Introduction

CIP-PODEROSA CROCANTE, CIP-PODEROSA POLLERA and CIP-PODEROSA WATIA are potato varieties generated from the International Potato Center (CIP by its acronym in Spanish) breeding population B, sub-population B3, cycle 2 (B3C2) (Gastelo et al. 2016a, b), obtained through traditional breeding by crossing advanced clones of cycle 1 (B3C1) (Landeo et al. 1995). The parental clones have high levels of yield, horizontal resistance to LB (Phytophthora infestans (Mont) de Bary) and frying quality for French fries. The crosses were made by CIP at Santa Ana Experimental Station in Huancayo, Peru (3288 m.a.s.l., 12°0′33.9"S, 75°13′41.7"W) during 1995 and 1996.

CIP-PODEROSA CROCANTE variety (CIP396026.101) was generated from the crossing of advanced clones CIP393046.7 as female and CIP393079.4 as male (Fig. 1). CIP-PODEROSA POLLERA (CIP395123.6) has as parents advanced clones CIP392633.4 as female and CIP393280.64 as male (Fig. 2). The male progenitor was released as a variety in Costa Rica under the name Pasqui (INTA 2012) and in Bangladesh as BARI Alu-53 (Mahmud 2022) due to its high yield, resistance to LB and excellent quality for frying. The variety CIP-PODEROSA WATIA (CIP396034.103) was generated from crossing of advanced clones CIP393042.50 as female and CIP393280.64 as male (Fig. 3).

Fig. 1
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Pedigree CIP-Poderosa Crocante

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Fig. 2
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Pedigree CIP-Poderosa Pollera

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Fig. 3
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Pedigree CIP-Poderosa Watia

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CIP-PODEROSA CROCANTE and CIP-PODEROSA POLLERA are varieties with high resistance to LB, high tuber yield, excellent quality for French fries and lower acrylamide content than levels recommended by the European Union (500 µg kg−1 of potato chips) (http: //data.europa.eu/eli/reg/2017/2158/oj). CIP-PODEROSA WATIA has excellent quality for baking, in addition to the characteristics mentioned for the other varieties.

Evaluation of these varieties for horizontal resistance to LB was carried out previously between 1998 and 2008, under field conditions in Oxapampa (1814 m.a.s.l., 12°34′3″ S, 75°24′14″ W) and Comas (2550 m.a.s.l., 11°37′09″S 75°05′22″W), two Peruvian locations with optimal environmental conditions for development of LB with temperatures ranging between 15 to 20 °C, high relative humidity (> 80%), and high annual precipitation (> 1500 mm). Readings (percentage of foliage area infected) for each plant were done weekly after 45 days after planting until plant senescence according to the method described by Forbes et al. (2014). The area under the disease progress curve (AUDPC) and standardized AUDPC (sAUDPC) were calculated from severity readings and used as indicators of resistance (Forbes et al. 2014; Yuen and Forbes 2009; Gastelo et al. 2016a, b).

Tuber yield also was evaluated at Comas and Oxapampa under high pressure of LB and at other Peruvian locations: La Molina (241 m.a.s.l., 12°4′40″ S, 76° 54′40″ W), Huaral (188 m.a.s.l., 1°30′2.74″ S, 77°12′32.62″ W) and Huancayo (3249 m.a.s.l., 2°4′0″ S, 75°13′0″ W), where the presence of LB was minimal (Gastelo et al. 2016a, b). French fries frying quality, baking quality, dry matter content, and reducing sugars were determined at the CIP Postharvest Laboratory in La Molina, Lima, Peru. Tubers were stored under room conditions in La Molina, Lima, at 15–16 °C for three months after harvest.

Many varieties with resistance to LB have not been adopted in the world, because market preferences have not been considered in addition to their resistance (Walker et al. 1999; Ahmadu et al. 2021). For the selection of these new varieties, other characters of economic importance have been considered, such as the color of tuber skin. In Peru, potato consumers prefer varieties with red or purple skin. French fries have a high demand in Peru, and it is increasing since it accompanies a traditional dish called grilled chicken (“Pollo a la brasa”), which is a window of opportunity for adoption of these varieties. A national survey with participation of the main actors of potato value chain was carried out to select the names for these varieties. Crocante and Pollera are related to quality characteristics: Crocante for its crispness and Pollera because it was consumed together with grilled chicken. Watia was selected because of its quality for baking and has origin in the Quechua word “Watia” which means baked. These varieties have been registered in the National Register of Commercial Varieties under Peruvian seed authorities with records No. 001, 002 and 003–2023-MIDAGRI-SENASA-DELYC.

