CONTRIBUTION OF STEMS AND LEAVES TO THE YIELD AND NUTRIENT LEVEL OF IRRIGATED ALFALFA AT DIFFERENT STAGES OF DEVELOPMENT

1974 ◽  
Vol 54 (4) ◽  
pp. 739-742 ◽  
Author(s):  
M. R. KILCHER ◽  
D. H. HEINRICHS

In Roamer alfalfa (Medicago media Pers.) the nutritive value in leaves deteriorated much more slowly than that in stems. The percentage of N declined 29% in leaves and 49% in stems; percentage P declined 4% in leaves and 34% in stems, and percentage digestible energy declined 3% in leaves and 34% in stems between early leaf and late bloom growth stages. The total yield of nutrient increased rapidly to the early bloom stage, but quite slowly thereafter. Because of possible leaf loss, delayed harvesting of an alfalfa crop beyond the mid-bloom stage would not be warranted to gain yield even when only one cutting is taken.

2003 ◽  
Vol 83 (2) ◽  
pp. 319-326 ◽  
Author(s):  
B. L. Johnson

Growth compensation of dwarf sunflower (Helianthus annuus L.) hybrids to low initial stands, later stand losses, or plant defoliation has not been reported regarding replanting decisions and crop insurance yield loss assessment. Three experiments were conducted to study the affect of stand reduction, defoliation, and row spacing on dwarf sunflower yield and quality when grown in eastern North Dakota. Experiment 1 evaluated stand reduction (0, 25, 50 and 75%) applied at growth stages (V4, R1 and R6) in 15, 45 and 76 cm spaced rows. Row spacing interactions with stand reduction and growth stage were not significant for yield indicating growth stage and stand reduction effects on yield response were independent of row spacing. In exp. 2, significant growth stage (V4, V8, R1, R2, R3, R5 and R6) by stand reduction (0, 12, 25, 37, 50, 62 and 75%) interaction showed stand reduction at vegetative growth stages not influencing yield, but as maturity progressed yield reductions became greater with increased stand reduction. Achene weight increased with increasing stand reduction at vegetative and early reproductive stages. A reciprocal relationship was noted between achene weight and achene oil content where oil content decreased as achene weight increased. Interaction of growth stage (R1 and R6) and defoliation (0, 25, 50, 75 and 100%) in exp. 3 indicated greater reduction in yield, test weight, 1000-achene weight, and achene oil conte nt as defoliatin increased at growth stage R6. Yield compensating ability of dwarf sunflower is dependent on type and level of damage and growth stage of occurrence, with total yield reduction considering all effects. Key words: Sunflower, Helianthus annuus L., row spacing, stand reduction, defoliation


Author(s):  
J. Hill ◽  
J.D. Leaver

Whole crop wheat (WCW) is a relatively new crop as a feed for dairy cows, and little information is available on its dry matter yield and nutritive value relative to stage of growth at harvest. Also, the role of urea (which hydrolyses to ammonia in the crop) addition in reducing fermentation and aerobic spoilage losses has not been investigated.The aim of this experiment was to examine three stages of growth at harvest for WCW, with and without urea.An area of winter wheat (cv Fortress) was cut (5 cm above ground) at three growth stages (GS 49, 71 and 87). The resultant forages were chopped through a precision-chop harvester and stored in air-tight barrels of 0.225 m3 capacity. Urea was added at 0 and 40 g/kgDM at each stage of growth and there were three replicates of each treatment. Thermocouples placed centrally were used to monitor temperature changes. The mini silos held approximately 100 kg of forages and they were opened after 90 days. Vertical cores were taken as samples and the mini silos were left open for a further 18 days to assess aerobic deterioration.


1993 ◽  
Vol 73 (2) ◽  
pp. 411-419 ◽  
Author(s):  
Bruno J. Marty ◽  
Eduardo R. Chavez

The influence of different heat treatments for full-fat soybeans (FFSB) on digestible energy (DE) values and fecal nutrient digestibilities was studied using 180 castrated male Landrace pigs at three different growth stages: weaner (17.1 ± 0.2 kg), grower (32 ± 0.2 kg) and finisher (61.6 ± 0.3 kg). The soybean products used in weaner (30%), grower (25%) and finisher (20%) diets were soybean meal (SBM) or FFSB processed by either extrusion (Ex), jet sploding (Js), micronization (Mi) or roasting (Ro). Digestibilities were determined by total fecal collections during the last 7 d of each 12-d period. Dry matter (DM) and neutral detergent fiber (NDF) digestibilities of FFSB were lower (P < 0.05) in weaner than in grower or finisher pigs, but DE values and apparent digestibilities of crude protein (CP) and ether extract were not influenced by growth stage. Extruded FFSB had a superior CP digestibility than the other soybean products (86.4 vs. 79.8, 79.8, 80.0 and 78.2% for Js, Mi, Ro and SBM, respectively), and it also had a higher DE value (21.0 vs. 20.0, 19.6, 18.5 and 16.6 MJ DE kg−1 DM, P < 0.05). Extrusion of FFSB was most beneficial for weaner pigs as this heat treatment resulted in higher (P < 0.05) CP (87.8 vs. 80.9, 80.8, 82.1 and 76.6% for Js, Mi, Ro and SBM, respectively) and NDF (76.2 vs. 62.7, 63.3, 61.9 and 53.8% for Js, Mi, Ro and SBM, respectively) digestibilities. The heat treatments did not influence the CP and NDF digestibilities during grower or finisher stages. The data suggested that extrusion of FFSB yielded superior DE values and CP digestibilities than other heat treatments. Key words: Full-fat soybean products, extrusion, digestibility, pigs


