Effects of Nitrogen on Melon (Citrillus lanatus) at Ibadan, Nigeria

1978 ◽  
Vol 14 (4) ◽  
pp. 357-365 ◽  
Author(s):  
E. A. Ogunremi

SUMMARYThree experiments testing the effects of nitrogen on melon showed significant varietal differences. Nitrogen increased yields by increasing fruits/plant, seeds/fruit and seed weight, had no effect on fruit weight, size and husk, and increased leaf area through leaf number and leaf size. Fruit growth coincided with a rapid decline in leaf area, indicating that the mottled green fruits contributed appreciable assimilates towards their own growth. The implications of the findings, and the inefficiency of the crop in seed formation, are discussed.

1997 ◽  
Vol 48 (1) ◽  
pp. 111 ◽  
Author(s):  
D. K. Singh ◽  
P. W. G. Sale

A glasshouse experiment was carried out to determine how an increasing P supply influences the growth and survival of white clover plants subjected to a range of defoliation frequencies. Treatments involved the factorial combination of P application rate (0, 30, 90, and 180 mg/pot) to a P-deficient Krasnozem soil and defoliation frequency (1, 2, or 4 defoliations over 36 days). The survival of P-deficient plants was threatened by the most frequent defoliation; their leaf area declined owing to a reduction in leaf number and individual leaf size with each successive defoliation. Increasing the P supply to 180 mg/pot reversed this downward trend as the high P plants were able to maintain leaf area by increasing leaf size and number. Increasing the frequency from 1 to 4 defoliations over the 36 days also changed the form of the leaf dry matter response to added P, from an asymptotic to a linear response. The P requirement of white clover for maximum leaf yield therefore increased under frequent defoliation. This effect was also apparent for a range of morphological measurements including stolon elongation rate, leaf area, root mass, leaf number, and stolon number, where the magnitude of the P response was consistently greater for frequently defoliated plants. Exceptions included stolon mass, which responded more to P addition under infrequent defoliation.


HortScience ◽  
2005 ◽  
Vol 40 (7) ◽  
pp. 2011-2015 ◽  
Author(s):  
Rongcai Yuan ◽  
Fernando Alferez ◽  
Igor Kostenyuk ◽  
Shila Singh ◽  
James P. Syvertsen ◽  
...  

The effects of 2 consecutive years of annual defoliation during the harvest season on fruit size, yield, juice quality, leaf size and number were examined in trees of the midseason cultivar `Hamlin' and the late-season cultivar `Valencia' orange [Citrus sinensis (L.) Osb.]. In `Hamlin', removal of up to 50% of the leaves in late November had no effect on fruit yield, fruit number, fruit size, soluble solids yield, juice °Brix, and °Brix to acid ratio of juice the following year. In `Valencia', removal of 50% of the leaves in late March decreased fruit yield and soluble solids yield but did not affect Brix or the Brix to acid ratio of the juice. Leaf size of new flush was reduced by removal of 50% of the leaves in both cultivars but there was little effect on total canopy size. There were no measured effects of removing 25% of leaves from tree canopies. Thus, canopy growth, fruit yield, fruit quality, and leaf size were not negatively impacted when annual defoliations did not exceed 25% of the total canopy leaf area in `Valencia' and `Hamlin' orange trees for two consecutive years. Overall, fruit weight increased linearly with increasing ratio of leaf area to fruit number, suggesting that fruit enlargement can be limited by leaf area.


1990 ◽  
Vol 115 (1) ◽  
pp. 39-45 ◽  
Author(s):  
Zana C. Somda ◽  
Stanley J. Kays

Changes in leaf distribution of the sweet potato [Ipomoea batatas (L.) Lam.] cultivar Jewel were assessed bi-weekly for 18 weeks at three plant densities (15, 30, and 45 cm × 96-cm spacing). The distribution of leaves on the branches and the timing at which leaf number stabilized were affected by the plant density. Plant density resulted in significant differences in the number of leaves and percentage of missing leaves during the growing season. Leaf number and total leaf area varied substantially in response to plant density, but individual lamina and petiole lengths and leaf area did not vary. Average petiole and leaf lengths and leaf size increased during the season, with the maximum length and area dependent on the type of branch on which the leaf was formed. Average petiole length per branch and the susceptibility to leaf loss increased with descending branch hierarchy (secondary branch < primary branch < main stem). Leaf losses after the 4th week tended to parallel a progressive increase in petiole length of new leaves, suggesting shading as a primary cause of leaf shedding and the loss of the oldest leaves first.


