3 
IV. 
PLOTS EXPERIMENTS. 
A series of beds were arranged at Morne Blanc estate, 
1200 feet elevation, in order to test the various varieties of 
sweet patatoes so often grown in this Colony at hicrh elevations 
on worn out and other estates. The soil was quite unsuitable 
for other crops. 
I«ocal name of variety. Amount of crop Quality of tubers. 
No. 1 Patate Blanc 
No. 2 Patate 40 jours 
No. 3 Patate la laine noire 
No. 4 Same as 1 
No. 5 Patate Noire 
non trailing 
No. 6 Dominica 
No. 7 Same as 5 
No. 8 Patate raisin 
No. 9 Same as 6 
No. 10 Same as 8 
No. 11 Do ninica thick set 
No. 12 Patate grosse liane 
No. 13 Same as 3 
No. 14 Patate flammand 
No. 15 Same as 2 
2 tons per acre Small white tubers, very good. 
2.500 kgs per acre. Very large, red, had. 
4.500 
Red, small, bad. 
2.300 
it 
Same as 1. 
2.750 
a 
Small white, very good. 
2 
a 
Red, small, bad. 
1.800 
a 
Same as 5. 
0.750 
a 
Dark red, good. 
0.90C 
a 
Same as 6. 
0.360 
* t 
Same a3 8. 
0.250 
Red, good. 
0.250 
H 
0.200 
a 
Same as 3. 
0.200 
a 
Large red, pretty good. 
0.200 
a 
Same as 2. 
The soil on plots 8 to 15 was still inferior a,ud almost 
sterile. These results show how precarious and variable are 
sweet potato crops iu this Colony in worn out soils on which so 
many African families are allowed to plant on the Moitie 
System. At Rs 3.00 per 100 lbs the largest crop represents a 
gi’oss value of Rs 270.00 per acre and the smallest Rs 12.00. 
It is cle.tr that the second type of soil should not be devoted to 
sweet potatoes as the labour involved in cleaning, planting, 
weeding and cropping amonut to about Rs 35.00. It is also too 
risky to allow the soil od slopes to become exposed to complete 
erosion for a crop often worth less than Rs 30. 
At the Botanic Station two manured beds were arranged 
to test the two varieties most commonly cultivated with the 
following results:— 
Patate Blanc 7 tons per acre. 
Patate 40 jours 3^ tons per acre. 
In both cases Patate blanc seems to be by far the best 
variety under cultivation in the Colony. Like most trailing 
varieties it gives several crops in succession, the first crop being 
obtained from the main stem and the others in succession from 
the trailing branches which take root at each joint. The n ime 
Patate 40 jours is a misnomer. Local planters understand by 
this name that in the variety in question the tubers begin to 
set 40 Jays after planting, a feature which is far from being 
uncommon with other varieties. The crop of the greatest 
number of local varieties comes to maturity iu 5 to 7 months, 
according to soil and climatic conditions. 
A series of plots were also arranged to test the yield of differ¬ 
ent varieties of Cassava at the Botanic Station but the experi¬ 
ments were upset by the great amount of pilfering which took 
place by the labourers and others. 
1. Manioc Allemand.—A variety introduced from Ceylon 
in 1911 with red stems and tubers, not unlike “ manioc droit ”, 
gave the best yield in manured plots but the yeld of about 100 
tons per acre was closely followed by that of—• 
2. Manioc Singapore newly introduced from Ceylon which 
should be preferred to the preceeding variety owing to its crop 
coming to maturity 6 months earlier. With cassava as with 
other plants propagated from cuttings newly introduced varie¬ 
ties yield better. 
The other varieties which gave lower yields were the 
following :— 
3. Manioc bleu, a supposed seedling with light coloured 
tubers obtained from the old Singapore variety. 
4. Manioc parasol, not unlike manioc droit which has red¬ 
dish stems ; but the former unlike the latter, branches a few feet 
from the ground. Manioc droit, with red stems and tubers, is 
disappearing from the Colony. 
5. Manioc Zoe a light coloured variety both as regards 
foliag' 1 and tubers not unlike Singapore in colour. 
