i) Site Selection

Soil type and irrigation facility are the two important considerations for the selection of site for nursery.

Poplar (Populus deltoides) needs preferably sandy loam, deep, fertile, well drained, neither alkaline nor too acidic, free from underlying impervious layer and rich in organic matter.

Coarse sand in areas where the water table drops below in winter and which are subject to summer drought, soils with top-layer removed by erosion and site with laterite occurring within 60 cm of surface are considered unfit for poplar cultivation.

Assured irrigation is essential besides other requirements of a good nursery site. As poplars are very sensitive to zinc deficiency, zinc sulphate @ 25 kg/ha should be applied in the area at the time of site preparation.

Site Preparation:

• A light preparatory irrigation should be given so that the soil has proper moisture at the time of ploughing.
• The field should be levelled after ploughing. One deep ploughing upto 25-30 cm depth is desirable.
• Phosphatic and Potassium fertilizers should be added at this point. After addition of fertilizers, one more harrowing should be arranged.

Clones: A lot of good quality clones have been developed and launched commercially. Some of them are G-48, S7C15, S7C8, L-34, L-49, L-52, Uday, Kranti, WS 39, WSL-22, WSL-27, WSL-32, WSL A-49, and PL-1 to PL-7 etc.

ii) Selection of Cuttings

• Cuttings from the main stem of the Populus deltoides give better results than those obtained from branches.
• One year old plants from existing nurseries are used for preparation of cuttings for the new nurseries.
• Diseased, dying off-type and suppressed plants must be culled from the beds where stock is reserved for preparation of cuttings for the new nurseries.
• The plants can be cut 2 cms. from ground level and the resultant sets should be graded and formed into bundled and should be transported to the new nursery site immediately and stored there in the storage pits, which should be kept full with fresh water to be replenished every day.
• Cuttings made from ripened one year old wood of the main stem give better results.
• Only well lignified shoots should be used; too tender shoots are not suitable for cuttings.
• Cuttings obtained from young, healthy and vigorous plants perform better.
• The length of cuttings should be 18-25 cm and these should contain four buds.
• When cuttings are taken from the trees, the age of trees and of the parts of trees from which the cuttings are taken markedly affect rooting (Zsuffa, 1976).

Preparation of Cuttings

Cuttings should be prepared with a very sharp and fairly heavy tool to obtain a very clean and smooth cut.

During the preparation of cuttings, the cut must be given at a point of the set which is fully supported on a log/beam of wood to prevent splitting of cuttings.

Maximum number of available cuttings from each plant down to one centimeter diameter can be used for planting.

All cuttings must be submerged under fresh water in drums immediately after preparation of the cuttings.

Treatment of Cuttings

• Before planting, cuttings are soaked in water for 24 hours.
• Cuttings should be treated with Aldrin (250 ml of Aldex 30 EC in 100 litres of water) and thereafter Emisan (250 g in 100 litres of water) for 10 minutes each and then only planted in the nursery.

iii) Planting of Cuttings

For production of healthy and vigorous entire plants, planting of cuttings at 80 cm x 60 cm is the best spacing.

To produce one year old plants, spacing of 1-1.4 m between the lines and of not less than 40 cm between the plants is normally adopted.

The best time of planting cuttings in the nursery is January to February.

Planting rods with the lower ends flattened and sharpened like a screw driver should be used for making the planting holes.

Each cutting with its thinner end up should be planted in the hole in such a way that the upper portion is just 2 cms above the ground level.

After planting the soil around each cutting should be compacted gently but firmly without injuring the bark of the cutting in any way.