scholarly journals Differential Effects of Shade on Early-season Fruit and Shoot Growth Rates in `Empire' Apple

HortScience ◽  
1998 ◽  
Vol 33 (5) ◽  
pp. 823-825 ◽  
Author(s):  
M. Bepete ◽  
A.N. Lakso
Keyword(s):  
Growth Rate ◽  
Growth Rates ◽  
Dry Matter ◽  
Growth Stage ◽  
Shoot Growth ◽  
Fruit Growth ◽  
Dry Matter Partitioning ◽  
Early Season ◽  
Differential Effects

To determine relative dry-matter partitioning to early-season growth of extension shoots vs. fruits under competitive conditions in the shade, heavily cropping branch sections of `Empire' apple (Malus ×domestica Borkh.) were girdled and shaded to 15%, 40%, and 60% of available light for 9 days, while control branches were girdled and fully exposed. Treatments were applied at both 17 and 27 days after bloom, when fruit diameters averaged 13 and 23 mm, and the number of unfolded leaves on extension shoots averaged 13 and 19, respectively. Fruit diameters, extension shoot lengths, and numbers of unfolded leaves were monitored on the treated branches. Shoot growth was not affected by shading at either growth stage. Fruit growth rate was similar at 100% and 60% available light, but declined 25% at 40% available light and 50% at 15% available light. These results indicate that shoot growth has priority over fruit growth for partitioning in light-limiting conditions early in the season.

scholarly journals Factors Influencing the Chlorine Susceptibility of Mycobacterium avium, Mycobacterium intracellulare, and Mycobacterium scrofulaceum

2003 ◽  
Vol 69 (9) ◽  
pp. 5685-5689 ◽  
Author(s):  
Joseph O. Falkinham
Keyword(s):  
Growth Rate ◽  
Mycobacterium Avium ◽  
Growth Phase ◽  
Growth Rates ◽  
Growth Stage ◽  
Tween 80 ◽  
Culture Conditions ◽  
C Cells ◽  
Mycobacterium Intracellulare ◽  
Factors Influencing

ABSTRACT The susceptibility of representative strains of Mycobacterium avium, Mycobacterium intracellulare, and Mycobacterium scrofulaceum (the MAIS group) to chlorine was studied to identify factors related to culture conditions and growth phase that influenced susceptibility. M. avium and M. intracellulare strains were more resistant to chlorine than were strains of M. scrofulaceum. Transparent and unpigmented colony variants were more resistant to chlorine than were their isogenic opaque and pigmented variants (respectively). Depending on growth stage and growth rate, MAIS strains differed in their chlorine susceptibilities. Cells from strains of all three species growing in early log phase at the highest growth rates were more susceptible than cells in log and stationary phase. Rapidly growing cells were more susceptible to chlorine than slowly growing cells. The chlorine susceptibility of M. avium cells grown at 30°C was increased when cells were exposed to chlorine at 40°C compared to susceptibility after exposure at 30°C. Cells of M. avium grown in 6% oxygen were significantly more chlorine susceptible than cells grown in air. Chlorine-resistant MAIS strains were more hydrophobic and resistant to Tween 80, para-nitrobenzoate, hydroxylamine, and nitrite than were the chlorine-sensitive strains.

A quantitative examination of the growth of swards of Medicago truncatula cv. Jemalong

1979 ◽  
Vol 30 (1) ◽  
pp. 53 ◽  
Author(s):  
JH Silsbury ◽  
L Adem ◽  
P Baghurst ◽  
ED Carter
Keyword(s):  
Growth Rate ◽  
Medicago Truncatula ◽  
Dry Matter ◽  
Growth Stage ◽  
Crop Growth ◽  
Stage Ii ◽  
Yield Data ◽  
Constant Growth Rate ◽  
Sowing Time ◽  
Crop Growth Rate

Shoot dry matter yield data for swards of Medicago truncatula cv. Jemalong established on two occasions at Adelaide in 1975 have been used to examine the influence of sowing rate on the seasonal growth pattern of this species. The patterns of dry matter growth are assessed: (i) by the use of a logistic function; (ii) by a growth stage approach involving an initial phase of approximately exponential growth (stage I) followed by a phase of almost constant growth rate (stage II). Two methods are given for determining the duration of these stages. It was found that stage I1 began at a shoot dry weight of about 300 g m-2, irrespective of sowing rate. End-of-season yield at about 10 t ha-1 was largely independent of sowing time and of sowing density. A maximum crop growth rate of 14.9 g m-2 d-1 was recorded for low density and late sowing. Sowing density had a marked effect on the shape of the growth curves; both the maximum crop growth rate and the average crop growth rate in stage II decreased with increase in sowing rate for each time of sowing.

