Acessibilidade / Reportar erro

Yam tubers yield and quality subjected to nitrogen doses and staking methods1 1 Research developed at Areia, PB, Brazil

Produção e qualidade de túberas do inhame submetido a doses de nitrogênio e tipos de tutoramento

ABSTRACT

Adequate mineral fertilization and staking are necessary to obtain good productivity in yam cultivation. The objective of this study was to determine the increase in yield and quality of yams subjected to nitrogen doses and staking methods. This study was carried out under field conditions using a randomized block design in a 5 × 3 factorial scheme, with five nitrogen doses (0, 50, 100, 150 and 200 kg ha-1) and three staking methods (wire trellises, single staking, and without staking) with four replicates. Nitrogen doses were applied in topdressing, and split into equal parts at 60 and 90 days after seed tuber planting. Tuber length and weight, starch and leaf nitrogen concentrations, and total and marketable yields were determined. Staking promoted higher total yield, mass, length, and leaf nitrogen concentration, but no changes were observed in starch concentration among the staking methods. Commercial productivity was higher with single staking. Planting yam with staking and a nitrogen dose of 120.70 kg ha-1 is recommended to promote maximum productivity.

Key words:
Dioscorea cayennensis; tuber; mineral nutrition; development

RESUMO

No cultivo do inhame a adubação mineral e o uso de tutoramento proporciona boa produção. O objetivo deste trabalho foi avaliar a produção e a qualidade do inhame submetidos a doses de nitrogênio e tipos de tutoramento. O trabalho foi realizado em condições de campo no delineamento experimental em blocos casualizados em esquema fatorial 5 × 3, com cinco doses de nitrogênio (0, 50, 100, 150 e 200 kg ha-1) e três tipos de tutoramento (espaldeiramento, vara e sem tutor), com quatro repetições. Na adubação em cobertura foram aplicadas as doses de nitrogênio parceladas em partes iguais aos 60 e 90 dias após o plantio. Foram avaliados comprimento, massa média, teores de amido e N foliar, produtividades total e comercial de túberas. O tutoramento promoveu maior rendimento total, massa média, comprimento e teor de nitrogênio foliar, entretanto não foram observadas alterações no teor de amido entre os tipos de tutoramento. A produtividade comercial é maior com a utilização do tutor em vara. Recomenda-se o plantio do inhame com tutoramento e dose de nitrogênio de 120,70 kg ha-1 para promover a máxima produtividade.

Palavras-chave:
Dioscorea cayennensis; tubérculo; nutrição mineral; desenvolvimento

HIGHLIGHTS:

The maximum marketable yield of the yam is obtained with staking.

Nitrogen provides tubers with commercial standard mass.

Nitrogen and the staking promotes the potential of cultivar Da Costa to produce more than 15 tons ha-1 in Entisol.

Introduction

Yam (Dioscorea spp.) cultivation in Brazil has great socio-economic importance because of its use in human consumption and profitability. The most widely cultivated species in the Northeast Region are yellow yam (Dioscorea cayennensis Lam.) and water yam (Dioscorea alata L.) (Lovera et al., 2020Lovera, M.; Castro, G. M. C. de; Pires, N. da R.; Bastos, M. do S. R.; Holanda-Araújo, M. L.; Laurentin, A.; Moreira, R. de A.; Oliveira, H. D. de. Pyrodextrinization of yam (Dioscorea sp.) starch isolated from tubers grown in Brazil and physicochemical characterization of yellow pyrodextrins. Carbohydrate Polymers, v.242, p.116382, 2020. https://doi.org/10.1016/j.carbpol.2020.116382
https://doi.org/10.1016/j.carbpol.2020.1...
), both of which contribute to the economic development of the Paraíba, Pernambuco, Sergipe, Alagoas, Bahia, and Maranhão states, because of their participation in farmers’ income and local commerce (Brito et al., 2011Brito, T. T. de; Soares, L. S.; Furtado, M. C.; Castro, A. A.; Carnelossi, M. A. G. Composição centesimal de inhame (Dioscorea sp.) in natura e minimamente processado. Scientia Plena, v.7, p.1-7, 2011. ).

However, the expansion of yam agribusiness in producing states is still limited, mainly because of the lack of scientific information required to increase productivity. Thus, research aimed at technologies that favor cultivation and nutritional management is essential to increase the productivity of this crop (Oliveira et al., 2015Oliveira, A. P. de; Silva, O. P. R.; Leonel, M.; Guimarães, L. M. P.; Andrade, G. P. Inhame (Dioscorea spp). In: Leonel, M.; Fernandes, A. M.; Franco, C. M. L. Culturas amilaceas: batata-doce, inhame, mandioca e mandioquinha-salsa. Botucatu: Cerat/Unesp, 2015. Cap.2, p.121-170. ).

