Post‐harvest physiological deterioration in several cassava genotypes over sequential harvests and effect of pruning prior to harvest

Abstract

Consumers, traders and processors consider post-harvest physiological deterioration (PPD) an important constraint. In Experiment 1, PPD was assessed three consecutive years in roots from five genotypes through seven storage days. PPD, scopoletin and dry matter content (DMC) was recorded during storage. Year, genotype, duration of storage and their interactions were significant. PPD was associated with duration of storage period, DMC and scopoletin contents. Ambient moisture and temperature during storage influenced PPD. In Experiment 2, roots from seven clones were harvested 10 months after planting from 30 consecutive biweekly plantings. PPD was assessed 0, 2 and 7 days after harvest. In 13 harvests, roots from plants pruned six days earlier were also evaluated. Results indicated large seasonal variation across genotypes. Pruning reduced PPD and DMC. Complex and contrasting relationships among the variables analysed were found. There is no uniform model explaining the relationship between PPD and the independent variables considered.

Exploring Farmers’ Knowledge and Approaches for Reducing Post-Harvest Physiological Deterioration of Cassava Roots in Malawi

“…These varieties would take three to five days before showing visible signs of PPD. This observation concurs with reports from several authors who reported variations among varieties for PPD [12,14,17,[33][34][35]. Some varieties could go up to 40 days with no visible PPD signs [14].…”

“…The results complement those in literature that effective control and preventative measures for PPD should properly integrate the following five strategies: (i) modifying storage conditions; (ii) improving processing of fresh cassava roots; (iii) selection of tolerant genotypes; (iv) pre-conditioning cassava tissue before harvesting; and (v) preventing active gene expression during storage. Some of these strategies can be combined [16,17].…”

“…Signs of PPD begin with blue-black to black vascular discoloration (vascular streaks) which may become visible within 24-72 h after harvest [15,16]. Most cassava varieties deteriorate within three to four days of harvest [17].…”

Advances in Genetic Analysis and Breeding of Cassava (Manihot esculenta Crantz): A Review

“…Saravanan et al [90] reported that the estimated yield losses of fresh cassava roots due to PPD are nearly a third of the total harvest worldwide. The expression of PPD is controlled by genotypic and environmental factors following microbial infections [91]. In Thailand where cassava is the most important industrial crop, PPD results in an economic loss of up to USD 35 million annually [92].…”

Fifty years of a public cassava breeding program: evolution of breeding objectives, methods, and decision-making processes

“…fr) is an ambitious initiative to elucidate basic information regarding root quality traits. Several research articles regarding root quality traits and post-harvest processing have recently been published (Alamu et al 2021;Bechoff et al 2018;Dufour et al 2021;Escobar et al 2021;Goddard et al 2015;Iragaba et al 2021;Luna et al 2021;Ndjouenkeu et al 2021;Teeken et al 2018Teeken et al , 2021Thiele et al 2021;Tran et al 2021). The availability of this critical knowledge and reliable high-throughput phenotyping protocols will improve the efficiency of breeding for root quality traits.…”