The investigation of corn kernel qualitycharacteristics during various stages of grain maturity
Subject Areas : Agroecology Journal
1 - Assistant proffesor of lslaic Azad Univversity of Fasa
Keywords:
Abstract :
Although production of hybrid corn kernel is low, the value per unit of yield is several limes greater than that of seed grain. The production of hybrid corn kernel is dependent on timely harvest operations that ensure maximum seed quality and yield of inbred parent and hybrid seed. The present research was conducted al the Experimental Farm of the Islamic Azad University of Fasa during summer 2000. The factorial experiment was designed based on complete randomized block design with 3 replications. The factors were time of seed harvest during various stages of kernel maturity and water deficit. There were several harvests from first week to third week of kernel maturity. The beginning of kernel maturity was determined from kernel growth curve and the end of linear grow th phase. Water deficit consisted of control, early and late water deficit after pollination. As the aim of this investigation was to study of corn kernel harvest different times during the stages of kernel maturity and the efTects of water deficit on kernel quality characteristics, kernels of Sc 704 hybrid parent were seeded. Dry matter weight and moisture percentage of kernels and starch and protein percentage of kernel was determined and used for the explanation of germination percentage and vigor changes of the kernels. The results showed that kernel kernel maturity began from seventh week after pollination and last three weeks. Statistical analysis of kernel dry matter weight showed significant effect at 5% probability level during this three weeks of the water deficit. Also early and late water deficit reduced kernel embryo dry matter weight by average 28.92% and 7.53% respectively during kernel maturity. Kernel moisture percentage has shown significant difference only during the first week of kernel maturity. The germination percentage of com kernels produced during kernel maturity stages was determined. The results showed that kernel germination percentage was minimum in control treatment during first week of kernel maturity (27%) and it was maximum (92%) during the third week of maturity. A linear relationship was obtained between germination percentage and kernel embryo dry matter weight in control and late water deficit treatments. Seedling dry matter weight obtained from germination of the first - week seeds was not affected by water deficit.
1 - Barlow, E.W.R., J.W. Lee, R. Munns, and M. G. Smart. 1980. Water relations of developing wheat grain.
Aust. J. Plant Physiol. 7: 519 - 525.
2 - Borowski, A.M., V.A. Fritz and L.J. Waters. 1991. Seed maturity influences germination and vigor of two shrunken-2 sweet com hybrids. J. Am. Soc. Hortic Sci. 116: 401 - 404.
3 - Bradford, K.J. 1994. Water stress and the water relations of seed development. Crop Sci. 34: 1 - 11.
4 - Bullok, D., and K. Moore. 1992. Protein and fat determination in com. pp: 181 - 197. In: H.F. Linskens, and J.F. Jackson (eds.). Seed analysis. Spring- Verlag, Berlin.
5 - Cochrane, M.P. 1983. Morphology of the crease region in relation to assimilatic uptake and water loss during caryopsis development in barley and wheat. Aust. J. Plant Physiol. 10: 473 - 491.
6 - Dornbos, D.L., and R.E. Mullen. 1985. Soybean seed quality and drought stress intensity during development. Iowa Seed Sci. 7(2): 9 - 11.
7 - Dungan, G.H. 1999. Some factors affecting the water absorption and germination of seed com. Iowa
Agriculture Experiment Station Research Bulltein.
8 - Fountain, D.W., and H.A. Outred. 1990. Seed development in Phaseolus vulgaris L. cv. Seminole: II Precocious germination in late maturation. Plant Physiol. 93: 1089 - 1093.
9 - Galston, A.W. 1994. Life processes of plants.Scientific American Library. pp: 245.
10 - Harrison, C.M., and A.H. Wright. 1979. Seed com drying experiments. Am. Soc. Agric. Vol. 21. pp: 10.
11 - Ingle, J., D. Beitz, and R.H. Haageman. 1965. Changes in composition during development and maturation of maize seeds. Plant Physiol. 40: 835 - 839.
12 - Knittle, K.H., and J.s. Burris. 1976. Effect of kernel maturation on subsequent seedling vigour in maize.
Crop Sci. 16: 851 - 855.
13 - McCarty, D.R., and C.B. Carson. 1991. The molecular genetics of seed maturation in maize. Plant Physiol.
81: 267 - 272.
14 - McDonald, M.B., and L.O. Copeland. 1997. Seed Production, principles and practices. Chapman & Hall
Publishing, London. pp: 750.
15 - Morrison, W.R. 1992. Analysis of cereal starches. pp: 199-215. In: H.F. Linskens, and J.F. Jackson (eds.).
Seed analysis. Spring - Verlag, Berlin.
16 - Ouattar, S., R.J. Jones, and R.K. Crookston. 1987a. Effect of water deficit during grain filling on the pattern of maize kernel growth and development. Crop Sci. 27: 730 - 735.
17 - Ouattar, S., R.J. Jones, R.K. Crookston, and M. Kajeiou. 1987b. Effect of drought on water relations of
developing maize kernels. Crop Sci. 27: 730 - 735.
18 - Romagosa, I., F. Han, J.A. Clancy, and S.E. Ullrich. 1999. Individual locus effects on dormancy during seed development and after ripening in barley. Crop Sci. 39: 74 - 79.
19 - Rush, G.E., and N.P. Neal. 1997. The effect of maturity and other factors on stands of com at low
temperatures. pp: 96 - 97. In: M.B. McDonald, and L. Copeland (eds.). Seed production, principles and practices. Chapman & Hall Publishing, London.
20 - Thome. J.H. 1981. Morphology and ultrastructure of maternal seed tissues of soybean in relation to the import of photosynthate. Plant Physiol. 67: 1016 - 1025.
21 - Westgate, M.E. ,and J.S. Boyer. 1986. Water status of the developing grain of maize. Agron. J. 78: 714 -
719.
22 - Wych, R.D. 1988. Production of hybrid seed com. pp: 565 - 604. In: G.F. Sprague and J.W. Dudley (eds.).
Com and com improvement. 3nd Ed. Agron. Monogr. 18. ASA, CSSA, and SSSA, Madison, WI.
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