Egypt AND FRUIT QUALITY OF MIT GHAMER PEACH TREES. EFFECT OF PACLOBUTRAZOL ON SHOOT GROWTH, YIELD AND FRUIT QUALITY OF MIT GHAMER PEACH TREES. Prof. Galal I. Eliwa Pomology Department Faculty of Agriculture Damietta University Egypt

INTRODUCTION The principle commercial peach cultivar grown in Dakahlia Governorate is Mit Ghamer. Trees of this cultivar were resulted from sexual seedlings. producing strong vegetative growth during fruit growth phases . Trees require much pruning and hand labor would be considerably high.

INTRODUCTION A reduction in the competition between Shoots and fruits growth for nutrients should result in an improvement in fruit size and quality. Also, exists to control tree size and consequently simplify management operations such as fruit thinning and harvesting . Many techniques have been used in an attempt to control vegetative growth of stone fruit, cincturing, regulated deficit irrigation and pruning.

INTRODUCTION However, most of these techniques have been only partially successful in controlling tree growth The growth retardant, paclobutrazol has shown promise in ; controlling the growth of extension shoots increased floral bud initiation , fruit numbers per tree and fruit size .

THE AIM OF THIS STUDY To investigate the exact concentration of paclobutrazol which can be control vegetative growth and improve yield and fruit quality of Mit Ghamer peach trees.

MATERIALS AND METHODS Treatments: Spraying PLZ at 0 ppm (control). The application was at approximately three weeks after full bloom

The following parameters were determined : Shoot growth Yield and Maturity Fruit characteristics Physical fruit characteristics Chemical fruit characteristics Leaf characteristics Leaf area and dry weight % Leaf nutrients

RESULTS Shoot growth

Effect of different concentrations of paclobutrazol on shoot growth of peach trees (data are the mean of 2002 and 2003 seasons). Shoot growth (cm) Treatments 1 Oct. 15 Sept. 1 Sept. 15 Augs. 1 Augs. 15 July 1 July 15 June 1 June 15 May 1 May 15 April 1 April 15 March 68.33 57.07 48.00 48.43 42.57 38.57 67.00 56.73 47.77 67.33 55.83 47.00 48.33 42.37 38.20 65.67 54.90 46.33 42.23 37.67 64.00 57.17 45.00 47.50 41.73 36.93 63.17 52.27 44.33 47.17 41.40 36.67 61.50 52.00 43.50 46.67 40.90 36.00 59.67 51.17 43.00 45.33 40.57 35.00 57.67 41.33 43.67 40.07 33.67 55.67 45.07 40.00 42.67 32.80 51.33 44.07 39.83 40.60 36.17 30.43 46.17 39.70 31.17 27.33 33.17 28.33 29.57 25.37 23.70 17.67 17.83 17.73 15.70 15.07 14.50 Contrl 250 ppm 500 ppm 750 ppm 1000 ppm 1500 ppm 11.33 16.11 11.38 16.19 11.22 15.96 11.26 16.01 11.40 16.21 11.03 15.69 10.85 15.42 10.65 15.14 9.27 13.18 7.73 11.0 7.22 10.27 7.81 11.11 --- NS L.S.D.at1% L.S.D.at5%

Effect of paclobutrazol spray on shoot growth of peach trees

First picking before control (Days) Effect of spraying Paclobutrazol on yield and precocity of peach trees during 2002 and 2003 seasons. First picking before control (Days) Yield (kg/tree) Treatments 2003 2002 -- 3.0 5.3 5.5 2.0 4.3 6.0 6.3 3.3 37.33 41.00 43.67 45.67 42.00 36.33 36.67 43.33 45.00 48.33 38.33 Control 250 ppm 500 ppm 750 ppm 1000 ppm 1500 ppm 3.83 5.44 4.12 5.86 L.S.D. at 5% L.S.D. at 1%

