scholarly journals Agronomic Performance and Hydrocyanic Acid Potential (HCN-p) of Single and Three-Way Sorghum-Forage Hybrids and DeKalb Hybrid SX-17

1969 ◽  
Vol 67 (1) ◽  
pp. 39-49 ◽  
Author(s):  
S. Torres-Cardona ◽  
A. Sotomayor-Ríos ◽  
L. Telek
Keyword(s):  
Puerto Rico ◽  
Leaf Area ◽  
Crude Protein ◽  
The Other ◽  
Hydrocyanic Acid ◽  
Agronomic Performance ◽  
Forage Production ◽  
Single Cross ◽  
Acid Potential ◽  
High Forage

Eleven sorghum forage entries, including five single crosses, five threeway hybrids and DeKalb hybrid SX-17 were evaluated for yield of green forage (GF), yield of dry forage (DF), crude protein (CP) content, CP yield, height, leaf area, number of tillers, leaf-stem ratio and hydrocyanic acid potential (HCN-p) at lsabela, Puerto Rico. Four cuttings were made. The second harvest, 112 days after planting, had the highest DF yield, and the lowest CP content. When data for all harvests were combined, the single cross of ATX624 x Common sudangrass, three-way hybrid (ATX624 x BRhodesian) x Common sudangrass and single cross hybrid ARhodesian x Common sudangrass produced the highest DF yields. These were significantly higher than those of OeKalb hybrid SX-17. The highest DF yield was that from single cross hybrid ATX624 x Common sudangrass (17,303 kg/ha in 217 days), which exceeded by 11% and 13% the 2nd and 3rd highest producers. Based on orthogonal comparisons, single crosses were on the average superior to three-way hybrids in yield and most of the other characteristics studied. Three-way hybrids had a lower average HCN content (250 p/m) than single crosses (285 p/m). These values are slightly higher than the 200 p/m level at which HCN toxicity may begin to affect animals. Results indicate that any of the three top hybrids of this study would be an excellent choice for farmers desiring high forage production under irrigation in Puerto Rico.

scholarly journals Agronomic Performance, Hydrocyanic Acid Potential (HCN-p) and Heterosis in Forage Sorghum Hybrids

1969 ◽  
Vol 68 (2) ◽  
pp. 131-141
Author(s):  
A. Sotomayor-Ríos ◽  
S. Torres-Cardona
Keyword(s):  
Leaf Area ◽  
Crude Protein ◽  
Hydrocyanic Acid ◽  
Yield Potential ◽  
F1 Hybrids ◽  
Agronomic Performance ◽  
F1 Hybrid ◽  
P Values ◽  
Forage Sorghum ◽  
Acid Potential

In 1981 field studies at the lsabela Experiment Farm in northwestern Puerto Rico, we evaluated agronomic performance, hydrocyanic acid potential (HCNp) and heterosis in forage sorghum hybrids (Sorghum bicolor (L.) Moench). Three cuttings were made at 60-day interval. The combined analyses showed significant differences in yields of green forage (GF), dry forage (OF) and crude protein (CP); contents of dry matter (OM) and crude protein; tillers/plant; height; leaf area; and HCN-p at 45 days. Harvests were not a significant source of variation in leaf/stem ratio or in HCN-p at 60 days. The F1 hybrids of CK-60 x Fa357, CK-60 x Common and CK-60 x Lahoma produced the highest OF and CP yields across the three harvests. The OF and CP yields of these top sorghum-sudangrass hybrids-about 20 and 2 metric tons, respectively in 180 days-and their relatively low HCN-p values, establish these genotypes among the most promising forage material for use under irrigation. The HCN-p values of all genotypes were lower at the 60-day harvest than at the 45-day sample. There were some instances of HCN-p value exceeding the "threshold of danger" of 200 p/m. Midparent heterosis was manifested for GF, OF and CP yields, height, tillers/plant and leaf area, but not for OF and CP content. High parent heterosis was less than midparent heterosis for most traits studied and was not observed for OM and CP content or for tillers/plant. The F1 hybrid of CK-60 x Common exhibited the greatest heterosis, producing 146 and 125% more DF than the midparent and high parent, respectively. Fa357 was superior to all other lines in having the lowest HCN-p among the male parents at 60 days. Lahoma had the highest yield potential of the male parent lines and an intermediate level of HCN-p compared to the other lines.

