Foliage and canopy characteristics in relation to aboveground dry matter increment of seven jack pine provenances

1986 ◽  
Vol 16 (3) ◽  
pp. 464-470 ◽  
Author(s):  
S. Magnussen ◽  
V. G. Smith ◽  
C. W. Yeatman

This paper reports on foliage and tree size data collected in 1984 in an Ontario Pinusbanksiana Lamb, (jack pine) provenance trial established in 1954 at the Petawawa National Forestry Institute, Chalk River, Ont. The ratio of total needle area to needle dry weight of seven provenances showed a substantial within-tree, between-tree, and between-provenance variation that was associated with position within the tree and the average provenance tree size. Provenance mean values ranged from 11.7 to 14.3 m2/kg. The highest values were found in the tallest trees. Tree size and dry matter content varied significantly among provenances, but the relative growth rates of stem volume and aboveground biomass between the ages of 29 and 34 years averaged 5.7 and 4.9% per year in all provenances respectively. Aboveground dry matter production per hectare per year increased linearly with increasing projected leaf area index. The average increase was 1.9 t dry matter per l m2 increase in the leaf area index. Projected leaf area indices for optimally stocked stands averaged 5.0 m2/m2. The results indicated an almost constant net assimilation rate of 1.9 g aboveground dry matter per square decimetre of projected foliage per year in all provenances. Canopy foliage area was strongly correlated with basal area at 1.3 m and stem cross-sectional area at the base of the live crown. Total foliage area per unit basal area averaged 0.31 m2/cm2 at breast height and 0.70 m2/cm2 in the live crown. No significant differences were found between provenances.

2012 ◽  
Vol 51 (No. 5) ◽  
pp. 213-224
Author(s):  
F. Tokár ◽  
E. Krekulová

In the paper we evaluate the influence of crown thinning with positive selection, different intensity (moderate PRP III and heavy PRP IV) and 5-year frequency on development of growth, production, quality and leaf area index of black walnut (Juglans nigra L.) monocultures growing on the series of three permanent research plots (PRP) Sikenica (Levice Forest Enterprise, Levice Forest District) as observed in 1978&ndash;2003. The trends of development of mean stem, basal area, standing volume and aboveground dendromass (in dry matter) were mainly influenced by heavy crown thinning. The index of growth was as follows: basal area 169.01%, standing volume 262.12%, aboveground dendromass (in dry matter) 324.48%. At the age of 64 years the black walnut monocultures tended by heavy crown thinning had the following parameters: basal area 31.03 m<sup>2</sup>/ha, standing volume 463.88 m<sup>3</sup>/ha and aboveground dendromass 194.98 t/ha. Mean periodic increment reached the values: basal area 0.51 m<sup>2</sup>/ha/year, standing volume 11.48 m<sup>3</sup>/ha/year and dendromass 5.39 t/ha/year. The index of increment percent growth was: basal area + 31.75%, growing stock + 30.85% and dendromass + 0.79%, compared to the control. The total production was also significantly influenced by heavy thinning. At the stand age of 64 years the tended stands had the total basal area of 4.92 m<sup>2</sup>/ha, total volume production of 572.77 m<sup>3</sup>/ha and total weight production of 246.04 t/ha. The total mean increment of basal area is 0.67 m<sup>2</sup>/ha/year, of volume 8.95 m<sup>3</sup>/ha/year and of weight 3.84 t/ha/year, which is by 24.07%, 23.96% and 16.01% more than on the control plot. The leaf area index at the age of 64 years ranges from 6.54 ha/ha (PRP III) to 7.82 ha/ha (PRP V). Dendrochronological analyses revealed minimum widths of annual rings in the years 1952, 1961, 1968, 1971, 1975, 1981, 1983, 1985, 1993, 2000, maximum ones in 1951, 1957, 1959, 1967, 1974, 1979, 1982, 1984, 1989, 1999.


