EFFECTS OF WATER AVAILABILITY AND VINE HARVESTING FREQUENCY ON THE PRODUCTIVITY OF SWEET POTATO IN SOUTHERN MOZAMBIQUE. IV. RADIATION INTERCEPTION, DRY MATTER PRODUCTION AND PARTITIONING

2005 ◽  
Vol 41 (1) ◽  
pp. 93-108 ◽  
Author(s):  
F. GOMES ◽  
M. K. V. CARR ◽  
G. R. SQUIRE
Keyword(s):  
Leaf Area ◽  
Sweet Potato ◽  
Water Availability ◽  
Harvest Index ◽  
Dry Matter ◽  
Dry Season ◽  
Dry Matter Production ◽  
Storage Roots ◽  
Radiation Interception ◽  
Matter Production

In Mozambique, the sweet potato (Ipomoea batatas) is grown both as a leafy vegetable, the terminal shoots or vines being progressively harvested during the season, and as a root crop. It is produced in the dry season, in areas with a high water table or with irrigation, and in the rainy season. This paper reports the results of measurements made during the 1995 dry season to evaluate the effects of water availability and the frequency of vine harvesting on the processes of radiation interception, dry matter production and partitioning. An irrigated crop (cv. TIS 2534) with a single, end of season vine-harvest (H1) intercepted 71% of the total solar radiation, reducing to 52% with weekly (H4) harvests. The corresponding values for a rain-fed crop were 33 and 20% respectively. When the leaf area index (L) exceeded 3–4, virtually full interception of photosynthetically active radiation (PAR) occurred, except when frequent vine-harvests modified the architecture of the leaf canopy. The extinction coefficient (k, PAR) was highly variable: at a given leaf area, interception was greatest earlier in the season, with infrequent harvests and with irrigation. Total dry matter production (vines, foliage and storage roots), over a period of 161 days, reached 23 t ha−1 in the single harvest (H1), irrigated crop, less when the vines were harvested weekly (H4). The corresponding value for the rain-fed crop, which was able to resume active growth immediately after a rainfall event, following a prolonged dry period, was 7 t ha−1. The efficiency of conversion of PAR into dry matter (εs) was 2.74 g MJ−1 in the irrigated treatments combined, decreasing to around 73% of this without irrigation. The value of εs appeared not to be influenced by dry air or high temperatures. The reduction in εs due to drought was less than the corresponding reduction in intercepted PAR. Increasing the frequency of vine harvests increased the partitioning of assimilates to vines. Irrigation had similar effects early in the season, but afterwards it encouraged preferential growth of the storage roots. The end of season harvest index (h) for vines increased with harvesting frequency from, for example, 0.08 (H1) to 0.38 (H4) in the irrigated crop. By comparison, irrigation increased ‘h’ for storage roots from 0.24 (rain-fed) to 0.57 in the H1 treatment. The total harvest index (vines plus roots) increased with the number of vine harvests from 0.32 (H1) to 0.55 (H4) in the rain-fed crop, and from 0.62 (H1) to 0.72 (H4) in the irrigated crop. Clearly, ‘h’ is not a conservative parameter in the sweet potato, but is sensitive to crop management practices and to soil water availability.

Season and plant type affect the response of rice yield to nitrogen fertilisation in a semi-arid tropical environment

1998 ◽  
Vol 49 (2) ◽  
pp. 179 ◽  
Author(s):  
A. K. Borrell ◽  
A. L. Garside ◽  
S. Fukai ◽  
D. J. Reid
Keyword(s):  
Grain Yield ◽  
Harvest Index ◽  
Dry Matter ◽  
Dry Season ◽  
Dry Matter Production ◽  
Northern Australia ◽  
Plant Type ◽  
Matter Production ◽  
Early Maturing ◽  
Semi Arid

