#102Deeper polybags
102⸱AConcept
- Improves the coffee plant’s tolerance to drought
- Reduces coffee mortality
- Increases the coffee yield
Using deeper polybags and keeping the seedlings longer in the coffee nursery helps them to further develop their root systems before being transplanted into the field. These so-called jumbo seedlings are better able to survive drought.
Recently planted trees are particularly susceptible. Therefore, long droughts can lead to major losses of trees. Giving coffee saplings a better start can prevent these losses.
The deeper polybags are up to 28 cm deep instead of the usual <20 cm. The seedlings stay up to 5-6 months longer in the nursery as the roots grow deeper, about 11 months in total. Watering from below will additionally encourage the deeper growth of the roots.
A trial in Brazil showed that the mortality rate of freshly transplanted jumbo seedlings was reduced by 20 %. In the initial development stages, these seedlings performed better compared to conventional seedlings with regards to the following characteristics: Plant height, stem diameter, percent survival, number of primary branches, length of first primary branches, and number of internodes. According to the trial, the first harvest of jumbo seedlings is higher than the conventional seedlings (see Further Readings below).
102⸱BTo be considered
The feasibility of this tool depends on the availability of larger polybags in the local market. Also, more potting soil and – if applied – Compost are required to fill them.
It needs to be considered that the seedlings of deeper polybags will be bigger and heavier when being transported from the nursery to the field and when planted.
Deeper polybags may be especially useful where vegetative rather than seed propagation is used, since root systems may be initially weaker.
They also give farmers more latitude on when to plant out, since the seedlings can stay longer in the nursery without root damage.
When used to avoid tree losses due to drought, the deeper polybags should be applied in conjunction with other soil protection tools, such as a thick mulch layer and temporary shade where mature shade is sparse, see Cover crops and Companion trees.
Timing: It takes 11 months from the sowing into the polybag to the transplantation into the field. The seed is placed in the polybag in the month of December to January. Later, the seedlings adapt to the full sunlight exposure and are planted at the beginning of the rainy season, between November and December.
102⸱CImplementation
Materials
102⸱1Procedure
The potting soil can be mixed with compost in a ratio of up to 30% of compost for better fertility.
102⸱2
Young coffee plants in deeper polybags
The young coffee plants should be transplanted right when the rainy season starts.
102⸱3
102⸱4
Comparison of growth between deeper polybag and normal polybag
102⸱DEconomic benefits
Lower renovation costs
This tool increases the lifespan of the coffee trees. They need to be renovated less frequently which reduces the long-term production costs.
Higher coffee yield
The effects of this tool can lead to a higher coffee yield and therefore a higher income.