Effect of Cultivar and Plant Population on Spotted Wilt in Virginia Market-Type Peanut

2004 ◽  
Vol 31 (2) ◽  
pp. 101-107 ◽  
Author(s):  
C. A. Hurt ◽  
R. L. Brandenburg ◽  
D. L. Jordan ◽  
G. G. Kennedy ◽  
J. E. Bailey

Abstract Field experiments were conducted in North Carolina during 2001 and 2002 to evaluate the impact of cultivar and plant population on the incidence of symptoms of tomato spotted wilt virus, which is transmitted primarily by tobacco thrips [Frankliniellafusca (Hinds) (Thysanoptera: Thripidae)]. Treatments included the Virginia market-type cultivars Gregory, NC-V 11, and Perry seeded at in-row plant populations of 7, 13, and 17 plants/m. In these experiments, there was a consistent trend for increased foliar injury from thrips as plant population decreased. Less thrips feeding injury was noted for Gregory and Perry than for NC-V 11. Incidence of visual symptoms of spotted wilt (SW) was recorded from mid-June through mid-September. A plant condition rating was recorded late in the season. Consistent with the results for thrips-induced injury, the percentage of plants infected with SW and the plant condition rating increased as plant population decreased. Gregory had the lowest SW incidence, while NC-V 11 was intermediate between Gregory and the most susceptible Perry. Establishing higher plant densities and planting Gregory rather than NC-V 11 or Perry reduced SW incidence and plant condition rating. Gregory had consistently the highest %ELK (extra large kernels) and %FP (fancy pods) across treatments and locations whereas no definitive trend in market grade characteristics were noted among treatments. In some cases, Perry had a higher incidence of SW, but still had higher pod yields than NC-V 11 with a lower incidence of SW. However, in most cases pod yield correlated with plant condition ratings, and as thrips injury increased, pod yield decreased.

2011 ◽  
Vol 62 (12) ◽  
pp. 1067 ◽  
Author(s):  
L. G. Gaynor ◽  
R. J. Lawn ◽  
A. T. James

The response of irrigated soybean to sowing date and to plant population was evaluated in field experiments over three years at Leeton, in the Murrumbidgee Irrigation Area (MIA) in southern New South Wales. The aim was to explore the options for later sowings to improve the flexibility for growing soybean in double-cropping rotations with a winter cereal. The experiments were grown on 1.83-m-wide raised soil beds, with 2, 4, or 6 rows per bed (years 1 and 2) or 2 rows per bed only (year 3). Plant population, which was manipulated by changing either the number of rows per bed (years 1 and 2) or the within-row plant spacing (year 3), ranged from 15 to 60 plants/m2 depending on the experiment. Two sowings dates, late November and late December, were compared in years 1 and 3, while in year 2, sowings in early and late January were also included. Three genotypes (early, medium, and late maturity) were grown in years 1 and 2, and four medium-maturing genotypes were grown in year 3. In general, machine-harvested seed yields were highest in the November sowings, and declined as sowing was delayed. Physiological analyses suggested two underlying causes for the yield decline as sowing date was delayed. First and most importantly, the later sown crops flowered sooner after sowing, shortening crop duration and reducing total dry matter (TDM) production. Second, in the late January sowings of the medium- and late-maturing genotypes, harvest index (HI) declined as maturity was pushed later into autumn, exposing the crops to cooler temperatures during pod filling. Attempts to offset the decline in TDM production as sowing was delayed by using higher plant populations were unsuccessful, in part because HI decreased, apparently due to greater severity of lodging. The studies indicated that, in the near term, the yield potential of current indeterminate cultivars at the late December sowing date is adequate, given appropriate management, for commercially viable double-cropping of soybean in the MIA. In the longer term, it is suggested that development of earlier maturing, lodging-resistant genotypes that retain high HI at high sowing density may allow sowing to be delayed to early January.


