Abstract
The results reported herein represent the first step in diagnosing the nutrient status of citrus trees by means of foliar analysis, for the average conditions of the State of Sao Paulo. A study was made concerning the seasonal variation in nitrogen, phosphorus, potassium, calcium and magnesium levels of spring-cycle Baianinha orange leaves. The trees were budded on sweet orange rootstock (Citrus sinensis Osbeck) in a foctorial fertilizer experiment started in 1947. The mineral composition changed with the age of leaves. Generally the N, P, K, and Mg contents decreased, while Ca increased fast in the young leaves and remained without great variation until the end of the cycle. Leaves 3 to 6 and 10 months old are suitable for sampling if referred to respective standards. Nitrogen and phosphorus levels in leaves increased linearly with fertilizer application, while potassium increases were due only to o single dosis. Application of fertilizer containing nitrogen shows o tendency to reduce the levels of P and K, and to increase Mg in the leaves. The simple superphosphate applied decreased the levels of N and K, and increased Ca in the leoves. There was a decline in Ca and Mg contents of leaves with potassium fertilizer application. The following negative correlations between leaf nutrients were found to be significant: 1) nitrogen and phosphorus; 2) nitrogen and calcium; 3) potassium and calcium; 4) potassium and magnesium.
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Claims 15
Claim · model-written summary
Leaf N, P, K and Mg generally decreased with leaf age.
Verbatim
e0“Generally the N, P, K, and Mg contents decreased”
t0“orange leaves”
Claim · model-written summary
Leaf Ca rose quickly in young leaves and then varied little.
Verbatim
e0“Ca increased fast in the young leaves and remained without great variation until the end of the cycle.”
t0“orange leaves”
Claim · model-written summary
Leaves aged 3 to 6 and 10 months are suitable sampling material with corresponding standards.
Verbatim
e0“Leaves 3 to 6 and 10 months old are suitable for sampling if referred to respective standards.”
t0“orange leaves”
Claim · model-written summary
Nitrogen fertilizer increased leaf nitrogen linearly.
Not reportedComparator
Verbatim
e0“Nitrogen and phosphorus levels in leaves increased linearly with fertilizer application”
t0“orange leaves”
Claim · model-written summary
Fertilizer increased leaf phosphorus linearly.
- Taxon
- oranget0
- Treatment
- fertilizer applicatione0
- Outcome
- phosphorus levelse0
- Direction
- increased linearlye0
Not reportedComparator
Verbatim
e0“Nitrogen and phosphorus levels in leaves increased linearly with fertilizer application”
t0“orange leaves”
Claim · model-written summary
Potassium rose only with one fertilizer dose.
Not reportedComparator
Verbatim
e0“potassium increases were due only to o single dosis.”
t0“orange leaves”
Claim · model-written summary
Nitrogen fertilizer tended to reduce leaf P and K.
- Taxon
- oranget0
- Treatment
- fertilizer containing nitrogene0
- Outcome
- levels of P and Ke0
- Direction
- reducee0
- Qualifier
- o tendencye0
Not reportedComparator
Verbatim
e0“Application of fertilizer containing nitrogen shows o tendency to reduce the levels of P and K”
t0“orange leaves”
Claim · model-written summary
Nitrogen fertilizer tended to increase leaf Mg.
- Taxon
- oranget0
- Treatment
- fertilizer containing nitrogene0
- Outcome
- Mge0
- Direction
- increasee0
- Qualifier
- o tendencye0
Not reportedComparator
Verbatim
e0“Application of fertilizer containing nitrogen shows o tendency to reduce the levels of P and K, and to increase Mg in the leaves.”
t0“orange leaves”
Claim · model-written summary
Superphosphate decreased leaf N and K.
Not reportedComparator
Verbatim
e0“The simple superphosphate applied decreased the levels of N and K”
t0“orange leaves”
Claim · model-written summary
Superphosphate increased leaf Ca.
Not reportedComparator
Verbatim
e0“The simple superphosphate applied decreased the levels of N and K, and increased Ca in the leoves.”
t0“orange leaves”
Claim · model-written summary
Potassium fertilizer lowered leaf Ca and Mg.
- Taxon
- oranget0
- Treatment
- potassium fertilizer applicatione0
- Outcome
- Ca and Mg contentse0
- Direction
- declinee0
Not reportedComparator
Verbatim
e0“There was a decline in Ca and Mg contents of leaves with potassium fertilizer application.”
t0“orange leaves”
Claim · model-written summary
A significant negative correlation was found between nitrogen and phosphorus.
Verbatim
e0“The following negative correlations between leaf nutrients were found to be significant: 1) nitrogen and phosphorus; 2) nitrogen and calcium; 3) potassium and calcium; 4) potassium and magnesium.”
t0“orange leaves”
Claim · model-written summary
A significant negative correlation was found between nitrogen and calcium.
Verbatim
e0“The following negative correlations between leaf nutrients were found to be significant: 1) nitrogen and phosphorus; 2) nitrogen and calcium; 3) potassium and calcium; 4) potassium and magnesium.”
t0“orange leaves”
Claim · model-written summary
A significant negative correlation was found between potassium and calcium.
Verbatim
e0“The following negative correlations between leaf nutrients were found to be significant: 1) nitrogen and phosphorus; 2) nitrogen and calcium; 3) potassium and calcium; 4) potassium and magnesium.”
t0“orange leaves”
Claim · model-written summary
A significant negative correlation was found between potassium and magnesium.
Verbatim
e0“The following negative correlations between leaf nutrients were found to be significant: 1) nitrogen and phosphorus; 2) nitrogen and calcium; 3) potassium and calcium; 4) potassium and magnesium.”
t0“orange leaves”
The same questions in other papers
fertilization · nutrient: content · Citrus sinensis (sweet orange)Positive and negative results
25 papers in the same direction as this paper · 5 in the opposite direction
- negative
- negative
- no effect
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See all 31 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.