Nitrogen is one of the most essential nutrients for plant growth and development, given its role in protein composition and metabolic processes (Filgueira, 2008Filgueira, F. A. R. Novo Manual de Olericultura: Agrotecnologia moderna na produção e comercialização de hortaliças. 3.ed. Viçosa: UFV, 2008. 421p.; Leghari et al., 2016Leghari, S. J.; Wahocho, N. A.; Laghari, G. M.; Hafeezlaghari, A.; Mustafabhabhan, G.; Hussaintalpur, K.; Lashari, A. A. Role of nitrogen for plant growth and development: A review. Advances in Environmental Biology, v.10, p.209-219, 2016.). During cultivation, yam plant staking promotes tuber production because it allows the yam leaves to be adequately positioned for greater photosynthetic efficiency (Saravaiya et al., 2013Saravaiya, S. N.; Chaudhari, B. N.; Mais, S. J.; Tekale, G. S.; Jarande, S. D. Performance of greater yam (Dioscorea alata L.) under different staking systems. Journal of Root Crops, v.39, p.250-254, 2013. ). However, single staking and wire trellises are the most frequently used staking methods during yam cultivation in the Northeast Region (Oliveira et al., 2015Oliveira, A. P. de; Silva, O. P. R.; Leonel, M.; Guimarães, L. M. P.; Andrade, G. P. Inhame (Dioscorea spp). In: Leonel, M.; Fernandes, A. M.; Franco, C. M. L. Culturas amilaceas: batata-doce, inhame, mandioca e mandioquinha-salsa. Botucatu: Cerat/Unesp, 2015. Cap.2, p.121-170. ), because of the following two reasons: the cost and the traditional areas for planting yams being located in the vicinity of the Atlantic Forest. As a result, the producer chooses to use wood obtained from the forest to carry out the single staking of the plants, damaging local biodiversity when exploited constantly.

Yam quality is directly related to the balanced nitrogen nutrition (Dantas et al., 2013Dantas, D. F. S. da; Oliveira, A. P. de; Dantas, T. A. G.; Bandeira, N. V. S. da; Gomes Neto, A. D. Produção do inhame adubado com doses de N e esterco bovino. Semina: Ciências Agrárias, v.34, p.3389-3396, 2013. https://doi.org/10.5433/1679-0359.2013v34n6Supl1p3389
https://doi.org/10.5433/1679-0359.2013v3...
). Thus, this study aimed to determine the increase in yield and quality of yam tubers subjected to nitrogen doses and staking methods.

Material and Methods

The experiment was conducted under field conditions in the experimental area of the Centro de Ciências Agrárias, Universidade Federal da Paraíba, from February to December 2017.

The experimental area is located in the municipality of Areia, Paraíba, Brazil, in the Brejo Paraibano Microregion, at an altitude of 574.62 m, latitude 6° 57’ 26” S and longitude 35° 45’ 31” W. According to Köppen’s classification, the predominant climate is As’, characterized as hot and humid, with autumn-winter rains, and an average annual precipitation of 1.200 mm (Francisco et al., 2015Francisco, P. R. M.; Medeiros, R. M. de; Santos, D. Oscilações pluviométricas dentre os regimes diferenciados de precipitação no Estado da Paraíba. Revista Brasileira de Agricultura Irrigada, v.9, p.360-371, 2015. https://doi.org/10.7127/rbai.v9n600354
https://doi.org/10.7127/rbai.v9n600354...
). The soil of the experimental area is classified as Entisol, with a sandy loam texture (Santos et al., 2018Santos, H. C. dos; Jacomine, P. K. T.; Anjos, L. H. C. dos; Oliveira, V. A.; Lumbreras, J. F.; Coelho, M. R.; Almeida, J. A. de; Araújo Filho, J. C. de; Oliveira, J. B. de; Cunha, T. J. F. Sistema brasileiro de classificação de solos. 5.ed. rev. e ampl. Brasília: Embrapa, 2018. 356p.). Meteorological data (INMET Automatic Weather Station of Areia, PB, Brazil) during the experimental period are presented in Figure 1.

Figure 1
Average meteorological variables during cultivation of yam cultivar Da Costa

The experimental design comprised randomized blocks, with treatments distributed in a 5 × 3 factorial scheme, with five nitrogen doses (0, 50, 100, 150 and 200 kg ha-1), and three staking methods (wire trellises, single staking, and without staking), in four replicates. The experimental units were composed of 50 plants distributed in five rows at 1.20 × 0.60 m spacing. However, only the 24 plants in the three central rows were evaluated. Planting fertilization, 10 tons ha-1 of cattle manure, 70 kg ha-1 of P2O5 (simple superphosphate) and 60 kg ha-1 of K2O (potassium chloride) were supplied (Cavalcante et al., 2008Cavalcante, F. J. de A.; Santos, J. C. P.; Pereira, J. R.; Leite, J. P.; Silva, D. J. da; Sousa, A. R. de; Messias, A. S.; Faria, C. M. B.; Burgos, N.; Lima Júnior, M. A.; Gomes, R. V.; Cavalcanti, A. C.; Lima, J. F. W. F. Recomendações de adubação para o Estado de Pernambuco: 2ª aproximação. 3.ed. Recife: Instituto Agronômico de Pernambuco. 2008. 212p.). The N doses were applied in topdressing in equal parts 60 and 90 days after yam planting, as described in the experimental design.

Soil samples were collected at 0-20 cm depth, before the experiment was set up for analyzing the chemical and physical attributes of the soil (Table 1).

Table 1
Chemical and physical properties of the experimental area soil

Tuber seeds of Da Costa yam cultivar (approximately 200 g) were sown at a depth of 10 cm at the top of the soil mound. During cultivation, weeds were controlled with hoes, and in the period without precipitation, a supplemental drip irrigation system was used in a two-day irrigation shift, with water depths of 5 mm per day and a flow rate of 2 L hour-1, with space between tapes and emitters, according to the experimental spacing.

