scholarly journals Effect of Three Harvest Intervals on Yield and Composition of Nineteen Forage Grasses in the Humid Mountain Region of Puerto Rico

1969 ◽  
Vol 60 ◽  
pp. 294-309
Author(s):  
A. Sotomayor-Ríos ◽  
J. Vélez-Santiago ◽  
S. Torres-Rivera ◽  
S. Silva
Keyword(s):  
Puerto Rico ◽  
Crude Protein ◽  
Sharp Decrease ◽  
Significant Negative Correlation ◽  
Forage Yield ◽  
Mountain Region ◽  
Forage Grasses ◽  
Average Temperature ◽  
Harvest Intervals ◽  
Positive Correlations

The response of 19 forage grasses to three cutting intervals in the humid mountain region of Puerto Rico was evaluated. Nine Brachiarias, nine Digitarias, and one Cynodon species were evaluated during a 2-year period under cutting management at the Corozal Substation for green forage (GF), dry forage (DF), and crude protein (CP) yields and for dry matter (DM), crude protein (CP), Ca, P, K, and Mg contents. In terms of green forage yield (GFY), the most productive species at the 30-day harvest interval was D. setivalva (PRPI 6402) with 86,794 kg/ ha/year. At the 45- and 60-day harvest intervals, Brachiaria sp. (PRPI 9626) produced 102,116 and 109,213 kg/ha/year, respectively. This species also produced the highest DFY at the 30-day harvest interval with 18,430 kg/ha/year. C. nlemfuensis, var. nlemfuensis (PRPI 2341), stargrass, and B. decumbens (PRPI 5365) produced the highest DFY at the 45- and 60-day intervals with 21,758 and 27,238 kg/ha/year, respectively. The highest CP content at the 30-, 45-, and 60-day intervals was observed on the three Digitaria hybrids, D. pentzii x D. smutzii (PRPI 9621), D. pentzii x D. milanjiana (PRPI 9619), and D. pentzii x D. pentzii (PRPI 9620) with 14.3, 12.0, and 11.1 %, respectively. D. decumbens (PRPI 6439), 'Transvala' Digitgrass, produced the highest CP yield at the 30-day harvest interval with 2, 179 kg/ha/year. Stargrass had the highest CP yield at the 45- and 60-day harvest intervals with 2,141 and 2,030 kg/ha/year, respectively. The P, Ca, Mg, and K contents of the 19 grasses on the average decreased as the harvest interval increased. A sharp decrease (from 1.81 to 1.47 to 1.42%) of the K content of the grasses was observed at the 30-, 45-, and 60-day intervals, respectively. The GFY, DFY, and DM of the 19 grasses increased on the average with the length of the harvest interval. On the other hand, the CP content and yield of the 19 grasses decreased as the harvest interval increased. No significant correlation was obtained between total rainfall, CP, and DFY of the 19 grasses. Significant positive correlations were obtained between DFY of the 19 grasses and average temperature. A significant negative correlation was obtained between average temperature and CP content.

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 Comparison of Six Stylosanthes Cultivars and Digitaria Milanjiana in the Humid Mountain Region of Puerto Rico

1969 ◽  
Vol 68 (4) ◽  
pp. 355-364
Author(s):  
J. Vélez-Santiago ◽  
J. A. Arroyo-Aguilú
Keyword(s):  
Puerto Rico ◽  
Crude Protein ◽  
Ground Level ◽  
Mountain Region ◽  
Above Ground Level ◽  
Stylosanthes Guianensis ◽  
Harvest Intervals ◽  
Cutting Interval ◽  
Calcium And Magnesium ◽  
Forage Yields

