Articles
EFFECT OF FOUR CALCIUM FORMULATIONS ON THE KINETICS OF GROWTH OF PERSIMMON ‘ROJO BRILLANTE’ FRUITS
Article number
833_50
Pages
313 – 318
Language
English
Abstract
The effect of four calcium treatments on persimmon fruit growth was investigated.
The treatments were: A – Winner GA Calcium plus Winner Activator-S fertigation, and Winner Fall plus Winner Algas by leaf spray; B – KSC Adur fertigation, and KSC Adur plus TradeBor by leaf spray; C Prominol® Ca fertigation, and KSC Adur plus TradeBor by leaf spray; D Prominol® Ca fertigation and spray.
All formulas were applied at the rates indicated by their manufactures, and all the other nutrients and soil amendments were the same.
In each treatment twenty fruits were labelled in six adjacent trees along an irrigation line, and measured every week (maximum and minimum diameters). Using destructive samples, a highly significant correlation was found between the weight of fruits and the cube of their average diameter.
This regression was used to calculate the weight of the labelled fruits.
The calculated weights were fitted to a composite logistic equation that describes a double sigmoid growth kinetics similar to that observed in stone fruits.
The obtained parameters were used to compare the treatments.
One treatment (C) yielded significantly bigger fruits, but the effects of the different calcium formulations are strongly biased by an intense physiologic drop after fruit set which induced marked differences in the final fruit loads.
The treatments were: A – Winner GA Calcium plus Winner Activator-S fertigation, and Winner Fall plus Winner Algas by leaf spray; B – KSC Adur fertigation, and KSC Adur plus TradeBor by leaf spray; C Prominol® Ca fertigation, and KSC Adur plus TradeBor by leaf spray; D Prominol® Ca fertigation and spray.
All formulas were applied at the rates indicated by their manufactures, and all the other nutrients and soil amendments were the same.
In each treatment twenty fruits were labelled in six adjacent trees along an irrigation line, and measured every week (maximum and minimum diameters). Using destructive samples, a highly significant correlation was found between the weight of fruits and the cube of their average diameter.
This regression was used to calculate the weight of the labelled fruits.
The calculated weights were fitted to a composite logistic equation that describes a double sigmoid growth kinetics similar to that observed in stone fruits.
The obtained parameters were used to compare the treatments.
One treatment (C) yielded significantly bigger fruits, but the effects of the different calcium formulations are strongly biased by an intense physiologic drop after fruit set which induced marked differences in the final fruit loads.
Publication
Authors
L.M. Sabbo, J.M.S. Martins
Keywords
kaki, calcium, fruit load, fruit growth
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