These new varieties are healthy for farmers as well as for consumers. In the case of farmers, they and their families will have less exposure to fungicides to control LB, and in the case of consumers, they will have potato tubers produced with less fungicides, and a lower content of acrylamides and glycoalkaloids when are processed. These varieties are sustainable and can be included in family farming systems for their comparative advantages of production, help to preserve the environment, and increase the income of small and medium scale farmers, thereby allowing them to improve their living standards.

Variety Description

The information was obtained from six Distinction, Homogeneity and Stability (DHE) trials (UPOV 2004) carried out in La Paccha, Quilcas, Jauja and Majes, during the 2019–2020 and 2020–2021 growing seasons (Table 1).

Table 1 Peruvian localities where field trials were conducted and their respective growing seasons
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CIP-PODEROSA CROCANTE

Plants

Growth habit

Upright growth of medium height (Fig. 4a) with medium maturity under Peruvian conditions (120 days from planting to harvest). Stems: green, vigorous, with weak anthocyanin pigmentation.

Fig. 4
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CIP PODEROSA-CROCANTE: (a) Upright growth of medium height growth habit, (b) compound leaf, (c) inflorescence, (d) flesh color, (e) skin color tuber, (f) conical shaped light sprout, and (g) French fries

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Leaves

Dark green, matte upper surface, medium size, open, absent edge waviness, medium presence of secondary leaflets, medium size second pair of leaflets, absence of coalescence in terminal and lateral leaflets (Fig. 4b).

Flowers

Flower bud with medium anthocyanin pigmentation, medium flowering, large inflorescences, peduncle with medium anthocyanin pigmentation. Corolla: medium size, violet color, with absent or very weak anthocyanin pigmentation on the inner side. It has fertile pollen; it can be used as a female and male parent in hybridizations (Fig. 4c).

Tubers

Oval shape with shallow eyes, red skin, cream flesh, 70–150 mm long with a mean of 100 mm, 114 g of average weight per tuber (Fig. 4d, e), dormancy 90–100 days stored under diffused light at 10-130C temperature. Large size and conical shaped light sprout, with medium anthocyanin pigmentation and weak pubescence at the base, weak anthocyanin pigmentation and medium pubescence at the tip (Fig. 4f), low number of radicles and short lateral shoots, good quality for French fries (Fig. 4g).

CIP-PODEROSA POLLERA

Plants

Growth habit

Semi-upright growth habit of medium height (Fig. 5a). with medium maturity (120 days from planting to harvest). Stems: Green, vigorous, with weak anthocyanin pigmentation.

Fig. 5
figure 5

CIP PODEROSA-POLLERA: (a) Semi-upright growth habit of medium height growth habit, (b) compound leaf, (c) inflorescence, (d) skin and flesh color tuber, (e) narrow cylindrical shaped light sprout, and (f) French fries

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Leaves

Dark green, medium size, intermediate glossiness upper surface, opening intermediate, medium edge waviness, medium presence of secondary leaflets, medium size second pair of leaflets, absent coalescence in terminal and lateral leaflets (Fig. 5b).

Flowers

Flower buds have medium anthocyanin pigmentation, medium flowering, medium inflorescences, peduncle with absent or low anthocyanin pigmentation. Corolla: Medium size, violet color, with absent or very weak anthocyanin pigmentation on the inner side. It has fertile pollen, and it can be used as a female and male parent in hybridizations (Fig. 5c).

Tubers

Elongated oval shape with shallow eyes, yellow skin with blue at the base of the eyes, medium yellow flesh (Fig. 5d), 70–160 mm long with a mean of 105 mm, 109 g of average weight per tuber, dormancy 90–100 days stored under diffused light at 10- 130C temp. Large sized and narrow cylindrical shaped light sprout, with medium anthocyanin pigmentation and medium pubescence at the base and tip, intermediate number of radicles and short lateral shoots (Fig. 5e), good quality for French fries (Figs. 5f).

CIP-PODEROSA WATIA

Plants

Growth habitat

Semi-upright growth habit of medium height (Fig. 6a) with medium maturity (120 days from planting to harvest).

