Effect Of Some Growth Regulator Sprays On Growth Fruiting And Fruit Quality Of Apple Fruits:

Amin Mohamed Galal Ei-din Amin

Effect of some growth regulator sprays on growth, flowering,fruiting and fruit quality of ”Anna” apple fiuits.The present work was carried out through two successiveseasons i.e. 1996 and 1997 in a private orchard at EI-Khatatba region,Menoafia Governorate on 5-year-old ”Anna” apple trees growing onM.M.I06 rootstock and planted at (2 X 4m) apart on a sandy soil. Themain objectives of the present research was studying the effect ofpaclobutrazol (PP333) and uniconazole (S-3307D) separately or incombination both at 1000 or 2000 ppm were used Growth, flowering, fruiting, fruit quality and minerals content of”Anna” apple trees were studied. Selected trees were sprayed in fullbloom or in Mid-May of 1996 and 1997 seasons. The obtained resultswere statistically analysed and L.S.R.’s method was used todifferentiate between means.However, the obtained results can be summerized as folIows : A- Effect on the vegetative growth : Spraying of S-3307D and PP333 at 1000 or 2000 ppm in Mid May hastened the growth of shoots than other treatment during 1996season. Moreover, all treatments done at full bloom were producedshort shoots than done in Mid-May.In 1997 season, all treatments sprayed at full bloom or Mid-Mayproduced short shoots compared to control. The rate of shoot lengthgrowth were less in second season than in the first one.During 1996 season, the highest number of leaves were obtainedwith spraying PP333 at 2000 ppm at full bloom, whereas the leastnumber of leaves were recorded by PP333 at 2000 ppm sprayed in Mid-May. During 1997 season, the treatment of S-3307D 2000 ppmsprayed at full bloom was superior than others in producing greatnumber of leaves. The using ofPP333 and S-3307D as growth retardantmeterials slightly affected leaves number in the first season butprabably affected it in following season.B- Effect on flowering : Flowering % was generally higher on spur than on one year oldshoot in ”Anna” apples. Both PP333 and S-3307D slightly affectedflowering % of ”Anna” apples during 1996 season. The highest valuesof flowering % on spur were obtained with S-3307D 1000 ppm at fullbloom + PP333 1000 ppm at Mid-May and S-3307D 2000 ppm in Mid-May. No effect to both PP333 and S-3307D on the number of flowers ininflorescence were it was 5.33 flower/infloresence.The Mid-May applications were more effective than thoseapplied at full bloom and these may be due to their great effect onflower bud differentiation hapend in Mid-May, lund (Shandler ).c- Effect on fruiting:Fruit set and fruit abscion % were higher on spurs than on oneyear old shoot. The treatment of2000 ppm S-3307D sprayed at fullbloom was superior than other treatments in fruit set % in both studied seasons. However, the highest fruit set % on one year old shoots wereobtained with 1000 ppm S-3307D sprayed at full bloom (1996 season) and PP333 2000 ppm sprayed at full bloom (1997 season). S-3307Dwas more effective than PP333 in increasing fruit set %.The higher % of fruit abscission on spurs than on one year oldshoot due to the higher flower on spurs than on one year old shoots.The great effect of PP333 1000 ppm treatment spraying at fullbloom on total yield compared to other treatments or control during(1996 season). The highest values of biennial bearing index wereobtained with Mid-May spraying with 1000 or 2000 ppm PP333 or 1000ppm S-3307D.Moreover) Annal apple is characterized by low biennialbearing during successive seasons.The trees sprayed at full bloom exhibited some effect in fruitnumbers/spur than control. The highest numbers of fruit/tree wereobtained with the trees sprayed with PP333 2000 ppm at full bloom orS-3307D 2000 ppm at full bloom.D- Effect on fru.it quality:The highest fruit weight was obtained with PP333 and S-3307D2000 ppm sprayed at Mid-May. On the other hand) all treatments inthe second season produced fruits with less weight than control.Slightly differences were noticed between different treatments andcontrol in their fruit size. However) no treatment was superior thancontrol in second season.The growth retardants application reduced both fruit length andwidth resulting in small fruits than control. All treatments reduced fruitlength than control in second season. Regarding to fruit shape) it isevident than ”Anna” apples tended to oblonge shape but in these treatments slight increase in LIW (Length : Width) was found in thetreatment ofS-3307D 1000 ppm in Mid-May.S-3307D or PP333 increased the development of seeds andreached to 5-667 for PP3331000 ppm at full bloom and 6.33 for PP3332000 ppm at Mid-May for (1996, 1997 season respectively).Slightly effect to the used growth retardants on fruit firmness.Moreover, PP333 at 2000 ppm sprayed at full bloom produced fruitswith least amounts of total soluble solids than other treatments.Additionally, total acidity was unaffected with PP333 or S-3307D.Total sugars greatly affected than other chemical componentsespecially to those treatments sprayed only at Mid-May which reducedtotal sugars than those sprayed at full bloom. In (1997 season) thetreatments ofPP333 1000 at full bloom and S-33-7D 1000 or 2000 ppmin Mid-May produced fruits with similar colour to control trees, exceptof these treatments, other treatments hastened fruit colouration.E-Effect on leaf mineral contents:I. The reduction in leaf nitrogen content was noticed in PP3331000or 2000 ppm sprayed at full bloom and S-3307D 1000 ppm atfull bloom + PP3331000 ppm at Mid-May.2. The highest values of leaf phosphorus content was obtained withS-3307D at 2000 ppm sprayed at full bloom and S-3307D 1000ppm sprayed at Mid-May.3. Deficient of leaf K content was noticed with control, 8-3307D2000 ppm at full bloom and PP333at Mid-May.4. The excessive value of leaf Ca content were obtained with alltreatments including control.5. There were an increase ofleaf-Mg in all treatments.6. S-3307D 2000 ppm sprayed at Mid-May produced leaves withhighest Fe and Mn contents than other treatments. There were on excessive value of leaf Zn content.GENERALSpraying growth retardants as paclobutrazol and uniconazolemay greatly affect the productivity of ”Anna” apple trees especially at1000 or 2000 ppm at full bloom compared to spraying in Mid-May.