Influence of Rootstock and Irrigation Methods on Water Use, Mineral Nutrition, Growth, Fruit Yield, and Quality in ‘Gala’ Apple

Abstract

<jats:p>The increasing trend in the world population and decreasing trend in the suitable land for fruit production, combined with a shortage of water, mandate the use of efficient methods of irrigation and establishment of high-density orchards that require size-controlling rootstocks. Method of irrigation and vigor of rootstock are among the most important factors affecting uptake of mineral nutrients, and thus tree growth and fruit yield and quality attributes of apple (<jats:italic>Malus domestica</jats:italic>). In a long-term experiment, effects of two irrigation methods and four rootstocks on water use, tree growth, fruit quality, and leaf mineral nutrients were studied in ‘Pacific Gala’ apple. The experiment was conducted in southwestern Idaho, which represents the high desert conditions of the Intermountain West region of the United States. Evapotranspiration-based irrigation scheduling (ET<jats:sub>c</jats:sub>), adjusted by percentage of ground shading, was used for sprinkler and drip systems. Significantly lower volume of water was applied to the trees with drip irrigation than those with sprinkler irrigation system. Leaf calcium (Ca) decreased but leaf potassium (K) increased with rootstock vigor, resulting in the greatest leaf Ca but lowest leaf K in trees on ‘Budagovsky 9’ (B.9). Fruit weight and yield per tree in ‘Pacific Gala’ on ‘Nic 29’ (RN29) rootstock was higher than those on B.9 and ‘Geneva 30’ (G.30) rootstocks. ‘Pacific Gala’ on B.9 rootstock had smaller trees and fruit size but higher fruit starch degradation pattern (SDP), suggesting earlier fruit maturity on this rootstock. On average, ‘Pacific Gala’ trees with drip irrigation had larger fruit and higher leaf magnesium (Mg) and manganese (Mn) but less fruit color and firmness and lower leaf Ca, K, zinc (Zn), and copper (Cu) than those with sprinkler system.</jats:p>

Apple Scion and Rootstock Contribute to Nutrient Uptake and Partitioning under Different Belowground Environments

“…The results reported here agree with previous studies where water supply was reduced for fruit trees that led to reduced leaf area, and hence leaf biomass, while root growth was less affected which increased the root:shoot ratio [30,31]. The effect of dwarfing rootstocks on the scion under water limitations was previously reported with an elevated production of ABA in leaves which could reduce biomass partitioning to the aboveground tissues and increase root tolerance to abiotic stresses by increasing the fine root:coarse root ratio [12,31,32]. In this study, root biomass was affected by scion and was consistently higher for 'Gala' than for 'Honeycrisp'.…”

“…These results correspond with the previous reporting that scion and rootstock can both affect tree vigor. Effects on plant growth and partitioning by scion and rootstock have been reported for trunk cross-sectional area (TCA), shoot growth, tree height and the number of branches among others, i.e., the rootstock affected the scion height, TCA and weight, while the scion affected the rootstock TCA and, to a lesser extent, the root biomass [32][33][34][35]. Scion-rootstock interactions identified in a greenhouse experiment are limited because of no fruit production but these conditions allow for the evaluation of tree growth and development under a controlled environment.…”

Rootstock and Nutrient Imbalance Leads to ‘‘Green Spot’’ Development in ‘WA 38’ Apples

“…The influence of rootstock on crop load (fruits/cm 2 TCSA), fruit to leaf ratio, and fruit size have been previously reported in apples (Fallahi, 2012;Fazio et al, 2018;Lordan et al, 2018;Silveira et al, 2012). Fallahi (2012) found higher yield and crop load in 'Gala' apple grown on 'M.9-Nic29' rootstocks when compared with 'Bud 9' and 'Geneva 30'.…”

Yield, Labor, and Fruit and Juice Quality Characteristics of Machine and Hand-harvested ‘Brown Snout’ Specialty Cider Apple

“…Washington State is the largest producer of apples in the United States, and with around 156,000 acres of apples, accounted for 48% of the U.S. apple supply in 2011 [U.S. Department of Agriculture (USDA), 2014]. Modern dessert apple orchards include dwarfing rootstock and trellis systems with 1200 to 1800 trees/acre (Fallahi, 2012;Lehnert, 2010;Marshall and Andrews 1994;Schotzko and Granatstein, 2005;Washington State University Extension, 2013). New specialty cider apple orchards in Washington include semidwarfing rootstocks and %700 trees/acre (Galinato et al, 2014).…”