Survey of tree dryness on panels BO-1 and BO-2 of clone PB260.
In a survey of estates in Peninsular Malaysia, the incidence of dryness was higher in clone PB260 than in clones PB217 and GTI. On panel BO-1, mean dryness ranged from 2.1% in the first year to 8.5% in the sixth year of tapping in PB260 compared with 0.2 and 2.7% in the first and fourth years, respectively for PB217. On panel BO-2, the range was 16.0 to 18.6% from the third to sixth years, respectively for PB260, compared with only 8.1% in the third year for GTI. The maximum dryness in individual fields of PB260 reached 23.5% on panel BO-1 and 44.6% on panel BO-2 (very high). Rainfall pattern and soil depth strongly influenced the extent of dryness in clone PB260. Tree dryness was highest on shallow soils located in Kedah, Kelantan and Negeri Sembilan, where a regular dry season lasting 3-4 months exists and where moisture deficits are most likely to occur. On the other hand, low incidence of dryness was observed on deep soils located in Perak, Selangor, Pahang and Johor, where climatic conditions are more favourable and moisture deficits are more likely to be less severe or even absent. Tree dryness 10% on panel BO-1 and 15% on panel BO-2 is considered high. All areas except deep soils in the states of Perak, Selangor, Pahang and Johor exceeded these values. The remedial measures proposed to minimise tree dryness include reduction in tapping intensity and increasing the stand per hectare for locations with high propensity to tree dryness.
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| Format: | Texto biblioteca |
| Language: | d |
| Subjects: | Clones., Cultivar, disorders, drought, harvesting, plant disorders, rubber plants, soil depth, surveys, tapping, tropical crops, Droughts, Harvesting, Rubber plants, Soil depth, Surveys, Tropical crops, |
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