Growing Seedlings in Nursery Beds
In coffee, generally the propagation is done through seeds and of late in Robusta, the clonal propagation was also established to be successful. To a limited extent, grafted plants are also being planted.
From the selected and certified seed blocks, healthy and fully matured fruits of normal appearance with three quarters of ripening are harvested selectively from the marked plants during November-December in the case of Arabica and in January-February in Robusta. Discarding the floats, the sound fruits are pulped and sieved to remove the defective beans. The beans are then mixed with wood ash @ 0.75 kg per kg of seeds and dried under shade stirring from time to time to facilitate uniform drying. To protect the seeds against any microbial infection, the seeds are treated with either carbendazim @ 1 g or with vitavax @ 0.66 g per kg of seed coffee.
Germination bed (Primary)
Seeds are sown in raised seed beds (15 cm above th
e ground level) provided with proper drainage prepared out of soil, compost and sand at 6:2:1 proportion. A bed of 4 x 3 m will be sufficient for 1.5 kg of seeds, if sown 1.0 to 1.5 cm apart in rows, with the flat side of the seed towards the soil. A thin layer of soil is spread after sowing and covered with dry straw to a thickness of about 5 cm to ensure uniform temperature and to regulate moisture retention. Sowing is to be taken up in December-January for Arabica and in February-March for Robusta. Watering of the seed beds is to be done twice a day in the initial week and thereafter regulated. The seeds sprout in about 40 days when the straw mulch is removed. The primary beds are provided with pandal covered with coir mats or dry leaves.
Polybag (Basket) Nursery
Seedlings from germination beds are transplanted to polythene bags in Feb-March when they are at the 'button' stage. Polythene bags of 23 cm x 15 cm and 150 gauge thickness with adequate number of holes of 3 mm in the bottom half of the bag, are preferred. The bags are filled with prepared mixture of 6 parts of sieved jungle soil, 2 parts of well rotten sieved cattle manure and 1 part of fine sand. The prepared mixture is thoroughly mixed and slightly moistened with water to facilitate packing. The soil is filled into the nursery baskets and pressed firm. Nursery baskets are arranged conveniently in rows of 10 within a rectangular frame with bamboo reapers. These frames are held in positions with bamboo or wooden props driven into the ground at suitable distance.
Coffee seedlings at the button stage are transplanted into nursery baskets. The seedlings are gently lifted from the germination beds with minimum injury to roots. Prior to transplanting, the nursery basket is watered and a vertical hole of 5 cm deep is made in the soil at the centre of the basket. At the time of transplanting it is preferable to slightly nip off the taproot of the seedling. The taproot and the feeder roots should be so disposed as to enable the plant to strike roots and make firm growth as quickly as possible. The shoot portion of the transplanted seedling should be at the same height above soil level as it was in the germination bed. Transplanting is done preferably in the early morning hours or late in the afternoon. Seedlings uprooted from the primary bed should not be stored for a long time but transplanted immediately.
Regular watering and aftercare of the seedlings should follow. Excess moisture and watering in the afternoon should be avoided as it may induce damping off.
Secondary Nursery Beds
In some areas, seedlings from the germination beds are transplanted to secondary nursery beds of the same soil composition as that of germination beds. Transplanting is done at button stage. Seedlings are planted 30 cm apart. If the taproot is bent or excessively grown, it is nipped off while transplanting. The beds are mulched and watered at regular intervals. Watering should be done during the early morning hours.
Aftercare of Seedlings
Seedlings are to be manured once in two months with urea dissolved in water or supernatant solution of fermented cow dung slurry. For an area of 1 m2, 20 g urea dissolved in 4.5 litres water is sufficient. Adequate protection is to be given against nursery diseases and pests. Overhead shade in the nursery has to be thinned and finally removed after the onset of monsoon (this is not applicable to northeastern areas). The seedlings grow vigorously if watered judiciously and protected against afternoon sun.
Preparation of Land
If it is a jungle, only selective felling of trees is done maintaining the trees, which are desirable at appropriate spacing. The under growth may be cleared to enable line marking with a base line and opening of pits. The entire plot may be conveniently divided into blocks with roads and footpaths.
In April, pits of 45 x 45 x 45 cm may be opened at appropriate spacing for different coffee cultivars as described below.
Tall Arabica like S 795, S 2882.1 m x 2.1 m
Semi-dwarfs like Cauvery1.8 m x 1.8 m
Dwarfs like S 7 (San Ramon)1.5 m x 1.5 m
Hybrids like Congensis x Robusta (CxR)2.5 m x 2.5 m
Robusta selections like S 274, BR series3.0 m x 3.0 m
The pits after digging will be kept open for weathering for a couple of months until monsoon. In June, the pits are covered with topsoil and staked. In poor soils, 250 g of FYM or compost per pit may be added before filling.
Planting in Field
Disease free and vigorous seedlings are selected for planting. Seedlings with stunted and twisted roots are discarded. Rooted plants (aged 16-18 months) with and without ball are planted during June and bag plants are generally planted during Sept- Oct. A hole is made at the centre of the pit after leveling the soil. The seedling is placed in the hole with its taproot and lateral roots spread out in proper position. The hole is then filled. The soil around the seedling is packed 3 cm high above the ground to prevent stagnation of water around the collar. The seedlings are provided with cross stakes to prevent wind damage and mulched properly.
Ball and bag seedlings are planted towards the end of the heavy monsoon rains and commencement of northeast rains, i.e., in September. First the bottom portion of the bag is cut and the tip of the root is nipped. The seedling is gently removed from the bag with its soil and root system intact and planted in the hole. The hole is covered with soil and the plant is firmly fixed similar to ball plants. It is wise to maintain both types of nurseries and have planting seasons, June and September.
Planting Shade Trees
Dadap is commonly used as a lower canopy shade. Stakes of 2 m length are planted for every two plants of coffee. Silver oak and dadap are planted during June when the southwest monsoon commences. During the dry seasons, stems of young dadap are either painted with dilute lime solution or wrapped in agave leaves to protect them from sun scorch.
Clonal Propagation
In the case of Robusta, which is highly cross-pollinated, clonal propagation is more adaptable. In the case of Arabica, the stabilization of desirable characters in the selected plants could be easily maintained by adopting clonal or vegetative propagation method. The vertical (orthotropic) shoots are marked after harvest is over in any selected plant. Single node green wood (semi-hardwood) cutting of 10 cm length and 3 to 6 months old are planted in polythene bags with the medium of jungle soil, sand and cattle manure in the proportion of 6:3:1. The bags with cuttings are arranged in a propagation chamber made of a trench of size 2 x 1 x 0.5 m covered over with a thick polythene sheet (500 gauge) spread over a framework of bamboos.
A trench could accommodate about 108 filled up bags of size 22 x 15 cm. Preplanting treatment of the base of cuttings with IBA (indole butyric acid) at 5000 ppm enhances early rooting. Under South Indian conditions, cuttings collected during June-July recorded the highest per cent of rooting. Cuttings will root in 3-4 months after planting. Rooted cuttings should be hardened by keeping them under shade for about two months and then can be transplanted into the field.