Stakes of Mimosa caesalpiniaefolia (L.) 1.50 m in length were purchased and inserted alongside the plants at the tuber emergence time as the single staking method. The wire trellises staking method was also composed ofM. caesalpiniaefolia canes 2.0 to 2.20 m in length and buried at 0.50 m depth. During seedling development, a string was tied around the basal stem up to the espalier wire, as described by Oliveira et al. (2015Oliveira, A. P. de; Silva, O. P. R.; Leonel, M.; Guimarães, L. M. P.; Andrade, G. P. Inhame (Dioscorea spp). In: Leonel, M.; Fernandes, A. M.; Franco, C. M. L. Culturas amilaceas: batata-doce, inhame, mandioca e mandioquinha-salsa. Botucatu: Cerat/Unesp, 2015. Cap.2, p.121-170. ).

The harvest occurred 210 days after tuber seeds were sown, when the tubers were immature, which is characterized by the end of flowering and senescence of the flowers, called the first harvest or “milking.” The tuber length and mass, total and marketable tuber yield, tuber starch, and leaf nitrogen concentration were determined.

The length was obtained by measuring all marketable tubers with a ruler, and the values were expressed in centimeters. The marketable tuber mass was obtained by dividing the plot production by the number of marketable tubers, and the results were expressed in kilograms. Total yield corresponded to the weight of all harvested tubers, and marketable yield corresponded to the weight of tubers ranging from 0.7 to 3.0 kg, as described by Santos (1996Santos, E. S. dos. Inhame (Dioscores ssp.) aspectos básicos da cultura. 1.ed. João Pessoa: EMEPA-PB, 1996, 158p. ), with data expressed in tons per hectare (tons ha-1).

Fresh tuber samples (1.0 kg) were randomly collected to assess the starch content, according to the analytical standards of the Adolfo Lutz Institute (2005Instituto Adolfo Lutz. Normas analíticas do Instituto Adolfo Lutz: métodos físicos e químicos para análises de alimentos. 4.ed. São Paulo: Instituto Adolfo Lutz, 2005. 1020p.). At 150 days after planting, 20 leaves from the middle portion of shoots were collected from each treatment and replicated, to evaluate the leaf N concentration, according to the methodology described by Tedesco et al. (1995Tedesco, M. J.; Gianello, C.; Bissani, C. A.; Bohnen, H.; Volkweiss, S. J. Análise de solo, planta e outros materiais. 2.ed. Porto Alegre: UFRGS, 1995. 174p.).

The results were subjected to analysis of variance (ANOVA) and polynomial regression to test the linear and quadratic models. The values of each staking method were compared at each nitrogen dose level by the Tukey test (p ≤ 0.05). The criteria for choosing the model were the significance of the F test (p ≤ 0.05) and a coefficient of determination (R2) greater than 0.60. Statistical analyses were performed using the statistical program R (R Core Team, 2021R Core Team. R: A language and environment for statistical computing. Vienna: R Foundation for Statistical Computing, 2017. Available on: <Available on: https://www.r-project.org/ >. Accessed on: Aug. 2018.
https://www.r-project.org/...
).

Results and Discussion

There was a significant interaction effect (p ≤ 0.05) on the length, marketable tuber mass, and marketable yield, with isolated effects of the factors on total yield, leaf nitrogen, and starch concentration of the yam cultivar Da Costa (Table 2).

Table 2
Summary of the analysis of variance for tuber length (TL), marketable tuber mass (TM), starch concentration (SC), leaf nitrogen concentration (NC), total yield (TY) and marketable yield (MY) of yam cv. Da Costa, fertilized with nitrogen and different methods of staking

Nitrogen doses of 118.33 and 129.75 kg ha-1 promoted the production of yam tubers with 23.6 and 24.37 cm in length, on wire trellises and single staking, respectively (Figure 2). When the plants were not staked, the tubers reached only 15.5 cm, at a dose of 118.75 kg ha-1. Staking promoted greater tuber length, regardless of the nitrogen dose applied, with emphasis on single staking, which resulted in higher lengths at doses of 0 and 200 kg ha-1 nitrogen. Similar results were reported by Carvalho et al. (2014Carvalho, E.; Sampaio, H. S. de V.; Santos, J. A. S.; Passos, A. R. Alternativas de tutoramento e uso de mulching plástico na cultura do inhame (Dioscorea rotundata Poir) fertirrigada por gotejamento. Magistra, v.26, p.416-423, 2014. ), who found a positive effect of staking methods on marketable tuber length.

Figure 2
Yam marketable tubers length in function of nitrogen doses in three staking methods