1997 ◽  
Vol 77 (4) ◽  
pp. 579-585 ◽  
Author(s):  
Donald J. Thompson ◽  
Darryl G. Stout

In the interior of British Columbia, spring barley (Hordeum vulgare L.) and Italian ryegrass (Lolium multiflorum var. italicum Beck.) are intercropped with fertilizer N as a 1-yr break before reseeding irrigated alfalfa (Medicago sativa L.). Persian clover (Trifolium resupinatum L.) was seeded with barley and ryegrass or only ryegrass to determine its effect on seasonal yield and forage nutritive value. All species mixtures were grown with and without a total of 200 kg ha−1 of N to compare N2 fixation by Persian clover with N fertilizer. Averaged over 2 yr, adding Persian clover to barley-ryegrass provided a total yield that was 96% of that obtained by adding fertilizer N to barley-ryegrass. Second cut yield averaged 58% more with clover than with N. However, the grasses yielded more than the grasses with added clover in the third cut. Adding clover to ryegrass provided 94% of the total yield of adding N fertilizer. Persian clover was higher in crude protein and in vitro digestibility of dry matter than ryegrass, so adding clover tended to improve the nutritive value of mixtures. This was most obvious without N, where Persian clover accounted for more of the total forage produced. The study shows that Persian clover is a valuable addition to barley-ryegrass mixtures; it reduces fertilizer needs, improves mid-season yield and improves forage nutritive value. Key words: Persian clover, barley, Italian ryegrass, forage mixtures


1968 ◽  
Vol 71 (1) ◽  
pp. 67-71 ◽  
Author(s):  
W. L. Johnson ◽  
W. A. Hardison ◽  
A. L. Ordoveza ◽  
L. S. Castillo

SummaryDry-matter intake (D.M.I.) fromPanicum maximum(guinea grass) was studied in digestibility trials with Holstein and water buffalo bulls and in a feeding trial with lactating cows.Differences in voluntary D.M.I. per unit body weight0·73between the Holsteins and water buffaloes were not significant. Average D.M.I. for all bulls in all main trials was 2·16 kg per 100 kg B.W. Average D.M.I. by the lactating cows was 2·08 kg per 100 kg B.W., for all practical purposes the same as for the bulls.D.M.I. was not related to stage of maturity or season of harvest of the guinea grass. Intakes of digestible protein, T.D.N., and digestible energy in different seasons and at different growth stages were related to the percentage of those nutrients in the grass.Correlation coefficients were 0·68 between D.M.I. and B.W.0·73, 0·59 between D.M.I. and T.D.N. content, and 0·58 between D.M.I. and crude protein content, D.M.I. was not closely related to dry-matter content (r= 0·30) or crude fibre content (r= 0–01) of the guinea grass.


2011 ◽  
Vol 25 (2) ◽  
pp. 222-229 ◽  
Author(s):  
Kristin K. Rosenbaum ◽  
K. W. Bradley ◽  
Craig A. Roberts

Separate field trials were conducted in 2007 and 2008 to investigate the effects of increasing densities of common ragweed or common cocklebur on total yield and forage nutritive values in tall fescue pastures. Common ragweed densities ranged from 0 to 188 plants m−2, and common cocklebur densities ranged from 0 to 134 plants m−2. Total biomass yields (weeds plus tall fescue) were determined in response to each weed density and species; pure samples of tall fescue, common ragweed, or common cocklebur were also hand collected from each plot at the time of the total biomass harvest. Near-infrared spectroscopy was used to predict crude protein (CP) concentration and in vitro true digestibility (IVTD) of the total harvested biomass, pure tall fescue, and pure weed species in each plot. Results indicate that biomass yields may increase by as much as 5 kg ha−1with each additional common ragweed plant m−2within a tall fescue stand. Additionally, CP concentration of the total harvested biomass, pure weed species, and tall fescue decreased by 0.2 to 0.4 g kg−1with each additional increase in common ragweed or common cocklebur plant per m−2. As weed densities increased, IVTD of pure tall fescue samples increased only minimally (0.04%), regardless of the weed species. An increase in common ragweed density also resulted in the CP concentration of pure samples of common ragweed to decrease by 0.2 g kg−1for each additional plant per m2and by 0.4 g kg−1for each additional common cocklebur per m2. Overall, results from these experiments indicate that plant biomass yield and nutritive values of the total harvested biomass are only marginally influenced by increasing common ragweed or common cocklebur densities.