Production of flooded direct-seeded rice (Oryza sativa L.) in semi-arid tropical regions of northern Australia would be enhanced by increasing the efficiency of fertiliser nitrogen (N) use. Short-statured and early-maturing genotypes have replaced the taller and later genotypes in northern Australia, and they may respond differently to N. This paper reports the results of 4 experiments comparing the response of 3 rice genotypes differing in maturity and stature to 5 rates of applied nitrogen (0, 70, 140, 210, and 280 kg/ha) over 4 seasons (2 wet and 2 dry seasons) in the Burdekin River Irrigation Area, northern Australia. Grain yield varied among seasons and was negatively correlated with average daily mean temperature during the 30-day period before anthesis. The response of yield to N fertilisation was generally higher in the dry season. Panicle number was correlated with grain yield in both seasons, yet responded to N fertilisation only in the dry season. In 3 of 4 experiments, grain yield responded to the application of up to 70 kg N/ha, yielding about 750 g/m2. In only 1 dry season experiment did grain yield respond to the application of 140 kg N/ha, yielding about 930 g/m2. In this experiment, the response of grain yield to N rate also varied among genotypes such that yield in the early-maturing genotypes (Newbonnet and Lemont) was more responsive to N rates above 70 kg/ha than in the late-maturing genotype (Starbonnet). Of the 3 genotypes examined, highest yields were attained in Newbonnet (early-maturing, medium-statured) by combining high total dry matter production with high harvest index, indicating that this plant type may have an advantage in northern Australia. Yields in Lemont (early-maturing, short-statured) and Starbonnet (late-maturing, tall-statured) were limited by dry matter production and harvest index, respectively. There is some evidence that increased dry matter production in Newbonnet compared with Lemont was related to increased stem length. The evidence linking high harvest index with increased earliness in Newbonnet compared with Starbonnet is less compelling.

Dry Matter Production and Rate of Change of Harvest Index at High Temperature in Peanut

Crop Science ◽  
2002 ◽  
Vol 42 (1) ◽  
pp. 146 ◽  
Author(s):  
P. Q. Craufurd ◽  
P. V. Vara Prasad ◽  
R. J. Summerfield
Keyword(s):  
High Temperature ◽  
Harvest Index ◽  
Dry Matter ◽  
Rate Of Change ◽  
Dry Matter Production ◽  
Matter Production

scholarly journals Nitrogen and potassium supply and the morphogenic and productive characteristics of marandu palisadegrass

2010 ◽  
Vol 39 (8) ◽  
pp. 1666-1675 ◽  
Author(s):  
Marcio Mahmoud Megda ◽  
Francisco Antonio Monteiro
Keyword(s):  
Leaf Area ◽  
Dry Matter ◽  
System Development ◽  
Block Design ◽  
Dry Mass ◽  
Dry Matter Production ◽  
Root System Development ◽  
Randomized Block Design ◽  
Matter Production ◽  
Specific Length

The objective of this work was to study morphogenic characteristics, and dry matter production of roots and shoots of marandu palisadegrass (Brachiaria brizantha cv. Marandu) submitted to combinations of nitrogen and potassium, in a nutritive solution, employing silica as substrate. The experiment was carried out in a greenhouse during the summer. It was used a 5² fractionated factorial scheme with 13 combinations of nitrogen and potassium, which were distributed in a randomized block design, with four replications. The nitrogen × potassium interaction was significant for the number of tillers and leaves, for leaf area, for shoots and root section dry mass, for total length and surface and specific length and surface in the roots. Production of aerial part dry mass positively correlated with the number of tillers and leaves and grass leaf area. Nitrogen rates modulated the root system development, and the root specific length and surface decreased when high rates of nitrogen and potassium were supllied. Nitrogen and potassium influence Marandu palisadegrass morphogenic characteristics, which are determinant for grass dry matter production.

Changes in the hay production and the harvest index of Australian oat varieties

1963 ◽  
Vol 3 (10) ◽  
pp. 198 ◽  
Author(s):  
HJ Sims
Keyword(s):  
Harvest Index ◽  
Dry Matter ◽  
Dry Matter Production ◽  
Standard Variety ◽  
Grain Yields ◽  
Matter Production

The hay and grain yields of oat varieties currently widely grown in Australia have been compared with the old standard variety Algerian. The increased yield of the newer varieties is due almost entirely to increased grain : hay ratios (harvest index) and not to any increase in dry matter production. Only one variety in the study showed a significant improvement in dry matter production and, in this, the grain : hay ratio (harvest index) was not significantly altered.

Depressed fodder quality and increased oestrogenic activity of lucerne infected with Pseudopeziza medicaginis

1980 ◽  
Vol 31 (6) ◽  
pp. 1103 ◽  
Author(s):  
WC Morgan ◽  
DG Parbery
Keyword(s):  
Protein Content ◽  
Leaf Area ◽  
Crude Protein ◽  
Dry Matter ◽  
Dry Matter Production ◽  
Crude Protein Content ◽  
Fodder Quality ◽  
Matter Production

As well as reducing dry matter production of lucerne, infection of 15 % of the leaf area by Pseucbpeziza medicaginis reduced digestibility by 14% and crude protein content by 16%. Infection caused oestrogenic activity in green lucerne.