Five Stylosanthes guianensis cultivars (Fine Stem, Endeavour, Schofield, USDA PI 361877, and USDA P1279603), Stylosanthes gracilis USDA Pl261266, and Digitaria milanjiana USDA PI 299699 were grown in small replicated plots at the Corozal Substation in the humid mountain region. All legumes were established in a period of 134 days and nodulated freely. The swards were harvested every 45 (9 cuttings) and 65 days (6 cuttings) at 20 cm above ground level, respectively. Forage yields and chemical composition were measured in each plot. Subsequently the same 65-day cutting interval swards were subjected to 5 additional cuttings, whereas the 45-day swards were substituted by a 79-day interval and 4 cuttings. D. milanjiana outyielded the 6 stylos in dry forage at the 3 cuttings intervals. Highest yielder among the stylos was cultivar Fine Stem, which produced total dry forage yields of 18,522, 18,936, and 11,329 kg per ha in 395-, 390-, and 316-day periods at 45-, 65-, and 79-day harvest intervals, respectively. At 45-day intervals, cultivar Fine Stem yielded more crude protein than the rest of the stylo cultivars. There was no difference in protein yields between cultivar Fine Stem and D. milanjiana at the 45- and 65-day harvest intervals. Stylo cultivars and D. milanjiana produced similar crude protein yields at the 79-day intervals. The stylo cultivars were higher in nitrogen, calcium and magnesium contents than D. milanjiana at all harvest intervals.

Effects of Harvest Intervals on the Yield and Composition of 10 Forage Grasses

1969 ◽  
Vol 58 (4) ◽  
pp. 448-455
Author(s):  
A. Sotomayor-Ríos ◽  
F. J. Juliá ◽  
J. A. Arroyo-Aguilú
Keyword(s):  
Crude Protein ◽  
Dry Matter ◽  
Dry Matter Yield ◽  
Forage Grasses ◽  
Mineral Absorption ◽  
Digitaria Decumbens ◽  
Harvest Intervals ◽  
Digitaria Eriantha ◽  
Digestible Protein ◽  
Cynodon Nlemfuensis

The effect of three harvest intervals (30, 45 and 60 days) on the yield, crude protein (CP), digestible protein (DP), and mineral (calcium, Ca; phosphorus, P; potassium, K; and magnesium, Mg) composition of 10 forage grasses was determined during a 1-year period at the Isabela Substation. The species studied included three Brachiarias, five Digitarias and two Cynodons. As the 30-day harvest interval, the dry matter yield (DMY) ranged from 25,859 to 19,041 pounds per acre per year. The highest DMY was obtained by Transvala digitgrass (Digitaria decumbens, PRPI. 6439) Stargrass (Cynodon nlemfuensis PRPI. 2341) had the highest CP and DP contents. The highest DMY at the 45-day interval was obtained by Transvala digitgrass, being significantly different (P < .05) from other grasses. The DMY ranged from 29,532 to 20,962 pounds per acre per year. Digitaria eriantha had the highest CP and DP contents. Stargrass had the highest DMY and CP at the 60-day harvest interval. The DMY ranged from 37,504 to 30,269 pounds per acre per year. Mean Ca and Mg contents in the grasses increased at the 45-day interval, with no Ca increase but a Mg decrease at 60 days. Mean P and K contents decreased as the harvest intervals increased. The yielding ability of the grasses was encouraging, especially in the Transvala digitgrass and Stargrass species. The CP and DP contents tended to vary as plants matured, suggesting that studies of mineral absorption and/or utilization of forage grasses by niminants should be undertaken.

Nitrogen Fertilization and Cutting Frequency, Yield and Chemical Composition of Five Tropical Grasses

1969 ◽  
Vol 67 (2) ◽  
pp. 61-69
Author(s):  
J. Velez-Santiago ◽  
J. A. Arroyo-Aguilu
Keyword(s):  
Crude Protein ◽  
Dry Matter ◽  
N Fertilization ◽  
Forage Grasses ◽  
Digitaria Decumbens ◽  
Tropical Forage ◽  
Cutting Frequency ◽  
Harvest Intervals ◽  
Agricultural Experiment ◽  
Cynodon Nlemfuensis

