Studies of B and R Reactions
 The necessity of hybrid production using other resources than
A, in order to improve yield and resistance to diseases and insects
is evident. In January 1983, 182 converted lines from SCP were
crossed with three genic-cytoplasmic male sterility sources (A1, A2
and A3) at TARS to determine the fertility-sterility reaction of the
produced F,'s. Preliminary results show that most of the con-
verted lines were fertility restorers (R) when crossed to A, and
maintainers (B) when crossed to A3. Approximately 50% of the
converted lines were fertility restorers (R) when crossed to A2.

SUMMARY
 Sorghum researchers at TARS, USDA-ARS, Mayaguez covers
two main areas:
 1. nursery programs and the sorghum conversion program,
 and
 2. local focus on sorghum breeding and genetic research for
 the tropics.
Agronomic studies have demonstrated the potential of sorghum
for the tropics and will lead to the development of complete
packages of practices for the high economic yields both on grain
and forage sorghum on the farmer level. Private industry utiliz-
ing converted lines benefit from our work. Information obtained
on sorghum breeding, genetics and agronomy has been useful
not only to breeders and agronomists but also to farmers in Puer-
to Rico engaged in sorghum production.










References
 1. Alconero, R., P. Powell, and M. Alameda. 1977. Effect of head bagging on
seedborne fungi and seed health. Sorghum Newsletter 20:78.
 2. Ayala, A., and D. Bee-Rodriguezo 1978. Control of phytoparasitic
nematodes attacking sorghum (Sorghum bicolor [L.] Moench) in Puerto Rico. J.
Agric. Univ. P.R. 62(1):119-132.
 3. Bee-Rodriguez, D., and A. Ayala. 1977. Interaction of Pratylenchus zeae
with four soil fungi in sorghum. J. Agric. Univ. P.R. 61(4):501-506.
 4. Craig, J., L.K. Edmunds, AJ. Casady, OJ. Webster and A. Sotomayor-
Rios. 1979. Registration of RSP3BR sudangrass germplasm. Crop Sci. (Mar.-Apr.)
19:300.
 5. Duncan, R.R., D.T. Rosenow, A. Sotomayor-Rios, and R.A. Fredericksen.
1982. Registration of GPT2RB anthracnose resistant germplasm population. Crop
Sci. 22:1274-75.
 6. Eastin,J.D.,J.H. Hoitquist, and C.Y. Sullivan. 1973. Physiologic maturity
in grain sorghum. Crop Sci. 13:175-178.
 7. Gorz, H.J., F.A. Haskins, S.D. Kindler, and A. Sotomayor-Rios. 1984.
Registration of NP22 sudangrass germplasm. Crop Sci. 24:391.
 8. Gourley, L.M. andJ.M. Lusk. 1978. Genetic parameters related to sorghum
silage quality. J. Dairy Sci. 61:1821-1827.
 9. Hepperly, P.R., C. Feliciano, and A. Sotomayor-Rios. 1982. Chemical con-
trol of seedborne fungi of sorghum and their association with seed quality and ger-
mination in Puerto Rico. Am. Phyt. Soc. Plant Dis. 66(10):902-904.