Author(s):  
M. Manjesh ◽  
Nagarajappa Adivappar ◽  
V. Srinivasa ◽  
G. K. Girijesh ◽  
Sharanabasappa .

The present investigation was carried out during Kharif 2016 at ZAHRS, Navile, Shivamogga. The experiment was laid out in split plot design with three replications. There were 24 treatment combinations comprised of three different environments (polyhouse, shadenet and open field) and eight spacing treatments (45 cm x 30 cm, 45 cm x 45 cm, 45 cm x 60 cm, 45 cm x 75 cm, 60 cm x 30 cm, 60 cm x 45 cm, 60 cm x 60 cm, 60 cm x 75 cm). The obtained results showed that all the characters were markedly affected by different environments and spacing. Among different environments significantly higher plant height (325.17cm), number of primary branches (12.46), number of pods per plant (21.66), pod length (70.67 cm), pod girth (3.73 cm), pod weight per plant (31.13 g), yield per plant (458.21 g) and higher pod yield per 1000 m2 (1605.99 kg) were recorded in polyhouse. Among spacing treatments significantly higher number of primary branches (12.91), pods per plant (22.30), pod length (71.73 cm), pod girth (3.94 cm), pod weight per plant (33.11g) and pod yield per plant (547.86 g) were recorded with wider spacing of 60 cm x 75 cm. Highest plant height (294.29 cm) and yield per 1000 m2 (1791.68 kg) were recorded with the closer spacing of 45 cm x 30 cm. The interaction of different environments and spacing were found to be statistically non-significant for all the traits. The evaluation of production economics revealed that growing of Yardlong bean in open condition with 45 cm x 30 cm spacing was most remunerative option with a highest benefit: cost of 3.14.


1990 ◽  
Vol 114 (1) ◽  
pp. 19-33 ◽  
Author(s):  
C. J. Pilbeam ◽  
G. Duc ◽  
P. D. Hebblethwaite

SUMMARYDeterminate varieties of Vicia faba are smaller and may require higher plant population densities than their conventional indeterminate counterparts to attain high yields. This hypothesis was examined at the University of Nottingham farm at Sutton Bonington, UK, and at INRA, Dijon, France in 1986 and 1987. The determinate varieties Ticol and TP667 and indeterminate M5.1 and Maris Bead were sown in the spring to give a range of densities of 10–100 plants/m2.Yields generally increased as population density increased. The optimum density for determinate varieties was higher than for indeterminate varieties. Indeterminate varieties yielded more than determinate varieties at all plant densities, perhaps because of their larger canopy. Seed yields were affected by year and location. Greater yields were associated with heavier seeds and more seeds per pod.Although several yield components, when expressed per unit area, were significantly correlated with seed yield, their coefficients of determination were never very large. This confirmed the plasticity of yield in field beans.


HortScience ◽  
1990 ◽  
Vol 25 (4) ◽  
pp. 399c-399
Author(s):  
Elden J. Stang ◽  
Gavin G. Weis

`Raritan' and `Guardian' strawberry were grown in the matted row system with controlled plant densities of 1, 2, 3, 4 or 5 plants/0.09m2 for comparison to a non-thinned matted row averaging 9 plants/0.09m2. Nitrogen treatments were superimposed on plant spacings at 3 week intervals in preharvest and postharvest applications. Total seasonal available N was 0, 36, 54 and 76 kg/ha. Fruit yield per plant decreased as plant population increased. Berry size declined with increased plant population but number of fruit per plant was not influenced. For both cultivars, plant populations of 4 to 5 plants/0.09m2 resulted in maximum fruit yield. Number of branch crowns for all treatments was 2.5-3.5/plant in the second growing season. Branch crown numbers were reduced with higher plant populations. N effects were independent of plant population effects and did not compensate for lower yields at low plant populations in more or larger berries. Optimum water management may be more important than N fertilizer in determing strawberry plant growth and yield.