Effect of spraying paclobutrazol on physical fruit characteristics of peach trees during 2003 and 2003 seasons. Red skin color % Firmness (kg/cm2) Fruit length (cm) Fruit diameter (cm) Fruit volume (cm³) Fruit weight (gms) Treatments 2003 2002 38.33 50.00 64.00 71.67 70.67 45.67 40.67 49.33 67.33 76.00 44.67 4.09 5.00 5.27 4.37 5.37 4.97 4.49 4.78 4.38 5.51 5.08 5.53 6.13 6.02 5.67 5.82 5.63 6.09 6.20 5.89 6.03 5.47 5.77 5.93 5.88 5.69 5.90 6.39 5.79 6.07 90.67 102.33 107.67 118.33 97.67 103.00 94.67 104.67 109.33 123.33 98.67 110.00 94.33 105.33 114.00 121.67 103.33 110.67 96.67 115.33 127.33 106.67 113.33 Control 250 ppm 500 ppm 750 ppm 1000 ppm 1500 ppm 5.86 8.34 8.32 11.83 0.73 -- 0.75 NS 0.28 --- 0.26 0.36 0.18 4.39 6.24 7.14 10.16 5.11 7.26 8.90 12.66 L.S.D. at 5% L.S.D. at 1%

Anthocyanin (optical density) Effect of spraying Paclobutrazol on chemical fruit characteristics of peach trees during 2002 and 2003 seasons. Acidity % TSS % Anthocyanin (optical density) Treatments 2003 2002 1.206 1.021 1.070 1.071 0.960 0.855 1.224 0.947 1.114 0.891 0.835 10.03 11.07 10.70 11.30 12.13 10.07 10.13 11.27 10.87 11.57 12.33 10.33 0.130 0.184 0.192 0.200 0.209 0.159 0.120 0.181 0.190 0.210 0.225 0.150 Control 250 ppm 500 ppm 750 ppm 1000 ppm 1500 ppm 0.080 0.114 0.115 0.163 0.77 1.10 1.09 0.020 0.029 0.015 0.022 L.S.D. at 5% L.S.D. at 1%

Effect of spraying Paclobutrazol on peach leaf characteristics and NPK contents during 2002 and 2003 seasons. K% P% N% Dry weight % Leaf area (cm2) Treatments 2003 2002 1.97 1.88 1.87 1.75 2.19 1.91 1.86 1.70 0.23 0.20 0.19 0.18 0.24 0.21 2.29 2.31 2.17 2.30 2.26 2.32 2.18 45.20 42.70 44.17 43.77 42.96 42.67 46.27 43.76 44.78 44.28 44.24 43.35 39.29 37.92 37.29 35.11 34.76 30.56 40.57 40.29 39.33 36.73 36.04 32.95 Control 250 ppm 500 ppm 750 ppm 1000 ppm 1500 ppm 0.07 --- 0.25 0.03 0.04 NS 0.41 0.77 4.10 5.83 2.05 3.56 L.S.D. at 5% L.S.D. at 1%

SUMMARY Spraying paclobutrazol highly significant decreased shoot extension at all concentrations were used. The highest concentration recorded the lowest values of shoot length during the two growing seasons. The reduction in shoot growth rate before pit-hardening stage, resulted in obtaining larger fruits, with a consequent increase in yield and earlier fruit maturity .

SUMMARY Spraying paclobutrazol at 750ppm achieved the highest values of yield/tree (48.33 and 45.67 kg/tree) ,fruit weight (127.33 and 121.67 gms); volume (123.33 and 118.33 cm³); diameter (6.39 and 6.13 cm) and red skin color (76.00 and 71.67 %), during the two seasons respectively. Moreover, spraying pacloputrazol at all concentrations used increased fruit content of anthocyanin and TSS % but reduced acidity % in fruit juice in the two seasons of study.

SUMMARY The results also showed that, leaf area and dry weight were reduced as a result of paclobutrazol spraying . No clear effect on nitrogen leaf content was noticed, but phosphorus and potassium leaf content was decreased in paclobutrazol treatments in both seasons of study.

Conclusion & Recommendations It could be concluded from this study that spraying Mit Ghamer peach trees with paclobutrazol at 750 ppm was more effective in controlling shoot growth, eliminating the need for summer pruning, increasing yield, advancing in fruit maturity and improving fruit quality. Conclusion & Recommendations

Bon appétit

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