Production of grazed tropical grasses in different agroecosystems in Puerto Rico: I. Humid mountain

1969 ◽  
Vol 72 (1) ◽  
pp. 99-108
Author(s):  
Luis E. Tergas ◽  
Jaime Vélez-Santiago ◽  
Doralisa Vera de Saldaña
Keyword(s):  
Puerto Rico ◽  
Crude Protein ◽  
Cynodon Dactylon ◽  
First Year ◽  
Panicum Maximum ◽  
Crude Protein Content ◽  
Forage Production ◽  
Tropical Grasses ◽  
Grazing Period ◽  
Second Year

A field experiment was conducted at the Corozal Experiment Substation in the humid mountain region of Puerto Rico to evaluate the production and persistence of tropical grasses, Brachiaria humidicula, Cynodon dactylon cv. Bermuda, C. nlemfuensis var. nlemfuensis cv. Star, Digitaria pentzii cv. Slenderstem, D. decumbens cv. Transvala, C. plectostachyus cv. Star and Panicum maximum cv. Makueni in small plots grazed at 5- to 7-week intervals for 2 years. P. maximum cv. Makueni was the most productive grass the first year, with a mean of 1.71 ton/ha dry forage per grazing period, but it was not statistically different (P = 0.05) from B. humidicola and C. dactylon cv. Bermuda. D. pentzii was the least productive. Production of all grasses, except P. maximum cv. Makueni, decreased during the short cool days in December and January. B. humidicola was the most productive grass the second year, with a mean of 1.73 ton/ha of dry forage, followed very closely by P. maximum cv. Makueni. Again D. pentzii cv. Slenderstem was one of the least productive, and C. nlemfuensis did not persist. Mean production of all grasses decreased during the drier periods; however, the crude protein content was higher. Total annual forage production was similar in both years, with means of 15.8 and 15.1 ton/ha dry forage, but much lower than the reported yields of these cultivars under cutting management in Puerto Rico.

scholarly journals Introduction of Digitaria and Cynodon on the semiarid southern Coast of Puerto Rico

1969 ◽  
Vol 78 (3-4) ◽  
pp. 137-145
Author(s):  
Rafael Ramos Santana ◽  
José E. Rodríguez ◽  
Ismael Reyes ◽  
Alvaro Acosta
Keyword(s):  
Puerto Rico ◽  
Crude Protein ◽  
Dry Matter ◽  
The Other ◽  
Forage Grass ◽  
Dry Matter Yield ◽  
Southern Coast ◽  
Short Day ◽  
Harvest Intervals

Nine forage grass introductions (eight Digitaria and one Cynodon) were evaluated at 49-day harvest intervals under irrigation in the semiarid southern region of Puerto Rico. C. dactylon USDAPI 255455 (Coast Cross No. 1) produced the highest dry matter yield (DMY) throughout the seven cuts of each of the 2 years. However, no significant differences were observed between C. dactylon USDAPI 255455 and D. milanjiana 6416 and 6415 during each of the years in which the grasses were evaluated. In terms of the combined DMY of both years, C. dactylon 255455 was significantly superior to the rest of the introductions with the exception of D. milanjiana PRPI 6416. The in vitro organic matter digestibility (IVOMD) of C. dactylon 255455 was significantly less than that of both D. milanjiana 6416 and 6415. On the other hand, D. milanjiana presented the highest IVOMD on the cuts of the long and short day season. The crude protein (CP) content was very similar in most of the introductions under evaluation; however, D. milanjiana PRPI 6416 was the lowest in CP content during the short day season cut.