Fig. 6
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CIP PODEROSA-WATIA: (a) Semi-upright growth habit of medium height, (b) compound leaf, (c) inflorescence, (d) skin and flesh color tuber, (e) broad cylindrical width light sprout, and (f) baked tubers

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Stems

Green, vigorous, with medium anthocyanin pigmentation.

Leaves

Intermediate green color, intermediate glossiness upper surface, medium size, intermediate opening, absent leaf edge waviness, medium presence of secondary leaflets, large size second pair of leaflets, absence of coalescence in terminal and lateral leaflets (Fig. 6b).

Flowers

Flower buds with medium anthocyanin pigmentation, medium flowering, medium inflorescences, peduncle with medium anthocyanin pigmentation. Corolla: medium size, light violet color, with absent or very weak anthocyanin pigmentation on the inner side. It has fertile pollen, and it can be used as a female and male parent in hybridizations (Fig. 6c).

Tubers

Short oval shape with slightly deep eyes, light red skin, cream flesh (Fig. 6d), 70–130 mm long with a mean of 90 mm, 102 g of average weight per tuber, dormancy 90–100 days stored under diffused light at 10-130C temperature. Large size and broad cylindrical width, light sprout, with strong anthocyanin pigmentation and weak pubescence at the base, weak anthocyanin pigmentation and medium pubescence at the tip, low number of radicles and medium lateral shoots (Fig. 6e), good quality for baking (Figs. 6f).

Tuber Yield

In the 2019–2020 and 2020–2021 growing seasons, 13 adaptation and efficiency trials were carried out in farmers' fields to meet the requirements of the Peruvian authority of seeds for the registration of new varieties: the National Service of Agricultural Health (SENASA, acronym of its Spanish name) (MINAGRI 2012). Field trials were carried out in northern Peru (La Paccha in Cajamarca; Chugay and Yanac in La Libertad); in central Peru (Chinchao in Huanuco; Quilcas, and Jauja in Junin); and in southern Peru (Majes and Santa Rita in Arequipa) (Table 1).

We used as controls the varieties: Canchan, susceptible to LB and UNICA, moderately resistant to LB (Forbes 2012, Gutiérrez-Rosales 2007) and for being the most used varieties for frying in Peru (Ordinola and Devaux 2021), but with variability in the frying color (MINAGRI 2020), due to its variability in the content of reducing sugars, which increases when they are planted at altitudes higher than 3000 m.a.s.l. where temperatures are cold.

A randomized complete blocks design with three replicates of 150 plants was used in each trial. Fertilizers were applied at 200–220-180 kg/ha, using ammonium nitrate (NH4NO3), diammonium phosphate ((NH4)2HPO4) and potassium sulfate (K2SO4) as sources of NPK. Pest control was carried out according to infestation of insects. LB control in new potato varieties was carried out with two contact fungicides sprays (mancozeb) (Calua and Otiniano 1999; Gastelo and Landeo 1999; Landeo et al. 2001; Sanabria et al. 2020; Pérez et al. 2020), while the control varieties INIA 303-CANCHAN and UNICA received eight fungicide applications ([mancozeb + (propineb + cymoxanil)]. All trials were planted in the rainy season, except in Arequipa where sprinkler irrigation was used.

The harvest was carried out 120 days after planting. Other agronomic practices were conducted following local customs. At harvest, weight of marketable tubers (extra > 120 g., first category from 91 to 120 g, second category from 61 to 90 g) and non-marketable tubers per experimental unit were registered and then total, extra, first and second tuber yield in tons per hectare (t/ha) was calculated. In addition, samples of tubers were taken and used in laboratory tests to determine dry matter and reducing sugars, glycoalkaloids, acrylamide contents, and frying color in French fries.

Total tuber yield of CIP-PODEROSA CROCANTE variety was 420 t/ha on average of the thirteen locations, with a range of 24.3 t/ha in Jauja (2020–2021) and 54.9 t/ha in Chugay (2019–2020). CIP-PODEROSA POLLERA variety obtained a total yield of 42.3 t/ha on average with a range of 26.0in Jauja (2020–021) and 54.6 t/ha in La Paccha (2019–2020). CIP-PODEROSA WATIA variety obtained a total tuber yield of 38.0 t/ha on average, being the lowest yield in Jauja (2020–2021) with 26.0 t/ha and the highest in Majes1 (Winter-spring season 2020–2021) with 52.2 t/ha. The total tuber yield of the three varieties was higher, statistically different (P < 0.01) to the control varieties INIA 303-CANCHAN and UNICA with 25.3 and 29.8 t/ha, respectively (Table 2).