1996 ◽  
Vol 72 (2) ◽  
pp. 170-175 ◽  
Author(s):  
Margaret Penner ◽  
Godelieve Deblonde

Relationships between leaf area and sapwood area, sapwood area and basal area, and leaf area and basal area growth are determined for jack pine and red pine. The relationships vary with species and stand origin. Growth efficiency (basal area growth per unit leaf area) is relatively independent of tree size under all but the densest conditions. Observed changes in the leaf area to leaf mass ratio from July to October indicate that allometric relationships vary seasonally. A procedure is outlined for obtaining estimates of stand leaf area index (LAI). These estimates may be used to calibrate instruments that measure LAI and, subsequently, to predict forest productivity. Key words: leaf area index, basal area, growth efficiency, red pine, jack pine, sapwood area


2017 ◽  
Vol 14 (2) ◽  
pp. 147-154 ◽  
Author(s):  
MM Kamrozzaman ◽  
MAH Khan ◽  
S Ahmed ◽  
N Sultana

An experiment was conducted at Sadipur charland under Farming System Research and Development Site, Hatgobindapur, Faridpur, during rabi season of 2012-13 and 2013-14 to study the growth and yield performance of cv. BARI Gom-24 as affected by different dates of sowing under Agro-ecological Zone-12 (AEZ-12) of Bangladesh. The experiment was laid out in randomized complete block design with six replications, comprising five different dates of sowing viz. November 5, November 15, November 25, December 5 and December 15. Results reveal that the tallest plant, leaf area index, total dry matter, and crop growth rate were observed in November 25 sown crop and leaf area index, total dry matter and crop growth rate were higher at booting, grain filling, and tillering stages of the crop. Maximum effective tillers hill-1 (3.49), spikes m-2, (311), number of grains spike-1 (42.20) and 1000-grain weight (52.10 g) were produced by November 25 sown crop exhibited the highest grain (4.30 t ha-1) and straw yield (4.94 t ha-1) as well as harvest index (46.88%) of the crop. Lowest performance was observed both in early (November 5) and late sown crop (December 15). The overall results indicated that November 25 sown crop showed better performance in respect of growth and yield of wheat under charland ecosystem of Bangladesh.J. Bangladesh Agril. Univ. 14(2): 147-154, December 2016


1982 ◽  
Vol 18 (1) ◽  
pp. 93-100 ◽  
Author(s):  
S. U. Remison ◽  
E. O. Lucas

SUMMARYTwo maize cvs, FARZ 23 and FARZ 25, were grown at three densities (37,000, 53,000 and 80,000 plants/ha) in 1979 and 1980. Leaf area index (LAI) increased with increase in plant population and was at a maximum at mid-silk. Grain yield was highest at 53,000 plants/ha. There was no relation between LAI and grain yield but there was a positive correlation between LAI and total dry matter yield.


Author(s):  
Faid Abdul Manan ◽  
Muhammad Buce Saleh ◽  
I Nengah Surati Jaya ◽  
Uus Saepul Mukarom

This paper describes a development of an algorithm for assessing stand productivity by considering the stand variables. Forest stand productivity is one of the crucial information that required to establish the business plan for unit management at the beginning of forest planning activity. The main study objective is to find out the most significant and accurate variable combination to be used for assessing the forest stand productivity, as well as to develop productivity estimation model based on leaf area index. The study found the best stand variable combination in assessing stand productivity were density of poles (X2), volume of commercial tree having diameter at breast height (dbh) 20-40 cm (X16), basal area of commercial tree of dbh &gt;40 cm (X20) with Kappa Accuracy of 90.56% for classifying into 5 stand productivity classes. It was recognized that the examined algorithm provides excellent accuracy of 100% when the stand productivity was classified into only 3 classes. The best model for assessing the stand productivity index with leaf area index is y = 0.6214x - 0.9928 with R2= 0.71, where y is productivity index and x is leaf area index.


1978 ◽  
Vol 90 (3) ◽  
pp. 569-577 ◽  
Author(s):  
G. O. Iremiren ◽  
G. M. Milbourn