scholarly journals Effect of Harvest Interval on Yields of Four Sudan Grass Sorghum Crosses with Irrigation on the South Coast of Puerto Rico

1969 ◽  
Vol 65 (2) ◽  
pp. 108-113
Author(s):  
Rubén Caro-Costas
Keyword(s):  
Puerto Rico ◽  
Crude Protein ◽  
The Other ◽  
Sudan Grass ◽  
Harvest Intervals ◽  
Lower Protein ◽  
One Year ◽  
High Yields ◽  
Grazing Lands ◽  
Very High

Yields of the Sudan grass-sorghum hybrids Space Maker, Grazer A, Sordan 70, and Graze and Bale averaged 23,028, 39,815 and 54,810 kg of dry forage/ha/yr when harvested every 30, 45 and 60 days, respectively, over a one year period with irrigation. Crude protein percentage of the forage averaged 9.0, 6.2 and 5.0% for the 30, 45 and 60 days cutting intervals, respectively. Sordan 70 and Grazer A were the highest yielders with 30. or 60-day harvest intervals. Sordan 70 outyielded all the other forages at the 45-day harvest interval. All the forages had similar crude protein contents at the various cutting intervals except Sordan 70 that had a lower protein content than the other forages at the 30. and 60-day cutting intervals. All the forages produced similar yields of crude protein at the various cutting intervals except that Sordan 70 which produced more total protein than the other grasses at the 45-day harvest interval. The very high yields produced by these forages show that the semiarid irrigated region of Puerto Rico can be used to grow forage to supplement pastures in nearby grazing lands during the annual dry season.

scholarly journals Forage production of nine alfalfa cultivars in the semiarid region of Puerto Rico

1969 ◽  
Vol 72 (2) ◽  
pp. 221-230
Author(s):  
Luis E. Tergas ◽  
Jaime Vélez-Santiago ◽  
Doralissa Vera de Saldaña
Keyword(s):  
Puerto Rico ◽  
Crude Protein ◽  
Agricultural Research ◽  
Semiarid Region ◽  
Forage Production ◽  
Agronomic Practices ◽  
Overhead Irrigation ◽  
Agricultural Research And Development ◽  
Calcium And Magnesium ◽  
Development Center

Dry forage production of alfalfa (Medicago sativa) cultivars with overhead irrigation was determined by cutting every 30 to 35 days for 3 years (1983-85) at the Fortuna Agricultural Research and Development Center. Florida 66 and 77, and a mixture of these two cultivars, produced highest yields with mean annual dry forage (DF) of 25.38, 28.86 and 26.96 ton/ha, respectively. Raidor and ARC were the least productive cultivars, with means of 15.40 and 16.27 ton DF/ha, respectively. Forage production per cutting was inversely related to rainfall, highest yields were obtained with irrigation during the dry season. Mean crude protein, phosphorus, potassium, calcium and magnesium contents for all cuttings were 20.2, 0.40, 4.54, 1.39 and 0.38%, respectively. Results confirm that it is feasible to grow alfalfa for hay on well drained Cumulic Haplustolls in the southern coast with well adapted cultivars and proper agronomic practices.

scholarly journals Agronomic Comparison and In Vitro Dry Matter Digestibility of Eight Sorghums at Two Locations in Puerto Rico.

