Effect of foliar application with urea, benzyladenine and dry yeast on flowering and fruiting of Minneola Tangelo trees to reduce the severity of alternate bearing phenomena
Year: 2020
Type: article
Abstract: This investigation was conducted during three successive seasons (2016/2017, 2017/ 2018 and 2018/2019) on Tangelo Minneola (Citrus paradisi Macf x Citrus reticulata Blanco) twenty two years old budded on sour orange ( Citrus aurantium L.) rootsock at Giza experimental station, Agricultural Research center, Egypt.To study the effect of foliar application with urea 20g/ L ,dry Yeast at 4g/L, benzyladenine at 60ppm, a mixture of(urea 20g/L + dry yeast at 4g/L), a mixture of ( urea 20g/L + benzyladenine at 60 ppm) ,and a mixture of ( urea 20g/L + benzyladenine at 60 ppm + dry Yeast at 4g/L ) compared with control treatment (spray with water) on flowering and fruiting of Minneola Tangelo trees to reduce the severity of alternate bearing phenomena .The result showed that treatment with (urea 20g/L + benzyladenine at 60 ppm ) gave the highest values of number of shoots ,Shoot diameter (cm), average leaf area (cm 2 ), fruit set % , remaining fruits after June drop % ,Mature fruits %,yield increment (%) over the control, fruit weight (g) Yield/tree (kg), Yield/ weight feddan (ton), pulp weight (g), Juice volume cm 3 , Fruit volume (cm 3 ) , Fruit diameter (cm), vitamin c (mg/100mljuice), sugars %, carotenoids ( mg/g fresh wt ) total carbohydrates (mg/g), Chlorophyll-a ,b (mg/g fresh wt), total chlorophyll (mg/g fresh wt),total indoles ( mg/100g F.W),TSS (%),TSS/acid ratio and recorded the lowest juice total acidity %, leaf mineral contents (N, P, Mg, Fe ,Mn and Cu) contents as compared with the control treatment and the other treatments in "off " years, "On" years and" off "years, respectively.Moreover, Foliar application with a combination of (urea 20g/L + dry yeast at 4g/L) gave the highest values of Shoot length (cm), number of leaf /shoot, average leaf dry weight(g), Specific leaf weight (SLW) (mg/cm 2 ), number of fruits/tree, peel weight (g), fruit length ( cm ), leaf mineral contents ( K, Ca, and Zn ) contents as compared with the control treatment and the other treatments in "off " years,"On" years and " off "years, respectively.Foliar spray with 60 ppm + dry Yeast at 4g/L+ urea 20g/L) gave significantly the highest peel thickness (cm) compared with other treatments including control trees.Foliar application with benzyladenine at 60 ppm) gave significantly the highest leaf Total phenols (mg/100g F.W) as compared with untreated (control trees) and the other treatments.Generally, Minneola tangelo trees treated in" off " years (2018/ 2019) gave a high positive effect in reducing biennial bearing severity than trees treated in "off "years (2016/ 2017) and "On" years (2017/ 2018) respectively.
Language: English
Subfield: Plant Science
Domain: Life Sciences
SDG: Zero hunger
Open Access status: diamond
OpenAlex ID: W4235225009