Table 2 Marketable and total tuber yield of the three new varieties and two control varieties in thirteen locations, in 2019–2020 and 2020–2021 growing seasons
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The marketable tuber yield of CIP-PODEROSA CROCANTE variety was 38.1 t/ha on average of the thirteen locations, with a range of 23.4 t/ha in Jauja (2020–2021) and 50.5 t/ha in Chugay (2019- 2020). CIP-PODEROSA POLLERA variety obtained a marketable tuber yield of 36.2 t/ha on average with a range of 24.8 in Jauja (2020–021) and 44.8 t/ha in Majes (2019–2020). CIP-PODEROSA WATIA variety obtained a marketable tuber yield of 33.9 t /ha on average, with a range of 25.9 t/ha in Jauja (2020–2021) and 47.8 in Majes1 (Winter-spring season 2020–2021). The marketable tuber yield of the three varieties was higher, statistically different (P < 0.01) relative to the control varieties INIA 303-CANCHAN and UNICA with 21.2 and 26.0 t/ha, respectively (Table 2).

The tuber yield of the extra and first categories of the new varieties on average of the thirteen locations was statistically different (P < 0.01) than the control varieties INIA 303-CANCHAN and UNICA, the yield of second category tubers was higher in the control variety UNICA being statistically different to the new varieties and the control variety INIA 303-CANCHAN (Table 3).

Table 3 Tuber yield by category in grams and percentage of total weight by category on average of thirteen locations, 2019–2020 and 2020–2021 growing seasons
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The percentage of extra and first category tubers were 79.24%, 75.92%, and 75.99%, in varieties CIP-PODEROSA CROCANTE, CIP-PODEROSA POLLERA and CIP-PODEROSA WATIA, respectively (Table 3). This is an important characteristic for its use in French fries and in baked potatoes. Control varieties INIA 303-CANCHAN and UNICA obtained a percentage of extra and first category tubers of 64.08% and 66.74%, respectively.

Late Blight Resistance

Trials for variety registration in Peru must be carried out in areas where potato crop is important but not necessarily in areas with high LB pressure. LB resistance was determined in earlier field trials carried out between 1998 and 2008 (Gastelo et al. 2016a, b), and was validated in 2019–2020 and 2020–2021 growing seasons in La Paccha (Cajamarca) and Chinchao (Huanuco), where the conditions of temperature, relative humidity and rainfall were optimal to have a high pressure of the disease (Forbes et al. 2014). Control of LB in the new varieties was done with two contact fungicides sprays (mancozeb), while the control varieties INIA 303CANCHAN and UNICA required eight sprays ([mancozeb + (propineb + cymoxanil)] to obtain tuber yield potential. due to their susceptibility to LB. This information was very important for economic analysis which must be included in the official register of commercial varieties in Peru. If LB is not controlled in susceptible varieties, yield can be lost. Results obtained with INIA-303 Canchan grown in Chinchao (Huanuco) during 2019–2020 growing season indicated high AUDPC value (2933) (Table 4) despite having been sprayed eight times with fungicides. INIA 303-Canchan was released as resistant to late blight in 1990, however it rapidly became susceptible as the pathogen population evolved (Forbes 2012), and UNICA was released as moderate resistant to LB (Gutiérrez-Rosales et al. 2007). Both varieties are used as controls in different field trials (Sanabria et al. 2020; Gastelo et al. 2022; Pérez et al. 2020).

Table 4 Area under the disease progress curve (AUDPC) and standardized AUDPC (sAUDPC) values obtained by new varieties and control varieties during 2019–2020 and 2020–2021 growing seasons
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Table 4 shows the AUDPC and sAUDPC values obtained by three new varieties which were lower than values obtained by control varieties INIA-303 CANCHAN and UNICA. These results confirm higher levels of LB resistance of the three new varieties compared to popular varieties grown by farmers.

