Effects of flooding and alluvium deposition on kiwifruit (Actinidia deliciosa): 1. Early vine decline

Abstract

Kiwifruit vines are reported to be very sensitive to anaerobic conditions in the root zone, but this has been little studied under orchard conditions. Opportunity to study this extensively arose when, in March 1988, Cyclone Bola caused flooding in kiwifruit orchards near Gisbome, New Zealand. We sought to identify factors responsible for early decline of flooded vines, and strategies to increase vine survival after flooding. Early decline was defined as premature defoliation in the first 11 weeks following the flood. Vine health and soil conditions were monitored at 10 sites. Vines frrst showed waterlogging damage 3-7 days after the flood, but the proportion of vines affected varied greatly between sites. Over all sites, one third of the vines experienced early decline. One half of these affected vines were still stressed or dead the following spring (October 1988). Early decline was closely associated with feeder root H91001 Received 7 January 1991; accepted 27 September 1991 death. Infections by Phytophthora spp. and site-tosite differences in flood conditions showed little relation to the incidence of early decline. A major factor in feeder root death and early vine decline was poor soil structure, which resulted in inadequate drainage, and soil anaerobisis. Vine sensitivity to waterlogging in the field varied greatly, apparently the result offactors such as variations in soil conditions and previous vine vigour. It appears the single most important means ofenhancing vine resistance to flood events is to ensure soil structure is well maintained.

Early Kiwifruit Decline: A Soil-Borne Disease Syndrome or a Climate Change Effect on Plant–Soil Relations?

“…Kiwifruits are vines, and they are usually cultivated in canopies. Since the beginning of their cultivation spread, physiological disorder symptoms were observed in orchards, including leaf epinasty, chlorosis, desiccation and abscission, growth stop, and reduced fruit production; these were associated with anomalous root morphology and anatomy, disappearance of fibrous roots, and rotting of structural roots (Savé and Serrano, 1986;Xyloyannis et al, 1986;Smith et al, 1989;Reid et al, 1991). These symptoms usually appeared mid-summer; a progressive worsening was usually observed in following years, which could lead to the complete harvest loss and to plant death.…”

“…Progressively, the seriousness and the diffusion of this disorder in kiwifruit orchards all over the world has attracted more attention and induced people to better take into consideration the physiological traits of the plant for crop management. The effect of flooding, due to either meteoric events or excessive or wrong watering management, was examined in view of the high sensitivity of kiwifruit roots to low oxygen availability (Savé and Serrano, 1986;Smith et al, 1989Smith et al, , 1990Reid et al, 1991Reid et al, , 1992. The effect of other soil-borne abiotic stress factors (structure and texture, elevation, and transmission properties Reid et al, 1991, nutrient availability, including organic matter, heavy metal content, xenobiotics phytotoxicity, water availability, and temperature (Xyloyannis et al, 1986;Smith et al, 1989), as well as management practices, e.g., overpruning and overcropping (Black et al, 2012), or soilborne pests (pathogenic microorganisms) (Reid et al, 1991;Tacconi et al, 2014Tacconi et al, , 2015 on the occurrence of the decline symptoms has also been assessed.…”

Possible Role of High Temperature and Soil Biological Fertility on Kiwifruit Early Decline Syndrome

“…The plant of kiwifruit is frequently prone to physiological disorder symptoms that have been associated with anomalous root morphology and rotting of structural roots, attributed to soil-borne pathogens (Reid et al, 1991;Tacconi et al, 2015;Donati et al, 2019;Prencipe et al, 2020;Spigaglia et al, 2020) as well as to soil-borne abiotic stresses (Savé and Serrano, 1986;Smith et al, 1989;Reid et al, 1991). Among abiotic stresses, soil structure and texture (Reid et al, 1991), nutrients availability, organic matter content, heavy metal content, xenobiotics phytotoxicity, water availability, and temperature (Xyloyannis et al, 1986;Smith et al, 1989), as well as management practices, e.g., overpruning and overcropping (Black et al, 2012), have been considered as possible factors inducing KEDS (Bardi, 2020). None of these factors was clearly identified as the sole KEDS cause; however, almost all of them can be directly or indirectly related to the extreme sensitivity of kiwifruit to low oxygen availability in soil (Savé and Serrano, 1986;Smith et al, 1989;Reid et al, 1991).…”

“…Among abiotic stresses, soil structure and texture (Reid et al, 1991), nutrients availability, organic matter content, heavy metal content, xenobiotics phytotoxicity, water availability, and temperature (Xyloyannis et al, 1986;Smith et al, 1989), as well as management practices, e.g., overpruning and overcropping (Black et al, 2012), have been considered as possible factors inducing KEDS (Bardi, 2020). None of these factors was clearly identified as the sole KEDS cause; however, almost all of them can be directly or indirectly related to the extreme sensitivity of kiwifruit to low oxygen availability in soil (Savé and Serrano, 1986;Smith et al, 1989;Reid et al, 1991). Therefore, soil management practices improving root aeration, limiting the risk of waterlogging and reducing the development of soil-borne diseases have been proposed to avoid KEDS occurrence (Reid et al, 1991;Sorrenti et al, 2016;Tacconi et al, 2019a).…”

“…None of these factors was clearly identified as the sole KEDS cause; however, almost all of them can be directly or indirectly related to the extreme sensitivity of kiwifruit to low oxygen availability in soil (Savé and Serrano, 1986;Smith et al, 1989;Reid et al, 1991). Therefore, soil management practices improving root aeration, limiting the risk of waterlogging and reducing the development of soil-borne diseases have been proposed to avoid KEDS occurrence (Reid et al, 1991;Sorrenti et al, 2016;Tacconi et al, 2019a). However, over the last few years these practices were not sufficient to prevent the worsening of KEDS occurrence in both young and adult orchards (Spigaglia et al, 2020).…”