Author(s):  
O B Bello

Optimum plant population is very important in enhancing high and stable grain yield especially in quality protein maize (QPM) production. A field trial was therefore conducted to compare the performance of six hybrids (three each of QPM and normal endosperm) at three population densities using a split-plot design at the sub-station of the Lower Niger River Basin Development Authority, Oke-Oyi, in the southern Guinea savanna zone of Nigeria during the 2010 and 2011 cropping seasons. Plant population -1 densities (53,333, 66,666, and 88,888 plants ha ) constituted the main plots and the six hybrids were assigned to the subplots, replicated three times. Our results showed a differential response of maize -1 hybrids to high densities, with plant populations above 53,333 plants ha reduced grain yield, and this is more pronounced in QPM than normal endosperm hybrids. This is contrary to the results observed in many other countries. This might be that the hybrids were selected in low yield potential area at low plant densities, and hence not tolerant to plant density stress. It may also be due to low yield potential of the experimental site, which does not allow yield increases at high plant densities. Though normal endosperm hybrids 0103-11 and 0103-15 as well as QPM Dada-ba were superior for grain yield among -1 the hybrids at 53,333 plants ha , hybrid 0103-11 was most outstanding. Therefore, genetic improvement of QPM and normal endosperm hybrids for superior stress tolerance and high yield could be enhanced by selection at higher plant population densities.


1970 ◽  
Vol 34 (1) ◽  
pp. 105-111 ◽  
Author(s):  
M Moniruzzaman ◽  
GMA Halim ◽  
ZA Firoz

Field experiments with French bean comprising two varieties (BARI bush bean-1 and BARI bush bean-2), three plant densities (500 x 103, 333 x 103, and 250 x 103 plants/ha as maintained by 20 x 10, 30 x 10, and 40 x 10 cm spacings, respectively) and three levels of N (0, 60, and 120 kg/ha) were conducted at the Agricultural Research Station, Raikhali in the district of Rangamati during the winter (rabi) seasons of 2004-05 and 2005-06. BARI bush bean-1 outyielded BARI bush bean-2. The lowest plant density (250 x 10 plants/ha) recorded significantly higher values of growth and yield attributes, except plant height which was the maximum with the highest plant density of 500 x 103 plants/ha. The highest plant density of (500 x 103 plants/ha) resulted in the highest pod yield in comparison with the lower and medium plant densities. Application of 120 kg N/ha coupled with the highest plant density (500 x l03 plants/ha) gave the maximum pod yield of 34.3 t/ha and 30.2 t/ha in BARI bush bean-I and BARI bush bean-2, respectively. Key Words: French bean; plant density; nitrogen.  DOI: 10.3329/bjar.v34i1.5760Bangladesh J. Agril. Res. 34(1) : 105-111, March 2009


2001 ◽  
Vol 54 ◽  
pp. 116-119 ◽  
Author(s):  
B.B. C Page ◽  
K. Betteridge ◽  
P.G. McGregor ◽  
J. Rapson ◽  
D.A. Costall

The impact of grazing animals on oviposition behaviour of ragwort flea beetle (RFB) (Longitarsus jacobaeae) was investigated in two field experiments In the first trial manually damaged ragwort plants were exposed for 5 days to RFB In the second trial ragwort plants grown in sheep and cattlegrazed pasture were collected both in April and May 1997 for the counting of eggs on plants and in the surrounding soil Removal of the majority of ragwort leaves reduced egg numbers/plant whereas damage to leaves did not Similarly ragwort from sheepgrazed pastures which was smaller than ragwort from cattlegrazed pastures had fewer eggs/plant but a similar number/g fresh weight of ragwort High local humidity under rosette ragwort plants is suggested as the critical factor determining oviposition behaviour of RFB