1969 ◽  
Vol 70 (1) ◽  
pp. 37-44
Author(s):  
Salvio Torres-Cardona ◽  
Antonio Sotomayor-Ríos ◽  
Fred Miller
Keyword(s):  
Puerto Rico ◽  
Leaf Area ◽  
Crude Protein ◽  
Dry Matter ◽  
Matter Content ◽  
Forage Yield ◽  
Dry Matter Content ◽  
High Positive Correlation ◽  
Dry Matter Digestibility

Eight sorghum (Sorghum bicolor L. Moench) genotypes were evaluated during four consecutive 60-day cuttings at two locations in Puerto Rico. Differences between genotypes and cuttings were significant for the eight traits studied (green forage yield, content and yield of dry matter and crude protein, in vitro dry matter digestibility, plant height and leaf area). The location x genotype interaction was significant for most traits except dry matter content and in vitro dry matter digestibility (IVDMD). At both locations the best dry forage producers over the 240-day period were ATx623 x Rio and ATx623 x TMTx430 with 34 and 30 t/ha, respectively, al Isabela; and 20 and 19 t/ha, respectively at Mayagüez. Average IVDMD and crude protein values of hybrids were 58 and 10.2%, respectively. Rio was lowest in dry forage yield but highest in IVDMD value: 62%. Leaf area had a high positive correlation with the three yield criteria. A rough estimate of net profit from growing forage sorghum in Puerto Rico for milk production is $1,211/ha.

Agronomic Comparison, Heterosis and Hydrocyanic Acid Potential (HCN-p) of Sudangrass-Sorghum and Sudangrass-Sudangrass Hybrids and Their Parents

1969 ◽  
Vol 68 (2) ◽  
pp. 143-155
Author(s):  
A. Sotomayor-Ríos ◽  
S. Torres-Cardona
Keyword(s):  
Crude Protein ◽  
Female Parent ◽  
Management Program ◽  
Hydrocyanic Acid ◽  
F1 Hybrids ◽  
Male Sterile ◽  
F1 Hybrid ◽  
Acid Potential ◽  
The Tropics ◽  
Combined Data

Cytoplasmic male-sterile sudangrass, A Rhodesian (Sorghum arundinaceum), was crossed with two sudangrasses (Sweet Sudan and Piper) and six forage sorghums (Sugar Drip, Brawley, Roma, Collier, Sumac and Meridian 55- 1). The eight F1 hybrids and their male parents were compared for yield of green forage (GF), dry forage (DF), and crude protein (CP); dry matter (DM) and CP contents; plant height, leaf area, number of tillers, leaf/stem ratio and hydrocyanic acid potential (HCN-p). The first cutting was made 60 days after planting and the two subsequent cuttings at a 60-day interval. The second harvest had the greatest DF yields but a lower CP content when compared to the first harvest. The  F1 hybrids were significantly superior than male parents for all traits except HCN-p at 45 and 60 days, leaf/stem ratio and DM and CP contents at each of the three harvests. Combined data for the three cuttings show that the  F1's of A Rhodesian x Sumac and A Rhodesian x Roma produced the greatest DF yields among hybrids. The DF yields of Sugar Drip were the highest among male parents. The average DF yield for  F1 hybrids was 19% more than for the male parents. The DF yields of about 19 t/ha of the best hybrids compared favorably with other high yielding forage sorghums. Heterosis was observed for the most important traits,  F1 hybrid A Rhodesian x Piper exhibiting the greatest value, 60 and 97% more DF than the midparent and high parent, respectively. The excellent DF yields, relatively low HCN-p values and high protein content of hybrids when A Rhodesian sudangrass was the female parent, make them potentially valuable genotypes for utilization in an intensive management program in the tropics. As in a previous study. A Rhodesian sudangrass proved to be a potentially useful male-sterile line in the development of superior F1 forage sorghum hybrids in Puerto Rico.

scholarly journals Effects of Three Harvest Intervals and Two Fertilizer Rates on the Yield and HCN Content of Ten Cynodon Cultivars

1969 ◽  
Vol 63 (1) ◽  
pp. 35-44
Author(s):  
J. Vélez-Santiago ◽  
A. Sotomayor-Ríos ◽  
S. Torres-Rivera
Keyword(s):  
Puerto Rico ◽  
Acid Content ◽  
Crude Protein ◽  
Cynodon Dactylon ◽  
Forage Yield ◽  
Protein Yield ◽  
Hydrocyanic Acid ◽  
Forage Grasses ◽  
Harvest Intervals ◽  
Fertilizer Rates