scholarly journals Interrelationship of Nitrogen and Light on Episodic Growth of Ligustrum japonicum

1994 ◽  
Vol 12 (1) ◽  
pp. 43-46
Author(s):  
Jeff S. Kuehny ◽  
Dennis R. Decoteau
Keyword(s):  
Growth Rate ◽  
Root Growth ◽  
Relative Growth Rate ◽  
Growth Rates ◽  
Shoot Growth ◽  
Fertilizer Application ◽  
Relative Growth ◽  
Mature Leaves ◽  
Episodic Growth ◽  
Ligustrum Japonicum

Abstract Exclusion of nitrogen and light from existing leaves at initiation of an episode of shoot growth decreased shoot and root relative growth rate. The combination of both nitrogen and light exclusion synergistically impacted relative growth rate for shoot (RGRs) and relative growth rate for root (RGRr). The next episode of shoot growth provided sufficient leaf area for carbohydrate assimilation and maintaining shoot and root growth rates when light was excluded from mature leaves. A better understanding of the developmental and biochemical changes of this episodic species provided useful information for timing of fertilizer application and transplanting of Ligustrum and other episodic species.

The effect of barley supplementation on the liveweight gains of autumn-born calves reared on whole or skimmed milk diets

1973 ◽  
Vol 13 (63) ◽  
pp. 360
Author(s):  
J Clark ◽  
JI Watts
Keyword(s):  
Growth Rate ◽  
Growth Rates ◽  
Dry Matter ◽  
Dry Matter Intake ◽  
Bull Calves ◽  
Whole Milk ◽  
Ad Libitum ◽  
Skimmed Milk ◽  
Four Levels

Forty, Friesian x Jersey bull calves were fed diets comprising factorial combinations of milk, either whole (4.0 per cent fat) or skimmed (0.1 per cent fat) milk, fed at the rate of 4.5 kg day-1 until the calves were ten weeks old, with crushed barley at four levels from two to 18 weeks of age. The four levels of barley were 0, 25, 50 and 75 per cent of the dry matter intake of the calves. The calves had access to hay ad libitum throughout the experiment. The restricted quantities of skimmed milk fed to the calves did not support rapid gains in liveweight, even when supplemented with high levels of barley. The addition of barley to the diet of the calves reared on whole milk produced no response in terms of growth rate (0.54 kg day-1). However, the calves reared on skimmed milk had greater growth rates when their diet contained 25 per cent barley than with no barley, 0.36 kg day-1 and 0.28 kg day-1 respectively. Further additions of barley did not produce additional responses in growth rate.

Genotypic differences in seed growth rates of Phaseolus vulgaris L. I. General characteristics, seed coat factors and comparative roles of seed coats and cotyledons

2000 ◽  
Vol 27 (2) ◽  
pp. 109 ◽  
Author(s):  
Melinda Thomas ◽  
Louise Hetherington ◽  
John W. Patrick
Keyword(s):  
Growth Rate ◽  
Growth Rates ◽  
Dry Matter ◽  
Cultivar Differences ◽  
Phaseolus Vulgaris L ◽  
Surface Areas ◽  
Parenchyma Cells ◽  
Absolute Growth ◽  
Cultivar Variation ◽  
Seed Coats

Developing seeds of four cultivars of Phaseolus vulgaris L., raised under glasshouse conditions, exhib-ited a 4-fold range in rates of storage product accumulation by their cotyledons. These growth rate differences were established during seed expansion. Patterns of dry matter distribution were consistent with absolute growth rates of cotyledons being an inherent property of developing seeds and not limited by photoassimilate supply. Seed surface areas and cotyledon volumes exhibited a 3.2-fold cultivar difference and were the principal components contribut-ing to cultivar variation in cotyledon absolute growth rates. The remaining cultivar variation was attributable to a 1.3- fold difference in dry matter fluxes, expressed on a seed surface area basis. Seed coats reflected these properties in terms of fluxes of dry matter released for cotyledon storage and surface areas supporting these fluxes. Seed coat surface areas correlated with estimates of total plasma membrane areas of ground parenchyma cells that are respon-sible for photoassimilate release. Cultivar differences in these membrane areas largely arose from variation in cell size. Coat turgor pressures correlated positively with dry matter fluxes imported into cotyledons. In contrast, sucrose concentration in bulk saps extracted from seed coats was identical across three cultivars but was positively related to growth rate in the remaining cultivar. Overall, these data suggested that cultivar dry matter fluxes were determined by variation in transport conductances for symplasmic movement through the post-sieve element pathway and for release across the plasma membranes of ground parenchyma cells. Comparable sucrose concentrations were found in seed apoplasmic saps across cultivars, and cultivar differences in absolute growth rates of in vitro cultured coty-ledons were retained. Together, these observations support the conclusion that cotyledons intrinsically express geno-typic variation in rates of dry matter transport comparable to those set independently by seed coats.

