Growth and expansion of strawberry fruit (Fragaria x ananassa Duch.) under water stress conditions

Abstract

This investigation was carried out to find out if a constant number of strawberry fruit in the plants would have differing rates of growth and expansion when subjected to different levels of water stress at specific growth stages. Soil water stress treatments were imposed at flowering (flo) and at fruiting (fru), by withholding water until the available soil water were 0.40 to 0.45% v/v for the normal stress treatment (normal), 0.35 to 0.40% v/v mild stress (ms) and 0.25 to 0.35% v/v for severe stress (ss). The ms fru, ss fru and ss flo treatments showed significantly lower fruit weights than other treatments while fruit firmness was significantly increased by ms fru and ss fru treatments in the primary, secondary fruit and tertiary fruit. The total soluble solids (TSS) were not affected significantly by the water stress treatments. Osmotic adjustment may be attributed to the ability of the water stressed strawberry fruit to grow and expand post anthesis. This research provides an understanding of the effects of water deficits on fruit quality when other factors such as fruit number and fruit positioning on the inflorescence are similar in all experimental units. Strawberry producers may consider reduced crop loading to ameliorate reduced fruit size, when faced with water deficit irrigation regimes. Key words: Crop load, fruit size, fruit weight, total soluble solids (TSS), water stress.