Nitrogen fertilization associated with staking promoted greater tuber length because this nutrient helps increase chlorophyll concentration, resulting in a greater net rate of photosynthesis, as well as increasing plant metabolism enzymes. Consequently, nitrogen fertilization improves the exposure of plants to sunlight and provides a higher photosynthetic rate (Nunes et al., 2016Nunes, A. R. A.; Fernandes, A. M.; Leonel, M.; Garcia, E. L.; Magolbo, L. A.; Carmo, E. L. do. Nitrogênio no crescimento da planta e na qualidade de raízes da mandioquinha-salsa. Ciência Rural, v.46, p.242-247, 2016. https://doi.org/10.1590/0103-8478cr20150339
https://doi.org/10.1590/0103-8478cr20150...
; Binang et al., 2017Binang, W. B.; Ojikpong, T. O.; Takim, F. O. Nodulation, Biomass production and yield of some indigenous legumes as influenced by rhizobium inoculation in the rainforest agro-ecological zone of Nigeria. Journal of Applied Life Sciences International, v.11, p.1-9, 2017. https://doi.org/10.9734/JALSI/2017/32624
https://doi.org/10.9734/JALSI/2017/32624...
; Abas et al., 2020Abas, N.; Kalair, E.; Kalair, A.; Hasan, Q. U.; Khan, N. Nature inspired artificial photosynthesis technologies for hydrogen production: Barriers and challenges. International Journal of Hydrogen Energy, v.45, p.20787-20799, 2020. https://doi.org/10.1016/j.ijhydene.2019.12.010
https://doi.org/10.1016/j.ijhydene.2019....
). In the absence of staking, self-shading may have occurred, making it difficult for plants to absorb solar radiation, resulting in reduced photosynthesis and less starch storage in tubers. Further, self-shading also forms a microclimate favorable for the development of fungal diseases, which indirectly affects tuber growth (Carvalho et al., 2014Carvalho, E.; Sampaio, H. S. de V.; Santos, J. A. S.; Passos, A. R. Alternativas de tutoramento e uso de mulching plástico na cultura do inhame (Dioscorea rotundata Poir) fertirrigada por gotejamento. Magistra, v.26, p.416-423, 2014. ; Norman et al., 2015Norman, P. E.; Whyte, J. B. A.; Samura, A. E.; Massaquoi, A.; Sesay, L.; Dixon, A. G.; Fomba, S. N.; Benya, M. T.; Sowa, M. M. Effect of staking and non-staking systems on disease severity, yield and quality attributes of yams (Dioscorea alata). Journal of Agriculture and Ecology Research International, v.1, p.219-229, 2015. https://doi.org/10.9734/JAERI/2015/14713
https://doi.org/10.9734/JAERI/2015/14713...
).

Tuber mass presented a quadratic behavior, and the nitrogen doses of 105 and 155 kg ha-1 promoted mean tuber mass of 1.39 and 1.43 kg, under single staking and wire trellises, respectively, with mean tuber mass of 0.8 kg in the method without staking (Figure 3). The staking methods showed no difference in the nitrogen doses applied. The tubers in all staking methods showed a commercial standard, due to their weight ranging from 0.7 to 3.0 kg, as described by Santos et al. (1996Santos, E. S. dos. Inhame (Dioscores ssp.) aspectos básicos da cultura. 1.ed. João Pessoa: EMEPA-PB, 1996, 158p. ). In contrast to the results obtained by Ennin et al. (2014Ennin, A.; Issaka, R. N.; Acheampong, P. P.; Numafo, M.; Danquah, E. O. Mechanization, fertilization and staking options for environmentally sound yam production. African Journal of Agricultural Research, v.9, p.2222-2230, 2014. https://doi.org/10.5897/AJAR2014.8487
https://doi.org/10.5897/AJAR2014.8487...
), the use of staking promoted greater accumulation of tuber mass.

Figure 3
Marketable yam tuber mass in function of nitrogen doses in two staking methods

The shortest tuber length was obtained using methods without staking, probably due to the contact of plant meristematic regions with the soil, causing blighting, in addition to inadequate disposition of leaves, which affected photosynthesis and resulted in low storage of plant photoassimilates (Saravaiya et al., 2013Saravaiya, S. N.; Chaudhari, B. N.; Mais, S. J.; Tekale, G. S.; Jarande, S. D. Performance of greater yam (Dioscorea alata L.) under different staking systems. Journal of Root Crops, v.39, p.250-254, 2013. ; Carvalho et al., 2014Carvalho, E.; Sampaio, H. S. de V.; Santos, J. A. S.; Passos, A. R. Alternativas de tutoramento e uso de mulching plástico na cultura do inhame (Dioscorea rotundata Poir) fertirrigada por gotejamento. Magistra, v.26, p.416-423, 2014. ).

Regardless of the staking method, the increase in the weight of tubers in response to nitrogen can be attributed to its influence on the concentration of chlorophyll, where it absorbs light energy to oxidize water, releasing oxygen, and producing NADPH and ATP; these are used to reduce carbon dioxide to form sugars, as well as to promote an increase in the starch enzyme synthetase in plants, promoting the rate of starch accumulation in tubers (Abas et al., 2020Abas, N.; Kalair, E.; Kalair, A.; Hasan, Q. U.; Khan, N. Nature inspired artificial photosynthesis technologies for hydrogen production: Barriers and challenges. International Journal of Hydrogen Energy, v.45, p.20787-20799, 2020. https://doi.org/10.1016/j.ijhydene.2019.12.010
https://doi.org/10.1016/j.ijhydene.2019....
; Du et al., 2020Du, X.; Zhang, X.; Xi, M.; Kong, L. Split application enhances sweet potato starch production by regulating the conversion of sucrose to starch under reduced nitrogen supply. Plant Physiology and Biochemistry, v.151, p.743-750, 2020. https://doi.org/10.1016/j.plaphy.2020.04.027
https://doi.org/10.1016/j.plaphy.2020.04...
).

Staking promoted a greater total yield regardless of the dose applied (Figure 4B). The maximum total productivity of 16.8 tons ha-1 was obtained at a dose of 115.63 kg ha-1, regardless of the staking method (Figure 4A). The simple staking method promoted higher marketable yield of tubers at all nitrogen doses, except for the application of 50 and 150 kg ha-1, which was statistically similar to wire trellises.

Figure 4
Total yield of yam tubers in function of nitrogen doses (A) and at each staking methods (B)

The two staking methods, in the same order together with the nitrogen doses of 111.58 and 120.70 kg ha-1, promoted the highest marketable yields of 15.5 and 16.6 tons ha-1, whereas, without staking, only 7.1 tons ha-1 was obtained (Figure 5).