A comparison of sires of Suffolk and Dutch Texel breeds and ewes of Greyface, Suffolk Cheviot and Dutch Texel breeds in terms of food intake, prolificacy and lamb growth rates

1999 ◽  
Vol 68 (4) ◽  
pp. 567-575 ◽  
Author(s):  
S. D. Johnston ◽  
R. W. J. Steen ◽  
D. J. Kilpatrick ◽  
D. E. Lowe ◽  
D. M. B. Chestnutt
Keyword(s):  
Growth Rate ◽  
Food Intake ◽  
Growth Rates ◽  
Dry Matter ◽  
Lower Number ◽  
The Other ◽  
Lower Growth ◽  
Lamb Growth

AbstractA comparison was made over 2 years of sires of Suffolk and Dutch Texel breeds and ewes of Greyface (Border Leicester × Scottish Blackface), Suffolk Cheviot and Dutch Texel breeds in terms of food intake, prolificacy and lamb growth rates under a grass-based system of production. Suffolk Cheviot ewes consumed significantly more silage dry matter than the Greyface ewes in both years of the study. There was no overall difference between Greyface and Suffolk Cheviot ewes in terms of prolificacy. However lambs from Suffolk Cheviot ewes had a higher growth rate than lambs from Greyface ewes from birth to weaning in year 1 (P < 0·01). In the comparison of the three ewe breeds sired by Dutch Texel rams in year 2, Dutch Texel ewes produced a similar number of lambs to the other genotypes but had a higher incidence of difficult lambings, higher lamb mortality and consequently a lower number of lambs weaned. Purebred Dutch Texel male lambs had lower growth rates than crossbred Dutch Texel lambs (143 compared with 158 glday for lambs from Greyface ewes and 166 (s.e. 13.4) glday for lambs from Suffolk Cheviot ewes in year 1 and 183 compared with 251 and 248 respectively (s.e. 10.9) glday in year 2). Lambs sired by Suffolk rams had higher growth rates than those sired by Dutch Texel rams (252 compared with 224 (s.e. 5.4) glday) in year 2.

Prediction of voluntary dry-matter intake, digestible dry-matter intake and growth rate of cattle from the degradation characteristics of tropical foods

1995 ◽  
Vol 60 (1) ◽  
pp. 65-74 ◽  
Author(s):  
M. N. Shem ◽  
E. R. Ørskov ◽  
A. E. Kimambo
Keyword(s):  
Growth Rate ◽  
Growth Rates ◽  
Dry Matter ◽  
Crop Residues ◽  
Correlation Coefficients ◽  
Insoluble Fraction ◽  
Water Soluble ◽  
Dry Matter Intake ◽  
Maize Stover ◽  
Banana Leaves

AbstractAn experiment using twenty-five bulls aged between 1 and 1·5 years and weighing 117 to 209 kg was carried out to estimate voluntary dry-matter intake (DMI), digestible dry-matter intake (DDMI), dry-matter apparent digestibility (DMD) and growth rate when the bulls were given 18 foods available from smallholder dairy farms on the slopes of Mount Kilimanjaro, Tanzania. The animals were randomly allocated to five groups of five animals each. Foods were then randomly allocated to the five groups for four periods of 60 days each during which DMI was measured. A digestion trial was made at the completion of each measurement. Outflow rates of solids from the rumen were determined by giving the animals 200 g Cr-mordanted fibre of each food and grab faecal samples were obtained. Dry matter (DM) degradation characteristics of the foods were determined in sacco in the rumen of three Boran steers fed on guatemala grass and the water soluble fraction (A) was measured. DMI varied from 2·2 kg for banana pseudostem to 4·77 kg/day for urea-treated maize stover. DMD ranged from 549 for untreated maize stover to 767 g/kg DM for banana pseudostem and growth rate ranged from 72 for banana leaves to 275 glday for urea-treated maize stover. Potential degradability (defined by A + B) (where B is the insoluble fraction degradable with time) for the DM ranged from 617 g for banana leaves to 874 g/kg DM for banana pseudostem and the degradation rate (c) ranged from 0·0168 for banana leaves to 0·0440 per h for green maize stover. The separate use of degradation characteristics A, B and c in multiple regression to predict DMI, DDMI, and growth rates gave better results than when A + B or (A + B) + c were used. Multiple correlation coefficients between degradation characteristics and DMI, DDMI and group rate were r– 0·90, 0·93 and 0·93 respectively. The results indicate that DMI, DDMI and growth rates by cattle fed on crop residues and forages could be predicted well using the rumen degradation characteristics of the foods.

Sign in / Sign up

Export Citation Format

Share Document