Requirement of heat units in the crop of the amaranth

Abstract

Five amaranth genotypes were analyzed; four Amaranthus hypochondriacus L. species, 153-5-3,655, 653, and Tlaxcala creole; the other species was Amaranthus cruentus L., thirty three in four environment, contrast  climates  and  topography located in  Northern Mexico. The studies  were carried out between 15th August 2000 and 15th November 2002. The objective of this paper was: determine the interaction genotype by environment (A x G) on heat units required in the phenology development from cultivates and the grain yielding of genotypes (RG). A complete random block experimental design with three repetitions for different environments was used. Results have shown that  for  MC  (marketing  ripeness)  Tlaxcala  Creole  from  A.  hypochondriacus  had  a  higher requirement with 977 UC (heat units) in the A1 environment, in A2; 655, 33, 653 have shown similar statistical behaviors each one with a requirement of 1475 UC, overcoming to Tlaxcala Creole and to 153-5-3 which required 1133 and 1473 UC, for A3 Tlaxcala Creole had the least requirement with an average of 1384 UC, the rest of the genotypes were statistically similar of UC requirements with an average of 1568, for A4 each of the genotypes of the study shown average requirements   of   315   UC.   The   higher   RG   (p<   0.05)   genotypes   were   153-5-3   from   A. hypochondriacus of environment A1 with 2144 kg ha-1, for A2 and A3 environments genotype 33 with 1637 and 1283 kg ha- 1, for A4 the genotypes 153-5-3 y 653 with 1539 and 1562 kg ha-1 respectively.