Abstract
The African root and tuber scale (ARTS), Stictococcus vayssierei Richard, is an insect species indigenous to Africa, which has recently become an economic pest of cassava (Manihot esculenta Crantz) in many parts of the Democratic Republic of the Congo (D R C). This scale infests underground parts of the plants and prevents young plants from tuberising, thus, causing yield losses of up to 100%. In order to evaluate control components that can be combined into an effective strategy for the management of the scale, six improved cassava genotypes were evaluated for resistance against the scale and NPK fertiliser was tested at the recommended rate as a pest control component. The fertiliser application was made as basal dressing and on one improved clone (F100) with a local variety. Results indicated that ARTS infestations were delayed on ‘Kinuani', F100 and the local clone, ‘Kileba', as no scales were observed on them 6 months after planting (MAP). The sweetest improved genotype, ‘Papayi', harboured the highest number (134.8 insects plant-1) of scales. At 9 and 12 (harvest) MAP, all clones were relatively highly infested, except for the bitter genotype, ‘Sadisa'. This clone also yielded more than the local clone. Mineral fertiliser application significantly increased scale population density on F100, and plant height on both F100 and the local clone. It did not significantly affect the number of tuberous roots and root yield on either the improved F100 or on ‘Kileba'. Key Words: Democratic Republic of Congo, Manihot, Stictococcus vayssierei RÉSUMÉ La gamme des racines et tubercules Africains, Stictococus vayssierei Richard, est une espèce indigène à l'Afrique qui est récemment devenue une peste économique de manioc (Manihot esculenta Crantz) dans beaucoup d'endroits de la République Démocratique du Congo (RDC). Cette gamme infecte les parties souterraines des plantes et empêche les jeunes plantes à former les tubercules, causant ainsi des pertes de rendements jusqu\'à 100%. En vue d'évaluer les composants de contrôle qui peuvent être combinés dans une stratégie effective pour la gestion de la gamme, six génotypes améliorés de manioc étaient évalués pour la résistance contre la gamme et le fertilisant NPK était testé au taux recommandé comme un composant de désinsectisation. L'application de fertilisant était faite comme engrais fondamental et sur un clone amélioré (F100) avec une variété locale. Les résultats ont indiqué que les infestations de la gamme des racines et tubercules Africains étaient retardées sur ‘ Kinuani', F100 et le clone local, ‘kileba', étant donné qu'aucune gamme n'était observée sur eux 6 mois après plantations (MAP). Le génotype amélioré le plus sucré, ‘Papayi', a hébergé le nombre le plus élevé (134,8 insectes plante-1) de gamme. A 9 et 12 mois (récolte) MAP, tous les clones étaient relativement gravement infectés, à l'exception du génotype amère, ‘Sadisa'. Ce clone a aussi produit plus que le clone local. L'application de fertilisant minéral a significativement augmenté la densité de population de gamme sur F100 et sur le clone local. Il n'a pas significativement affecté le nombre des racines tubercules et la racine produite sur le F100 amélioré ou sur ‘Kilemba'. Mots clés: République Démocratique du Congo, Manihot, Stictococus vayssierei African Crop Science Journal Vol.12(3) 2004: 217-222
Abstract from the paper’s OpenAlex record, shown for indexing and research. Copyright remains with the authors or the publisher. Read at the source ↗
The text the model read, with the source record’s inline markup (italics, sub- and superscripts) rendered and its character entities decoded; quote offsets refer to the raw text.
Claims 8
Claim · model-written summary
Scale infestations were delayed on Kinuani, F100 and Kileba, with no scales at six months.
- Taxon
- cassava
Manihot esculentat0 - Material
- ‘Kinuani'e0
- Interactor
- ARTSe0pest
- Outcome
- ARTS infestationse0
- Direction
- delayede0
- Qualifier
- 6 months after planting (MAP)e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“ARTS infestations were delayed on ‘Kinuani', F100 and the local clone, ‘Kileba', as no scales were observed on them 6 months after planting (MAP)”
t0“Management of African root and tuber scale using improved cassava genotypes and mineral fertilisers”
Claim · model-written summary
Papayi harboured the highest scale count, 134.8 insects per plant.
