scholarly journals Leaf Growth and Canopy Development of Three Sugarcane Genotypes under High Temperature Rainfed Conditions in Northeastern Mexico

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Sergio Castro-Nava ◽  
Alfredo J. Huerta ◽  
José Manuel Plácido-de la Cruz ◽  
Epifanio Mireles-Rodríguez

The aim of this study was to compare sugarcane (Saccharumspp.) canopy developmental components of three commercial varieties (CP 72-2086, Mex 79-431, and Mex 68-P-23) in a subtropical environment under rainfed and high temperature conditions, a poorly described topic in the literature. A field experiment was carried out in southern Tamaulipas, Mexico, throughout November 2011–January 2013 crop cycle, during which 111 of the days had daily maximum temperatures at or above 35°C. Number of leaves, leaf area, leaf appearance rate, and leaf area index (LAI) were determined. Thermal time exposure, °Cd (°C day−1), was determined based on total number of green ligulate leaves using 10°C as the base temperature. At 5000°Cd the number of leaves per plant ranged from 32 to 40 and the dependence of leaf emergence rate as a function of temperature was confirmed. The leaf emergence rate of CP 72-2086 was significantly greater than that of the other two varieties. Cultivars did not differ with respect to leaf length but differed for all other parameters measured. These results show the potential importance of considering sugarcane varietal differences in leaf phenology and canopy development for breeding programs focusing on rainfed and high temperature conditions.

Author(s):  
M Mataa ◽  
P Cheelo ◽  
D Lungu ◽  
T Kinkese

The objective of the study was to identify the grafting method, which will have a higher success rate of scion development. The study was conducted at Mount Makulu Central Research station in Chilanga, Zambia (15o33’S / 28o11’E) from April 2010 to November 2011. The study had 4 vegetative propagation methods that varied in the treatment of the rootstock and scion. The four methods were Standard T- budding (STB); Modified TBudding with decapitation (TBD); T- budding with scion bending (TBB); Crown grafting (CG). Bud take, shoot growth, leaf emergence and Leaf area index were measured up to 11 weeks after treatment (WAT). With CG there was 100 % bud take. STB had a bud take of 58.3 %. TBD had a bud take of 50 %. The lowest bud take percentage was recorded in TBB, which had a bud take of 41.7 %. At 5 weeks the STB and TBB treatment had shoot length of 0.7 and 1.0 cm respectively which were the shortest; this was followed by the CG treatment at 15.3 cm and the modified TBD with apical shoot decapitation (21.7 cm). STB shoots did not start growing until about 5 weeks, which was 2 weeks after the rootstock was cut off. At 5 weeks, the TBB and STB were yet to form leaves. The CG had close to 20 leaves and the TBD had almost 15.2 leaves. At the end of 11 weeks, the TBB had the highest number of leaves. Across the grafting methods; the Leaf area exhibited a pattern similar to leaf number; it kept on doubling every 2 weeks to until the 9th week after which the increase was negligible. At 11 weeks, the highest leaf area was in the TBD followed by the STB and lowest in the CG treatment.Int. J. Agril. Res. Innov. & Tech. 7 (1): 64-70, June, 2017


1979 ◽  
Vol 93 (2) ◽  
pp. 291-307 ◽  
Author(s):  
E. J. Littleton ◽  
M. D. Dennett ◽  
J. Elston ◽  
J. L. Monteith

SUMMARYThe pattern of leaf growth and death was followed in stands of cowpea grown in the field at Ibadan, Nigeria. Temperature affected this pattern. Leaf area index increased quicker and leaf death started sooner during warm seasons. Individual leaves died while pods at the same node were filling. The rate of leaf appearance increased with temperature and the duration of expansion of individual leaves decreased so that a constant number of leaves were expanding at one time. The mean rate of expansion of individual leaves increased with temperature proportionately more than the duration decreased, hence final leaf size increased with temperature. Base temperatures for leaf appearance and leaf expansion were 16 and 20 °C respectively.


Horticulturae ◽  
2021 ◽  
Vol 7 (10) ◽  
pp. 369
Author(s):  
Federico J. Ladux ◽  
Eduardo R. Trentacoste ◽  
Peter S. Searles ◽  
M. Cecilia Rousseaux

Tree densities have increased greatly in olive orchards over the last few decades. In many annual crop species, increased density reduces the horizontal red/far-red (R/FR) and blue/green (B/G) ratios during canopy development even before direct shading occurs, and such changes are known to alter plant morphology. This study with olive trees evaluated: (1) whether the leaf area index (LAI) of neighboring trees modifies the light quality environment prior to a tree being directly shaded and (2) the potential morphological responses of three olive cultivars to changes in light quality. Increasing LAI using different spatial arrangements of potted, three-year-old trees reduced the horizontal R/FR ratio more than that of the B/G ratio. Cultivar-specific responses to low R/FR ratio were observed for individual leaf area and aboveground/belowground biomass ratio using laterally positioned FR mirrors or green fences. No statistically significant responses were detected in response to green vegetation fences that reduced both horizontal R/FR and B/G ratios, but a cluster analysis grouped together the overall morphological responses to both FR mirrors and green fences. These results in olive trees suggest that cultivar differences in response to light quality may be relevant for understanding adaptation to dense orchards and identifying cultivars best suited to them.


