Trials

Summary

With the aim of finding the most suitable varieties for the current market situation, five Hokkaido varieties, five butternut varieties, five kabocha varieties, and five Halloween varieties were compared in the summer of 2025. The trial was designed with three replicates and 72 plants per variety.

Among the Hokkaido varieties, Orange Summer, Kaori Kuri, and Bolp 5110 were characterized by their uniform fruit size. Orange Summer has the highest yield in the 0.8-2 kg segment. Kaori Kuri and Bolp 5110 have a smaller size range and are interesting for farms that often have problems with oversized fruits. Caldor and Ker Madec have very high storage losses from August 15 to October 15.

As expected, the butternut varieties are dominated by Tiana, JWS 6823, and Mieluna. Mieluna shows significantly higher yields than the comparison varieties. Tiana exhibits its uniform fruit size. JWS 6823 produces smaller fruits, which may be of interest to farms that often have overly large fruit sizes.

The kabocha varieties Delica and Delica Star are a very good choice overall. Yield, flesh quality, and size distribution meet the requirements of most customers and producers. TSX 843 and TSX 819 are premium kabocha varieties with exceptionally good flesh quality. However, this has a slightly negative effect on yield and storability. Midor has a very high yield and attractive, but small fruits. Unfortunately, Midor compromises significantly on quality. The flesh is fibrous, bland, and lacks sweetness compared to classic kabochas.

The Halloween varieties Hermes and Magician both achieve yields of over 60 tons per hectare. Boomer has the fewest losses in storage. Fort Knox has the lowest yield at 36 t/ha, but also produces significantly smaller fruits with an average weight of 1.9 kg. Hermes has slightly more losses in storage than Magician and Boomer. The robust appearance of the fruits, their beautiful shape, strong stems, and, last but not least, their enormous yield make Hermes the favorite.

Method and general framework

Uniform fruit size is becoming increasingly important in pumpkin production. Buyers are increasingly focusing on unit prices. It is challenging for producers to produce precisely within a specific weight range. Genetics have the greatest influence, but fertilization, weather conditions, and other production factors also affect size. Our goal is to identify the exact size distribution of the individual varieties and their yield characteristics. In a trial with 20 varieties, 3 replicates, and 72 plants per variety, over 4,000 individual fruits were weighed. We deliberately test modern and new varieties with high resistance potential.

Trial type: Randomized block trial

Plants/variety: 72

Replications: three

Plant density: 1 plant/m²

Previous crop: Maize

Location: Silty loam, 350 meters above sea level, 850 mm precipitation per year, Bottmingen, Switzerland

Fertilization: 130 kg K/ha with Kali 60 and 60 kg P/ha with P26 before tillage

100 kg N/ha with urea spread under the mulch film and not incorporated.

Cultivation: April 8 in Jiffy 7 Eco 42 mm

Planting: May 2 in mulch film

Crop protection: Howicover 38 grams/m² against crow damage and frost

Weed control: Netting in the tramlines, manually in the planting holes

Irrigation: None

Plant protection: June 4 Pirimor 0.5 kg/ha, July 10 Nativo 0.3 kg/ha, July 24 Topas Vino 0.25 l/ha

Harvest: August 15 with a second harvest on September 15 for butternut squash

Hokkaido

Evaluation Hokkaido

Caldor achieved the highest yield at 36 t/ha, followed by Ker Madec and Orange Summer. Ker Madec produced the largest fruits and Caldor the smallest. Bolp 5110 was the most uniform in size.

Orange Summer achieved the highest yield in the 0.8-2 kg size range. Bolp 5110 achieved the highest yield in the 0.8-1.5 kg segment.

Ker Madec and Caldor showed very high losses during two months of storage. Orange Summer showed the best storage characteristics. Kaori Kuri and Bolp 5110 performed almost equally well in storage.

Discussion Hokkaido

Caldor achieved the highest total yield with many fruits that were too small (under 0.8 kg). Caldor is also highly susceptible to sunburn and has very poor storage properties. Its slightly heart-shaped, pale orange color and poor flesh quality are reminiscent of the Amoro breeding line. Ker Madec produces beautiful large fruits with a good yield, but has very limited storage properties. Orange Summer impresses with very good size distribution, great yield, and good storage life. Kaori Kuri and Bolp 5110 also show attractive fruits, good storage properties, and great size distribution.

It is surprising that Orange Summer has better or equal storage capacity to Kaori Kuri in trials. The small difference is not significant. Both breeders and experience suggest that Kaori Kuri is a more storable variety than Orange Summer. With regard to storage capacity, several years must be taken into account in order to draw accurate conclusions in the long term.

Conclusion Hokkaido

The three varieties Orange Summer, Kaori Kuri, and Bolp 5110 have good yield characteristics and uniform sizing. Orange Summer has the largest fruit size of the three, with an average weight of 1.25 kg. Kaori Kuri has a few outliers above 2 kg in this trial, but is also very uniform in size and slightly smaller on average than Orange Summer, with an average weight of 1.16 kg. Bolp 5110 has the smallest average weight of these three varieties at 1.02 kg and the most uniform size.