2010 ◽  
Vol 34 (1) ◽  
pp. 115-124 ◽  
Author(s):  
Roberto Santos Trindade ◽  
Adelson Paulo Araújo ◽  
Marcelo Grandi Teixeira

Low phosphorus supply markedly limits leaf growth and genotypes able to maintain adequate leaf area at low P could adapt better to limited-P conditions. This work aimed to investigate the relationship between leaf area production of common bean (Phaseolus vulgaris) genotypes during early pod filling and plant adaptation to limited P supply. Twenty-four genotypes, comprised of the four growth habits in the species and two weedy accessions, were grown at two P level applied to the soil (20 and 80 mg kg-1) in 4 kg pots and harvested at two growth stages (pod setting and early pod filling). High P level markedly increased the leaf number and leaf size (leaf area per leaf), slightly increased specific leaf area but did not affect the net assimilation rate. At low P level most genotypic variation for plant dry mass was associated with leaf size, whereas at high P level this variation was associated primarily with the number of leaves and secondarily with leaf size, specific leaf area playing a minor role at both P level. Determinate bush genotypes presented a smaller leaf area, fewer but larger leaves with higher specific leaf area and lower net assimilation rate. Climbing genotypes showed numerous leaves, smaller and thicker leaves with a higher net assimilation rate. Indeterminate bush and indeterminate prostrate genotypes presented the highest leaf area, achieved through intermediate leaf number, leaf size and specific leaf area. The latter groups were better adapted to limited P. It is concluded that improved growth at low P during early pod filling was associated with common bean genotypes able to maintain leaf expansion through leaves with greater individual leaf area.


2020 ◽  
Vol 3 (1) ◽  
pp. 32-45
Author(s):  
Abubaker H. M. Adam ◽  
Abdalla Adam Hassam Mohamed ◽  
Faiza M. A. Magid ◽  
Bahar Eldeen Z. Abakar ◽  
Mohamed M. A. Mohamed ◽  
...  

A field experiment was conducted during 2017/2018 to assess the effects of Argel (Solenostemmaargel, Del. Hayne) and Nitrogen fertilizer on the performance of two Sunflower Hybrid cultivars, with the objectives to exploit an easy, economic, and accessible organic fertilizer, the Argel in the phase of the continuous increasing prices of chemical fertilizers.. This experiment was laid out on spilt-split-plot experiment in Randomized Complete Block Design (RCBD) with four replications. Observations were taken on some agronomic traits (Plant height (m), Leaf area (LA), leaf Number (NL), Leaf Area Index (LAI) and Mean Seed Weight). The results revealed that the application of Argel and Nitrogen fertilizer have significantly increased the leaf Area (F= 7.22, P < 0.001), Plant Height (F=2.68, P < 0.2001), Leaf Number (F= 3.90, P < 0.0024), Leaf Area Index (F= 3.83, P < 0.0026) and Mean Seed Weight of both Serena and Opera cultivars respectively compared to the control. However, the different treatments of Argel and Nitrogen reflected variable degree of increase for the studied parameters. The study concludes that Argel is very promising, therefore a further study with different levels of Argel including other plant parameters is recommended.