Ten forage grasses (Cynodon spp.), including recent introductions, and Stargrass (C. nlemfuensis var. nlemfuensis) were grown in the central mountains of Puerto Rico to measure the effect of two fertilizer rates and three harvest intervals on the forage yield, crude protein yield and hydrocyanic acid content (HCN) for a 2-year period. Fertilizer treatments applied after each harvest consisted of 2.24 and 4.48 metric tons/ha/year of a 15-5-10 fertilizer. Significant differences occurred between fertilizer rates as to dry forage and crude protein yields. Number of harvests per year were 6, 8 and 12 for 30-, 45- and 60-day intervals, respectively. Significant differences occurred among cultivars and harvest intervals. Cynodon dactylon (PRPI 11504), C. plectostachyus (PRPI 11487) and C. nlemfuensis var. nlemfuensis (PRPI 2341) occupied most of the top yield positions at the three harvest intervals. HCN within the cultivars ranged from 0 to 333 p/m.

scholarly journals Persistence of Hemarthria and Cynodon cultivars in mob grazing in the humid tropical region of Puerto Rico

1969 ◽  
Vol 75 (2) ◽  
pp. 147-152
Author(s):  
Rafael Ramos-Santana ◽  
José E. Rodríguez-Arroyo
Keyword(s):  
Puerto Rico ◽  
Forage Yield ◽  
The Other ◽  
Tropical Region ◽  
Forage Production ◽  
Short Day ◽  
Long Day ◽  
Weed Infestation

The persistence and dry forage production of nine accessions (8 Hemarthrias and one Cynodon) in mob grazing were measured during a 387-day period. During the short day season, accession H. altissima USDAPI 364888 produced the highest dry forage yield, but did not differ significantly (P<.05) from the others except for H. altissima USDAPI 364873 and 364875. During the long-day season, H. altissima USDAPI 364888 again produced the highest dry forage yield, not differing significantly (P<.05) from H. altissima 364873, 364875 and 409744 and C. plectostachyum 341818. For the whole 387-day period, accessions H. altissima USDAPI 364888, 364873 and 409744 and C. plectostachyum 341818 showed excellent yields in terms of consumed forage. However, no significant differences (P<.05) were observed among accessions during the period mentioned. Similarly although no significant differences (P<.05) were observed in terms of weed infestation percentages, accessions H. altissima USDAPI 364875 and C. plectostachyum USDAPI 341818 had higher weed infestation percentage than the other accessions. In terms of leaves to stem ratios C. plectostachyum USDAPI 341818 produced the highest percentages without differing significantly (P<.05) from H. altissima USDAPI 364873 and 379617.

scholarly journals Effect of four herbicides on the establishment and forage yield of stargrass in Puerto Rico

1969 ◽  
Vol 73 (2) ◽  
pp. 149-153
Author(s):  
María de L. Lugo ◽  
Li C. Liu ◽  
Carlos E. Ortiz
Keyword(s):  
Puerto Rico ◽  
Protein Content ◽  
Weed Control ◽  
Crude Protein ◽  
Forage Yield ◽  
The Other ◽  
Crude Protein Content

An experiment was performed at the AES-UPR Gurabo Substation to evaluate atrazine, simazine, diuron, and tebuthiuron for preemergence control of weeds in a stargrass pasture. Tebuthiuron at 3.36 kg a.i./ha was the most effective, and tebuthiuron at 1.68 kg a.i./ha was the second most effective. The remaining herbicides also provided satisfactory weed control. At 3.36 kg a.i./ha, tebuthiuron was somewhat phytotoxic to stargrass, but less so at 1.68 kg a.i./ha. None of the other herbicides produced severe stargrass injury. Stargrass yield was not affected by any of the herbicides. Crude protein content of stargrass was not affected by any herbicide tested.

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