Influence of early haulm killing of seed crops on subsequent sprouting, physiological ageing and tuber yield

1989 ◽  
Vol 32 (1) ◽  
pp. 3-7 ◽  
Author(s):  
Mabel Panelo ◽  
D. O. Caldiz

1986 ◽  
Vol 107 (1) ◽  
pp. 83-101 ◽  
Author(s):  
P. J. O'Brien ◽  
E. J. Allen

SUMMARYNine experiments are reported in which effects of site of seed production on dormancy, sprout and field growth of progeny tubers were recorded. The experiments used early varieties, Home Guard (four experiments), Red Craigs Royal (three experiments) and Arran Comet (two experiments) and in each, seed crops were grown with similar husbandry at sites differing in altitude and location in western England and Wales. There was no consistent effect of site of seed production on the timing of the end of dormancy, and the maximum effect in any year was 11 ± 1·2 (S.E.) days. The small effects of site on dormancy influenced initial sprout lengths, and this effect usually persisted up to planting in Home Guard and Red Craigs Royal, although the effects were small in magnitude. There was no effect of site of seed production on sprout lengths at planting or on field growth and yields in Arran Comet. In the other two varieties there was no effect of site of seed production on yield at early harvests, but at later harvests seed from cooler upland sites sometimes significantly outyielded lowland seed. There was, therefore, no evidence to support the view that locally produced seed was advantageous for early potato production. The results, together with those of the concurrent series with maincrop varieties reported by Wurr (1979), show that on half the occasions on which yields were measured covering the whole of the harvesting period, site of seed production had no effect on yields. In these experiments with early varieties effects of site occurred only at harvests later than the commercial harvesting of such old seed. It is therefore suggested that site of seed production is a much less important determinant of tuber yield than hitherto suggested, and of little practical significance.



PLoS ONE ◽  
2021 ◽  
Vol 16 (8) ◽  
pp. e0255536
Author(s):  
Yasin Bedrettin Karan

Disease-free and superior quality seed tubers could be obtained by haulm (vine) killing, which also reduces weight loss during storage. Higher resistance during storage ensures that seed tubers will be at the desired physiological age at the time of planting. The use of healthy seed tubers of appropriate physiological age will have positive impact on yield and quality. This study aimed to investigate the effects of haulm killing on seed potato yield and yield components (total tuber yield, average tuber yield/plant, number of tubers and average tuber weight) under semi-arid climate of Artova district in Tokat province, Turkey. The field studies were carried out during potato growing seasons of 2017 and 2018. The experiment consisted of two factors, i.e., potato cultivars and haulm killing. Five different potato cultivars, i.e., ‘Agria’, ‘Marabel’, ‘Hermes’, ‘Marfona’ and Madeleine were included in the study. The haulm killing treatments were ‘haulm killing’ and ‘no haulm killing’. Haulm killing positively affected the number of tubers per plant and average tuber weight, which are directly related to the tuber yield. Tuber seed yield in the first and second year with haulm killing treatment was 40.78 and 44.05 tons/ha, respectively. The yield without haulm killing in the first and second years was 37.78 and 38.76 tons/ha, respectively. The dry matter ratio of tubers with haulm killing was 21.89% in 2017 and 22.35% during 2018. The dry matter ratio of tubers without haulm killing was 20.57% in 2016 and 21.03% during 2017. The results revealed haulm killing had positive impact on yield, yield-related parameters and dry matter content of seed tubers. Therefore, haulm killing is recommended for higher yield and better quality of seed tubers.