Butternut

Evaluation Butternut

Mieluna achieved the highest yield at 36 t/ha, followed by JWS 6823 and Tiana. Pilgrim produced the largest fruits and JWS 6823 the smallest. The most uniform in size was the JWS 6823 variety, closely followed by Tiana.

Mieluna achieves the highest yield in the 0.8-2 kg size range. Mieluna also achieves the highest yield in the 0.8-1.5 kg segment. Early Nutter and JWS perform poorly in this size range, as both varieties account for over 50% of the yield in the size range below 0.8 kg. However, on farms with predominantly larger fruits, this higher proportion of smaller fruit sizes can be an advantage.  

Mieluna has the highest early yield. JWS and Tiana are practically identical in terms of ripening. Pilgrim is the fastest ripening variety, but also has the lowest yield potential.

Discussion Butternut

Mieluna produces the highest yields and has not yet shown any disadvantages in terms of storage or meat quality. Tiana and JWS 6823 also show good yields and great size distribution, although JWS 6823 is significantly smaller in size. Early Nutter and Pilgrim show the greatest variation among the varieties tested and also exhibit increased susceptibility to didymella. Pilgrim sometimes produces crooked necks. Early Nutter sometimes has slightly deformed fruits or unusual shapes.

Conclusion Butternut

Tiana and JWS 6823 are the most uniform in size. JWS 6823 tends to be too small in most regions and years. Tiana is ideal for most markets in terms of size distribution. Mieluna varies slightly more, but produces better yields, which compensates for the slightly greater variation.

Kabocha

Evaluation Kabocha

Midor achieves the highest yield at 43 t/ha, followed by Delica and Delica Sr. Delica has the largest fruits and Midor the smallest. The TSX 843 variety is the most uniform in size.

Midor achieved the highest yield in the 0.8-2 kg size range. Midor also achieved the highest yield in the 0.8-1.5 kg segment. Midor accounted for 66% of the yield in the 0.8-2 kg size range. The other varieties have the following shares of the total yield in the 0.8-2 kg size range: TSX 819 84%, TSX 834 82%, Delica Star 80% and Delica 79%. All varieties except Midor produce very precisely in the 0.8-2 kg segment.

Discussion Kabocha

Midor achieved the highest overall yield with many small fruits. The flesh quality of Midor is significantly more fibrous, bland, and less sweet than ordinary green kabochas. TSX 819 and TSX 843 are very uniform in size and slightly lower in yield than Delica and Delica Star. TSX 819 and TSX 843 have creamier and even sweeter flesh than Delica and Delica Star. This has a slightly negative effect on yield and shelf life.

Delica is good in terms of size, yield, and taste. Delica Star shows hardly any significant differences from Delica. Delica Star is a new breed of the Delica variety with mildew tolerance.

Conclusion Kabocha

The Midor variety stands out with its high yield and small fruits. However, Midor's flesh quality is significantly inferior. TSX 819 and TSX 843 both have uniform fruit size and exceptionally good flesh quality. However, this has a slightly negative effect on yield and storability. Delica and Delica Star have good flesh quality with good size distribution and an above-average yield for kabocha varieties.

Halloween

Evaluation Halloween

Hermes achieves the highest yield at 61 t/ha, closely followed by Magician at 60 t/ha. Boomer achieves 56 t/ha and the smaller-fruited varieties Flynn 42 t/ha. Boomer has the largest fruits, while Magician and Hermes have a very similar distribution of fruit size.

Magician achieved the highest yield in the 2.5-4 kg size range, followed by Hermes. Boomer has a greater spread. Fort Knox has 85% of its yield below 2.5 kg and Flynn produces 58% below 2.5 kg and 48% in the 2.5-4 kg segment.

Boomer has the lowest storage losses at 11.5% over the two months of storage. Flynn has 13% storage loss, Fort Knox 14%, and Magician 15%. Hermes has the highest storage losses at 18%.

Discussion Halloween

Hermes has the highest yield at 61 t/ha. Magician comes in second with 60 t/ha. Boomer yields 56 t/ha. The two smaller-fruited varieties, Flynn and Fort Knox, both have very good size distribution, but significantly lower yields. Boomer has the greatest variation in fruit size. Magician stands out with light-colored fruits, weak stems, and a soft, relatively less robust fruit. Surprisingly, Magician had the second lowest storage loss. Flynn is a robust variety with a strongly fused stem. It produces uniform fruits weighing around 2.5 kg. Fort Knox is a very beautiful, classically shaped Halloween pumpkin that weighs slightly less than 2 kg on average. In terms of storability, several years must be taken into account in order to draw accurate conclusions in the long term.

Conclusion Halloween

Hermes produces impressive yields of beautiful fruit with strong stems. The fruit size is also uniform. Magician can fully compete with Hermes in terms of yield and fruit size. However, Magician has significantly weaker stems and softer fruit that does not appear as robust. Boomer is a slightly flatter fruit with a beautiful dark orange color and performs best in terms of shelf life. However, it cannot compete with the other four varieties in terms of fruit size uniformity.