when required also decide the sowing.
• No labor scarcity at cheaper rate, sowing manually proves equally efficient.
• The spacing between the intra-seed placements depends upon the seed size.
• Large and medium sized Potato for attaining high tuber yield should be placed at a distance of 15-20 cm.
• The distance between row to row is recommended for high tuber yield realization at 60 cm apart.

For manually planting of tubers, following points need attention

• Apply all fertilizer at the prepared field by broadcasting which will be mixed with soil at ridge formation with spades / manual bund maker (Jandra).
• Place the Potato tubers at the marker sign at a fixed distance.
• The soil is placed on these tubers up to 7.5 cm height with manual bend maker (Jandra) or with spade.
• Too high ridges formation delays the germination of tubers.
• Less than 6 cm height of ridge cause sun-burn to the tubers.
• All the Potato tubers should be covered thoroughly.
• Care is taken that seed does not come in direct contact with fertilizer otherwise the seed will not germinate.
• Apply irrigation after the sowing of Potato tubers, to provide sufficient moisture required for the germination. Of the tubers and repeat irrigation after 8-10 days interval.
• Do not allow the level of water to rise more than half otherwise the Potato tubers will rot, due to crustation of top soil.
• Flat planting is common in areas having light sandy soils.
• Do follow 2 earthing; first 25-30 days after sowing and second 40-50 days after sowing in flat planting it. This method is not considered a scientific one.
• Planting on ridges is done after preparation of field; the ridges of 30 cm height and 60 cm width are made with the help of spade (Jandra). Planting is done either at the top or on the sides of ridges.
• Scientifically, Planting with Potato planter has been found very effective with respect to the germination and for maintaining the proper pant population stands.

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Mechanical Planters

Manual planting on Flat bed and ridging by tractor

• In Jalandhar, Gurdaspur, Ludhiana, the farmers having tractors do their sowing with the use of Potato planter.
• It marks three rows in one round and Potato tubers are placed on these marks.
• The fertilizer is placed at a distance of 6cm away from the mark.
• The seeds are placed manually.
• The ridges are formed after placing the seed using tractor with bund maker is run with tractor.
• In one round three ridges are formed.
• This is three line ridge farmer and it cost almost Rs.2,000.

Semi-Automatic

• During these days semi-self propelled potato planter is mostly used; in which mechanical power of tractor and manual labor is involved for the sowing of Potato at desired depth and spacing.
• The seeds are placed in the hole for placing tubers at a desired distance and ridges are made on the placed seed.



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Crop Rotations And Intercropping

Potato is grown in rotation with other crops, usually to maintain

• Desirable soils texture and state of fertility
• To build up organic matter
• To reduce crop loss from insect and plant disease
• To increase per unit productivity per unit area and time
• To improve the quality of produce



Potato, being a fast growing crop, fits well in different rotations and inter cropping systems. It can very successfully be grown in the following sequences.

1. Maize-Potato-Wheat
2. Paddy -Potato-Wheat
3. GM - Potato - Wheat



For successful cultivation of these rotations, the following time schedule needs to be considered.

• Maize and paddy sowing should be done in early June
• Grow short duration early maturing varieties
• Grow potato in October
• Prefer late sown varieties of wheat viz. PBW373, PBW138, Raj 3765 in the end of December and early January
• Green manuring is done during rainy season
• Green manure should be ploughed in the field at least 15 days before potato planting
• Green manure improves the soil fertility



The potato crop is also grown in different inter-croppings such as

1. Sugarcane + Potato
2. Maize + Potato

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Seed and Seed Treatment

• Potato is propagated vegetatively.
• Hence the disease pathogens are carried from mother plants and the crop gets spoiled.
• Therefore the seed must be produced by following seed production techniques.
• Seed should be pure, healthy and of uniform size for getting high yield.
• Following points need to be considered while making selection of potato for seed purpose.

Seed

• Seed tuber should be uniform in shape, desired size and colour
• The ideal tuber size for planting should be 3.5-5.0 cm in diameter and should be graded
• Seed tubers should be purchased from the trusted agency like National Seed Corporation or State Seed Corporation or State Department of Horticulture or CPRI
• Seed tuber should not be shriveled
• Seed tuber showing, black scruff, potato scab, brown rot and nematode infection must be separated before planting.
• Keep the seed in diffused sunlight under shade and do not sow the seed directly from the cold storage.
• Allow the seed to acclimatize with the normal conditions and to develop the sprouts in shade.
• The weight of each tubers may vary from 30-50 gm.
• Too small seed (chats) must be rejected ruthlessly as they often are virus infected.
• The seed is considered suitable for sowing when the sprout becomes 6-8 mm long.
• While collecting seed for sowing purpose, handle the sprouted seed with care and gently so that sprouts do not break / detach.

Seed Treatment

• The weight of each tuber may vary from 30 - 50 gm.
• Too small seed (chats) must be rejected ruthlessly as they often are virus infected.
• To check the incidence of any infectious disease from seed is controlled by treating the seed with fungicides.

Following points are to be considered while giving seed treatment to tubers

• The tubers should be free from soil because soil adhering to potato reduces the efficiency of fungicide
• Treat the tubers even when taken from the cold storage or from any other source
• Treatment should be given before the sprouting initiates
• Select the fungicide and adjust its dose accordingly
• Common approach in Punjab is to treat seed with Agallol 0.5% or Aretan/Tafasan 0.25% solution prepared by dissolving 500 g of Agallol or 250g of Tafasan/Aretan in 100 liters water
• Put tubers in this solution for 10 minutes
• After treatment, seed should be kept in a clean, well-ventilated place and where direct sun rays do not fall.