Figure 5
Total and marketable yield of yam tubers in function of nitrogen doses at each staking methods

Single staking provided increments of 3.4% and 28% in total yield, and 6.6% and 57% in marketable productivity, compared to staking with wire trellises and without staking. The marketable yields of staked yam in this study were above the average yield in the state of the Northeast region, with an average productivity of 9.6 tons ha-1 (Garrido et al., 2017Garrido, M. da S.; Soares, A. C. F.; Menezes, R. S.; Sampaio, E. V. de S. B.; Souza, E. M. da S.; Macedo, B. L. do N. Quality and yield of yam tubers cultivated with green manure in the Northeastern Brazil. Comunicata Scientiae, v.8, p.275-280, 2017. https://doi.org/10.14295/cs.v8i2.1725
https://doi.org/10.14295/cs.v8i2.1725...
).

Although the highest yields were obtained with single staking, according to Oliveira et al. (2015Oliveira, A. P. de; Silva, O. P. R.; Leonel, M.; Guimarães, L. M. P.; Andrade, G. P. Inhame (Dioscorea spp). In: Leonel, M.; Fernandes, A. M.; Franco, C. M. L. Culturas amilaceas: batata-doce, inhame, mandioca e mandioquinha-salsa. Botucatu: Cerat/Unesp, 2015. Cap.2, p.121-170. ), this method caused problems to the ecosystem in some yam producer states of the Northeast region, since they are usually taken from native species of the Atlantic Forest, causing an environmental disequilibrium. According to the same authors, the use of stakes obtained from species are from areas under management, such as the sabiá tree (Mimosa caesalpiniaefolia L.) or common bamboo (Bambusa vulgaris).

Nitrogen fertilization promoted yield increment regardless of the staking method, an effect already reported by Dantas et al. (2013Dantas, D. F. S. da; Oliveira, A. P. de; Dantas, T. A. G.; Bandeira, N. V. S. da; Gomes Neto, A. D. Produção do inhame adubado com doses de N e esterco bovino. Semina: Ciências Agrárias, v.34, p.3389-3396, 2013. https://doi.org/10.5433/1679-0359.2013v34n6Supl1p3389
https://doi.org/10.5433/1679-0359.2013v3...
) and Rezaei et al. (2017Rezaei, A. Q.; Kikuno, H.; Babil, P.; Tanaka, N.; Park, B. J.; Onjo, M.; Shiwachi, H. Nitrogen-fixing endophytic bacteria is involved with the lesser yam (Dioscorea esculenta L.) growth under low fertile soil condition. Tropical Agriculture and Development, v.61, p.40-47, 2017.). The yam yield increment provided by nitrogen fertilization via topdressing was also reported by Oliveira et al. (2007Oliveira, A. P. de; Barbosa, L. J. das N.; Pereira, W. E.; Silva, J. E. L. da; Oliveira, A. N. P. de. Produção de rizóforos comerciais de inhame em função de doses de nitrogênio. Horticultura Brasileira, v.25, p.73-76, 2007. https://doi.org/10.1590/S0102-05362007000100014
https://doi.org/10.1590/S0102-0536200700...
) and Santos et al. (2015Santos, F. N. dos; Oliveira, A. P. de; Araújo, J. R. G.; Silva, O. P. R. da; Silva, D. T. de A. F.; Medeiros, D. A. Response of yams exposed to different sources and doses of nitrogen fertilizers in the State of Maranhão, Brazil. Semina: Ciências Agrárias , v.36, p.3605-3614, 2015. https://doi.org/10.5433/1679-0359.2015v36n6p3605
https://doi.org/10.5433/1679-0359.2015v3...
), with production ranging from 120 to 154.3 kg ha-1.

The nitrogen doses recommended for yam cultivation in the Northeast region are between 50 and 100 kg ha-1 (Filgueira, 2008Filgueira, F. A. R. Novo Manual de Olericultura: Agrotecnologia moderna na produção e comercialização de hortaliças. 3.ed. Viçosa: UFV, 2008. 421p.). Thus, nitrogen doses that promoted the maximum yields were slightly above these intervals, demonstrating that in the edaphoclimatic conditions of Areia - PB, this nutrient must be supplied above the dose recommendations.

