MSc.

In Kerala, ginger is cultivated as a rainfed crop, usually planted during April -
May and harvested during December - January with a subsequent storage of seed
rhizome for a period of 3 to 4 months to raise the next crop. Raising a transplanted
ginger crop can decrease seed rate to 500-700 kg per hectare from1500 kg per hectare,
reducing the cost of cultivation. Yield from rhizome sprouts of 3-5 g used as transplants
is reported to be on par with the conventional system of direct planting of 20 g rhizome
seed. Bio-priming ginger rhizome before transplanting was also found to be beneficial
in increasing the yield of off-season green ginger. Hence, the present study was
conducted to analyze the performance of primed portray transplants of ginger at various
planting times.
The experiment was conducted in Department of Plantation crops and Spices,
College of Horticulture, Vellanikkara using seed rhizomes of variety Aswathy. The
research work was grouped into three experiments viz., studies of seed rhizomes during
storage, effect of priming on ginger transplants in the nursery and field performance of
primed protray raised ginger transplants. Studies on seed rhizome revealed that, a
weight loss of 28 per cent was recorded in the seed rhizomes stored in Zero Energy
Cool Chambers for three months (February to May 2017). Seed rhizome buds varied
in length from 0.847μm to 2.19μm and breadth from 1.19 μm to 0.703μm before
storage and at three months after storage respectively. Histochemical comparison of
the rhizomes showed that the size of starch grain decreased from 40μm to 20 μm and
the size of oil globules increased from 20 to 40 μm on three months’ storage.
The performance of primed protray raised ginger transplants in nursery was
assessed with 13 treatments during four planting times viz., February, March, April and
May to identify the optimum planting time and priming treatment for seed rhizomes.
The study revealed that, priming had influence on survival rate. The mean survival per
cent of seed rhizomes planted in May (3MAS) was found to be superior (58.89%) to
all other planting times irrespective of the priming treatments. The survival per cent of
seed rhizome planted immediately after harvest (February) was the least (11.6%).
However, the survival of seed rhizomes was found to increase drastically to 50.3 per
cent and 50.1per cent during March (1 MAS) and April (2 MAS) respectively. In
pooled analysis, seed rhizome primed with Ethephon 200 ppm performed better to all
other priming treatments with a survival rate of 68.66 per cent irrespective of planting
season.
In transplants raised in March and April, priming with Ethephon 200 ppm was
found to be superior with high survival per cent (96.9 and 99.0 % respectively).
However in May, seed rhizomes primed by soaking in water for one hour (88%) was
on par with soaking in water for half an hour (84.03%).
These transplants were field planted at 45 days after sowing in nursery to
polybags under partial shade at four planting time’s viz., March, April, May and June.
The fresh rhizome yield was superior in transplants planted in the month April
(451.83g/p) irrespective of priming treatments. In pooled analysis, the fresh rhizome
yield from seed rhizome primed with Ethephon 200ppm (372.33g/p) was superior
irrespective of planting seasons. Other priming treatments viz., Humigration
(340.21g/p), Trichoderma viridae (343.89g/p), Pseudomonas fluorscens (340.2g/p),
Trichoderma viridae + Pseudomonas fluorscens combination (335.94 g/p) and soaking
in water for 1 hour (355.62g/p) were also on par with that of Ethephon 200 ppm with
respect to fresh rhizome yield.
The quality parameter like oil, oleoresin and crude fibre varied according to the
planting season. Irrespective of the priming treatments, the oil content was high in the
crop raised during March (1.42%). Priming with a combination of Trichoderma viridae
+ Pseudomonas fluorscens (0.96%), Hydropriming (0.86%), Humigration (0.91%) and
Pseudomonas fluorscens (0.87%) were also superior in rhizome oil content,
irrespective of planting time.
The result indicated that to obtain maximum fresh rhizome yield, the optimum
time of raising nursery is March (1 MAS) using seed rhizomes primed with Ethephon
200ppm. Seed rhizomes primed with Pseudomonas fluorscens, Trichoderma viridae,
Humigration and Soaking in water can also be recommended considering the higher
fresh rhizome yield and survival per cent in the nursery with a low seed rate.