toxicity – Journal of Oil Palm Research

ALUMINIUM TOXICITY TOLERANCE OF DIFFERENT VARIETIES OF OIL PALM (Elaeis guineensis L. Jacq) SEEDLINGS

mpob_admin — Mon, 10 Jun 2024 02:07:36 +0000

Aluminium (Al) toxicity is one of the problems experienced by crops cultivated on acid soil, inhibiting root growth and nutrient absorption capability. This study evaluated the effects of different concentrations of Al-toxicity (0 μM-control; 100, 200 and 300 μM) on the physiological growth, chlorophyll content and selected nutrient uptake in roots and shoots of different varieties of oil palm seedlings, specifically the Elite Deli Dura x BM119 AVROS Pisifera, Elite Deli Dura x Elite AVROS Pisifera, Ulu Remis Deli Dura x Dumpy AVROS and Ulu Remis Deli Dura x Ulu Remis Tenera varieties. Results showed that Al-toxicity has no significant effect on the height of shoots for all oil palm seedling varieties. The Ulu Remis Deli Dura x Ulu Remis Tenera seedlings appeared to be more tolerant, showing no significant effect on bole diameter, chlorophyll content and biomass of both shoot and roots upon Al-toxicity treatment. For selected nutrient uptake, all tested oil palm seedling varieties showed significant effects upon Al-toxicity treatment primarily from the 100 μM Al-toxicity application. The findings from this study suggested that the Elite Deli Dura x BM119 AVROS Pisifera oil palm variety exhibited the lowest tolerance towards Al-toxicity compared to the other oil palm varieties tested.

EFFECT OF Bacillus thuringiensis, TERAKIL-1® AND TERACON-1® AGAINST OIL PALM POLLINATOR, Elaeidobius kamerunicus AND BENEFICIAL INSECTS ASSOCIATED WITH Cassia cobanensis

mpob_admin — Sat, 13 Nov 2021 15:28:52 +0000

A laboratory study on the effect of Bacillus thuringiensis (Bt) product, Terakil-1^® and Teracon-1^® on oil palm pollinating weevil, Elaeidobius kamerunicus and beneficial insects such as predators and parasitoids was studied to evaluate the safety and specificity of Bt product against non-target organisms in particular the beneficial insects as compared to chemical. The male spikelets were sprayed with Terakil-1^® and Teracon-1^® at different doses, ranging from 3.7×107 cfu ml^-1 3.7×1011 cfu ml^-1 and 0.1124 μg ml^-1 – 1124 μg ml^-1, respectively. At five days after treatment (DAT), Terakil-1^® and Teracon-1^® being target specific at dose of C5, 3.7×1011 cfu ml^-1 and 11.24 μg ml^-1, resulted in 21% and 25% mortality of beneficial insects, respectively. Whereas, at seven DAT, Terakil-1^® and Teracon-1^® being a safe Bt products at dose of C5, 3.7×1011 cfu ml^-1 and 11.24 μg ml-1, resulted in 22% and 23% corrected mortality of beneficial insects, respectively. Cypermethrin at 5.5% w/w as a chemical control led to 100% corrected mortality of beneficial insects at five DAT. As for oil palm pollinating weevil, E. kamerunicus, Terakil-1^® and Teracon-1^® being a safe and environmental-friendly products, each resulted in 26% and 33% mortality of E. kamerunicus at seven DAT at 100-fold higher dose than the recommended dose of C3, 3.7×109 cfu ml^-1 and 11.24 μg ml^-1. Whereas, at seven DAT, Terakil-1^® and Teracon-1^® being a safe Bt products at dose of C5, 3.7×1011 cfu ml^-1 and 1124 μg ml^-1, resulted in 14% and 16% corrected mortality of E. kamerunicus, respectively. At five to seven DAT, the mean mortality of the adult E. kamerunicus subjected to the five different doses, 3.7x107cfu ml^-1 to 3.7×1011 cfu ml^-1 and 0.1124 μg ml^-1 – 1124 μg ml^-1 of Terakil-1^® and Teracon-1^®, respectively was not significantly different at P=0.05 when tested using Duncan’s Multiple Range Test, implying that even at very high doses, Bt products were equally safe to the weevils. Cypermethrin was significantly toxic to pollinating weevils as compared to high doses of Terakil-1^® and Teracon-1^®. Unlike chemicals, B. thuringiensis, Terakil-1^® and Teracon-1^®were found to be safe for beneficial insects under the oil palm and is therefore recommended for integrated control of bagworm under oil palm.

EFFECT OF BT PRODUCTS, LEPCON-1, BAFOG-1(S) AND ECOBAC-1(EC), AGAINST THE OIL PALM POLLINATING WEEVIL, Elaeidobius kamerunucus, AND BENEFICIAL INSECTS ASSOCIATED WITH Cassia cobanensis

mpob_admin — Sat, 13 Nov 2021 08:03:40 +0000

The effects of Bacillus thuringiensis products, Lepcon-1, Bafog-1 (S) and Ecobac-1 (EC), on the oil palm pollinating weevil, Elaeidobius kamerunicus, and beneficial insects, especially parasitoids, were studied. For pollinating weevils, oil palm male spikelets with weevils were treated by spraying with Lepcon-1 and Ecobac-1 (EC) at five different concentrations, ranging from 5.2 x 107 to 5.2 x 10¹¹ cfu ml^-1 for Lepcon-1, and 7.34 x 107 to 7.34 x 1011 cfu ml^-1 for Ecobac-1 (EC). For Bafog-1 (S), male spikelets with weevils were fogged at a dose of 7.7 x 10¹¹ cfu ml^-1. The Bt products Lepcon-1, Bafog-1 (S) and Ecobac-1 (EC) were safe for E. kamerunicus. Direct spraying of Lepcon-1, Bafog-1 (S) and Ecobac-1 (EC) at the highest concentrations caused 13%, 10% and 11% corrected mortality at nine days after treatment (DAT), respectively. Cypermethrin was toxic to the pollinating weevils as it killed 100% of the weevils at as early as five DAT. Lepcon-1, Bafog-1 (S) and Ecobac-1 (EC) were also harmless to beneficial insects. Application of these products by spraying at the highest concentrations resulted in low mortality of the beneficial insects, ranging from 8% to 13%. Cypermethrin was toxic to the parasitoids as spraying of the chemical at 7.5% w/w killed 100% of the beneficial insects at as early as five DAT. The laboratory study showed that Lepcon-1, Bafog-1 (S) and Ecobac-1 (EC) were safe for the oil palm pollinating weevils and beneficial insects and, therefore, they are recommended for use in the integrated control of bagworms in oil palm.