Five tropical forage grasses: Star (Cynodon nlemfuensis), Transvala digit (Digitaria decumbens), Pangola (Digitaria decumbens) and two Limpos (Hemarthria altissima, Bigalta and Greenalta), were cultivated without irrigation for 1.5 years at the Corozal Agricultural Experiment Substation to study the effects of 3 N fertilization levels and 3 harvest intervals (30, 45, and 60 days) on the green forage (GF), dry forage (DF), and crude protein (CP) yields and on the dry matter (DM), CP, P, and K contents. The soil is a Corozal clay (Uitisol). N levels, as (NH4)2SO4, applied after each harvest, included low, 224; medium, 448; and high, 896 kg/ha/yr. P and K were applied at rates of 112 and 336 kg/ha/yr, respectively. DM content and DF and CP yields increased significantly with longer harvest intervals. The medium N level resulted in the highest CP yields, except in the case of Star grass, in which high N fertilization gave greater CP yield. Bigalta, Star, and Transvala digit cultivars exhibited the highest GF, DF, and CP yields. DF yields (means across the 3 harvest intervals and the 3 N levels) for Bigalta, Greenalta, Transvala, Star, and Pangola grasses were 35,421; 29,209; 31 ,699; 32,383; and 24,461 kg/ha/yr, respectively.

scholarly journals Effect of Three Harvest Intervals on the Yield and Protein Content of Ten Brachiarias

1969 ◽  
Vol 65 (2) ◽  
pp. 147-153
Author(s):  
A. Sotomayor-Ríos ◽  
J. Rodríguez-García ◽  
J. Vélez-Santiago
Keyword(s):  
Puerto Rico ◽  
Protein Content ◽  
Crude Protein ◽  
Dry Matter ◽  
Brachiaria Humidicola ◽  
Harvest Intervals ◽  
Signal Grass

Ten Brachiarias were evaluated during an 18-month period at various harvest intervals at the Corozal Substation for yields of green forage (GF), dry forage (DF), and crude protein (CP), and for contents of (CP) and dry matter (DM). At the 30-day harvest interval, the most productive introduction was Brachiaria humidicola (P.I. 299497), with 119,567 and 22,548 kg/ha/year of GF and DF, respectively. Para grass (B. mutica) and B. ruziziensis (P.I. 247404) had the highest DM content, 22.5%. Para grass also had the highest CP yield, 2,961 kg/ha/year. At the 45-day harvest interval, B. humidicola (P.I. 299497) had the highest GF yield, 160,459 kg/ha/year, while para grass had the highest DM content, 22.5%. Para grass was the highest DF yielder, with 31,338 kg/ha/year, and B. humidicola (P.I. 299497) was the highest CP yielder, with 3,787 kg/ha/ year. At the 60-day harvest interval, B. humidicola (P.I. 299497) was the highest GF yielder, with 146,318 kg/ha/year, while para grass had the highest DM content and DF and CP yields, 25.9%, 36,946 kg/ha/year, and 3,264 kg/ha/ year, respectively. The GF and DF yields increased with length of the harvest interval. The DM contents, however, were similar at the 30- and 45-day intervals and higher at the 60-day interval. The CP yields increased from 2,651 kg/ha/year at the 30-day harvest interval to 2,912 kg/ha/year at the 60-day harvest interval. The DF and CP yields of B. humidicola (P.I. 299497), para grass, signal grass (B. brizantha, P.R. P.I. 1525), and others were excellent and compared favorably with those of the recognized top-yielding grasses 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 Forage Yield of Five Grasses Under Intensive Grazing Management in the Humid Region of Puerto Rico

1969 ◽  
Vol 64 (3) ◽  
pp. 259-263
Author(s):  
Edmundo Rivera ◽  
José Rodríguez
Keyword(s):  
Puerto Rico ◽  
Large Scale ◽  
Forage Yield ◽  
Grazing Management ◽  
Yield Potential ◽  
Experimental Plot ◽  
Forage Grasses ◽  
Humid Region ◽  
Second Year ◽  
Intensively Managed

Three grasses on intensively managed and grazed 10 x 10 m plots produced statistically similar yields of dry forage over a 3-year period expressed in kg/ha/yr as follows: Stargrass—12,445; Coast Cross #1—12,285; and Hemarthria PI 299995—13,685. Hemarthria PI 299994 produced significantly higher yields—15,370 kg/ha/yr. Cynodon plectostachyus, on the other hand, did not tolerate intensive grazing and produced only 4,695 kg/ha during the second year. Yields of Star and Hemarthria PI 299995 were comparable to yields obtained in a large scale grazing experiment nearby, which confirmed the validity of the small experimental plot technique in determining yield potential of grazed forage grasses.