2002 ◽  
Vol 127 (1) ◽  
pp. 13-19 ◽  
Author(s):  
Kirk W. Pomper ◽  
Desmond R. Layne ◽  
Snake C. Jones

The North American pawpaw [Asimina triloba (L.) Dunal] has great potential as a fruit crop or as a landscape plant. The influence of incident irradiance on pawpaw seedling growth and development in containers was examined in the greenhouse and outdoors. Root spiraling can be a problem for container-grown pawpaw seedlings; therefore, the influence of paint containing cupric hydroxide [Cu(OH)2] at 100 g·L-1 applied to the interior of containers on plant growth was also examined in a greenhouse environment. In pawpaw seedlings grown outdoors for 11 weeks, low to moderate shading levels of 28%, 51%, or 81% increased leaf number, total leaf area, and total plant dry weight (DW) compared to nonshaded seedlings. A shading level of 81% decreased the root to shoot ratio by half compared to nonshaded plants. Shading of 98% reduced leaf number, leaf size, and shoot, root, and total plant DW. Shading increased leaf chlorophyll a and b concentrations for pawpaw seedlings grown outdoors, while it decreased average specific leaf DW (mg·cm-2). In a separate greenhouse experiment, pawpaw seedlings subjected to shade treatments of 0%, 33%, 56%, 81%, or 98% did not respond as greatly to shading as plants grown outdoors. Greenhouse-grown plants had greater total and average leaf area under 33% or 56% shading than nonshaded plants; however, shading >56% reduced root, shoot, and total plant DW. Total shoot DW was greater in greenhouse grown plants with 33% shading compared to nonshaded plants. Pawpaw seedlings in control and most shade treatments (33% to 81%) in the greenhouse environment had more leaves and greater leaf area, as well as larger shoot, root, and total plant DW than seedlings in similar treatments grown outdoors. The greenhouse environment had a 10% lower irradiance, a 60% lower ultraviolet irradiance, and a significantly higher (1.23 vs. 1.20) red to far-red light ratio than the outdoors environment. Treatment of container interiors with Cu(OH)2 decreased total and lateral root DW in nonshaded seedlings, and it adversely affected plant quality by causing a yellowing of leaves and reduction of chlorophyll levels by the end of the experiment in shaded plants. Growth characteristics of pawpaw seedlings were positively influenced by low to moderate shading (28% or 51%) outdoors and low shading (33%) in the greenhouse. Seedlings did not benefit from application of Cu(OH)2 to containers at the concentration used in this study. Commercial nurseries can further improve production of pawpaw seedlings using low to moderate shading outdoors.


Author(s):  
V.E. Rosenzweig ◽  
◽  
D.V. Goloenko ◽  

Water supply is one of the key factors limiting soybean yield. Coming from the monsoon climate region, soybean lacks effective means of leaf surface growth restriction and is prone to produce excessive leaf area that leads to undesirable transpiration increase. Reducing branching rate and, correspondingly, leaf number per plant is usually proposed to decrease leaf area. However, as far as branching ability is generally a useful trait contributing to yield stability, we have undertaken a search for possible alternative ways of leaf area reduction. Soybean canopy structure was studied in our germplasm nursery in Kursk region. We have updated an express method of soybean trifoliate leaf surface calculation. A regression index for soybean trifoliate leaf surface by central leaflet length and width product characterizes leaflet shape and depends from its length to width ratio. In the sampling studied, trifoliate leaf surface varied from 79 to 150sq. cm. Leaf area index (LAI) varied from 4.0 to 8.6 sq. m/sq. m, with optimal LAI equal to 6.0 sq. m/sq. m. Excessive LAI (over 7.7 sq. m/sq. m) decreased yield by 20 %. Optimal LAI may be achieved by various combinations of leaf size and leaf number per plant. Lines possessing good branching rate but remaining within optimal LAI values due to small leaf size were revealed. Thus, lamina size reduction may be proposed as an alternative breeding direction to solve a conflict of bushy plant type and drought tolerance.


