How to harvest Jatropha?

Manually picking.

Reading all data one has to realise that there are differences between picking fruits and picking seeds. Hand picking means picking fruits, either fresh or dry. This means that all data related to picking seeds are based on the conversion rate between fruits (either dry or fresh) and seeds (either dry or fresh.), probably without counting the hours to de-husk. That explains the big differences.

The data below come from FACT in the Netherlands but are a bit confusing as well since it is not clearly stated whether it is fruits ore seeds that are being picked.

My comments are in red. (AvP)

I assume that these data are based on a 4 years old stand of Jatropha, which however is not specifically stated by FACT

  1. Nicaragua 50 kg/day to 80 kg. (Must be  seeds)

  2. The best pickers in Nicaragua harvest up to 30 kg of fruit/hour, which would mean approximately 18 kg of seeds/hr, or 144 kg/day. (Calculated from 240 kg/fruit per day, conversion rate 1.66?)

  3. Nicaragua: 64 kg dry seed/day (Which is the average of 1 and 2!)

  4. Tanzania assumption: Picking seeds. Between 2 and 10 kg of seeds can be picked per hour, (it depends on the density of the plants).(16-80 kg/seeds/day!)

  5. Tanzania: collection of seeds: 2 kg of dry seeds in 1 hour.

  6. Tanzania 52 kg/dry seed per day. (Which is the average of 4 and 5!)

  7. India assumption: Hours necessary to harvest the seeds 125 hrs per MT This comes to 65 kg dry seed/day

  8. India: 8 kg of dry seeds/1 hr work

  9. Sudan: 12 kg of dry seeds/ 4 hr work

  10. Indonesia: 60 kg of dry seeds/ 8 hr day (model based) (so this is an assumption as well)

  11. Congo: 40-50 kg of dry seeds/ day

  12. Brazil: ca 48 kg dry seed /day

  13. Honduras: 40 kg dry seed/day

Yield counts and/or yield assumptions from different locations cannot be compared, due to a whole range of parameters.

It is important to know how much a worker can pick. It is also important to know when to pick. Picking at the right time gives the highest yield in oil. Premature fruits (green) do have a lower oil content than yellow and brown fruits.

 

Some people say  commercial Jatropha plantations  will not survive without a mechanized system simply because you cannot get the labour and even if you get them, you cannot pay them.

They probably do not know that in California the total area of strawberries is about 20.000 ha, producing  25 tonnes of strawberries per ha and it is all handpicked!!

Looking around in the world of fruit harvesters, one can find machines for olives, grapes, citrus, coffee, apples, black current etc.

Non of these crops however are comparable with Jatropha

crop

1 harvest per cycle

tree structure

easy to shape

fruit structure

latex

mtr/ton/ha

extra handling

coffee

yes

woody

yes

tough

no

1-2 (dry)

de-hulling

olive

yes

woody

yes

tough

no

10

 

jatropha

no

soft

yes

tough

yes

2-8

de-shelling

black current

yes

woody

yes

soft

no

6-10

 

grapes

yes

soft

yes

soft

no

6-10

 

citrus

yes

woody

yes

tough

no

20

 

Mechanical picking

Jatropha creates some major road blocks for mechanical harvesting.

1.There are flowers and fruits in several stages of ripeness on the same branch, requiring a long picking period

2. The latex might make the whole process a mess.

3. Depending on climate and rain the picking period will be either cyclical or continuous.

4.Yield per ha is low, both in volume and value

As in most crops, mechanical harvesting is a trade off between fruit quality costs, but if Jatropha becomes a commercially important crop, there will be harvesters available

 

Several companies are working on Jatropha harvesters and the first results can be seen on the internet. As expected, it still needs a lot of fine tuning to pick the fruits in the right stage .

Tempo                http://www.rakennustempo.fi/eng/?ID=1479

Oxbocorp           http://www.oxbocorp.com/news.php, http://www.youtube.com/watch?v=68wcBFI7Bv4

 

BEI                     http://www.beiintl.com/Jatropha%20Harvester.pdf

Gregoire              http://www.gregoire.fr/index_uk.html