Abstract
Declining soil fertility is threatening the productivity of sweetpotato in the highlands of Papua New Guinea (PNG). A survey of sweetpotato gardens (SMCN/2005/043) identified K, S and P deficiencies as the main nutritional limitations on tuber production in the region. A pot experiment was conducted to evaluate how sweetpotato vines, propagated on three important soil types (Humult, Aquept and Aqoll), are affected by sequentially omitting 13 nutrients (N, P, K, Ca, Mg, S, Fe, Bo, Zn, Mn, Cu, Mo, Ni) from fertiliser applications. On the Humult, only the minus Mo treatment produced significantly less shoot yield than the all nutrient control (ALL), but symptoms of S deficiency were also present in plants on the minus S treatment. On the Aquept, the minus N, P, Ca, S, B and Mn treatments had significantly less shoot yields than the control, but the minus S and N treatments were lowest yielding, and the S deficiency being clearly manifest. On the Aqoll, the minus N, P, S, Mn, Zn, Mo and Ni treatments had significantly lower shoot yields than the control, and again the minus S treatment produced the lowest yield. On all three soils, vine yields in the minus K treatments were not significantly less than those in the ALL, even though the concentrations of K in soil were very low (0.02 meq/100g). It was concluded that the early stage of vine propagation is probably less K-demanding than the tuber production stage in mature crops.
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Claims 9
Claim · model-written summary
Omitting Mo reduced shoot yield on Humult.
- Taxon
- sweetpotato
_Flower.jpg?width=60)
Ipomoea batatast0 - Treatment
- minus Mo treatmente0
- Outcome
- shoot yielde0
- Direction
- lesse0
- Comparator
- all nutrient control (ALL)e0
- Setting
- Humulte0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
_Flower.jpg?width=500)
Verbatim
e0“On the Humult, only the minus Mo treatment produced significantly less shoot yield than the all nutrient control (ALL)”
t0“sweetpotato”
Claim · model-written summary
S deficiency symptoms occurred on Humult when S was omitted.
- Taxon
- sweetpotatoIpomoea batatast0
- Treatment
- minus S treatmente0
- Outcome
- symptoms of S deficiencye0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“symptoms of S deficiency were also present in plants on the minus S treatment”
t0“sweetpotato”
Claim · model-written summary
Omitting N, P, Ca, S, B or Mn reduced sweetpotato shoot yield on Aquept.
- Taxon
- sweetpotatoIpomoea batatast0
- Treatment
- minus N, P, Ca, S, B and Mn treatmentse0
- Outcome
- shoot yieldse0
- Direction
- lesse0
- Comparator
- the controle0
- Setting
- Aquepte0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“On the Aquept, the minus N, P, Ca, S, B and Mn treatments had significantly less shoot yields than the control”
t0“sweetpotato”
Claim · model-written summary
Omitting S and N gave the lowest yields on Aquept.
- Taxon
- sweetpotatoIpomoea batatast0
- Treatment
- minus S and N treatmentse0
- Outcome
- lowest yieldinge0
- Direction
- loweste0
- Setting
- Aquepte0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“On the Aquept, the minus N, P, Ca, S, B and Mn treatments had significantly less shoot yields than the control, but the minus S and N treatments were lowest yielding”
t0“sweetpotato”
Claim · model-written summary
S deficiency was clearly manifest on Aquept.
- Taxon
- sweetpotatoIpomoea batatast0
- Outcome
- S deficiencye0
- Setting
- Aquepte0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“On the Aquept, the minus N, P, Ca, S, B and Mn treatments had significantly less shoot yields than the control, but the minus S and N treatments were lowest yielding, and the S deficiency being clearly manifest.”
t0“sweetpotato”
Claim · model-written summary
Omitting N, P, S, Mn, Zn, Mo or Ni reduced shoot yield on Aqoll.
- Taxon
- sweetpotatoIpomoea batatast0
- Treatment
- minus N, P, S, Mn, Zn, Mo and Ni treatmentse0
- Outcome
- shoot yieldse0
- Direction
- lowere0
- Comparator
- the controle0
- Setting
- Aqolle0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“On the Aqoll, the minus N, P, S, Mn, Zn, Mo and Ni treatments had significantly lower shoot yields than the control”
t0“sweetpotato”
Claim · model-written summary
Omitting S produced the lowest yield on Aqoll.
- Taxon
- sweetpotatoIpomoea batatast0
- Treatment
- minus S treatmente0
- Outcome
- yielde0
- Direction
- loweste0
- Comparator
- the controle0
- Setting
- Aqolle0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“On the Aqoll, the minus N, P, S, Mn, Zn, Mo and Ni treatments had significantly lower shoot yields than the control, and again the minus S treatment produced the lowest yield.”
t0“sweetpotato”
Claim · model-written summary
K omission did not significantly reduce vine yield on any of three soils.
- Taxon
- sweetpotatoIpomoea batatast0
- Treatment
- minus K treatmentse0
- Outcome
- vine yieldse0
- Direction
- not significantly lesse0
- Comparator
- ALLe0
- Setting
- all three soilse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“On all three soils, vine yields in the minus K treatments were not significantly less than those in the ALL”
t0“sweetpotato”
Claim · model-written summary
Early vine propagation is probably less K-demanding than mature tuber production.
- Taxon
- sweetpotatoIpomoea batatast0
- Outcome
- K-demandinge0
- Direction
- lesse0
- Comparator
- tuber production stage in mature cropse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the early stage of vine propagation is probably less K-demanding than the tuber production stage in mature crops.”
t0“sweetpotato”
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This paper is about lacking the nutrient, so it counts the other way round here.
- negative
- no effect
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See all 35 papers →8 of 9 groups shown: named compounds and organisms first, then groups whose results differ (checked claim by claim), then those with positive and negative results, then the smaller groups.
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.