2020 ◽  
Vol 3 (2) ◽  
Author(s):  
Abubaker H. M. Adam ◽  
Abdalla Adam ◽  
Faiza M.A Magid

Today; there is an increasing demand for fertilizers due to the intensive and extensive agricultural activity to meet the ever increasing demand for food and fiber by the rapid world population expansion. This study is mainly concern with the Bat Guano which is usually collected from the Caves. This experiment was conducted at the Farm of the College of Agriculture, University of Bahri, Alkadaro, Khartoum North-Sudan during the period from July to November, 2017 with the objective to investigate the efficacy of Bat Guano and Nitrogen fertilizer on growth and yield of Serena and Opera (Helianthusannus, L.) Hybrid Sunflower cultivars. The study was based on split-plot experiment in randomized complete block design (RCBD) with four (4) replications. Data pertaining Plant Height (cm), Leaf Number (LN), Leaf Area (LA), Leaf Area Index (LAI) and Seed Weight (SW) were studied. The said data were analyzed using Statistic 8- software. The results reflected significant increase in plant height (F= 6.05, P < 0.0001, leaf number (F=2.37, P<0.0388), leaf area (F= 7.44, P<0.001), leaf area index (F= 6.53, P < 0.0001) and seed weight of both Sunflower cultivars respectively due to application of Guano and Nitrogen fertilizer compared to the control. It also reflected non-significant difference between all studied traits as application of either Guano or Nitrogen fertilizer. Moreover, all studied characters of the two cultivars have similarly responded to the application of the two types of fertilizers. Further studies are recommended to assess the benefits from the use of Bat Guano as a fertilizer.


2010 ◽  
Vol 148 (3) ◽  
pp. 353-361
Author(s):  
S. SRIPHADET ◽  
P. KASEMSAP ◽  
P. SRINIVES

SUMMARYThe current work was designed to compare 13 agronomic and four physiological traits in mungbean isogenic lines (ILs) with different leaflet sizes and numbers. The IL population was developed from a cross made in 2006 at Kasetsart University, Thailand, between two pure lines (one with five small and the other with seven large leaflets), followed by continuous selfing of the progenies until F6. The resulting four IL families each exhibited seven leaflet types, viz. three normal-sized leaflets per leaf, seven large leaflets, nine large, five small, seven small, nine small or 11 small. A trial was conducted in 2008 to compare the 28 ILs using a randomized complete block design with three replications. The large multiple-leaflet lines gave higher values for seeds/pod, pod size, seed weight, seed yield, leaf area, leaf area index and proportion of light interception, but fewer clusters of pods, branches and pods per plant than the small multiple-leaflet ILs. Seed yield/plant was positively correlated with pods/plant, seeds/pod, mean seed weight, light interception, leaf area and plant height at maturity. Leaflet size showed association with more traits than did leaflet number.


HortScience ◽  
2005 ◽  
Vol 40 (4) ◽  
pp. 1146B-1146
Author(s):  
Rongcai Yuan ◽  
Francisco Garcia-Sanchez ◽  
Fernando Alferez ◽  
Igor Kostenyuk ◽  
Shila Singh ◽  
...  

The effect of annual defoliation over two consecutive years on fruit yield, juice quality, leaf size, and number was examined in 11-year-old `Hamlin' and 13-year-old `Valencia' orange [Citrus sinensis (L.) Osb.] trees. Removal of up to 50% of the leaves in late November had no effect on fruit number, fruit weight, fruit yield, soluble solids yield, juice °Brix, and °Brix: acid ratio of juice in `Hamlin' oranges. In `Valencia' oranges, removal of up to 50% of the leaves in late March also did not affect °Brix or the °Brix: acid ratio of the juice, but decreased fruit yield and soluble solids yield. Leaf size was reduced by removal of 50% of the leaves in both cultivars. Removal of up to 50% leaves in late November had no significant influence on net CO2 assimilation (aCO2) of the subsequent spring flush leaves in early May in `Hamlin' oranges, whereas aCO2 of `Valencia' spring flush leaves in early May increased linearly with increasing levels of defoliation in late March. The results indicate that fruit yield, fruit quality, leaf size, and number were not negatively impacted when annual defoliations did not exceed 25% of the total canopy leaf area for `Valencia' and `Hamlin' oranges for two consecutive years. Overall, in whole `Hamlin' or `Valencia' orange trees, fruit weight increased linearly with increasing ratio of leaf area to fruit, suggesting that fruit enlargement depends on available photosynthate and can be limited by leaf area.


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