Dry Matter and Reducing Sugars Content

Dry matter content (%) was determined using the oven drying method (Naeem and Caliskan 2020). Two hundred fifty grams of tubers were cut into small cubes (fresh weight), placed in an oven at 100 °C for 72 h, and then the dry weight was registered. The percentage of dry matter was determined with the following formula:

$$\mathrm{DM\% \ in \ Oven \ drying \ method}=\left(\mathrm{Dry \ weight}/\mathrm{Fresh \ weight}\right)\times 100$$

Reducing sugars content (%) was determined using Accu-Chek(R) Active strips. The Accu-Chek Active kit is based on the principle of photometric determination of glucose by staining glucose with oxidoreductases or reaction by glucose dehydrogenase pyrrolquinolinequinone (PQQ). This kit shows results in quantitative values from 10 mg/dl to 600 mg/dl (Misener et al. 1996; Garcia et al. 2002; Pandey et al. 2009; Brandt 2012). The percentage of reducing sugar was calculated with the following formula:

$$\mathrm{Percentage \ reducing \ sugar}=0.000705 \left(\mathrm{Accu}-\mathrm{Chek \ value}\right)+0.00453.$$

Dry matter content obtained in the 2019–2020 and 2020–2021 growing seasons by CIP-PODEROSA CROCANTE, CIP-PODEROSA POLLERA, and CIP-PODEROSA WATIA ranged between 20.07 to 29.88%, 19.46 to 30.38%, and 20.51 to 26.51% respectively, Overall average (from thirteen locations) of dry matter percentages of the new varieties were higher than control varieties (Tables 5 and 12). The high values of dry matter in the three new varieties are sufficient to obtain quality products when frying and baking (Pandey et al. 2009).

Table 5 Dry matter content (%) in thirteen locations, 2019–2020 and 2020–2021 growing seasons
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Percentages of reducing sugars obtained in 2019–2020 and 2020–2021 growing seasons, are shown in Table 6, in which the new varieties had lower values than the maximum allowed (0.20%) to obtain a good frying color. INIA 303-CANCHAN variety had 0.39% of reducing sugars in Chugay 2020–2021 and the UNICA variety presented values greater than 0.20%, in La Paccha 2020–2021 (0.28%) and in Chugay 2019–2020 (0.20%). The low percentages of reducing sugars of the new varieties will allow them to have a good French fries color (Kummar et al. 2004).

Table 6 Reducing sugars content (%) in thirteen locations, 2019–2020 and 2020–2021 growing seasons
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Quality of French Fries

This test was carried out in CIP post-harvest laboratory in La Molina, Lima, Peru. Quality of fry color in French Fries was measured in strips of 9 mm caliber, and color of sticks was determined using the USDA French fry color scale (USDA 1967; Sabbaghi and Ziaiifar 2013). Scale degrees 1 and 2 indicate an acceptable color; scale degrees greater than 2 are considered an unacceptable color. Frying was performed immediately after harvest and in tubers stored under room conditions (14–16 °C) for 90 days after the harvest (in La Molina, Lima, Peru). These frying methods were compared to see their similarity or difference using Pearson correlation coefficients (α = 0.01) (Wang 2013). Frying process was carried out in two stages: 1) at 160 °C for three minutes and 2) at 180 °C for 2 min using vegetable oil.

The new varieties had excellent fry color immediately after harvest in all locations with grades 1 or 2, except in Chugay, where CIP-PODEROSA POLLERA variety had grade 3. The control varieties INIA 303-CANCHAN and UNICA presented color variability with values from 1 to 4 (Tables 7 and 8).

Table 7 Quality of fry color in French fries at harvest of three new varieties and two control varieties in thirteen locations, 2019–2020 and 2020–2021 growing seasons
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Table 8 Fry color of French Fries at harvest and 90 days after harvest of three new varieties and two control varieties in average of six locations in 2019–2020 growing season and seven locations in 2020.2021 growing season
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The correlation between fry color immediately after harvest (at harvest) and 90 days after harvest was high (r = 0.86) and statistically significant (P < 0.01). The new varieties CIP-PODERA CROCANTE, CIP-PODEROSA POLLERA and CIP-PODEROSA WATIA, had acceptable fry color ratings of 1 or 2 (Table 8, Fig. 7), which will allow having good quality tubers for seasons when there is no harvest of fresh tubers, a limitation in areas where there is only one rainy growing season (Agblor and Scanlon 2002).

