Bong, C.L. & Phua, P.K. 1989
Screening of hybrid materials for resistance to VSD. In: Research on Cocoa VSD in Sabah. Technical Bulletin No. 9, Dept. of Agriculture, Sabah, Malaysia. pp. 43-39.
Notes
Malaysia - Quion Hill, Sabah and Ulu Dunsun, Sandakan Datafile: DIS_VSDS - Disease reaction to VSD Descriptors: Resistance to infections from Vascular Streak Dieback Environment: Set 1 assessed at Quoin Hill at seedling stage in a nusery with the source of natural inoculum from surrounding infected mature fields. Sets 2 and 3 were evaluated at the mature tree stage. Germplasm: 79 hybrids evaluated in three sets. Set 1 consists of Sabah mixed hybrids raised specifically for this purpose at Quoin Hill, Sabah. Sets 2 and 3 are progeny trials established at Quoin Hill, Sabah and Ulu Dunsun, Sandakan respectively. Experimental conditions: VSD disease severity was recorded at intervals of one to two months throughout the epidemic period or at longer intervals throughout the rest of the year. Apparent infection rate (r or ADPC (area under disease progress curve)) are used as criteria to compare differences in the resistance of the hybrids. r is obtained by regressing In(1/1 - x) against time in months where x is the disease severity index. Differences between any two r values is tested using a t - test. ADPC is calculated and analysed using analysis of variance.
Disease