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Cook, C.G. and A.W. Scott, Jr. 1993. Utilization of methanol stress for evaluating kenaf quality. p. 411-412. In: J. Janick and J.E. Simon (eds.), New crops. Wiley, New York.

Utilization of Methanol Stress for Evaluating Kenaf Quality

Charles G. Cook and Andrew W. Scott, Jr.

  1. METHODOLOGY
  2. RESULTS
  3. DISCUSSION
  4. REFERENCES
  5. Table 1
  6. Table 2
Problems encountered in the establishment of uniform, vigorously growing kenaf (Hibiscus cannabinus L.) may result from poor seed quality. Although germination may remain relatively high, poor quality seeds often lack seedling vigor and are more susceptible to diseases and environmental stresses. Studies with soybeans (Mugnisjah and Nakamura 1986) and cottonseed (Hernandez 1987) show that methanol stress mimics the effects of weathering and accelerated aging, and may be a useful screening tool for evaluating seed quality and seedling performance. The objective of this study was to determine whether methanol stress could be used in the evaluation of kenaf seed to rapidly ascertain seed quality.

METHODOLOGY

Seed of five kenaf genotypes with similar seed production and weather exposure history were immersed in 20% methanol-water solutions for four selected durations (0, 1, 3, 5 h), and sown in the field. Genotypes included: 'Everglades 71' (E71), 'Tainung 1' (T1), 'Cuba 108' (C108), '15-2' (X15), and '19-117-2' (X117). The study was conducted at two Texas locations, Weslaco and Monte Alto. Experimental design was a randomized complete block, with four replications. Single row plots were 6.7 m in length and spaced 1.0 m apart. One hundred seed were planted with a cone planter in each plot and the number of emerged seedlings were counted on weekly basis for six weeks. Initial emergence and final stand establishment were determined at seven and 42 days after planting respectively. Post-emergence damping off was determined throughout the six week period and expressed as the percentage of dead emerged seedlings.

RESULTS

No significant genotype x location or treatment x location interaction was observed for initial emergence, final stand establishment, or post-emergence damping-off. Therefore, results presented here were combined over the two locations. Genotypes differed for initial emergence under the methanol treatments (Table 1). Emergence of E71 and T1 was greater than X117 under the control treatment. Differences also occurred among genotypes in the methanol treatments, with E71 consistently having the highest emergence. In the 3 and 5 h treatments, lower seedling emergence occurred for T1, X15, and X117, with X15 having the least emergence in the 5 h treatment.

Final stand establishment differed among genotypes across treatment durations. In the control treatment, final stand of E71 was significantly greater than X15 and X117. All genotypes produced greater stands than X117 in the 1 h treatment. For the 5 h treatment, E71 had significantly greater stands than the other genotypes. In the 5 h treatment X15 produced the lowest final plant stands.

Initial emergence and final stand establishment differed significantly between treatments (Table 2). Compared to the control, seed and seedling performance were adversely affected in the 3 and 5 h treatments. Post-emergence damping-off in the 3 h treatment was observed to be significantly greater than in the untreated control and 1 h methanol treatments.

DISCUSSION

Genotypes differed significantly in seed quality. When the control and 5 h treatments were compared, stand reductions due to artificial aging were greatest for X15 (43.2 vs 24.8%) and T1 (50.7 vs 30.5%). Except for T1, emergence and final stand were not severely reduced until seeds were soaked with methanol for 3 h. Although X117 exhibited poorest seed quality in the untreated treatment, T1 and X15 showed the greatest deterioration when exposed to the longer methanol treatments. These results suggest that methanol stress may be used to artificially deteriorate kenaf seed for the evaluation of seed quality. Such a methanol stress test may possibly be utilized as a selection tool for genetically improving or for screening kenaf seed quality.

REFERENCES

Table 1. Effect of simulated aging by 20% methanol-water seed treatment on initial plant emergence and final stand of five kenaf genotypesz.

Emergence (%)y Final stand (%)y
Genotype Genotype
Methanol treatment (h) E71 T1 C108 X15 X117 E71 T1 C108 X15 X117
0 60.3ax 55.8a 52.3ab 49.5b 42.5b 53.3a 50.7ab 46.2abc 43.2bc 36.8c
1 57.5a 55.6ab 55.5ab 48.8b 39.0b 51.1a 48.9a 48.7a 45.5a 36.7b
3 52.0a 39.8b 47.8ab 41.2b 39.8b 45.1a 35.3b 42.0ab 36.1b 36.3b
5 44.2a 33.6b 35.4b 26.7c 34.3b 40.4a 30.5b 31.3b 24.8c 30.3b
zInitial plant emergence and final stand establishment were recorded at 7 and 42 days after planting, respectively, and expressed as % of total seed planted.
yCombined over the Weslaco and Monte Alto, TX locations.
xMeans in a row followed by the same letter are not significantly different according to Duncan's multiple range test (P = 0.05). Data were arc sin transformed for statistical analysis, actual means presented.

Table 2. Initial plant emergence, final stand, and post-emergence damping-off of kenaf seed across five genotypes under 20% methanol-water treatments to simulate artificial aging.

Methanol treatment
(h)		 Emergence
(%)		 Final stand
(%)		 Damping-off
(%)
0 52.1az 46.0a 21.5a
1 51.3a 46.2a 22.2a
3 44.7b 39.0b 25.4b
5 34.8c 31.6c 23.9ab
zMeans in a column followed by the same letter are not significantly different according to Duncan's multiple range test. (P = 0.05). Data were arc sin transformed for statistical analysis, actual means presented.

Last update April 23, 1997 aw