Transplanting Hybrid Potato Seedlings at Increased Densities Enhances Tuber Yield and Shifts Tuber-Size Distributions

Abstract

To contribute to the development of a novel cropping system for potato grown from greenhouse-derived seedlings from hybrid true potato seeds, planting density trials were carried out under normal Dutch agronomic conditions. For two consecutive years, 5-week-old seedlings of two experimental genotypes were transplanted into farmers’ potato production fields at two contrasting locations: a flat-bed system on sandy soil and a traditional ridge system on clay soil. Planting densities were 6.25, 12.5, 25, 50, 100 and 200 plants/m2 in the flat-bed system, and 3.125, 4.688, 6.25, 12.5, 25 and 50 plants/m2 in the ridge system. In general, increasing planting density of hybrid seedlings per area decreased tuber fresh weight per plant and reduced the number of tubers per plant. On a per hectare basis, an increased planting density resulted in increased total tuber yield and number of tubers up to very high densities, but finally both parameters levelled off. Highest total tuber yields harvested were 107 and 45 Mg/ha for the flat-bed and ridge system, respectively. On flat-beds, the optimal planting density for total yield was 50 plants/m2. On ridges, planting density interacted with year and genotype, resulting in an optimum planting density of 25 plants/m2 to reach the maximum total yield. Obtained yields in the commercial size classes Baby Baker (20 < size class ≤ 35 mm) and Seed Tubers (28 < size class ≤ 50 mm) were in general very high on the flat-beds, with a maximum Seed Tuber yield of 64 Mg/ha at 50 plants/m2. The current study showed that transplanted hybrid seedlings are feasible alternatives for seed-tuber-grown systems for certain potato outlets.

Little heterosis found in Diploid Hybrid Potato

“…Likewise, average tuber number was 136 tubers in Est and 199 tubers in Heelsum. The differences in performance between these two trials coincide with previous trials at these same locations (Dijk et al 2021). Trial means for tuber volume were comparatively more stable between trial locations with means of 21.3cm 3 in Est and 24.2cm 3 in Heelsum.…”

Converting Hybrid Potato Breeding Science into Practice

“…In recent years, the use of field transplanted, nursery-raised, hybrid potato seedlings has been tested as a potential alternative system for seed and ware potato production [ 54 ]. Ultimately, to obtain a highly productive transplanted crop, aspects of seedling production, field establishment and transplant field crop management need be considered and successfully executed [ 55 ]. These aspects include, but are not limited to, nursery climatic conditions and nursery management factors, field conditions at transplanting (soil and climatic conditions) and crop management factors, all of which, when successfully carried out, contribute to high productivity in transplanted crops [ 53 ].…”

“…The longer duration of the growing season was one observation from the transplanting moment study that became apparent. The timing of harvest was of some maturity types more important than the timing of -or conditions during- transplanting [ 55 ]. With these studies, we have shown the feasibility of the field transplanted systems.…”

“…This coincides, in temperate regions, with the period of highest irradiation level, which aggravates the impact of slower growth in the beginning of the season. Transplanted crops also have a longer cropping cycle [ 55 ], which increases costs of production, compared to a seedling grown crop. Lastly, farmers are currently used to producing their potato crop from seed-tubers.…”

“…In one, two or three seasons ware tubers can be produced. Transplanted seedlings were investigated by Van Dijk et al [ 53 , 54 , 55 ]. Seedling tubers for ware production were investigated by Stockem et al, 2020 [ 56 ].…”