Nagpur orange planting (santra lagwad): soil, spacing, pit size, rootstock and planting time

Which soil and site suit Nagpur orange?

Choose well-drained soil at least 1 m deep, with the water table deeper than 2 m. ICAR-CCRI's June guideline asks for clay below 60 per cent, pH below 8.3 and free calcium carbonate below 12 per cent.

CCRI adds that good orchards can also be raised on soil shallower than 1 m, but only with precise fertiliser and water management. Test the soil before you plant. Depth, pH and free lime (calcium carbonate) are the three numbers you need first.

What spacing and pit size should I use?

Space plants 6 m by 6 m and dig pits of 75 cm by 75 cm by 75 cm. Dr. PDKV (AICRP, Akola) recommends 6 m by 6 m for Vidarbha, and CCRI's May guideline gives the same pit size.

The arithmetic: 6 m by 6 m gives each tree 36 square metres. One acre (about 4,047 square metres) holds about 112 trees; one hectare about 277.

Which rootstock, and where do I get plants?

Buy budded plants on rough lemon (jamberi) or Rangpur lime rootstock. Dr. PDKV recommends these two for nurseries to reduce Phytophthora root rot, and CCRI names the same two for sowing rootstock seed. We do not rank one above the other; ask the nursery or the KVK for your soil.

Buy only certified, disease-free plants. ICAR-CCRI Nagpur makes a limited number of budded Nagpur mandarin plants available every year from July. Applications go by registered or speed post in April, with the 7/12 extract. Allotment is not guaranteed and is first come, first served.

When do I dig pits, fill them and plant?

CCRI's calendar is: dig pits in May and leave them open to the sun. Fill them in June with 2 parts soil, 1 part sand and 1 part farmyard manure, plus 1 kg single super phosphate and 1 kg neem cake. Plant in July with the bud union 20 to 25 cm above the ground.

CCRI also advises dipping the roots in a fungicide solution before planting, and its June guideline adds an insecticide powder to the pit. Which product and how much is not in this guide; ask the KVK.

How do I look after trees in the first years?

Water: CCRI's January table gives 7 to 30 litres per tree per day by drip for trees 1 to 4 years old, depending on age and month. In October it gives 9 litres a day for a one-year tree. Keep water from standing near the trunk, and keep drainage channels open in the rains.

Mulch: a 5 to 10 cm layer of straw or husk around the tree. In a Dr. PDKV trial a 5 cm straw mulch held about 17.6 per cent more moisture in the top 22 cm of soil. Remove shoots that sprout below the bud union. The fertiliser schedule is in the separate fertiliser guide.

Which intercrops can I grow in the early years?

CCRI's July guideline allows urad, moong, soybean and groundnut between the rows. For green manure, sow dhaincha or sunhemp seed at 40 kg per hectare.

Dr. PDKV advises against cotton as an intercrop in an orchard that has not started bearing. Cowpea has been tried as a rabi intercrop. When you irrigate the intercrop, keep track of the tree's own moisture.

What does the satellite show in a new orchard?

In an orchard of small trees, one 10 m satellite pixel is mostly ground and weeds between the trees, not tree canopy. So the greenness number there reflects ground cover more than the trees. Once the trees grow, over a few years, the number becomes more useful for showing change across the orchard. A satellite does not count trees.