Recommendations for nitrogen fertilization in yams are complex. This can be attributed to the dynamics of nitrogen transformations in the soil, its mobility, and the factors that influence its absorption by plants (Malavolta et al., 2006Malavolta, E. Manual de nutrição de plantas. 1.ed. São Paulo: Ceres, 2006. 638p.; Silva et al., 2017Silva, J. B. G.; Martinez, M. A.; Matos, A. T. de; Pires, C. S.; Terração, G. Mobilidade dos íons nitrato e amônio em área agrícola sob adubação com água residuária de bovinocultura de leite e torta de mamona. Revista Engenharia na Agricultura-Reveng, v.25, p.200-211, 2017. https://doi.org/10.13083/reveng.v25i3.678
https://doi.org/10.13083/reveng.v25i3.67...
). However, reductions in total and marketable yields at doses above those responsible for maximum yields may indicate that the excess of this nutrient is harmful to plant development. Moreover, how it produces intense dynamics in the soil can be attributed to many reasons, such as toxicity due to excess ammonium, as this favors the formation of reactive oxygen species and unbalances the cell pH, as well as, due to the source used (ammonia), it promotes a reduction in the absorption of metallic micronutrients; on the other hand, as it is a soil with low acidity and aerated, there is the possibility that this ammonium was oxidized to nitrate by nitrification and, in this case, decreased the absorption of phosphorus, sulfur, boron, and molybdenum (Miller & Cramer, 2005Miller, A. J.; Cramer, M. D. Root nitrogen acquisition and assimilation. Plant Soil, v.274, p.1-36, 2005. https://doi.org/10.1007/1-4020-4099-7_1
https://doi.org/10.1007/1-4020-4099-7_1...
; Malavolta, 2006; Liu et al., 2017Liu, Y.; Wiren, N. V. Ammonium as a signal for physiological and morphological responses in plants. Journal of Experimental Botany, v.68, p.2581-2592, 2017. https://doi.org/10.1093/jxb/erx086
https://doi.org/10.1093/jxb/erx086...
; Abas et al., 2020Abas, N.; Kalair, E.; Kalair, A.; Hasan, Q. U.; Khan, N. Nature inspired artificial photosynthesis technologies for hydrogen production: Barriers and challenges. International Journal of Hydrogen Energy, v.45, p.20787-20799, 2020. https://doi.org/10.1016/j.ijhydene.2019.12.010
https://doi.org/10.1016/j.ijhydene.2019....
).

The use of staking methods, regardless of the applied nitrogen dose, promoted greater nitrogen leaf content (Figure 6B). Leaf N concentration increased linearly in response to the nitrogen doses, reaching a maximum value of 23.1 g kg-1 at the highest dose (Figure 6A). These values are below the variation range (40-45 g kg-1), described as normal for this crop, according to Malavolta et al. (2006Malavolta, E. Manual de nutrição de plantas. 1.ed. São Paulo: Ceres, 2006. 638p.). However, visual difference was observed only in the plants without staking.

Figure 6
Nitrogen leaf concentration of yam plants in function of nitrogen doses (A) and at each staking methods (B)

The linear behavior of N concentrations in leaves indicated that the nitrogen doses did not reach the saturation level of absorption by plants, a fact also described by Oliveira et al. (2007Oliveira, A. P. de; Barbosa, L. J. das N.; Pereira, W. E.; Silva, J. E. L. da; Oliveira, A. N. P. de. Produção de rizóforos comerciais de inhame em função de doses de nitrogênio. Horticultura Brasileira, v.25, p.73-76, 2007. https://doi.org/10.1590/S0102-05362007000100014
https://doi.org/10.1590/S0102-0536200700...
) with the same yam cultivar. Thus, it demonstrates that increasing N concentration is necessary because nitrogen is one of the essential nutrients absorbed by yam plants (Oliveira et al., 2015).

The maximum starch concentration in yam tubers (39.3%) was obtained at a dose of 165.2 kg ha-1 of nitrogen, decreasing its concentrations at doses above that level (Figure 7). This percentage indicates that starch accumulation in yam was not related to the staking method but was influenced by nitrogen, because it is a component of the starch synthetase enzyme and chlorophyll, which directly influences starch accumulation (Abas et al., 2020Abas, N.; Kalair, E.; Kalair, A.; Hasan, Q. U.; Khan, N. Nature inspired artificial photosynthesis technologies for hydrogen production: Barriers and challenges. International Journal of Hydrogen Energy, v.45, p.20787-20799, 2020. https://doi.org/10.1016/j.ijhydene.2019.12.010
https://doi.org/10.1016/j.ijhydene.2019....
; Du et al., 2020Du, X.; Zhang, X.; Xi, M.; Kong, L. Split application enhances sweet potato starch production by regulating the conversion of sucrose to starch under reduced nitrogen supply. Plant Physiology and Biochemistry, v.151, p.743-750, 2020. https://doi.org/10.1016/j.plaphy.2020.04.027
https://doi.org/10.1016/j.plaphy.2020.04...
). The decrease in starch concentrations with the nitrogen doses above those responsible for the maximum concentrations may indicate a nutritional imbalance in plants, which decreased starch biosynthesis in the tubers (Oliveira et al., 2002Oliveira, A. P. de; Freitas Neto, P. A. de; Santos, E. S. dos. Qualidade do inhame ‘Da Costa’ em função das épocas de colheita e da adubação orgânica. Horticultura Brasileira, v.20, p.115-118, 2002. https://doi.org/10.1590/S0102-05362002000100023
https://doi.org/10.1590/S0102-0536200200...
).

Figure 7
Starch concentration in yam tubers in function of nitrogen doses

Conclusions

Yam cultivation must be carried out with staking to promote its agronomic performance.

The single staking method and nitrogen dose of 120.70 kg ha-1 are recommended to promote the maximum marketable yield of the yam cultivar Da Costa.

Acknowledgments

To the Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) for granting the scholarship and to the employees of the Universidade Federal da Paraíba (UFPB).