Author(s):  
M. P. Kavitha ◽  
R. Balakumbahan ◽  
G. Prabukumar

Field experiments were conducted to study the effect of foliar spray and fertilizer levels on growth and yield of vegetable cowpea (PKM 1) during kharif season of the years 2015 and 2016 at Western block, Horticultural College and Research Institute, Periyakulam. Results revealed that in general vegetable cowpea responded well to the increased dose of fertilizers along with foliar spraying of 2 % DAP and pulse wonder during flowering and pod formation stages. Application of 125 % RDF along with 2 % DAP spray at flowering and pod formation stages recorded significantly higher plant height (59.3 cm), more number of branches per plant (10.8), increased root bio mass per plant (0.85 g) and shoot bio mass per plant (7.8 g) and more number of flowers per plant (58) resulted in increased green pod yield of 17.40 t /ha as compared to 100 % RDF. Lowest yield and economics was recorded with 75 % RDF. Application of 125 % RDF along with 2 % DAP spray at flowering and pod formation stages recorded higher net returns and BC ratio of Rs.117120/- and 3.06 respectively followed by 125 % RDF + Pulse wonder @ 5 kg ha-1 at flowering. The available nutrient status of the post harvest soil sample viz., N (287 kg/ha), P (10.6 kg/ha) and K (217 kg/ha) also increased significantly with the application of 125 % RDF along with 2 % DAP spray at flowering and pod formation stages.


2021 ◽  
Author(s):  
J. C. Moor ◽  
Jeffrey Gore ◽  
J. Gore ◽  
A. Catchot ◽  
D. Cook ◽  
...  

Experiments were conducted in 2016 and 2017 in Stoneville, MS and Starkville, MS to determine the impact of different insecticide management options for thrips on herbicide injured peanut. Insecticide treatments included imidacloprid in-furrow at-planting, one or two foliar applications of acephate, and an untreated control with and without an application of flumioxazin. In Stoneville, herbicide applications were made immediately following planting, and in Starkville, applications were made as plants were emerging to maximize herbicide injury. The Stoneville experiment also had an additional factor in which plots were flooded or not flooded to simulate a heavy rainfall in order to maximize herbicide injury and also to give added stress from saturated soils. Thrips counts, thrips injury ratings, plant vigor ratings, plant biomass, width between plant canopies, and yield were recorded.  Few interactions were observed, but temporary flooding, herbicide injury, and thrips injury affected peanut growth as measured by biomass and canopy.  Imidacloprid was the most consistent insecticide treatment for reducing thrips numbers and injury, but acephate provided some protection.  Temporary flooding during the seedling stage, flumioxazin injury, and thrips injury all reduced peanut pod yield.  Based on these results, every attempt should be made to minimize early season stress in peanuts including the use of an effective in-furrow insecticide.


2021 ◽  
Vol 51 ◽  
Author(s):  
André Luis Vian ◽  
Christian Bredemeier ◽  
Maicon Andreo Drum ◽  
João Leonardo Fernandes Pires ◽  
Elizandro Fochesatto

ABSTRACT The estimated corn grain yield is dependent on plant density and should be monitored from the beginning of its development, especially between the phenological stages V3 and V10, since these stages are more responsive to management strategies. This study aimed to evaluate the efficiency of two methods [normalized difference vegetation index (NDVI) and plant occupation index (POI)] to estimate the density of corn plants, in order to identify the plant population in different phenological stages and corn grain yield. Two field experiments were conducted in two crop seasons and treatments consisted of four plant densities (4, 6, 8 and 10 plants m-2). The NDVI measurements of the vegetative canopy were performed in the growth stages V4, V5, V6, V7, V8 and V9 (2014) and V3, V5, V6, V8, V9, V10 and V13 (2015/2016). For the POI, the measurements were performed in the stages V5, V6, V8 and V9, in both crop seasons. The different plant densities were efficient in generating variability in the NDVI and POI values throughout the corn crop development cycle, and both tools were efficient in identifying density variations. It was observed that these tools should be used between the V4 and V9 growth stages.


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