SPAD VALUE MEASUREMENT ¬ A BASIS TO SCHEDULE NITROGEN FOR POTATO CROP

Authors

  • shiv pratap singh ICAR - Central Potato Research Station, Gwalior-474006, India
  • Manoj Kumar ICAR - Central Potato Research Institute Campus, Modipuram, Meerut, India
  • V K Dua ICAR - Central Potato Research Institute, Shimla-171001,
  • S K Sharma ICAR-CPRI-RS, Gwalior
  • M J Sadawarti ICAR-CPRI-RS, Gwalior
  • S Roy Presently at ICAR-Directorate of Medicinal & Aromatic Plants Research, Anand, Gujarat

Keywords:

Chlorophyll Meter, Nitrogen, Potato Varieties, SPAD

Abstract

ABSTRACT: A leaf chlorophyll meter (SPAD 502) was used as a tool for N-fertilization in potato. SPAD value of an over
fertilized plot was used as reference to application of subsequent split doses after earthing up in different treatment plots
for two prevalent varieties Kufri Jyoti and Kufri Chandramukhi. In different treatments the SPAD values differed for
two varieties. Among different treatments (N schedules) higher SPAD value was observed throughout in over fertilized
reference plots where 125% of recommended N was applied. In tuber yield, Kufri Jyoti (36.7 t/ha) was higher than Kufri
Chandramukhi (30.5 t/ha) at all N levels/treatments. Total tuber yield under different N doses ranged from 33.1(Kufri Chandramukhi) to 34.8 (Kufri Jyoti) t/ha. Among various N schedules and levels there was no significant difference in tuber yield, though, the highest yield was obtained in the treatment where 10% of recommended N was applied at 95% of reference SPAD after basal (50%) and earthing up (20%) applications followed by in over fertilized plot there by saving 20% of recommended N (36 kg/ha). This indicated that increasing the number of splits of N supplied N to the crop for longer duration to maintain the yield level of both varieties compared to over fertilized plot even at much lower N application rate. The best period to detect N deficiency in potato for corrective N fertilization was found to be on or
before 45 DAP which is tuberization phase. Gross return (2.26 lakh/ha), net return (1.53 lakh/ha) and B:C ratio (3.1) was higher with Kufri Jyoti compared to Kufri Chandramukhi. Among different N treatments gross return (2.09 thousand /
ha), net return (1.37 thousand/ha) and B : C (2.9) ratio were highest with 50% at planting + 20% at earthing + 10% at 95% reference value. Thus, there was 20% saving of N by splitting of N based on SPAD value.

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Author Biographies

shiv pratap singh, ICAR - Central Potato Research Station, Gwalior-474006, India

Principal Scientist and Head

ICAR-CPRI-RS, Gwalior, MP

 senior most

Manoj Kumar, ICAR - Central Potato Research Institute Campus, Modipuram, Meerut, India

Joint Director, Senior most

V K Dua, ICAR - Central Potato Research Institute, Shimla-171001,

Principal Scientist & Head, Division of Crop Production

S K Sharma, ICAR-CPRI-RS, Gwalior

Senior echnical Officer

M J Sadawarti, ICAR-CPRI-RS, Gwalior

Scientist SS

S Roy, Presently at ICAR-Directorate of Medicinal & Aromatic Plants Research, Anand, Gujarat

Principal Scientist

Published

2019-08-16

How to Cite

singh, shiv pratap, Kumar, M., Dua, V. K., Sharma, S. K., Sadawarti, M. J., & Roy, S. (2019). SPAD VALUE MEASUREMENT ¬ A BASIS TO SCHEDULE NITROGEN FOR POTATO CROP. Potato Journal, 46(1). Retrieved from https://epubs.icar.org.in/index.php/PotatoJ/article/view/84766