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Materials and Methods
Plant material: Seeds of- Coffea erabica var. Catuz-z-a from the Tropical Agricultural Center for Research and Training (CATIE) Turrialba, Costa Rica were germinated in sterile quartz sand in the Greeley Greenhouse at the Yale University School of Forestry and Environmental Studies. When germinated they were transplanted to one quart pots containing a mix of potting soil and vermiculite (1:1 in volume).


Treatments: When seedling were approximately 5 cm in height (in June 15, 1988) the following treatments were applied: (1) Full fertilization, consisting of 3.8 g of Miracle-Gro grade 15-30-15 per gallon of water; (2) Half fertilization, consisting of 1.9 g of Miracle-Gro grade 15- 30-15 per gallon of water; and (3) Half fertilization plus ROOTS 38 ml of the master solution per gallon of the fertilizer solution (1%).

Twelve applications were made to each treatment according to the folløwing schedule and the total amount of N applied per seedling was 1.9 g for the full fertilization treatment and 0.95 g for the half fertilization treatment:

Month:
Applic.#
-
g of N/plant
g of N/plant
 in full fert.
in half fert.
June
2
0.317
0.158
July
2
0.317
0.158
August
2
0.317
0.158
September
2
0.317
0.159
- October
1
0.158
0.079
November
1
0.158
0.079
December
1
0.158
0.079
January
1
0.158
0.079
February
0
0.000
0.080
Totals

1.900

0.950
The amount chosen as the full corresponds with that recommended by the Office of Coffee from Costa Rica for nursery conditions.

Early leaf area evaluation: two months after starting the treatment an evaluation of leaf area development was performed. The length and width (in millimeters) of the largest pair of leaves of each plant were measured (8 plants per treatment were randomly selected) and the mean area of the pair was taken as the value of the largest leaf.

Repotting: four months after initiation all plants were repotted to one gallon pots. Care was taken to minimize disturbance to the root system.
 

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