1986 ◽  
Vol 107 (2) ◽  
pp. 307-327 ◽  
Author(s):  
P. J. O'Brien ◽  
J. L. Jones ◽  
E. J. Allen ◽  
G. S. M. Raouf

SummaryFour experiments are reported in which the effects of a range of physiological ages of seed tubers on growth and yield in seed crops and regrowth of the progeny seed were studied. Increasing the age of seed in Home Guard, Arran Comet, Pentland Javelin and Désirée advanced emergence, tuber initiation and early growth but restricted leaf area index and reduced the number of tubers and seed tuber yield. In these varieties increasing the physiological age of seed shortened the dormancy of the progeny seed and slightly increased sprout lengths at replanting but in Home Guard had no effects on field growth and tuber yield.In a further series of experiments at Tenby seed of five varieties (Home Guard, Red Craigs Royal, Désirée, Maris Piper and Stormont Enterprise) was multiplied over 2 years using husbandry methods designed to produce seed of contrasting ages. Once-grown seed from Tenby which had been planted and harvested early in the season was stored at either 4 or 12 °C and grown again at Tenby before being stored again at either 4 or 12 °C. The seed resulting from this multiplication over 2 years was compared with seed imported from seed-growing areas stored at the two temperatures. The seasons for the two multiplications at Tenby (1975 and 1976) were hot and were followed by an especially cold and late spring yet few differences between seed from Tenby and other areas could be detected. Where seed from different areas entered sprouting temperatures at different times and therefore produced different ages of seed at replanting large effects on yield were found. Storage temperature had large effects on regrowth of tubers in Home Guard, Red Craigs Royal and Stormont Enterprise for storage at 12 °C produced ‘little potato disorder’ in the majority of plants in one storage phase while storage at lower temperature produced full plant stands and yields. The results provided no support for the suggestion that repeated multiplication in warm lowland areas may lead to cumulative deterioration in the performance of seed.



Author(s):  
R. Horrell ◽  
A.K. Metherell ◽  
S. Ford ◽  
C. Doscher

Over two million tonnes of fertiliser are applied to New Zealand pastures and crops annually and there is an increasing desire by farmers to ensure that the best possible economic return is gained from this investment. Spreading distribution measurements undertaken by Lincoln Ventures Ltd (LVL) have identified large variations in the evenness of fertiliser application by spreading machines which could lead to a failure to achieve optimum potential in some crop yields and to significant associated economic losses. To quantify these losses, a study was undertaken to calculate the effect of uneven fertiliser application on crop yield. From LVL's spreader database, spread patterns from many machines were categorised by spread pattern type and by coefficient of variation (CV). These patterns were then used to calculate yield losses when they were combined with the response data from five representative cropping and pastoral situations. Nitrogen fertiliser on ryegrass seed crops shows significant production losses at a spread pattern CV between 30% and 40%. For P and S on pasture, the cumulative effect of uneven spreading accrues, until there is significant economic loss occurring by year 3 for both the Waikato dairy and Southland sheep and beef systems at CV values between 30% and 40%. For nitrogen on pasture, significant loss in a dairy system occurs at a CV of approximately 40% whereas for a sheep and beef system it is at a CV of 50%, where the financial return from nitrogen application has been calculated at the average gross revenue of the farming system. The conclusion of this study is that the current Spreadmark standards are a satisfactory basis for defining the evenness requirements of fertiliser applications in most circumstances. On the basis of Spreadmark testing to date, more than 50% of the national commercial spreading fleet fails to meet the standard for nitrogenous fertilisers and 40% fails to meet the standard for phosphatic fertilisers.Keywords: aerial spreading, crop response, economic loss, fertiliser, ground spreading, striping, uneven application, uneven spreading, yield loss





2019 ◽  
Vol 45 (5) ◽  
pp. 714
Author(s):  
Yu-Zhang CHEN ◽  
Hui-Hui TIAN ◽  
Ya-Wei LI ◽  
Yu-Wei CHAI ◽  
Rui LI ◽  
...  


1979 ◽  
Vol 71 (4) ◽  
pp. 671-675 ◽  
Author(s):  
M. Philip Rolston ◽  
W. Orvid Lee ◽  
Arnold P. Appleby
Keyword(s):  


2020 ◽  
Vol 7 (03) ◽  
Author(s):  
S. K. YADAV ◽  
R. K. SINGH ◽  
V. K. DUA ◽  
S SINGH ◽  
SARALA YADAV ◽  
...  

