How To Grow Large Gala's.Terence Robinson, Mike Fargione, LailiangCheng, Steve Hoying and Jim Schupp.Dept. of Horticultural SciencesCornell UniversityGeneva, NY 14456
The Problem• The fresh market rewards large fruit size.Price ($)2520151050-5FOB Price ($) Farm Gate Price* ($)160's140's120's113's100's80'sFruit Size (Number/40 lb box)*Excludes picking, storage, packing and sales charges.72's
Gala is genetically smallfruited.Gala is very fruitful andoften oversets.Gala produces flowersand fruits on one yearwood.Gala is difficult to thinwith standard chemicalthinners.
Approaches to Improving Fruit Size• Climatic effects on fruit size.• Warm Temperatures during the period from bloom to 50DAFB result in greater fruit size.• High light climates results in greater fruit size.• Management• Pruning.• Fertilization.• Thinning.• Irrigation.
The Balance Between VegetativeGrowth and FruitingVegetativeGrowthPruningNitrogenOver thinNo PruningNo NitrogenHeavy CropsFloweringandFruitingVigorous, UnfruitfulTrees with LargeFruit Size andLight CropsWeak, FruitfulTrees withSmall Fruit Size anBiennial Bearing
uning Approaches to Improving Fruit Size• Limb Renewal Pruning.• Spur Pruning (SpurExtinction).• Stubbing Back Pruning.
•Limb Renewal Pruning•Annual removal of 1-2limbs with minimaldetail pruning.
Spur Pruning (Spur Extinction)= Removal of 1/3 of allspurs on each branch plus removal of 1-2 branchescompletely.
Stubbing Back Pruning=Removal of distal 1/3 of eachbranch plus removal of 1-2 branches completely.
151050Minard 2003Stubbing BackSpur PruningLimb RenewalFlower Cluster Density(Clusters/cm 2 TCA)
Stubbing BackSpur Pruning450400350300250200150100500Hudson Valley 2003Geneva 2003Geneva 2004Limb RenewalFruit No. / Tree
Stubbing BackSpur PruningHudson Valley 20032000150010005000Geneva 2003Geneva 2004Limb RenewalYield (bu/ac)
Stubbing BackSpur PruningHudson Valley 2003180160140120100Geneva 2003Geneva 2004Limb RenewalFruit Size (g)
Stubbing BackSpur PruningLimb Renewal151050Hudson Valley 2003Geneva 2003Geneva 2004Cropload(fruit no./cm 2 TCA)
Stubbing BackSpur PruningHudson Valley 20031000080006000400020000Geneva 2003Geneva 2004Limb RenewalCrop Value ($/acre)
Fertilization Approaches toImproving Fruit SizeNitrogen Fertilization.• 50 lb N/acre• 100 lb N/acre• 150 lb N/acre (bud break vs split bud break+petal fall
180Hudson ValleyGeneva 2003Geneva 2004Fruit Size (g)16014012010050100150N Fertilization Rate (lb/acre)
Fertilization Approaches toImproving Fruit SizeNitrogen Fertilization.• Yield generally increases with increasing nitrogen up to2.6% leaf N but fruit color decreases with increasing leafnitrogen concentration.Potassium Fertilization.• Yield and fruit size increase with increasing potassium upto 1.6% leaf K 2 O.
Thinning Approaches to ImprovingFruit SizeBloom Thinning• Ammonium Thiosulfate (ATS)• PromalinPetal Fall Thinning• Carbaryl• Split applications of BA/Carbaryl10mm Thinning• NAA/Carbaryl• BA/Carbaryl• Split applications of BA/Carbaryl
Effect of Various Thinners on Gala Fruit Size-2003hinning Cropload Fruit Size Yield Crop Valuenthinned Control 15.7 a 139 b 2173 a 8203 b.5 NAA/Carbaryl 11.2 b 152 a 1797 b 9822 ab00 BA/Carbaryl 10.2 b 162 a 1831 b 12059 affect of various additionsromalin @ FB NS NS NS NSTS @ FB NS * NS NSarbaryl @ PF NS NS NS NSplit Applications of BA NS NS NS NS
Effect of Various Thinners on Gala Fruit Size-2004hinning Cropload Fruit Size Yield Crop Valuenthinned Control 10.7 a 158 a 2477 a 15304 a.5 NAA/Carbaryl 7.4 b 170 a 2037 b 15388 a00 BA/Carbaryl 9.4 ab 169 a 2296 ab 16468 affect of various additionsromalin @ FB NS NS NS NSTS @ FB NS * NS **arb aryl @ PF NS NS NS NSplit Applications of BA * ** * NS
est Thinning Strategies for Improving GalFruit Size2003• 2 gal ATS /100 @ Full Bloom + 1 pt Carbaryl/100 @ PF + 100ppmBA/Carbaryl @ 10mm fruit size. (av. size=185g)• 100ppm BA/Carbaryl @ 10mm fruit size. (av. size=162g)2004• 2 gal ATS /100 @ Full Bloom. + 1 pt Carbaryl/100 @ PF + 100ppmBA/Carbaryl @ 10mm fruit size. (av. size=191g)• Promalin @ Full Bloom + 50ppm BA/Carbaryl @ PF + 50ppmBA/Carbaryl @ 7DAPF + 50ppm BA/Carbaryl @ 14DAPF. (av.size=194g)
Irrigation Approaches to ImprovingFruit Size• In the wet years like 2003 and 2004 there was noimprovement in fruit size with irrigation.• In dry years, irrigation gives a 5-10% improvement infruit size.• Trickle irrigation gives the same response asmicrosprinklers in most NY soils.
What Fruit Size will Give theGreatest Returns to the Grower?• 80 count fruit?• 100 count fruit?• 120 count fruit?• Bag size fruit?
2520FOB Price ($)Farm Gate Price* ($)Price ($)151050-5160's140's120's113's100's80's72'sFruit Size (Number/40 lb box)*Excludes picking, storage, packing and sales charges.
Predicted Gala Fruit Size and Yield from 4 Plots in NYFruit Size (g)20018016014012030002500200015001000500Yield (bu/acre)1000 5 10 15 20Cropload (fruit no/cm 2 TCA)Geneva 1 2003 Geneva 2 2003Geneva 1 2004 Hudson Valley 20030
Crop Value ($/acre)8,0007,0006,0005,0004,0003,0002,000Predicted Farm Gate Crop Value with DifferentAverage Fruit Size of 4 Gala Orchads in NYGeneva 1 2003Geneva 1 2004Geneva 2 2003Hudson Valley 20031,0000160's 140's 120's 113's 100's 88's100 120 140 160 180 200Fruit Size (g)
Fruit Size (g)200180160140120Predicted Gala Fruit Size from 4 Plots in NYGeneva 1 2003Geneva 1 2004Geneva 2 2003Hudson Valley 20031000 5 10 15 20Cropload (fruit no/cm 2 TCA)
Conclusions• The greatest returns to the grower came fromhigh yields of moderate fruit size.• Stubbing back pruning appears to be an effectiveway to increase fruit size for NY growers.• Spur extinction also is an effective method ofincreasing fruit size.• BA/Sevin has given the best improvements in fruitsize with Gala. Multiple spray strategies havebeen the most effective.• High Nitrogen fertilization has not improved fruitsize.• Irrigation can improve fruit size during dry years.
ain Cornell Fruit Web Pagettp://www.fruit.cornell.eduY Fruit Quarterlyttp://www.nysaes.cornell.edu/hort/fq