Disease resistance - witches' broom (Marasmius perniciosa); black pod (Phytophthora palmivora)
Nineteen Witches' broom inoculation tests were made during the year. Twelve of the tests involved crosses between progenies selected from two families (SCA 6 x ICS 111 and SCA 6 x ICS 89) on the basis of field resistance over a period of 13 years. Generally the results are inconsistent, partly a result of the small samples inoculated. In two sets of reciprocal crosses AX 27-84 confers greater resistance as the female parent. MX 76-5 selected in 1958 after inoculation screening continues to show field resistance and its progenies appear to segregate for resistance. Amongst the Scavina crosses all show a high degree of resistance. The crosses need repeating to determine whether there is any significant difference between the reciprocal crosses of SCA 6 SCA 9. This material will be planted at Las Hermanas in 1973 for field observation. At Las Hermanas the oldest block of Scavina progenies screened by the Witches, broom inoculation test were planted in 1958. On the basis of data on yield, pod, cushion and vegetative infection collected over the past two years several trees have been selected as highly resistant. These will be crossed to ICS 8 and subjected to further inoculation tests.
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| Format: | biblioteca |
| Published: |
St. Augustine (Trinidad y Tobago)
1973
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| Subjects: | THEOBROMA CACAO, CRUZAMIENTO, CRINIPELLIS PERNICIOSA, PHYTOPHTHORA PALMIVORA, ENFERMEDADES FUNGOSAS, RESISTENCIA A LA ENFERMEDAD, INOCULACION, CLONES SCAVINA, RENDIMIENTO, TRINIDAD Y TOBAGO, |
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| Summary: | Nineteen Witches' broom inoculation tests were made during the year. Twelve of the tests involved crosses between progenies selected from two families (SCA 6 x ICS 111 and SCA 6 x ICS 89) on the basis of field resistance over a period of 13 years. Generally the results are inconsistent, partly a result of the small samples inoculated. In two sets of reciprocal crosses AX 27-84 confers greater resistance as the female parent. MX 76-5 selected in 1958 after inoculation screening continues to show field resistance and its progenies appear to segregate for resistance. Amongst the Scavina crosses all show a high degree of resistance. The crosses need repeating to determine whether there is any significant difference between the reciprocal crosses of SCA 6 SCA 9. This material will be planted at Las Hermanas in 1973 for field observation. At Las Hermanas the oldest block of Scavina progenies screened by the Witches, broom inoculation test were planted in 1958. On the basis of data on yield, pod, cushion and vegetative infection collected over the past two years several trees have been selected as highly resistant. These will be crossed to ICS 8 and subjected to further inoculation tests. |
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