2010 ◽  
Vol 61 (5) ◽  
pp. 379 ◽  
Author(s):  
N. L. Teakle ◽  
A. Snell ◽  
D. Real ◽  
E. G. Barrett-Lennard ◽  
T. D. Colmer

Perennial legumes are needed for productive pastures in saline areas. We evaluated 40 lines of Lotus tenuis for tolerance to salinity at both germination and vegetative growth stages. Salt tolerance during the early vegetative stage was assessed in a sand-tank experiment with NaCl concentrations of 0–450 mm NaCl for 5 weeks. Most L. tenuis lines were more salt tolerant and had at least 50% lower shoot Na+ plus Cl– (% dry mass (DM)) compared with some other common pasture legumes, Medicago sativa, M. polymorpha and Trifolium subterraneum. Within L. tenuis significant variation in salt tolerance was found, with C50 values (concentrations of NaCl that decreased shoot dry matter to 50% of control) ranging from ~100 to 320 mm. Shoot concentrations of Cl–, Na+ and K+ did not always correlate with salt tolerance; some tolerant lines had low shoot Na+ and Cl– (and thus better nutritive value), while others tolerated high shoot Na+ and Cl–. We also found variation within L. tenuis for salt tolerance of seeds, with lines ranging from 0 to 70% germination after recovery from a prior exposure to 800 mm NaCl for 15 days. There was no relationship between salinity tolerance of scarified seeds and subsequent growth of seedlings; therefore, testing of seeds alone would not be an appropriate screening method for salt tolerance in L. tenuis. This study of 40 L. tenuis lines has shown significant genetic variation for salt tolerance within this species, and we have identified key lines with potential to be productive in saltland pasture systems.


2019 ◽  
Vol 7 ◽  
pp. 60-68
Author(s):  
S.H. Mohammed ◽  
Maarouf I. Mohammed

Maize (Zeamays L.) forage quality traits are reported to show varying responses to abiotic stress. Four trials were conducted in Sudan (Africa) during the summer and winter seasons (2013 – 2014) at two locations: Shambat (normal soils) and Soba (salt affected soils) to investigate the effects of abiotic stress on the nutritive value of maize forage. In each trial nine maize genotypes were studied under two watering regimes arranged in split plot experiment in randomized complete block design. The compound effect of salt, water and heat stresses created by the combination of locations, seasons and watering regimes were used to investigate the effect of abiotic stress on forage quality at silk initiation and dough growth stages. Character associations under stressed and none stressed conditions were studied. NDF, ADF, CP, forage yield and related traits were measured. Abiotic stress significantly lowered the nutritive value in terms of crude protein, digestibility and intake potential. Digestibility under stressed condition was slightly improved as growth stage advanced from silk initiation to dough stage. Correlations under non stress conditions between forage yield and quality traits were either favorable with NDF and weak or insignificant with ADF and CP. Under stress conditions, similar trend generally exists apart from the unfavorable correlation of CP with each of yield and ADF, in addition to earliness with NDF. The compound effect of salt, water and heat stresses have adverse impact on the nutritive value of maize forage. Varieties combining high performance in quality and forage yield could be developed under non-stressed or stressed conditions.


2000 ◽  
Vol 53 ◽  
pp. 103-108
Author(s):  
M.G. Cromey ◽  
M. Braithwaite ◽  
B.J.R. Alexander ◽  
S. Ganev ◽  
T.R. Cookson

Two field trials were conducted in autumnsown wheat cv Domino which is highly susceptible to speckled leaf blotch in Central and South Canterbury Eighteen fungicide treatments were applied at two growth stages (tillering and ear emergence) at the manufacturers recommended rates Severity of speckled leaf blotch and other diseases was assessed on several occasions Speckled leaf blotch was severe in the South Canterbury trial but only low levels of the disease were recorded in the central Canterbury trial Most fungicides reduced disease severity and increased yield especially in the South Canterbury trial where disease pressure was highest and yield increases greater than 30 were recorded The second fungicide application appeared to provide most of the increase in yield The increases in thousand grain weights following fungicide applications contributed approximately onethird of the total yield increases in the South Canterbury trial and half in the Central Canterbury trial


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