Effects of shading on the growth and nitrogen content of green panic and Siratro in pure and mixed swards defoliated at two frequencies

1980 ◽  
Vol 31 (2) ◽  
pp. 269 ◽  
Author(s):  
CC Wong ◽  
JR Wilson

A study was made of the effect of illumination at 100, 60 and 40% of sunlight on the growth of Macroptilium atropurpureum cv. Siratro and Panicum maximum var. trichoglume cv. Petrie (green panic) in pure and 50150 mixture swards, dcfoliated every 4 (D4) 01 8 (D8) weeks. The plants were grown without nitrogen fertilizer on a soil of moderate nitrogen status. Shading to 60 and 40% of full sunlight increased the shoot yield of green panic in pure sward by 30 and 27% respectively in the D8, but reduced it in the D4 treatment by 3 and 14%. Shade (40% full sunlight) reduced the shoot yield of Siratro in pure swards by 38 and 33 % in the D4 and D8 treatments. Nitrogen accumulation in green panic was markedly improved by shading: the increase in shoot nitrogen yield in pure sward under 60 and 40% light levels was 29 and 32% for the D4 and 45 and 76 % for the D8 treatment. All plant fractions of green panic increased in percentage nitrogen with increasing shade. The nitrogen yield of Siratro in pure sward declined with shading in proportion to dry weight. Shaded green panic swards had a higher leaf area index, better distribution of leaf area with height, and lower light extinction coefficients. The individual leaves had greater photosynthetic activity than those from the full sunlight swards. Shade-grown Siratro swards had a lower leaf area index and their leaves had a lower photosynthetic potential than in the full sunlight treatment. Nodulation was reduced under shade. Competition between green panic and Siratro was most severe in relation to shoot yield, and was accentuated by shading, frequent defoliation, and time. The proportion of Siratro in the mixture declined from 40 % initially to as low as 4-6 %. The extra competitiveness of the tropical grass, green panic, under shade in this experiment was due to a substantially increased ability to accumulate nitrogen and also to changes in canopy structure. In soils of markedly different nitrogen status or with nitrogen fertilizer the shade response might be modified.

2021 ◽  
Vol 4 (1) ◽  
pp. 6-13
Author(s):  
Baha Eldin. M. Idris ◽  
Wael. A. Marajan ◽  
Abubaker Haroun Mohamed Adam

Despite the existing several Sugar manufacturing companies in Sudan, there is an acute shortage in sugar supply, therefore the government imports Sugar to bridge the gap. One of the strategies to be followed is the introduction of Sugar beet (Beta vulgaris) crop, mainly for sugar production. This crop has several advantages over Sugarcane such as short duration, less water requirement, in addition to other uses like animal feed. Therefore it became necessary to have good understanding of agricultural operations, cultural practices and adaptation. However, the main objective of this study was to assess the effect of Nitrogen fertilizer and plant spacing on vegetative growth of Sugar beet. This study was conducted at the farm of the College of Agriculture, University of Bahri, Alkadro, Khartoum State-Sudan; during the season 2016/2017. The experiment was arranged in Split plot in Randomized Complete Block Design with six treatments and four replications. Two plant spacing (15 and 20 cm.) were used as main plot, referred as (S1, S2) along with three levels of Nitrogen fertilizer (40, 80 and 120 kg/ha.), as subplot; referred as (N1, N2 and N3) and the control (0). Data regarding leaf number, leaf area index (LAI), leaf dry weight (g) (LDW), root diameter (mm.) and root fresh weight were recorded and statistically analyzed. The results showed S2 (20 cm) increased all the studied plant characters, namely the leaf number (29.139), leaf area index by (7.54), leaf dry weight (g) to (89.870), root diameter (mm) (94,992), root fresh weight (g) (695.80) compared to S1(1015 cm). On the other hand; the application of N3 (120 kg/ha.) increased the lead number (30.956), leaf Area Index (8.841), Leaf dry weight (102.47), root diameter (97.955) and root fresh weight (851.77) compared to S2 and S1 as presented in (table 4, table 5 and table 6).


2011 ◽  
Vol 103 (1) ◽  
pp. 119-122 ◽  
Author(s):  
Jim Kiniry ◽  
Mari-Vaughn Johnson ◽  
Robert Mitchell ◽  
Ken Vogel ◽  
Jerry Kaiser ◽  
...  

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.


Author(s):  
Ewerton Gonçalves de Abrantes ◽  
Josinaldo Lopes Araujo Rocha ◽  
Kariolania Fortunato De Paiva ◽  
Railene Hérica Carlos Rocha ◽  
Alexandre Paiva da Silva ◽  
...  