- Taxon
- cassavaManihot esculentat0
- Material
- ‘Papayi'e0
- Interactor
- scalese0pest
- Outcome
- numbere0
- Direction
- higheste0
- Value
- 134.8 insects plant-1e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The sweetest improved genotype, ‘Papayi', harboured the highest number (134.8 insects plant-1) of scales”
t0“Management of African root and tuber scale using improved cassava genotypes and mineral fertilisers”
Claim · model-written summary
At nine and twelve months, all clones except Sadisa were highly infested.
- Taxon
- cassavaManihot esculentat0
- Material
- all clonese0
- Interactor
- scalet0pest
- Outcome
- infestede0
- Qualifier
- except for the bitter genotype, ‘Sadisa'e0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“At 9 and 12 (harvest) MAP, all clones were relatively highly infested, except for the bitter genotype, ‘Sadisa'”
t0“Management of African root and tuber scale using improved cassava genotypes and mineral fertilisers”
Claim · model-written summary
Sadisa yielded more than the local clone.
- Taxon
- cassavaManihot esculentat0
- Material
- ‘Sadisa'e1
- Outcome
- yieldede0
- Direction
- moree0
- Comparator
- local clonee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“This clone also yielded more than the local clone”
e1“except for the bitter genotype, ‘Sadisa'”
t0“Management of African root and tuber scale using improved cassava genotypes and mineral fertilisers”
Claim · model-written summary
Mineral fertilizer significantly increased scale density on F100.
- Taxon
- cassavaManihot esculentat0
- Material
- F100e0
- Treatment
- Mineral fertiliser applicatione0
- Interactor
- scalee0pest
- Outcome
- scale population densitye0
- Direction
- increasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Mineral fertiliser application significantly increased scale population density on F100”
t0“Management of African root and tuber scale using improved cassava genotypes and mineral fertilisers”
Claim · model-written summary
Mineral fertilizer significantly increased plant height on F100 and the local clone.
- Taxon
- cassavaManihot esculentat0
- Material
- F100 and the local clonee0
- Treatment
- Mineral fertiliser applicatione0
- Outcome
- plant heighte0
- Direction
- increasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Mineral fertiliser application significantly increased scale population density on F100, and plant height on both F100 and the local clone”
t0“Management of African root and tuber scale using improved cassava genotypes and mineral fertilisers”
Claim · model-written summary
Fertilizer did not significantly affect tuberous root number on F100 or Kileba.
- Taxon
- cassavaManihot esculentat0
- Treatment
- Mineral fertiliser applicatione1
- Outcome
- number of tuberous rootse0
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“It did not significantly affect the number of tuberous roots and root yield on either the improved F100 or on ‘Kileba'”
t0“Management of African root and tuber scale using improved cassava genotypes and mineral fertilisers”
e1“Mineral fertiliser application significantly increased scale population density on F100, and plant height on both F100 and the local clone”
Claim · model-written summary
Fertilizer did not significantly affect root yield on F100 or Kileba.
- Taxon
- cassavaManihot esculentat0
- Treatment
- Mineral fertiliser applicatione1
- Outcome
- root yielde0
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“It did not significantly affect the number of tuberous roots and root yield on either the improved F100 or on ‘Kileba'”
t0“Management of African root and tuber scale using improved cassava genotypes and mineral fertilisers”
e1“Mineral fertiliser application significantly increased scale population density on F100, and plant height on both F100 and the local clone”
The same questions in other papers
fertilization · pest · Manihot esculenta (cassava)Positive and negative results
2 in the opposite direction
- positive
- positive
fertilization · growth · Manihot esculenta (cassava)Positive and negative results
64 papers in the same direction as this paper · 6 in the opposite direction
- positive
- no effect
- no effect
67 papers more in this group
See all 71 papers →fertilization · yield · Manihot esculenta (cassava)Positive and negative results
11 papers in the same direction as this paper · 141 in the opposite direction
- positive
- positive
- positive
149 papers more in this group
See all 153 papers →Claims are grouped by organism, treatment and what was measured or targeted. A paper counts as positive when any of its claims in the group is positive.