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 Yield and Protein Content of Millo Blanco (Sorghum bicolor) and Two F1 Hybrids

1969 ◽  
Vol 61 (3) ◽  
pp. 300-304
Author(s):  
A. Sotomayor-Ríos ◽  
L. Telek
Keyword(s):  
Puerto Rico ◽  
Sorghum Bicolor ◽  
Crude Protein ◽  
Forage Yield ◽  
Male Parent ◽  
F1 Hybrids ◽  
Forage Crops ◽  
Mean Values ◽  
Growing Period ◽  
Forage Yields

Millo blanco (MB), Sorghum bicolor (L.) Moench, and two F1 hybrids (Redlan x MB and CK-60 x MB) were compared for yields of green forage (GF), dry forage (DF), crude protein (CP) content, CP yield, and height at Isabela, Puerto Rico. Six cuttings were made, the first, 58 days after planting and the remaining five, approximately every 30 days. The first harvest produced the highest forage yields. Dry forage yields (DFY) of 7,700 kg/ha produced by CK-60 x MB were 27.3% more than those of the male parent. The CP content of the three genotypes 58 days after planting was about 16% and crude protein yield (GPY) of 1,362 kg/ha was observed on CK-60 x MB, 33% more than that of MB. Although forage yields of the three genotypes were reduced at 30 day harvest intervals, the CP remained high and mean values of 18% were obtained. The GFY of Redlan x MB (118,519 kg/ha) during the 211-day growing period was 16.6% higher (P < .05) than that of the male parent MB. CK-60 x MB had 18.7% more DFY and 21.2% CPY than MB (P < .05). No significant differences in height and CP content were observed among the three genotypes. The forage yields and high CP content obtained on MB and the two F1 hybrids were excellent. The results indicate that these genotypes, especially the MB F1 hybrids, are potentially good forage crops for Puerto Rico.

scholarly journals Yield, Crude Protein, and Chemical Composition of Five Napier Grass Cultivars on the Northwestern Coastal Plains of Puerto Rico

1969 ◽  
Vol 67 (2) ◽  
pp. 70-78
Author(s):  
J. Velez-Santiago ◽  
J. A. Arroyo-Aguilu ◽  
S. Torres-Rivera
Keyword(s):  
Puerto Rico ◽  
Crude Protein ◽  
Sandy Loam ◽  
Forage Yield ◽  
Napier Grass ◽  
Pennisetum Purpureum ◽  
Coastal Plains ◽  
High Input ◽  
Loam Soil ◽  
Forage Yields

Five Napier grass cultivars (Pennisetum purpureum Schum.) were evaluated under cutting management on a Bayamón sandy loam soil on the northwestern coastal plains of Puerto Rico for a period of 2.05 years without irrigation. Grasses received a high input of fertilizer (4,484 kg/ha/yr) and were harvested every 5') days. Mean dry forage yield for cultivars PRPI 13079, 7350, Merker, 13078, and 532 were 46755, 45449, 39439, 38816, and 37581 kg/ha/yr, respectively. Cultivars 13079 and 7350 had similar dry forage yields, which were significantly (P < .05) higher than those of the remaining cultivars. Cultivar 7350 was the highest crude protein yielder, with 5413 kg/ ha/yr. Mean crude protein, P, K, Ca, and Mg contents for the 5 cultivars were 11.44, .37, 2.56, .31, and .34%, respectively. Leaf/stem ratios for all cultivars ranged from a maximum of 60 to a minimum of 52%. Cultivars 13079 and 7350 are the most outstanding grasses for this region of Puerto Rico. Cultivars 13078 and 532 are recommended as substitutes for the Merker cultivar. However, cultivar 13078 yields can be adversely affected by prolonged droughts.

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