1999 ◽  
Vol 124 (1) ◽  
pp. 99-105 ◽  
Author(s):  
Claudio M. Dunan ◽  
Philip Westra ◽  
Frank D. Moore

A simulation model was built as a decision aid for management of five weed species in direct seeded irrigated onion (Allium cepa L.). The model uses the state variable approach and simulations are driven by temperature and sunlight as photosynthetically active radiation (PAR). It predicts yield reduction caused by competition for PAR according to the ratio of crop leaf area index (LAI) to weed LAI and respective light extinction coefficients (k). Input variables are plant density by species and average number of leaves by species. Number of leaves per plant is used by the model to provide an estimate of initial leaf area per plant. The model calculates initial species LAIs by multiplying species density times average leaf area per plant. The model accurately describes competitive interactions, taking into account respective plant densities, time of emergence, and time of weed removal. It permits economic evaluation of management factors such as handweeding, chemical weed control, herbicide phytotoxicity due to early application, and control of weed flushes during the season. The model is also used to evaluate mechanisms of plant competition for sunlight. In a sensitivity analysis, onion yield loss was more sensitive to weed PAR interception than to PAR use efficiency, the latter a species-dependent constant in the model.


2021 ◽  
Vol 25 (8) ◽  
pp. 1513-1518
Author(s):  
A.S. Gunu ◽  
M. Musa

Field trial was carried out during the 2019 rainy season (June to October) at the Dryland Teaching and Research Farm of the Faculty of Agriculture, Usmanu Danfodiyo University, Sokoto to determine the growth and yield of sorghum varieties in the study area. The treatments consisted of five (5) sorghum varieties (Samsorg 45, Samsorg 46, Janjari, Yartawa and Jardawa), the treatments were laid out in a Randomized Complete Block Design (RCBD) replicated three (3) times. Data were collected on the growth and yield of the crop. Janjari and Jardawa varieties were higher in plant height. Jardawa and Yartawa varieties were higher in number of leaves. Janjari and Yartawa varieties were higher in total dry weight. Janjari, Jardawa and Yartawa varieties were higher in harvest index. Yartawa variety was higher in leaf area, leaf area index and 1000-grain weight. Jardawa variety was higher in panicle length. Janjari variety was early in number of days to heading, flowering, and maturity and was higher in dry stalk weight. The grain yield (249 – 1506kg ha-1 ) was higher in Janjari and Yartawa varieties (1268 – 1506 kg ha-1). Based on the findings of this research, it could be concluded that Janjari and Yartawa varieties performed better than other varieties in the study area.


Author(s):  
Y. Rajasekhara Reddy ◽  
G. Ramanandam ◽  
P. Subbaramamma ◽  
A. V. D. Dorajeerao

A field experiment was carried out during rabi season of 2018-2019, at college farm, College of Horticulture, Dr. Y.S.R. Horticultural University, Venkataramannagudem, West Godavari District, Andhra Pradesh. The experiment was laidout in a Randomised Block Design with eleven treatments (viz., T1- NAA @ 50 ppm, T2-NAA @ 100 ppm, T3-GA3 @ 50 ppm,  T4-GA3 @ 100 ppm, T5-Thiourea @ 250 ppm, T6-Thiourea @ 500 ppm, T7-28-Homobrassinolide @ 0.1 ppm, T8-28-Homobrassinolide @ 0.2 ppm, T9-Triacontinol @ 2.5 ppm, T10-Triacontinol @ 5 ppm, T11-(Control) Water spray) and three replications. The treatments were imposed at 30 and 45 DAT in the form of foliar spray. Foliar application of GA3@ 100 ppm (T4) had recorded the maximum plant height (108.20 cm), leaf area (9.53 cm2) and leaf area index (0.74). Foliar application of thiourea @ 250 ppm (T5) had recorded the maximum values with respect to number of primary branches (15.03 plant-1), number of secondary branches (83.40 plant-1), plant spread (1793 cm2 plant-1), fresh weight (376.29 g plant-1), dry weight (103.54 g plant-1) and number of leaves plant-1((298.8). The same treatment (T5) had recorded the highest values with respect to crop growth rate (1.44 gm-2d-1), chlorophyll-a (1.40 mg g-1), chlorophyll-b (0.076 mg g-1) and total chlorophyll contents (1.48 mg g-1) in the leaves.