Seed Rate

• Depends upon the purpose for which it is grown (seed, ware, multiplication), tubers size, spacing, season and uniformity of seed. However the following conditions are to be considered at sowing.
• 28 - 30 stem/m2 were emerged when 3.0 t/ha seed rate was used and considered as optimum plant populations.
• 26 - 27 stem/m2 were recorded at 2.25 t/ha seed rate.
• 24 stem/m2 were found at 1.5 t/ha seed rate.
• For obtaining optimum yield 28 - 30 stem/m2 are desired.
• Tuber size should vary from 30 - 40g.
• Small sized tubers (25 - 30g and 15 - 20g) for planting have low emergence rate index and produce less number of stems.
• Seed rate effects the grade wise tubers yield. Tuber yield in large grade 775g may be similar in all seed rates.
• Tuber yield in 50 - 75g, 25 - 50g and 25g grade was higher with higher seed rate (3 t/ha).
• Increased seed rate improves the yield of tubers weighing less than 75g or the seed sized tubers.
• Use of optimum seed rate (3 t/ha) increased total number of tubers to 46,00000 - 47,00000/ha.
• No of tubers reduced considerably when seed rate is reduced of tuber having 3.75 cm diameter.
• The optimum seed rate range may be 2.5 to 3.0 t/ha with tuber no.1 ha 44 pack to 46 pack. (avg yield raised 31.7 to 33.9 t/ha by wt).

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Tuberisation vs Seed Size and Spacing

• The number and size of tubers produced is affected by sprouting treatment, seed size and spacing.
• Early sprouting results in fewer sprouts per seed piece and fewer plants per hill than late sprouting.
• No of tubers produced is directly related to the no. of sprouts and plants.
• Early sprouting, small seed, and wide spacing increase tuber size but early sprouted seed planted closely gave higher yields than late sprouted seed planted further apart.
• Larger seed pieces and closer spacing produce higher yield of smaller tubers.
• When plants are crowded, development is restricted and yields are reduced.
• On the other hand, yield per plant does not increase beyond a certain spacing. This spacing being dependent on factors such as variety, growing environment, soil, size of seed pieces.
• Bireeki and Roztropowicz (1963) report that the wt of tuber per eye is higher in large tuber.
• The wt of tuber per stem is about the same regardless of tuber size.
• It appears that each eye requires a minimum weight of tuber substance to develop a stem and that this minimum is about the same for the eyes with large or small tubers.
• The no. of eyes from which stems develop depends on the tuber weight and the minimum tubers wt per stem required.
• Plants from large seed tubers develop twice or more stems than plants from small seed tubers.
• The larger the no. of stems the greater the assimilation area for plant and the higher the yield.
• Therefore the no. of stems and the leaf area per acre are two of the most important factors in potato production.
• The larger seed tubers provide a larger no. of eyes with a minimum tuber substances required for developing the stem and therefore produce more stems.
• High productivity in the present plant is important in seed production
• No. of tubers per acre increased but average weight of tuber decreased as the size of seed increased or as seed was spaced closer in the row.

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Sowing Time

The potato sowing depends upon the

• The soil temperature
• The length of rainy season
• The workable conditions of the soil.
• The cropping sequence in which potatoes are grown.
• The availability of seed of varieties
• The purpose for which potatoes are being grown.
• High temperature causes rotting of the seed during autumn season.
• The sowing time for autumn crop in Punjab extends from early September to mid October.
• Moreover, the high temperature at germination increases the incidence of insect - pest particularly sap sucking insect and haulms leaves becomes necrotic.
• Low temperature delays the appearance of sprouts and therefore optimum sowing time for spring potatoes is first week of January.
• On account of low temperature in spring season does not pose any problem for the rotting of seed.
• Therefore, potato seed may be used after cutting into small piece; each comprising of at least 2 eyes and 30g weight.
• The best time identified for the planting of potato is when the maximum and minimum temperature ranges from 30 °C to 32 ° C and 18 ° C to 20 ° C respectively.
• In Punjab, usually, rainy season is over by mid September and if sowing is done too early, rainfall many time reduces the potato emergence by creating crust formation, causes rotting of seed.
• While practising sowing, rainfall recorded must be taken into account.
• The optimum time for autumn potato sowing is at the fag end of rainy season.
• The good physical condition comprising well pulverized field soil, free from clod and with optimum moisture content for ridge formation at sowing time.
• Such conditions prevail only if optimum moisture is present in the soil.
• This factor is also taken care of by the rainfall intensity and interval.
• Wet condition creates hindrance in field preparation which influences the emergence intensity of potatoes.
• Potato being a short duration crop fits well in different cropping system.
• Adoption of 200 or 300 or 400 cropping index sequence will determine the sowing time, which is based on the varieties duration and purpose of potato cultivation.
• These types of potatoes varieties are recommended for cultivation viz., early varieties, mid season varieties and late season varieties.
• The total duration not only affect the yield but also decide the field occupancy period.
• The availability of seed plays a crucial role about the time of sowing.
• Early varieties, mature in 75 - 90 days should be grown in early September, mid season varieties in late September to early October and late season varieties mature in 120 days should be planted in end October to early November.
• Above all, the purpose decides about the sowing time.
• If crop is sown for commercial / ware purpose, it should be planted early to fetch good margin by sending the produce in the market in off season.
• Secondly, multiplication or for getting high productivity per unit area, the main growing season is preferred.
• While for seed purpose is kept in the field till February or early March though their haulms are removed in end of December as a protective measure against the spread of virus diseases.
• Keeping in view all the above mentioned factors the sowing time for different crops is as under

1. Autumn Crop:1^st September - 15 October
2. Spring Crop:1^st January - 15 January