Choice of cultivar, training system, planting density, and rootstock affect orchard performance and profitability. To provide guidance to growers in northern cold climates on these choices, a field trial was established in Peru, Clinton County, NY, in 2002, with two apple cultivars (Honeycrisp and McIntosh). From 2002 through 2016, we compared Central Leader on ‘M.M.111’; Slender Pyramid on ‘M.26’ and ‘Geneva® 30’ (‘G.30’); Vertical Axis on ‘M.9 (Nic® 29)’ (‘M.9’), ‘Budagovsky 9’ (‘B.9’), and ‘G.16’; SolAxe on ‘M.9’, ‘B.9’, and ‘G.16’; and Tall Spindle on ‘M.9’, ‘B.9’, and ‘G.16’. Central Leader was planted at 539 trees/ha, Slender Pyramid at 1097 trees/ha, Vertical Axis and SolAxe at 1794 trees/ha, and Tall Spindle at 3230 trees/ha. Cumulative yield was higher with ‘McIntosh’ than with ‘Honeycrisp’. High planting densities (Tall Spindle) gave the highest cumulative yields (593 t·ha−1 on ‘McIntosh’ and 341 t·ha−1 on ‘Honeycrisp’). Tall Spindle (3230 trees/ha) on ‘M.9’ appeared to be the best option for ‘McIntosh’. On the other hand, for a weak-growing cultivar such as ‘Honeycrisp’, Tall Spindle on ‘B.9’ (366 t·ha−1) and Slender Pyramid (1097 trees/ha) on ‘G.30’ (354 t·ha−1) were the two combinations with the highest cumulative yield, largest fruit size (220–235 g), and greatest efficiency index (4.6–3.9 kg·cm−2).
Jaume Lordan, Anna Wallis, Poliana Francescatto, and Terence L. Robinson
Jaume Lordan, Anna Wallis, Poliana Francescatto, and Terence L. Robinson
Orchard profitability relies on multiple factors such as cultivar, planting density, training system, rootstock, and fruit quality but is also strongly affected by growing climate and soil resources. To evaluate orchard profitability in a northern cold climate, a field trial was planted in Peru, Clinton County, NY, in 2002, with two apple cultivars (Honeycrisp and McIntosh), where we compared the Central Leader (CL) training system on ‘M.M.111’ rootstock; Slender Pyramid (SP) on ‘M.26’ and ‘Geneva® 30’ (‘G.30’); Vertical Axis (VA) on ‘M.9 (Nic® 29)’ (‘M.9’), ‘Budagovsky 9’ (‘B.9’), and ‘G.16’; SolAxe (SA) on ‘M.9’, ‘B.9’, and ‘G.16’; and Tall Spindle (TS) on ‘M.9’, ‘B.9’, and ‘G.16’. CL was planted at 539 trees/ha, SP at 1097 trees/ha, VA and SA at 1794 trees/ha, and TS at 3230 trees/ha. The aim of this study was to evaluate the economic profitability of ‘Honeycrisp’ and ‘McIntosh’ at a wide range of planting densities, training systems, and rootstocks for cold areas such as northern New York state. A secondary goal was to assess the effect of various economic factors on the net present value (NPV) of each combination of training system, rootstock, and density. High NPV was achieved with ‘Honeycrisp’ (≈$450,000/ha), whereas NPV was significantly lower with ‘McIntosh’ (≈$80,000/ha). Within ≈5 years, ‘Honeycrisp’ planted in a TS (3230 trees/ha) reached a positive NPV, whereas 9 years were needed when ‘Honeycrisp’ was planted in a CL system at 539 trees/ha. With ‘McIntosh’, break-even year to positive NPV (BYPNPV) was reached at 9 years for TS on ‘M.9’. Most of the other training system and rootstock combinations needed up to 11–13 years to show a positive NPV. The most important variables affecting orchard NPV in our trial were fruit price and yield. The best option for ‘Honeycrisp’ in northern New York State appears to be TS on either ‘B.9’ or ‘M.9’, whereas with ‘McIntosh’, the best option appears to be TS on ‘M.9’.