Fig. 7
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Fry color of French Fries of CIP-PODEROSA CROCANTE, CIP-PODEROSA POLLERA, INIA 303-CANCHAN and UNICA varieties in the 2020–2021 growing seasons

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Quality for Baking

In 2019–2020 and 2002–2021 growing seasons, tuber baking tests were carried out at the CIP post-harvest laboratory, and in the field during harvest in Chugay and Yanac in the 2020–2021 growing season. Evaluations in the post-harvest laboratory in both growing seasons were carried out with a panel of three evaluators, who were trained for these sensory tests and have been collaborating with CIP for many years. In the field the panel consisted of six local evaluators.

A sample of 2 tubers for each variety was taken in each replicate from all locations, then washed with running water, dried with a paper towel, and then wrapped in aluminum foil. They were placed in an oven previously heated to 180ºC and then baked for 40 to 50 min. They were considered baked when they were easily penetrated by a stainless-steel probe.

Flavor (5 excellent, 3 good and 1 bad) and texture (5 floury, 3 intermediate and 1 watery), were evaluated using the scoring system described by De Haan et al. (2017) and Kadam et al. (1991). To determine the final score for each variety, scores assigned by each panel evaluator were added.

The variety CIP-PODEROSA WATIA obtained the highest score for both flavor and texture, followed by CIP-PODEROSA CROCANTE, CIP-PODEROSA POLLERA, and the control varieties INIA 303-CANCHAN and UNICA (Table 9). In addition to its resistance to LB, high tuber yield, the CIP-PODEROSA WATIA variety obtained excellent quality for baking.

Table 9 Values for flavor and texture of baked tubers in three new varieties and two control varieties during 2019–2020 and 2020–2021 growing seasons
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Acrylamide Content

Acrylamide is a carcinogenic compound found in foods that have been fried, baked, or toasted, related to the darkening of the product and is formed from the reaction of reducing sugars with the amino acid asparagine at temperatures above 120 °C (Maillard reaction) (Zúñiga and Pedreschi 2009; Tajner-Czopek et al. 2021; Mesias et al. 2020). In commercial fried potato production is a crucial challenge for the food industry.

Acrylamide content was determined in 1 kg of French Fries, from five locations harvested in the 2020–2021 growing season (Table 10). Samples were sent to the AGQ Labs Peru SAC laboratory to determine the acrylamide content, using the method of liquid chromatography and mass spectrometry ( LC–MS) based on the method developed by the Food and Drug administration (FDA) U.S. (https: // www.fda.gov/food/chemicals/detection-and-quantitation-acrylamide-foods). Subsamples of 200 g were taken from sample of 1 kg, which have a limit of quantification of 30 µgkg−1 and a confidence level 95%. Acrylamide content of new varieties at all locations was less than 500 µg acrylamide/kg French Fries, the maximum limit established by the European Union (http://data.europa.eu/eli/reg/2017/2158/oj (Tables 10 and 12). These values ​​are related to low contents of reducing sugars in the different localities (< 0.20%). In comparison, control variety INIA 303-CANCHAN at Chugay presented values above maximum permitted limit and UNICA variety also had high values in Chugay and La Paccha, where their reducing sugar content was also high, probably because these localities are located above 3400 m.a.s.l. (Table 1) in which lower temperatures increase reducing sugar content. Control varieties were not stable for this character in comparison to the new varieties which show stability for reducing sugar content in all localities. A positive and statistically significant correlation (r = 0.68) (P < 0.01) was found between reducing sugars percentage and acrylamides content. These results demonstrate that the three new varieties are healthier for consumers due to their lower acrylamide content compared to control varieties.

Table 10 Acrylamide content in French Fries, 2020–2021 growing season
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Glycoalkaloid Content

Climate change is affecting weather patterns in traditional potato growing areas, where unpredictable rainfall and higher temperatures increase pressure by pests and diseases and reduce tuber yield (Hijmans 2003). Other effects reported are a greater frequency of tuber disorders such as second growth, growth cracks, sprouting, deformations and raised glycoalkaloid content (Levy and Veilleux 2007). High levels of glycoalkaloids can produce a bitter taste and can be unsafe for human consumption at levels exceeding 20 mg/per 100 g fresh weight of potatoes (Storey and Davies 1992; Ruprich et al. 2009).