To evaluate the effect of fertilization with N and Si on gaseous exchanges, dry mass, concentrations, accumulations and compartmentalization of nitrogen fractions in eggplant. The experimental design was a randomized entirely design, in a 5 x 4 factorial arrangement with four replications and one plant per plot, totaling 80 experimental units. The experiment was conducted in a protected environment at Center of Sciences and Agri-Food Technology of the Federal University of Campina Grande, Campus of Pombal, Paraiba, Brazil, between July and September 2016. The nitrogen doses applied was 25, 125, 250, 350 and 500 mg dm-3 and four silicon doses was 0, 75, 150 and 200 mg dm-3 both supplied by root. In pre-flowering stage were evaluated growth components; gas exchange, which are: photosynthesis, stomatal conductance, transpiration rate and intercellular CO2 concentration; levels and accumulation of fractions of nitrogen (NO3-, NH4+, and total), and the silicon concentration in the leaves. There was no significant interaction (p >0.05) between the factors nitrogen and silicon doses for any of the evaluated variables. Nitrogen and silicon doses influenced the variables evaluated only independently each other. The nitrogen doses promoted increases in the photosynthetic rate and associated variables, dry matter yield of stem leaves and roots and in the concentration and accumulations of nitric, ammoniacal and total nitrogen in leaf, stem e roots and decrease the concentration of silicon in leaves. The silicon doses increased the leaf area index, the nitrate levels and accumulation in the roots and the silicon content in the leaves. In conclusion, the nitrogen supply increased the photosynthetic rate, dry mass and nitrogen accumulation and decreased the concentrations of silicon in leaf. Silicon did not interfered with growth of eggplant, however increased leaf area index, decreased nitrate levels and accumulations in the roots at lower doses of this element.


2016 ◽  
Vol 27 (6) ◽  
pp. 1211-1217 ◽  
Author(s):  
Alexandre Behling ◽  
Carlos Roberto Sanquetta ◽  
Ana Paula Dalla Corte ◽  
Sylvio Péllico Netto ◽  
Aurélio Lourenço Rodrigues ◽  
...  

1984 ◽  
Vol 11 (4) ◽  
pp. 255 ◽  
Author(s):  
HM Rawson ◽  
RL Dunstone ◽  
MJ Long ◽  
JE Begg

Well watered mini-crops of sunflower were grown either in summer or winter in glasshouses maintained under five temperature regimes and a 16 h photoperiod. A field crop was grown concurrently with the summer glasshouse study. Summer radiation (25.5 MJ day-1) increased the size and/or number of many of the variables measured compared with winter radiation (9.5 MJ day-1). However, there was interaction between light and temperature upon phenological development, plant height, leaf number and harvest index. Seed production declined at temperatures above 18/13°C in summer and above 24/19°C in winter radiation, but fatty acid composition of the seed oil changed progressively with increasing temperature and was unaffected by radiation. Leaf area per plant increased faster under summer than winter radiation and in almost all temperature regimes reached considerably higher final values which resulted in a greater percentage of the incident radiation being intercepted. Temperature, though affecting the growth patterns and final areas of individual leaves in the canopies, did not alter the relationship between leaf area index and radiation interception. The light extinction coefficient changed with leaf area index and differed between summer and winter. Biomass per plant at maturity (B, g) was best related to radiation interception up to anthesis (I, MJ m-2), such that B = -234 + 541ogl, r2 = 0.91, but seed number (S) was correlated similarly with radiation interception and with the number of degree days (D) accumulated between floral initiation and anthesis (S = 1137+ 0.0051-0.762D, R2 = 0.90). Yield (Y, g per plant) was dependent on seed number, mean temperature (T) and radiation intercepted between anthesis and maturity, and the leaf area present at anthesis. However, over 97% of the variation in yield could be accounted for by the temperature and radiation factors in the manner Y = 39.07+0.047I- 1.26T. Harvest index and yield were not correlated for the cultivar examined.


2020 ◽  
Vol 48 (1) ◽  
pp. 44-51
Author(s):  
Resti Fadillah ◽  
Heni Purnamawati ◽  
Supijatno

Cowpea is prospective as a substitute for soybeans, as raw material for tempeh. In this study, low inputs of cowpea production is proposed. This study aimed to determine the effect of manure and nitrogen fertilizer on the growth and production of cowpea. The study was conducted at the Cikabayan Experimental Station, IPB, Bogor, Indonesia, from November 2018 to March 2019, using a split-plot design. As the main plot was goat manure rates consisted of 0, 2.5, and 5 tons ha-1. The subplots consisted of four rates of nitrogen, namely 0, 15, 30, and 45 kg N ha-1. The results showed that the application of manure increased the fresh weight of the leaf, the number of flower bunches, and the number of flowers. The application of N fertilizer increased leaf fresh weight, leaf area index, dry root weight, and shoot/root ratio at five weeks after planting. The combination of organic fertilizer with a dose of 2.5 tons ha-1 combined with 45 kg ha-1 nitrogen fertilizer tends to give better productivity than without fertilizer. Thus, cowpea can be produced using low input of manure and N. Keywords: leaf area index, leaf weight, flower bunches


Sign in / Sign up

Export Citation Format

Share Document