Literature Cited

  • Abas, N.; Kalair, E.; Kalair, A.; Hasan, Q. U.; Khan, N. Nature inspired artificial photosynthesis technologies for hydrogen production: Barriers and challenges. International Journal of Hydrogen Energy, v.45, p.20787-20799, 2020. https://doi.org/10.1016/j.ijhydene.2019.12.010
    » https://doi.org/10.1016/j.ijhydene.2019.12.010
  • Binang, W. B.; Ojikpong, T. O.; Takim, F. O. Nodulation, Biomass production and yield of some indigenous legumes as influenced by rhizobium inoculation in the rainforest agro-ecological zone of Nigeria. Journal of Applied Life Sciences International, v.11, p.1-9, 2017. https://doi.org/10.9734/JALSI/2017/32624
    » https://doi.org/10.9734/JALSI/2017/32624
  • Brito, T. T. de; Soares, L. S.; Furtado, M. C.; Castro, A. A.; Carnelossi, M. A. G. Composição centesimal de inhame (Dioscorea sp.) in natura e minimamente processado. Scientia Plena, v.7, p.1-7, 2011.
  • Carvalho, E.; Sampaio, H. S. de V.; Santos, J. A. S.; Passos, A. R. Alternativas de tutoramento e uso de mulching plástico na cultura do inhame (Dioscorea rotundata Poir) fertirrigada por gotejamento. Magistra, v.26, p.416-423, 2014.
  • Cavalcante, F. J. de A.; Santos, J. C. P.; Pereira, J. R.; Leite, J. P.; Silva, D. J. da; Sousa, A. R. de; Messias, A. S.; Faria, C. M. B.; Burgos, N.; Lima Júnior, M. A.; Gomes, R. V.; Cavalcanti, A. C.; Lima, J. F. W. F. Recomendações de adubação para o Estado de Pernambuco: 2ª aproximação. 3.ed. Recife: Instituto Agronômico de Pernambuco. 2008. 212p.
  • Dantas, D. F. S. da; Oliveira, A. P. de; Dantas, T. A. G.; Bandeira, N. V. S. da; Gomes Neto, A. D. Produção do inhame adubado com doses de N e esterco bovino. Semina: Ciências Agrárias, v.34, p.3389-3396, 2013. https://doi.org/10.5433/1679-0359.2013v34n6Supl1p3389
    » https://doi.org/10.5433/1679-0359.2013v34n6Supl1p3389
  • Du, X.; Zhang, X.; Xi, M.; Kong, L. Split application enhances sweet potato starch production by regulating the conversion of sucrose to starch under reduced nitrogen supply. Plant Physiology and Biochemistry, v.151, p.743-750, 2020. https://doi.org/10.1016/j.plaphy.2020.04.027
    » https://doi.org/10.1016/j.plaphy.2020.04.027
  • Ennin, A.; Issaka, R. N.; Acheampong, P. P.; Numafo, M.; Danquah, E. O. Mechanization, fertilization and staking options for environmentally sound yam production. African Journal of Agricultural Research, v.9, p.2222-2230, 2014. https://doi.org/10.5897/AJAR2014.8487
    » https://doi.org/10.5897/AJAR2014.8487
  • Filgueira, F. A. R. Novo Manual de Olericultura: Agrotecnologia moderna na produção e comercialização de hortaliças. 3.ed. Viçosa: UFV, 2008. 421p.
  • Francisco, P. R. M.; Medeiros, R. M. de; Santos, D. Oscilações pluviométricas dentre os regimes diferenciados de precipitação no Estado da Paraíba. Revista Brasileira de Agricultura Irrigada, v.9, p.360-371, 2015. https://doi.org/10.7127/rbai.v9n600354
    » https://doi.org/10.7127/rbai.v9n600354
  • Garrido, M. da S.; Soares, A. C. F.; Menezes, R. S.; Sampaio, E. V. de S. B.; Souza, E. M. da S.; Macedo, B. L. do N. Quality and yield of yam tubers cultivated with green manure in the Northeastern Brazil. Comunicata Scientiae, v.8, p.275-280, 2017. https://doi.org/10.14295/cs.v8i2.1725
    » https://doi.org/10.14295/cs.v8i2.1725
  • Instituto Adolfo Lutz. Normas analíticas do Instituto Adolfo Lutz: métodos físicos e químicos para análises de alimentos. 4.ed. São Paulo: Instituto Adolfo Lutz, 2005. 1020p.
  • Leghari, S. J.; Wahocho, N. A.; Laghari, G. M.; Hafeezlaghari, A.; Mustafabhabhan, G.; Hussaintalpur, K.; Lashari, A. A. Role of nitrogen for plant growth and development: A review. Advances in Environmental Biology, v.10, p.209-219, 2016.
  • Liu, Y.; Wiren, N. V. Ammonium as a signal for physiological and morphological responses in plants. Journal of Experimental Botany, v.68, p.2581-2592, 2017. https://doi.org/10.1093/jxb/erx086
    » https://doi.org/10.1093/jxb/erx086
  • Lovera, M.; Castro, G. M. C. de; Pires, N. da R.; Bastos, M. do S. R.; Holanda-Araújo, M. L.; Laurentin, A.; Moreira, R. de A.; Oliveira, H. D. de. Pyrodextrinization of yam (Dioscorea sp.) starch isolated from tubers grown in Brazil and physicochemical characterization of yellow pyrodextrins. Carbohydrate Polymers, v.242, p.116382, 2020. https://doi.org/10.1016/j.carbpol.2020.116382
    » https://doi.org/10.1016/j.carbpol.2020.116382
  • Malavolta, E. Manual de nutrição de plantas. 1.ed. São Paulo: Ceres, 2006. 638p.