Gemma Reig, Jaume Lordan, Stephen Hoying, Michael Fargione, Daniel J. Donahue, Poliana Francescatto, Dana Acimovic, Gennaro Fazio, and Terence Robinson
We conducted a large (0.8 ha) field experiment of system × rootstock, using Super Chief Delicious apple as cultivar at Yonder farm in Hudson, NY, between 2007 and 2017. In this study, we compared six Geneva® rootstocks (‘G.11’, ‘G.16’, ‘G.210’, ‘G.30’, ‘G.41’, and ‘G.935’) with one Budagovsky (‘B.118’) and three Malling rootstocks (‘M.7EMLA’, ‘M.9T337’ and ‘M.26EMLA’). Trees on each rootstock were trained to four high-density systems: Super Spindle (SS) (5382 apple trees/ha), Tall Spindle (TS) (3262 apple trees/ha), Triple Axis Spindle (TAS) (2243 apple trees/ha), and Vertical Axis (VA) (1656 apple trees/ha). Rootstock and training system interacted to influence growth, production, and fruit quality. When comparing systems, SS trees were the least vigorous but much more productive on a per hectare basis. Among the rootstocks we evaluated, ‘B.118’ had the largest trunk cross-sectional area (TCSA), followed by ‘G.30’ and ‘M.7EMLA’, which were similar in size but they did not differ statistically from ‘G.935’. ‘M.9T337’ was the smallest and was significantly smaller than most of the other rootstocks but it did not differ statistically from ‘G.11’, ‘G.16’, ‘G.210’, ‘G.41’, and ‘M.26EMLA’. Although ‘B.118’ trees were the largest, they had low productivity, whereas the second largest rootstock ‘G.30’ was the most productive on a per hectare basis. ‘M.9’ was the smallest rootstock and failed to adequately fill the space in all systems except the SS, and had low cumulative yield. The highest values for cumulative yield efficiency (CYE) were with ‘G.210’ for all training systems except for VA, where ‘M.9T337’ had the highest value. The lowest values were for all training systems with ‘B.118’ and ‘M.7EMLA’. Regardless of the training system, ‘M.7EMLA’ trees had the highest number of root suckers. Some fruit quality traits were affected by training system, rootstock or system × rootstock combination.
Jaume Lordan, Terence L. Robinson, Mario Miranda Sazo, Win Cowgill, Brent L. Black, Leslie Huffman, Kristy Grigg-McGuffin, Poliana Francescatto, and Steve McArtney
The use of highly feathered trees can make high-density apple plantings more profitable through enhanced precocity and increased early yield. Currently, nurseries are asked to provide highly feathered trees with wide branch crotch angles. The use of plant growth regulators (PGRs) can play a key role when it comes to branch induction; however, dose and timing both need to be tested to enhance branching without compromising other tree quality attributes. Over the last 4 years, we have conducted studies of the use of MaxCel® (6-benzyladenine) and Promalin® (a mixture of 1.8% 6-benzyladenine and 1.8% GA4+7) in comparison with Tiberon™ SC (cyclanilide) at several nurseries in NY, WA, DE, Ontario (Canada), and Chile. The best results were obtained with four applications of MaxCel® or Promalin® (400 mg·L−1) beginning when leader growth reached 70 cm above the soil line and reapplied at 10–14 days intervals. Promalin® was a slightly less effective branching agent than MaxCel®. On the other hand, Promalin® stimulated leader growth resulting in improved final tree height, whereas MaxCel® induced the widest branch angles. Overall, we observed good response and quality ratings with ‘Cameo’, ‘Cripps Pink’, ‘Enterprise’, ‘Fuji’, ‘Ambrosia’, ‘Crimson Crisp’, ‘Gingergold’, and ‘Granny Smith’, whereas less quality ratings were observed on ‘Ambrosia’, ‘Cortland’, ‘Goldrush’, ‘Honeycrisp’, and ‘Suncrisp’. Response with ‘Gala’ varied depending on the temperature range. Multiple sprays of Gibberellins (GA4+7, or GA3) at 250 mg·L−1 applied to nursery trees in the late summer inhibited flower bud development and flowering in the orchard the next year. This reduces the risk of fire blight infection in newly planted trees.