 10. Hernandez-Catalan, O.V. 1977. Nemitodos del sorgo (Sorghum bicolor
[L.] Moench) en Puerto Rico: Patogenicidad y combat. MS Thesis, Univ. of P.R.,
Mayaguez Campus.
 11. Martin, F.W. 1984. Handbook of Tropical Food Crops. CRC Press, Boca
Raton, FL.
 12. Powell, P., M. Ellis, M. Alameda, and A. Sotomayor-Rios. 1977. Effect of
natural anthracnose epiphytotic on yield, grain quality, seed health and seed-borne
fungi in Sorghum bicolor. Sorghum Newsletter 20:77.
 13. Quinby, J.R. 1972. Grain filling period of sorghum parents and hybrids.
Crop Sci. 12:690-91.
 14. Ross, W.M., S.D. Kindler, H.L. Hackerott, T.L. Harvey, A. Sotomayor-
Rios, O.J. Webster, and K.D. Kofoid. 1977. Registration of RP1R and RP2B
sorghum germplasm. Crop Sci (Nov.-Dec.) 17:983.
 15. Schertz, K.F., D.T. Rosenow, and A. Sotomayor-Rios. 1981. Registration of
three pairs (A and B) of sorghum germplasm with A2 cytoplasmic-genic sterility
system. (Re. Nos. GP 70 and 72). Crop Sci. 21:148.
 16. Sotomayor-Rios, A., and M.A. Lugo-L6pez. 1978. Nitrogen fertilization of
sorghum in an Oxisol in northwestern Puerto Rico. J. Agr. Univ. P.R.
62(4):380-388.
 17. Sotomayor-Rios, A. and F.R. Miller. 1977. Performance of ten grain
sorghum lines from the conversion program. J. Agr. Univ. P.R. 61(4):443-449.
 18. Sotomayor-Rios, A. and A. Santiago. 1981. Performance ofF, hybrids from
crosses of three sudangrasses and six forage sorghums with A Rhodesian sudangrass.
J.Agr. Univ. P.R. 55(2):73-112.
 19. Sotomayor-Rios, A. and L. Telek. 1977. Forage yield and protein content of
millo blanco (Sorghum bicolor) and two F, hybrids. J. Agr. Univ. P.R.
61(3):300-304.
 20. Sotomayor-Rios, A. and S. Torres-Cardona. 1982. Agronomic comparison
and hydrocyanic acid potential (HCN-p) of single crosses, three-way forage sorghum
hybrids and their parents during two years in Puerto Rico. In XXVIII Annual
Meeting, PCCMCA, San Jose, Costa Rica.
 21. Sotomayor-Rios, A. and S. Torres-Cardona. 1984a. Agronomic comparison,
heterosis and hydrocyanic acid potential (HCN-p) of sudangrass-sorghum and
sudangrass-sudangrass hybrids and their parents. J. Agr. Univ. P.R. 68(2):143-155.
 22. Sotomayor-Rios, A. and S. Torres-Cardona. 1984b. Agronomic perfor-
mance, hydrocyanic acid potential (HCN-p) and heterosis in forage sorghum
hybrids. J. Agr. Univ. P.R. 68(2):131-141.
 23. Sotomayor-Rios, A. and D.E. Weibel. 1978. Evaluation of seven sorghums,
selfed and crossed to three cytoplasmic male-sterile lines. J. Agr. Univ. P.R.
62(2): 156-164.
 24. Sotomayor-Rios, A., S. Torres-Cardona, and A. Quiles-Belen. 1983. Effect
of nitrogen levels and cutting intervals on forage yield and other characters in
sorghum hybrids. In: XXIX Annual Meeting, PCCMCA, Panami.
 25. Sotomayor-Rios, A., S. Torres-Cardona, and A. Quiles-Bel6n. 1984. Grain
sorghum performance at two locations in Puerto Rico. Abstract, American Society of
Agronomy, Annual Meeting, Las Vegas, NV.
 26. Sotomayor-Rios, A., F. Zannier-Valenzuela, and S. Torres-Cardona. 1981.
Agronomic comparison hydrocyanic acid potential (HCN-p) and nutritive evalua-
tion of parents, single crosses and three-way hybrids in Puerto Rico. In: XXVII An-
nual Meeting, PCCMCA, Santo Domingo, Domincan Republic.
 27. Stephens, J.C., F.R. Miller and D.T. Rosenow. 1967. Conversion of alien
sorghums to early combine genotypes. Crop Sci. 7(4):396.
 28. Torres-Cardona, S., A. Sotomayor-Rios, and F.R. Miller. 1984. Agronomic
comparison and in vitro dry matter digestibility of eight sorghums at two locations in
Puerto Rico. J. Agr. Univ. P.R. (Unpublished).
 29. Torres-Cardona, S., A. Sotomayor-Rios, and L. Telek. 1983. Agronomic
performance and hydrocyanic acid potential (HCN-p) of single and three-way forage
sorghums hybrids and DeKalb hybrid SX-17. J. Agr. Univ. P.R. 67(1):39-49.
 30. Wahab, A., H. Talleyrand, M.A. Lugo-L6pez. 1976. Rooting depth,
growth and yield of sorghum as affected by soil water availability in an Ultisol and
an Oxisol. J. Agr. Univ. P.R. 60(3):329-335.
 31. Webster, O.J. 1976. Registration of PR1BR sorghum germplasm. Crop Sci.
 16(3):447.
 32. Weibel, D.E., A. Sotomayor-Rios, H.M. Pava, and R.W. McNew. 1982.
Relationship of black layer to sorghum kernel moisture content and maximum
kernel weight in the tropics. Crop Sci. 22:219-222.


PROCEEDINGS of the CARIBBEAN FOOD CROPS SOCIETY-VOL. XX


292