Investigating Effects of Over-Irrigation and Deficit Irrigation on Yield and Fruit Quality in Pink Ladytm ‘Rosy Glow’ Apple

Abstract

Fruit production has to be adapted to climate change that is often associated with heat and water deficit episodes. To develop efficient strategies on how to manage commercial orchards under deficit water supply, we need to know the effects of water-stress on crop production. However, when the water supply is abundant apple growers often think that over-irrigation gives higher marketable fruit yield than potential evapotranspiration-based or sensor-based (e.g. tensiometer, dendrometer) irrigation. We therefore aimed to evaluate the effects of three water regimes, namely well-watered (100% of crop evapotranspiration -ETc, WW), 25% of ETc water deficit over the season (water-stressed, WS), and twofold of WW (200% of ETc, 2xWW), on midday stem water potential (SWP), crop yield and fruit quality of Pink Lady TM 'Rosy Glow' apples. As expected, SWP was lower in WS than in the others, but both WS and 2xWW decreased fruit yield, although 2xWW tended to increase yield in the >70% color class and ensured quite a constant amount of yield at each picking time. Soluble solid content (SSC) in fruit was higher in WS. As a whole, our results suggest that over-irrigation that is sometimes recommended to keep a safety margin should be considered with caution. Rather, a mild water-stress, between WS and WW in our experiment, may represent a good compromise for a good quality yield.

Late Ripening Apple Production Benefits from High Shading and Water Limitation under Exclusion Netting

“…190 mm, during each year, Table 1). Again, such outputs are confirmed from previous studies focusing on the benefits of regulated deficit irrigation on apple [23,[31][32][33] and other fruit crops [34][35][36][37].…”

Machine Learning for Precision Agriculture Using Imagery from Unmanned Aerial Vehicles (UAVs): A Survey

“…For example, a study conducted by Mitchell et al [36] found that deficit irrigation reduced fruit water accumulation and fresh fruit yield. In addition, Atay et al [37] hypothesized that over-irrigation could have a negative impact on total yield and fruit quality. Lastly, with water being a scarce resource in most production areas, an efficient water management scheme that maintains crop yield but has a moderate and controlled level of moisture stress on their crops is required [29].…”

Effects of Different Crop Loads on Physiological, Yield and Fruit Quality of ‘JoyaTM’ Apple Trees: High Crop Load Decreases Maximum Daily Trunk Diameter and Does Not Affect Stem Water Potential

“…Fruit quality: The fruit quality characteristics analyzed here have been described elsewhere (Atay et al, 2017). In summary, average fruit weight of all crop harvested was determined by dividing yield (kg/tree) to fruit number (fruit number/tree).…”

“…There is a strong negative correlation between tree yield and fruit size (Forshey et al, 1992). High crop load extends ripening (Atay et al, 2017). Leaf and fruit nutrient concentrations can be affected by crop load (Neilsen et al, 2015).…”