Shading Net and Paclobutrazol can Improve Tuber Formation in Potato?

Potato (Solanum tuberosum L.) is considered as an important horticultural crop, nutritionally as well as economically in Indonesia; where it is used as an alternative starch source. However, in case of potato production, some restrictions are there, including shortage of accessibility of high seed quality in genetic. In addition, an inadequate high land area for potato seed production worsens this situation.

Therefore, use of medium land was needed as a substitute of high land to produce potatoes. But, major issue in case of utilizing medium land is the high temperature. According to Stark and Love¹, potato plants are much susceptible to high temperature stress. Because of which, biosynthesis and activity of gibberellic acid enhances in shoots except in mature leaves which will ultimately cause inhibition of tuber formation² as well as tuber growth³.

For this reason, experts are applying microclimate manipulation in order to cope with this situation by decreasing the temperature lower than ambient around the plant. Microclimate manipulations involve various methods such as shading treatment. Accordingly, shading net is one of the artificial shadings, which is being extensively utilized in greenhouse. The shading net 45% of density, enhances the leaf area index (LAI) of potato, amplifies the potato yield as well as improved tuber quality⁴.

Additionally, amplification of tuber quality can also be done through inhibiting gibberellin biosynthesis by using paclobutrazol that will ultimately slow down cell elongation in apical meristem, decreasing stem extension rate without affecting the growth as well as development of leaves⁵.

This fact encouraged Jajang Sauman Hamdani, Anne Nuraini and Syariful Mubarok⁶ to design an experiment to assess the interaction effect between shading net and paclobutrazol on growth and yield of potato ‘medians’ tuber of G₂ in medium land of Indonesia. In this experiment, scientists followed the randomized block design having two factors, which consisted of 3 levels of shading net density (0, 30 and 40%) and four levels of paclobutrazol concentration (0, 50, 100 and 150 mg L^–1). Afterwards, all parameters were examined via two ways ANOVA by means of Fisher test followed by Duncan’s multiple range test.

At the end, researchers found that Paclobutrazol is affective to suppress plant height and leaf area, though it enhanced leaves chlorophyll content, tuber number as well tuber weight per plant. Moreover, the maximum tuber number as well as %age of class tuber for seed size was obtained from plant with 50 mg L^–1 of paclobutrazol application. Conclusively, scientists suggested that potato tuber propagation of G₂ can also be done in medium land of Indonesia.

References:

1. Stark, J.C. and S.L. Love, 2003. Tuber Quality. In: Potato Production Systems, Stark, J.C. and S.L. Love (Eds.), University of Idaho Agricultural Communications, Moscow, Idaho.
2. Menzel, C.M., 1985. Tuberization in potato at high temperatures: Interaction between temperature and irradiance. Ann. Bot., 55: 35-39.
3. Sarquis, J.I., H. Gonsales and I. Bernal-Lugo, 1996. Response of two potato clones ( tuberosum L.) to contrasting temperature regimes in the field. Am. Potato J., 73: 285-300.
4. Hamdani, J.S., Sumadi, Y.R. Suradinata and L. Martin, 2016. The effect of shade and growth regulator on growth and yield of Atlantic cultivar potatoes in the medium plains. J. Agron. Indones., 44: 33-39.
5. Tumewu, P., P.C. Supit, R. Bawotong, A.E. Tarore and S. Tumbelaka, 2012. Urea fertilization and paclobutrazol on growth of sweet corn (Zea mays saccharata). Eugenia, 18: 39-48.
6. Jajang Sauman Hamdani, Anne Nuraini and Syariful Mubarok, 2018. The Use of Paclobutrazol and Shading Net on Growth and Yield of Potato ‘Medians’ Tuber of G₂ in Medium Land of Indonesia. Journal of Agronomy, 17: 62-67.