Vigorous Early Growth Research Articles

Variability Parameters in Pearl Millet

The investigation was carried out with 65 genotypes of Pearl millet Pennisetum americanum (L) K. Shum,, comprised of 15 parents and their 50 crosses, to know the pattern of genetic variability for twelve metric traits. The genotypes showed highly significant differences for all the characters included. Almost all the traits. had high values of heritability estimates excepting early growth vigour and grain yield. Genetic coefficient of variation was high for synchrony of tillering, flag leaf area, grain yield and grain density in a ear. Selection would be effective for synchrony of tillering, ear length, grain density and 1000 grain weight.

Selection for phosphorus efficiency in corn

Abstract A total of seventy‐three U.S. corn (Zea mays L.) inbreds and hybrids were grown in the greenhouse for two to four weeks in low and high available P nutrient solutions and soils to select for phosphorus efficiency based on yield differences in a low available P medium. Variation in growth in the low P medium was partially explained by differences in early growth vigor (especially when inbreds and hybrids were compared in the same trial) but not by any apparent differences in P absorption characteristics. Seventeen hybrids with high yields in the adequate P medium and contrasting yields in the low P cultures were grown to maturity in a very low available P (5 ppm Bray 1) Berks soil (a Typic Dystrochrept) in the field with and without added fertilizer P but with other nutrients and lime adequately supplied to both treatments. The relative growth rate of these hybrids in a low P medium in the greenhouse was not correlated with their yield in the low available P soils in the field. This may be due to the relatively small differences in yield in the low P soil in the field and the strong influence of seedling vigor on early growth in the greenhouse. Based on this study, screening corn for P efficiency in the field is much more likely to succeed than are short term greenhouse screenings. Seven corn lines from Colombia and Mexico were also tested in the field for relative P efficiency. One of these (La Posta, from Mexico) appeared to be superior to any of the other U.S. or Latin American corn lines in its ability to absorb P from the soil.

Studies on the Status of Unburnt Eucalyptus Woodland at Ocean Grove, Victoria. II. The Differential Seedling Establishment of Eucalyptus ovata Labill. And Casuarina littoralis Salisb

At Ocean Grove, Vic., Eucalyptus woodland which has remained unburnt for many years is being replaced by Casuarina scrub. Neither poor germination or poor seed supply is responsible for the lack of eucalypt regeneration. However, ants harvest substantial numbers of eucalypt seeds, but not those of Casuarina. Furthermore, powdered cladode litter of Casuarina littoralis delayed germination of Eucalyptus orata substantially, but not that of its own seeds. Survival and establishment of young eucalypts is prevented by the dense grass sward, while establishment of C. littoralis, C. Stricta and Acacia pycnantha is not greatly hindered. Removal of the sward by firing promoted establishment of eucalypts. Successful establishment of A. pycnantha seedlings in the sward is largely due to vigorous early growth of roots and shoots as a result of its larger seed size. Survival of C. Littoralis in the sward is not due to rapid early development of roots and shoots, but is probably due to greater shade tolerance and/or drought resistance.

Growth patterns of Slash and Caribbean Pine and their hybrids in Queensland

Seasonal height and girth growth patterns of hybrids between Slash Pine (Pinus elliottii Engelm. var elliottii L. & D.) and Caribbean Pine (Pinus caribaea Mor. var hondurensis B. & G.) were compared with those of the parental species over one year at Beerwah Forest in southern coastal Queensland, Australia. The parental growth patterns differed markedly. Slash Pine had very vigorous early season growth, the rate then declined steadily through the later part of the season until the species entered winter dormancy. Caribbean Pine grew steadily throughout the year with late summer the most active period and winter the least. The hybrids combined the parental growth patterns with a consequent vigour advantage. Slash Pine showed a high degree of stem to stem synchronization of height growth in the early season, but much less in the later part, whilst height growth of Caribbean Pine was totally asynchronous. The hybrid was intermediate in stem to stem synchronization. The number of branch whorls produced by individual trees of Slash Pine on the main stem in the season 1965–1966 were found to be directly related to the length of the growing season for the tree concerned and also to the total height of the tree. Counts on trees at various centres in Queensland showed a decrease in branch whorl number per season with movement northwards suggesting a decrease in the length of the growing season of the species at lower latitudes. Possible physiological reasons for this are discussed.

The effects of glass cloche and coloured polyethylene tunnels on microclimate, growth, yield and disease severity of strawberry plants

SUMMARYMarked differences in the microclimate and the performance of strawberry plants were observed under glass cloches and clear polyethylene tunnels as compared with coloured polyethylene tunnels. Under glass and clear film the average air and soil temperatures were higher and fluctuated more, and the vapour pressure deficit was greater during the day, than under coloured film. The plants under glass and clear film made more vigorous early growth and cropped earlier than those under the other tunnels, but the heaviest yields were picked from plants under red and pink covers. Flowering and fruiting were delayed under green and blue covers by at least one month, and yields were comparatively small owing to poor pollination and fruit set.Both strawberry mildew (Sphaerotheca macularis (Wallr. ex Fr.) Lind.) and Botrytis fruit rot were more severe on plants under the coloured films than under glass or clear film.