  • Miller, A. J.; Cramer, M. D. Root nitrogen acquisition and assimilation. Plant Soil, v.274, p.1-36, 2005. https://doi.org/10.1007/1-4020-4099-7_1
    » https://doi.org/10.1007/1-4020-4099-7_1
  • Norman, P. E.; Whyte, J. B. A.; Samura, A. E.; Massaquoi, A.; Sesay, L.; Dixon, A. G.; Fomba, S. N.; Benya, M. T.; Sowa, M. M. Effect of staking and non-staking systems on disease severity, yield and quality attributes of yams (Dioscorea alata). Journal of Agriculture and Ecology Research International, v.1, p.219-229, 2015. https://doi.org/10.9734/JAERI/2015/14713
    » https://doi.org/10.9734/JAERI/2015/14713
  • Nunes, A. R. A.; Fernandes, A. M.; Leonel, M.; Garcia, E. L.; Magolbo, L. A.; Carmo, E. L. do. Nitrogênio no crescimento da planta e na qualidade de raízes da mandioquinha-salsa. Ciência Rural, v.46, p.242-247, 2016. https://doi.org/10.1590/0103-8478cr20150339
    » https://doi.org/10.1590/0103-8478cr20150339
  • Oliveira, A. P. de; Barbosa, L. J. das N.; Pereira, W. E.; Silva, J. E. L. da; Oliveira, A. N. P. de. Produção de rizóforos comerciais de inhame em função de doses de nitrogênio. Horticultura Brasileira, v.25, p.73-76, 2007. https://doi.org/10.1590/S0102-05362007000100014
    » https://doi.org/10.1590/S0102-05362007000100014
  • Oliveira, A. P. de; Freitas Neto, P. A. de; Santos, E. S. dos. Qualidade do inhame ‘Da Costa’ em função das épocas de colheita e da adubação orgânica. Horticultura Brasileira, v.20, p.115-118, 2002. https://doi.org/10.1590/S0102-05362002000100023
    » https://doi.org/10.1590/S0102-05362002000100023
  • Oliveira, A. P. de; Silva, O. P. R.; Leonel, M.; Guimarães, L. M. P.; Andrade, G. P. Inhame (Dioscorea spp). In: Leonel, M.; Fernandes, A. M.; Franco, C. M. L. Culturas amilaceas: batata-doce, inhame, mandioca e mandioquinha-salsa. Botucatu: Cerat/Unesp, 2015. Cap.2, p.121-170.
  • R Core Team. R: A language and environment for statistical computing. Vienna: R Foundation for Statistical Computing, 2017. Available on: <Available on: https://www.r-project.org/ >. Accessed on: Aug. 2018.
    » https://www.r-project.org/
  • Rezaei, A. Q.; Kikuno, H.; Babil, P.; Tanaka, N.; Park, B. J.; Onjo, M.; Shiwachi, H. Nitrogen-fixing endophytic bacteria is involved with the lesser yam (Dioscorea esculenta L.) growth under low fertile soil condition. Tropical Agriculture and Development, v.61, p.40-47, 2017.
  • Santos, E. S. dos. Inhame (Dioscores ssp.) aspectos básicos da cultura. 1.ed. João Pessoa: EMEPA-PB, 1996, 158p.
  • Santos, F. N. dos; Oliveira, A. P. de; Araújo, J. R. G.; Silva, O. P. R. da; Silva, D. T. de A. F.; Medeiros, D. A. Response of yams exposed to different sources and doses of nitrogen fertilizers in the State of Maranhão, Brazil. Semina: Ciências Agrárias , v.36, p.3605-3614, 2015. https://doi.org/10.5433/1679-0359.2015v36n6p3605
    » https://doi.org/10.5433/1679-0359.2015v36n6p3605
  • Santos, H. C. dos; Jacomine, P. K. T.; Anjos, L. H. C. dos; Oliveira, V. A.; Lumbreras, J. F.; Coelho, M. R.; Almeida, J. A. de; Araújo Filho, J. C. de; Oliveira, J. B. de; Cunha, T. J. F. Sistema brasileiro de classificação de solos. 5.ed. rev. e ampl. Brasília: Embrapa, 2018. 356p.
  • Saravaiya, S. N.; Chaudhari, B. N.; Mais, S. J.; Tekale, G. S.; Jarande, S. D. Performance of greater yam (Dioscorea alata L.) under different staking systems. Journal of Root Crops, v.39, p.250-254, 2013.
  • Silva, J. B. G.; Martinez, M. A.; Matos, A. T. de; Pires, C. S.; Terração, G. Mobilidade dos íons nitrato e amônio em área agrícola sob adubação com água residuária de bovinocultura de leite e torta de mamona. Revista Engenharia na Agricultura-Reveng, v.25, p.200-211, 2017. https://doi.org/10.13083/reveng.v25i3.678
    » https://doi.org/10.13083/reveng.v25i3.678
  • Tedesco, M. J.; Gianello, C.; Bissani, C. A.; Bohnen, H.; Volkweiss, S. J. Análise de solo, planta e outros materiais. 2.ed. Porto Alegre: UFRGS, 1995. 174p.
  • 1 Research developed at Areia, PB, Brazil

Edited by

Editors: Lauriane Almeida dos Anjos Soares & Walter Esfrain Pereira

Publication Dates

  • Publication in this collection
    21 Feb 2022
  • Date of issue
    May 2022

History

  • Received
    13 Aug 2021
  • Accepted
    18 Nov 2021
  • Published
    27 Dec 2021
Unidade Acadêmica de Engenharia Agrícola Unidade Acadêmica de Engenharia Agrícola, UFCG, Av. Aprígio Veloso 882, Bodocongó, Bloco CM, 1º andar, CEP 58429-140, Tel. +55 83 2101 1056 - Campina Grande - PB - Brazil
E-mail: revistagriambi@gmail.com