SummaryTotal dry-matter yield of maize silage rose asymptotically as density was increased up to 17 plants/m2. Over the range 11–17 plants/m2, which is generally higher than is used in the U.K., the increase in yield was 1–1·6 t dry matter/ha which can justify the higher seed cost and although there was no adverse affect on time of maturity the risk of lodging increased at the highest density. During the harvest period whilst whole crop dry-matter percentage was rising from 23 to 28%, the ear dry-matter content rose steadily from 29 to 35%, whereas the leaf and stem dry-matter content remained essentially constant and only dried out at a later stage after a frost.Caldera 535 had a higher leaf area index and net assimilation rate than the earlier variety Julia which it outyielded by 15%. The additional yield was mainly stem tissue and the greater vegetative production caused an 11-day delay in reaching the silage stage of maturity (25% crop D.M.). NO differences occurred between density treatments and varieties in the forage quality components considered, namely percentage drymatter digestibility, modified acid-detergent fibre, crude protein and ash. Thus in U.K. conditions, total dry-matter yield exerts an overriding influence on the yields per unit area of these quality constituents. This contrasts with reports from the U.S.A. in which a reduced grain/stover ratio adversely influences silage quality.Removal of the whole ear (including husk and rachis) at an early stage in ear development resulted in a 50% reduction in the final dry-matter yield. In the earless plants, leaf area and net assimilation rate was lower, but the dry-matter content of the leaves and stem was considerably higher, and a marked purple coloration developed indicative of excess starch concentration. These results emphasize the need in maize silage not only for an adequate leaf canopy, best obtained early in the growing season by using high planting density and subsequently by using late maturing varieties, but also for sufficient sink capacity in the ear as well as in the stem fraction.


2016 ◽  
Vol 40 (5) ◽  
pp. 845-854 ◽  
Author(s):  
Domingos Mendes Lopes ◽  
Nigel Walford ◽  
Helder Viana ◽  
Carlos Roberto Sette Junior

ABSTRACT Leaf area index (LAI) is an important parameter controlling many biological and physiological processes associated with vegetation on the Earth's surface, such as photosynthesis, respiration, transpiration, carbon and nutrient cycle and rainfall interception. LAI can be measured indirectly by sunfleck ceptometers in an easy and non-destructive way but this practical methodology tends to underestimated when measured by these instruments. Trying to correct this underestimation, some previous studies heave proposed the multiplication of the observed LAI value by a constant correction factor. The assumption of this work is LAI obtained from the allometric equations are not so problematic and can be used as a reference LAI to develop a new methodology to correct the ceptometer one. This new methodology indicates that the bias (the difference between the ceptometer and the reference LAI) is estimated as a function of the basal area per unit ground area and that bias is summed to the measured value. This study has proved that while the measured Pinus LAI needs a correction, there is no need for that correction for the Eucalyptus LAI. However, even for this last specie the proposed methodology gives closer estimations to the real LAI values.


1984 ◽  
Vol 20 (2) ◽  
pp. 161-170
Author(s):  
D. Boobathi Babu ◽  
S. P. Singh

SUMMARYThe effects of irrigation and spraying of transpiration suppressants on growth and nutrient uptake by spring sorghum (CSH 6) have been investigated. Crop growth, measured by plant-height, leaf area index and dry matter production, and uptake of N, P and K increased with more frequent irrigation and in response to the spraying of transpiration suppressants. Foliar applications of atrazine at 200 g ha−1 and CCC at 300 ml ha−1 proved to be the best in this NW Indian location.


Agronomy ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 232
Author(s):  
Nangial Khan ◽  
Fangfang Xing ◽  
Lu Feng ◽  
Zhanbiao Wang ◽  
Minghua Xin ◽  
...  

The number of cotton plants grown per unit area has recently gained attention due to technology expense, high input, and seed cost. Yield consistency across a series of plant populations is an attractive cost-saving option. Field experiments were conducted to compare biomass accumulation, fiber quality, leaf area index, yield and yield components of cotton planted at various densities (D1, 1.5; D2, 3.3; D3, 5.1; D4, 6.9; D5, 8.7; and D6, 10.5 plants m−2). High planting density (D5) produced 21% and 28% more lint yield as compared to low planting density (D1) during both years, respectively. The highest seed cotton yield (4662 kg/ha) and lint yield (1763 kg/ha) were produced by high plant density (D5) while the further increase in the plant population (D6) decreased the yield. The increase in yield of D5 was due to more biomass accumulation in reproductive organs as compared to other treatments. The highest average (19.2 VA gm m−2 d−1) and maximum (21.8 VM gm m−2 d−1) rates of biomass were accumulated in reproductive structures. High boll load per leaf area and leaf area index were observed in high planting density as compared to low, while high dry matter partitioning was recorded in the lowest planting density as compared to other treatments. Plants with low density had 5% greater fiber length as compared to the highest plant density, while the fiber strength and micronaire value were 10% and 15% greater than the lowest plant density. Conclusively, plant density of 8.7 plants m−2 is a promising option for enhanced yield, biomass, and uniform fiber quality of cotton.


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