TITLE:
Diagnosis of Premature Senescence of Cotton Using SPAD Value
AUTHORS:
Pengcheng Li, Helin Dong, Aizhong Liu, Jingran Liu, Miao Sun, Guoping Wang, Siping Zhang, Yabing Li, Shuchun Mao
KEYWORDS:
Diagnosis, Premature Senescence, Cotton (Gossypium hirsutum L.), SPAD Values
JOURNAL NAME:
Agricultural Sciences,
Vol.5 No.11,
September
25,
2014
ABSTRACT: Field experiments were conducted in 2011 on an experimental farm at the Cotton Research Insti-tute, Chinese Academy of Agricultural Sciences, Anyang, China. We conducted experiments with a “SPAD-502” meter to quickly measure the relative value of chlorophyll content in the leaf blades of field cotton. Our goal was to seek a suitable leaf on a cotton plant to diagnose senescence status of crop plants at later stages of growth. We began by studying the dynamic change rule of the dis-tal-most four leaves of the cotton plant during the entire growth period with two early-maturing cultivars (CCRI 36, CCRI 50) and two mid-maturing cultivars (CCRI 41, SCRC 28). We also examined the effect of different nitrogen and potassium fertilizer rates on SPAD values of the leaves of SCRC 28. Our results suggest that SPAD values of the 1st distal stem leaves from two early cultivars can act as good indicators of senescence status in the plants, if they are measured between 10 d before the boll-opening stage and 10 d after boll opening stage. Differences of SPAD values of the 3rd distal stem leaves of two mid-maturing cultivars measured between about 15 d before the boll opening stage and 15 d after the boll opening stage can also be used to measure senescence status in these cotton cultivars. The conclusion can be used for cotton producer to manage N fertilizer better at later growth stage.