At harvest, 15 tubers of each sample were collected and sent to Quality and Nutrition Laboratory in CIP-Lima, Peru, for glycoalkaloid analysis. Freeze-dried and milled samples of each tuber were prepared and stored at − 20 °C until analysis. Total glycoalkaloid analysis was performed using the method described by Burgos et al. (2014) in which glycoalkaloid extraction was executed using methanol and chloroform following a concentration process at 60 °C in a rotary evaporator. The extract was transferred to a 2% acetic acid solution and then purified using ammonium hydroxide at 85 °C and ultracentrifugation at 27,000 rpm. The pellet was placed in reaction with 85% orthophosphoric acid and read at 408 nm in a spectrophotometer. The determination of total glycoalkaloids was achieved against a standard curve of α-chaconine as reference. New varieties and control varieties presented less than 20 mg/100 g fresh weight, the maximum limit so that they do not affect people's health (Tables 11 and 12). The varieties CIP-PODEROSA CROCANTE and CIP-PODEROSA POLLERA presented relatively high values in Chugay at 3712 m.a.s.l. (Tables 1 and 11) in the 2020–2021 growing season, since in this campaign there were periods of drought and frost, probably causing stress in these varieties increasing their total glycoalkaloid contents compared to the 2019–2020 season. Despite these unfavorable conditions, the new varieties did not exceed the maximum limit allowed.

Table 11 Glycoalkaloid content in potato tubers determined in the 2019–2020 and 2020–2021 growing seasons
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Table 12 Average values of quality characters in new potato varieties and popular control varieties obtained in the 2019–2020 and 2020–2021 growing seasons
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CIP-PODEROSA CROCANTE, CIP-PODEROSA POLLERA and CIP-PODEROSA WATIA varieties combine several favorable characters to have a good frying color and maintain their quality for up to three months after harvest, as well as their low content of acrylamides and glycoalkaloids in addition to the lower use of fungicides to control LB, which helps to preserve the health of farmers and consumers and reduce the impact on the environment (Table 12).

Economic Profitability

The economic profitability of new potato varieties was determined taking as reference the production costs and sale price in Peru.

The profitability per hectare in percentage, was calculated both in the new varieties and in the control varieties, using the following formulas for each of the 13 localities:

$$\begin{array}{l}\mathrm{Profitability }(\mathrm{\%})=\left(\mathrm{Net \ income}/\mathrm{cost \ of\ production}\right)\times 100\\ \mathrm{Net\ income}=\mathrm{Total \ income}-\mathrm{Cost \ of \ production}\\ \mathrm{Total \ income}=\mathrm{Commercial \ yield \ per \ hectare}\times \mathrm{sale \ price}\end{array}$$

The sale price of US$ 0.26 was considered for the control varieties and US$ 0.21 for the new varieties. A lower price was considered for the new varieties because they are not yet well known by the final consumer.

Finally, the profitability of the thirteen locations was averaged to obtain the average profitability of each variety.

The profitability of three new varieties was approximately twice the profitability of popular varieties INIA 303-CANCHAN and UNICA, as is showed in Table 13. CIP-PODEROSA CROCANTE variety had an average profitability of 84.2%, i.e.., for each dollar invested it is possible to have a return of 0.84 dollars, which is higher than the profitability obtained for the control varieties. The same occurs with the varieties CIP-PODEROSA POLLERA and CIP-PODEROSA WATIA (Table 13). A factor that influences profitability is the reduction of production costs in the new varieties due to the lower use of fungicides compared to the control varieties that used more fungicide to control LB.

Table 13 Economic profitability of three new varieties compared to popular varieties in Peru, 2019–2020 and 2020–2021 growing season
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Conclusions

  • CIP-PODEROSA CROCANTE, CIP-PODEROSA POLLERA and CIP-PODEROSA WATIA have been released as new potato varieties in Peru in 2022 due to their high horizontal resistance to LB, high tuber yield, excellent quality for French fries and baking, high percentage of dry matter and low content of reducing sugars, glycoalkaloids and acrylamides. These new varieties are superior to INIA 303-CANCHAN and UNICA, popular Peruvian potato varieties which are preferred by consumers for fresh and fried consumption, but they are susceptible and moderate resistant to LB respectively. The new varieties have been registered in National Register of Commercial Varieties of Peru—REGISTERS N° 001, 002 and 003–2023-MIDAGRI-SENASA-DELYC.

  • CIP-PODEROSA CROCANTE, CIP-PODEROSA POLLERA and CIP-PODEROSA WATIA varieties are beneficial for both producer and consumer because they require less fungicides to control LB. These varieties can be used for family and commercial farming systems because they help preserve the environment, are economically profitable and help improve the living standards of potato producers.