Growth and yield studies of Lupinus angustifolius and L. albus in Victoria

1982 ◽  
Vol 22 (115) ◽  
pp. 76 ◽  
Author(s):  
KA Boundy ◽  
TG Reeves ◽  
HD Brooke
Keyword(s):  
Grain Yield ◽  
Leaf Area ◽  
Dry Matter ◽  
Yield Component ◽  
Early Flowering ◽  
Growth And Yield ◽  
Dry Matter Production ◽  
Sowing Time ◽  
Dry Matter Partitioning ◽  
Matter Production

The effect of serial planting on dry matter production, leaf area, grain yield and yield components cf Lupinus angustifoiius (cvv. Uniwhite, Uniharvest and Unicrop) and L. albus (cv. Ultra) was investigated in field plots at Rutherglen in 1973 and 1974. Delayed planting reduced dry matter production of all cultivars, and leaf area for Ultra. Differences in dry matter partitioning were observed between the late flowering Uniharvest, and the early flowering Unicrop and Ultra. In Uniharvest, delayed plantings resulted in a greater proportion of total dry matter being produced during the flowering phase, whereas the reverse was true for Unicrop and Ultra. The later flowering cultivars showed marked grain yield and yield component reduction with later sowing. Yields were reduced by 160.6 kg/ha and 222.5 kg/ha for each week's delay in sowing Uniharvest and Uniwhite, respectively. This effect was offset in the early flowering cultivars by greater development of lateral branches. In addition, when Unicrop and Ultra were planted in April, pod and flower abortion on the main stem resulted from low temperatures at flowering time. Optimum sowing time was early April for Uniwhite and Uniharvest, and early May for Unicrop and Ultra. Excellent vegetative growth under ideal moisture conditions highlighted the poor harvest indices of lupins and the scope for genetic improvement in the genus.

AN ANALYSIS OF DRY MATTER PRODUCTION OF DOUGLAS-FIR SEEDLINGS IN RELATION TO TEMPERATURE AND LIGHT INTENSITY

1967 ◽  
Vol 45 (11) ◽  
pp. 2063-2072 ◽  
Author(s):  
Holger Brix
Keyword(s):  
Light Intensity ◽  
Leaf Area ◽  
Dry Matter ◽  
Douglas Fir ◽  
Dry Matter Production ◽  
Dry Matter Distribution ◽  
Pronounced Increase ◽  
Light Intensities ◽  
Matter Production ◽  
Net Assimilation

Seedlings of Douglas fir (Pseudotsuga menziesii (Mirb.) Franco) were grown in growth chambers under all combinations of three temperatures (13, 18, and 24 °C) and three light intensities (450, 1000, and 1800 ft-c). Dry matter production of leaves, stem, and roots was determined at 65 and 100 days after germination. The leaf area produced per unit of leaf dry weight and the dry matter distribution to the plant organs was measured. Net assimilation rates between the ages of 65 and 100 days were calculated. Rates of photosynthesis per unit of leaf were determined at different light intensities and temperatures, and rates of respiration of plant top and of roots were found for different temperatures.Increasing light intensity affected dry matter production in two opposing ways: (i) it increased the rate of photosynthesis per unit leaf area, and (ii) it decreased the leaf area added per unit of dry matter produced. A pronounced increase in growth with increase in temperature from 13 to 18 °C was a result of a temperature influence on production of leaf area rather than the effect of photosynthesis per unit of leaf. Net assimilation rates decreased with increase in temperature at all light intensities.

Effects of Time of Sowing and Phosphamidon (Dimecron) on Cowpea (Vigna unguiculata)

1974 ◽  
Vol 10 (2) ◽  
pp. 87-95 ◽  
Author(s):  
B. A. C. Enyi
Keyword(s):  
Grain Yield ◽  
Leaf Area ◽  
Vigna Unguiculata ◽  
Dry Matter ◽  
Dry Matter Production ◽  
Matter Production ◽  
Area Development ◽  
Leaf Area Development

SUMMARYApplication of dimecron to cowpea plants increased grain yield, its effect being more pronounced in widely spaced plants and those planted in March. Dimecron increased grain yield by encouraging greater leaf area development, by increasing the number of flowering inflorescences and the number of pods set per inflorescence, and by decreasing the number of shrivelled pods. March planting encouraged greater dry matter production than January and May planting. Dimecron application decreased the number of Ootheca beningseni, reduced the proportion of leaf damaged by these insects, and reduced the number of plants infested with aphids and Acidodis larvae.

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