Effects of Nitrogen Supply During Propagation on Flowering and Fruiting of Glasshouse Tomatoes

SummaryDuring the propagation of tomato plants, which were later stopped at the fifth truss, two levels of nitrogen were applied in factorial combination before and after initiation of the first truss. The high level of nitrogen prior to initiation produced earlier flowering and an increased weight of fruit in the first truss. Flower number and earliness of flowering of certain trusses was increased by the high level of nitrogen applied after initiation.Initially the plants grew faster and cropped earlier in response to high nitrogen, but there were no differences in either the final amount of growth or the final crop. The constancy of the final crop was explained in terms of the concept of a fixed fruit load.Under the conditions of light in this experiment the results did not suggest that vigorous early growth was detrimental.

Pasture establishment on a podzolised soil in Northland

Summary Trials were conducted on a strongly podzolised soil, Wharekohe silt loam, to detcrmine nutrient deficiencies hindering the establishment of clovers. White and subterranean clovers were used as indicator plants. Phosphate deficiency is acute, and 4 cwt per acre of superphosphate at sowing is inadequate. High rates of lime are necessary to ensure good nodulation and vigorous early growth. Liming can induce a boron deficiency and at higher levels a copper deficiency. The quantities of lime adequate to establish pastures successfully are not likely to induce a copper deficiency. Boron deficiency in white clover is not likely to appear after initial application of lime but may do so after subsequent liming. Boron deficiency symptoms exhibited by the leaves. roots, and nodulation of subterranean clover are described. This clover is more susceptible to boron deficiency than is white clover. Lime-pelleted clover seeds should be most effective in supplying adequate lime for good noduhtion, without inducing a boron deficiency. White clover can be successfully established, provided adequate phosphate, potassium, and lime are supplied. Subterranean clover is more difficult to establish, and the necessary conditions for successful establishment have not been defined. A magnesium deficiency may appear after some years.

On the Culture of Upland Rice by Early Transplanting in a Cool Region

Present study has been curried out from 1956 to 1958, for the purpose of security as well as yield increase in the culture of upland rice in a cool region. The important remarks concluded throughout this study are as follows: (1) In the transplanted groups, an early heading. date and a high percentage of available stems are observed as compared with the direct-sowned, thus the yield of grain increases from 40 to 60 per cent. It is seen also that it increases with the number of ears in every varieties of the transplanted. (2) As the growing period of rice is short in Tohoku district, it is necessary to secure the number of ears in the early season, by the selection of good seedlings and dense planting (3, 000 hills per one are and about 5 seedlings per one hill) in accompany with the good rooting. Therefore, it is advisable to be cultivated in the fields having the irrigation facilities. As the fertilizer, it is desirable to put a large amount of phosphate. That is, in the rich phosphate groups, a good growth of rice plant after transplanting, a large number of ears and a tendency of early heading are observed as compared with the poor ones. (3) It seems at present that such a paddy-rice variety as Fujisaka No. 5 is more suitable for transplanting than uplan-drice varieties, because Fujisaka No. 5 shows a good rooting, a vigorous early growth anh a little lodging by dense planting in a cool region.

Seed values of the pieces in relation to their position in the mother tuber from which they were cut, and of the whole tubers raised from aerial tubers in relation to their size, for early harvesting in Chinese yam

It is well known that the Chinese yam grown on sandy soils has good appearence and excellent quality, matures early, and is easily dug up at harvest. Therefore, it is one of the important crops in the sandy soil area of Tottori Prefecture. This report deals with the results of some experiments on the productivity of the seed tubers in relation to their position in the mother tuber from which they were cut, or to their size, on the sandy soil. 1. Pieces of 56.3g each were taken from various parts (from top to base) of long mother tubers, and were planted as seeds. The pieces cut from the top portion of the mother tubers germinated earliest, made most vigorous early vine growth, and produced highest early yield. As the position of the seed piece was far apart from the top, its germination was delayed, its yield of new tubers became less, though there was little difference among several sections of the basal portions. 2. Whole tubers which had been cultivated for one year from the aerial tubers are prefered as seeds, since they are less likely to be rotted after planting than the cut pieces. Tubers of from 37.5 to 150g were compared on their productivity in early harvesting (middle of August). The result revealed that the larger the size of the seed tuber, the higher was the early yield of new tuber, within the range of the size tested. To obtain of good size (750g or more) in middle August, it was desirable to use the seed tubers of larger size (112.5 to 150g).

The Problem Of “Potato Sickness”: A Report Upon Certain Experiments

Summary.1. A study of the causes of “potato sickness” has been made during the past two years, both in the field and by means of pot experiments.2. The sickness does not occur in the absence of the nematode H. schachtii, but potato plants may grow normaliy even when heavily attacked by this eelworm. No correlation was found between the cyst content of the soil and the intensity of the sickness.3. There is no reason to suspect that the fungus C. Solani plays any primary part in causing the sickness, and no other parasitic organism (apart from the eelworm) likely to be responsible for the trouble was discovered.4. The evidence suggests that the sickness is due to an attack by the eelworm in conjunction with a soil factor that inhibits a vigorous early growth of roots; it is possible that this second factor is a nutritional defect which is not made good by the ordinary manurial measures adopted in potato‐growing districts.