1995 ◽  
Vol 43 (2) ◽  
pp. 247-260
Author(s):  
H. Biemond

In a series of greenhouse and field trials, spinach cv. Trias plants were supplied with different amounts of N fertilizer in various split applications. Rates of leaf emergence and expansion were recorded, as well as final leaf size. The rate of leaf appearance varied between 0.16 and 0.57/day across experiments, but was hardly affected by N treatment. The rate of leaf expansion and mature leaf area increased with leaf number, reaching maximum values at leaf pair 3+4 or 5+6 and decreasing subsequently. Both characteristics were positively correlated with N supply. The duration of expansion was not influenced by N treatments and varied between 15 and 30 days in most experiments. The rate of leaf expansion was the main factor determining mature leaf size. Specific leaf area over all green leaves slowly decreased with time in most experiments and was around 300 cmsuperscript 2/g. As the differences in the number of leaves were small, the differences in total green leaf area per plant resulted from differences in the areas of individual mature leaves.


1958 ◽  
Vol 51 (3) ◽  
pp. 347-352 ◽  
Author(s):  
R. H. M. Langer

1. Swards of S. 48 timothy and S. 215 meadow fescue growing alone or together were sampled at intervals of 3 weeks throughout the season. The number and weight of leaves, stems and ears were determined, and leaf area was estimated.2. Despite high rainfall, the total number of tillers in both species declined from the beginning of the experiment until early July, but increased again from then onwards until the original complement had been approximately restored. The number of leaves failed to show a corresponding increase in the autumn because each tiller carried fewer leaves than earlier in the year.3. In the spring total dry weight increased more rapidly in meadow fescue than in timothy which in turn out-yielded meadow fescue later in the season. Both species attained their greatest dry weight soon after ear emergence, a period which was marked by considerable crop growth and relative growth rates.4. Leaf area index reached a maximum before total dry weight had increased to its highest level, but then declined in both species. Meadow fescue differed from timothy by producing a second crop of foliage after the summer with a leaf area index of about 7. This second rise appeared to be due mainly to increased leaf size in contrast to timothy whose leaves became progressively smaller towards the end of the season.5. The differences in growth between the species discussed with reference to their dates of ear emergence which in this experiment differed by about 6 weeks.


1995 ◽  
Vol 125 (2) ◽  
pp. 175-182 ◽  
Author(s):  
J. M. Ramos ◽  
I. De La Morena ◽  
L. F. Garcia Del Moral

SUMMARYNitrogen is an important factor determining grain yield of barley (Hordeum vulgare L.). Optimal rates and application timing can vary according to the environmental conditions under which the crop is grown. For 8 years (1979–86) barley yield, tillering, and leaf-area response to N application rates and timing were studied in southern Spain. The results showed that, under our experimental conditions, the most advantageous N rate for grain yield was 60 kg/ha, either split equally between sowing and tillering, or else with the greater proportion applied at tillering. Nitrogen applied at sowing increased number of tillers per plant, and N applied at tillering favoured tiller survival for later spike formation. In addition, N applied at tillering increased the number of leaves per plant, leaf area per plant, and the leaf area index, the maximum value of which occurred at anthesis.


2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Samuel Maina ◽  
Rossa Nyoike Ng’endo

Maize (Zea mays L.) is a significant food security crop in Kenya and it serves as the main source of nutrition and calories among the small-holder farmers. The overall maize yields per hectare have been fluctuating in the past few years posing a great risk to food security. Among the stress factors associated with maize yield loss include plant-feeding nematodes. In this regard, this study was conducted to evaluate the impacts of plant-parasitic nematodes specifically Scutellonema spp. under field conditions on maize performance in Mwea, Kenya. The field trials were laid out in a randomized complete block design with each treatment comprising of four replicates. The treatments included maize plots without nematicide (MPWN) and control plots treated with nematicide. The experiments were conducted in two trials. Soil samples were taken at a 0–20 cm depth at monthly intervals during 2018–2019. During the two trials, MPWN recorded significantly lower plant height and number of leaves per plant. Correlation analysis revealed a significant negative relationship between Scutellonema abundance with leaf area index, plant height, and number of functional leaves in MPWN during the 2019 trial. This implies that high population of Scutellonema perhaps has the potential to affect leaf area index, plant height, number of leaves per plant, which are aspects that in turn influence maize productivity. Therefore, holistic sustainable management practices to control Scutellonema spp. in maize fields such as use of organic amendments, resistant maize cultivars, and antagonistic organisms are crucial in order to alleviate negative impacts linked to Scutellonema infestation.


Sign in / Sign up

Export Citation Format

Share Document