A field experiment was carried out during 2015-16 and 2016-17 at ICAR-Central Potato Research Station, Patna, Bihar, in randomized block design with four replications with objective to quantity the optimum requirement of nitrogen to potato crop. Significantly the highest plant height was recorded with nitrogen level of 300 kg/ha. Distributions of the smallest size of tuber yield of potato were decreasing with increasing the level of nitrogen. There was about 26.0% more yield of the smallest size tuber of potato was recorded with zero nitrogen as compare to the highest level of nitrogen i.e. 300 kg/ha. Increasing the nitrogen over the level of 150 to 225 kg per hectare, increasing the yield of tuber gradually slower rate than nitrogen level from 0 to 150 kg/ha. Total and marketable tuber yield of potato were increasing significantly with increasing level of nitrogen up to 150 kg/ha. There was no significant difference in marketable tuber yield was found for nitrogen level between 150 and 225 kg/ha. Highest (1.66) net benefit cost ratio was also recorded with level of nitrogen @ 150 kg/ha in potato. Hence, application of nitrogen @ 150 kg/ha was found statistically and economically more beneficial for potato cultivation in Eastern Indo-Gangatic plain of India.



Helia ◽  
2001 ◽  
Vol 24 (35) ◽  
pp. 25-32 ◽  
Author(s):  
Janoš Berenji ◽  
Vladimir Sikora

SUMMARYThe objective of this paper was to estimate the genetic and ecological variation as well as the stability of tuber yield per plant, tuber number per plant and tuber size of Jerusalem artichoke based on the results of a variety trial carried out with 20 different Jerusalem artichoke varieties during the period of 1994-2000. Significant genetic as well as ecologycal variation was observed for all of the traits studied. The most promissing varieties showing high tuber yield combined with high yield stability were “BT-4”, “Violet Rennes” and “UKR 4/ 82”. It is encouraging that the highest yielding varieties exibited a rather stable performance over environments.



Thorax ◽  
2001 ◽  
Vol 56 (6) ◽  
pp. 450-455
Author(s):  
E Mund ◽  
B Christensson ◽  
K Larsson ◽  
R Grönneberg

BACKGROUNDAge related changes in the immune system have been studied frequently but a possible relation to sex has not, to our knowledge, previously been examined. The effect of age and sex on the composition of lymphocyte subsets in bronchoalveolar lavage (BAL) fluid and peripheral blood was therefore examined.METHODSBronchoscopy with lavage was performed in 32 healthy non-atopic, non-smoking volunteers (16 women aged 26–63 years (mean 44) and 16 men aged 23–63 years (mean 39)). Cytospin preparations for differential counts of BAL fluid cells and surface antigen expression of lymphocytes from BAL fluid and blood were analysed by flow cytometry.RESULTSMost parameters in the BAL fluid changed with age in women. The percentage of CD4+ lymphocytes increased with age from a mean of 48 (SD10)% in women aged ⩽40 years to 69 (11)% in women aged >43 years (p=0.001). The percentage of CD8+ lymphocytes tended to decrease with age and the CD4/CD8 ratio was 5.8 (1.2) in women aged >43 years compared with 2.1 (0.7) in those aged ⩽40 years (p<0.0001). Women aged >43 years differed from men aged >43 years as well as from younger subjects of both sexes with respect to CD4+ cells and CD4/CD8 ratio, and from younger women with respect to CD8+ cells. There was no age related change in the CD4/CD8 ratio in blood. No sex related differences were seen in the blood or BAL fluid of adults below the age of 40 years.CONCLUSIONSThe composition of lymphocytes with different phenotypes in the lower respiratory tract changes with age in women but not in men. This may have implications for some clinical conditions such as chronic dry cough which are observed predominantly in women.



Sign in / Sign up

Export Citation Format

Share Document