Abstract
A problem with young guava trees is that they carry light and variable crops, and both young and old trees flower and fruit over protracted periods. A 25 % urea spray plus wetting agent applied to 15-month-old guava seedlings of the variety GA9-EX39, produced a three-fold increase in yield over untreated trees at 22 months of age. In addition, the harvesting period was shortened from 15 weeks for control trees to four weeks for sprayed trees. Mean yields for sprayed trees were 34.69 kg, equal to 27.93 t ha-1 at a plant density of 805 trees ha-1; yields for unsprayed trees were 10.85 kg, or 8.73 t ha-1. Such yields exceed those attained in other countries at a similar age. Fruit size was not affected by the urea spray compared with controls, and the second crop 12 months later, also induced with urea sprays, was 40% more than the first. The use of urea as a defoliant spray permits early cropping of young, densely planted orchards and thus faster economic returns. In addition, shortening of the harvest period reduces labour costs and allows better economic control of fruit fly, a major pest of guava.
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
A 25 % urea spray tripled yield of GA9-EX39 guava seedlings over untreated trees.
- Taxon
- guava
Psidium guajavae0 - Material
- GA9-EX39e0
- Organ / stage
- 15-month-old guava seedlingse0
- Treatment
- 25 % urea spray plus wetting agente0
- Outcome
- yielde0
- Direction
- increasee0
- Value
- three-folde0
- Comparator
- untreated treese0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“A 25 % urea spray plus wetting agent applied to 15-month-old guava seedlings of the variety GA9-EX39, produced a three-fold increase in yield over untreated trees at 22 months of age.”
Claim · model-written summary
Urea spray shortened guava harvesting from 15 to four weeks.
- Treatment
- sprayed treese0
- Outcome
- harvesting periode0
- Direction
- shortenede0
- Value
- four weekse0
- Qualifier
- 15 weekse0
- Comparator
- control treese0
Not reportedTaxon
Verbatim
e0“the harvesting period was shortened from 15 weeks for control trees to four weeks for sprayed trees.”
Claim · model-written summary
Sprayed trees yielded 34.69 kg, equivalent to 27.93 t ha-1.
- Treatment
- sprayed treese0
- Outcome
- Mean yieldse0
- Value
- 34.69 kge0
- Qualifier
- 27.93 t ha-1 at a plant density of 805 trees ha-1e0
Not reportedTaxon
Verbatim
e0“Mean yields for sprayed trees were 34.69 kg, equal to 27.93 t ha-1 at a plant density of 805 trees ha-1”
Claim · model-written summary
Unsprayed trees yielded 10.85 kg, or 8.73 t ha-1.
Not reportedTaxon
Verbatim
e0“yields for unsprayed trees were 10.85 kg, or 8.73 t ha-1.”
Claim · model-written summary
Guava fruit size was unaffected by urea spray.
Not reportedTaxon
Verbatim
e0“Fruit size was not affected by the urea spray compared with controls”
Claim · model-written summary
A second urea-induced guava crop was 40% larger than the first.
- Treatment
- urea sprayse0
- Outcome
- second crope0
- Direction
- moree0
- Value
- 40%e0
- Qualifier
- 12 months latere0
- Comparator
- the firste0
Not reportedTaxon
Verbatim
e0“the second crop 12 months later, also induced with urea sprays, was 40% more than the first.”
Claim · model-written summary
The authors conclude that urea defoliation allows early cropping and faster economic returns.
- Taxon
- guavaPsidium guajavat0
- Treatment
- urea as a defoliant spraye0
- Outcome
- early cropping of young, densely planted orchardse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The use of urea as a defoliant spray permits early cropping of young, densely planted orchards and thus faster economic returns.”
t0“guava”
Claim · model-written summary
Shortening harvest is expected to lower labor costs and improve fruit fly control.
- Taxon
- guavaPsidium guajavae0
- Interactor
- fruit flye0pest
- Outcome
- reduces labour costs and allows better economic control of fruit flye0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“shortening of the harvest period reduces labour costs and allows better economic control of fruit fly, a major pest of guava.”
The same questions in other papers
nitrogen · yield · Psidium guajava (guava)Results agree
32 papers in the same direction as this paper
- positive
- positive
- positive
29 papers more in this group
See all 33 papers →application · yield · Psidium guajava (guava)Results agree
61 papers in the same direction as this paper
- positive
- positive
- positive
58 papers more in this group
See all 62 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.