scholarly journals The relationship between the nutrient supply and the yield of maize hybrids with different genetic traits on chernozem soil in variant years

2015 ◽  
pp. 27-31
Author(s):  
Zsófia Egriné Becze ◽  
Mihály Sárvári

The experiments were set on lime-coated chernozem soil in 2013 and in 2014, in our study four hybrids were included with different FAO number. We studied the effect of NPK fertilization and row spacing on the yield. The fertilizer doses were based on a 25-year longterm experiment. Compared to control, the N40 +PK treatment has also achieved a significant yield increase, although some hybrids responsed with yield loss to the increasing fertilizer doses; this effect was observed especially in 2014. The majority of hybrids reached higher yields in both years using the 50 cm row spacing. The water release of hybrids was measured weekly during the maturation, at the same time points. The rainy September slowed ripening and the water release of the hybrids in 2013, so the grain wet content at harvest showed higher values. The moisture contents were increased for some hybrids, in spite of the positive and favorable dynamic of water loss.

2014 ◽  
pp. 13-17
Author(s):  
Zsófia Becze

The year 2013 was rather extreme breeding year because of the uneven distribution of precipitaion and the summer heat. The experiment was set on with eight different genetic characteristics maize hybrids in 2013. In our study were included different kind of breeding season hybrids. We studied the effect of NKP fertilization and row spacing on the yield. The fertilizer doses are based on 25-year long-term experiment. Compared to control, the N40+PK treatment has also achieved a significant yield increase, although some hybrid of increasing fertilizer doses yield response to loss. The majority of hybrids reached higher yields using the 50 cm row spacing. The water release of hybrids was measured between 21th August and 17th September weekly, at the same time points. The rainy September slowed ripening hybrids and water release, so the grain wet content at harvest showed higher values.


1989 ◽  
Vol 3 (1) ◽  
pp. 44-47 ◽  
Author(s):  
Roland K. Roberts ◽  
Robert M. Hayes

A decision criterion is presented for postemergence johnsongrass control in soybeans. Models derived from actual data describing the relationship between johnsongrass density (X) and soybean yield loss are used to develop the decision criterion for soybeans planted in 0.25- and 1-m row spacings. The yield loss equations are L1 = 424–424 exp (-0.023X2) for 0.25-m row spacing and L2 = 643-643 exp (−0.004X2) for 1-m row spacing. When combined with the cost of control (Px) and the expected price of soybeans (Py), these equations can be used to find the density thresholds where johnsongrass control becomes profitable. For the 0.25-m row spacing, this relationship was Px = Py [424–424 exp (−0.023X2) or more simply Px = Py L1, which equates the cost of control to the value of the soybean yield increase from control. The johnsongrass density (X) that satisfies this equality is the threshold (X*) above which control is profitable.


Plants ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 1366
Author(s):  
Andrei I. Kuzin ◽  
Natalia Ya. Kashirskaya ◽  
Anna M. Kochkina ◽  
Alexey V. Kushner

The proper use of potassium fertilizer can stimulate a significant yield increase. However, the application of excessively high rates of potassium can reduce the availability of soil calcium for apple trees. The potassium fertigation rate must meet the apple tree’s requirements so that the applied fertilizers can be absorbed by the roots as much as possible. Crop load in apple orchards sometimes varies significantly in different years. The potassium content in apple fruits is relatively high, and the maximum requirement for this nutrient occurs when fruits grow and ripen. Different crop loads at that time mean the various demands of trees and need for changing application rates for this nutrient. The investigation was carried out in the experimental orchard of I.V. Michurin Federal Scientific Centre (Michurinsk, Russia) in 2016 and 2017 (52.885131, 40.465613). We studied seasonal changes of potassium and calcium contents in soil, fruits, and leaves and their relationship with yield during the research. We paid much attention to the potassium rate shift on its content in leaves and fruits and cultivars “Lobo” and “Zhigulevskoye” yield. If the potassium application rate changes according to the actual crop load, it stimulates the yield growth or (if the crop load was relatively low) the reduction of the rate did not lower the productivity. Moreover, we studied the relationship between potassium and calcium nutrition. The decrease in potassium fertigation rate increased the availability of soil calcium. It was the reason for fruit calcium concentration enlargement and mitigation of the K/Ca ratio. We also specified some parameters for soil–leaf diagnosis for potassium nutrition during the growing season.


1995 ◽  
Vol 125 (1) ◽  
pp. 39-42
Author(s):  
J. H. Zhang ◽  
Y. N. Luo ◽  
Z. X. Wang ◽  
X. Z. Gao

SUMMARYMaize (Zea mays L.) hybrids with different productivity per unit approximate leaf projected area (ALPA) were compared in China, 1990–92. The results showed that the selection index (SI) values of all the hybrids tested decreased with an increase in population density. Nevertheless, the hybrids with high SI values at low plant densities also had relatively high SI values at high plant densities. Thus, high SI hybrids could be selected at any of these densities. Although no significant yield increase was obtained by using high SI hybrids at plant densities of 52500 plants/ha or lower; significant increases in yield were obtained for high SI hybrids at > 67 500 plants/ha. Leaf area was one of the parameters necessary for determining SI, and this could be predicted with a skewed bell-shaped function simply by measuring the length and breadth of the largest leaf and counting the total number of leaves per plant.


Agronomy ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 605
Author(s):  
Peder K. Schmitz ◽  
Hans J. Kandel

Planting date (PD), seeding rate (SR), relative maturity (RM) of cultivars, and row spacing (RS) are primary management factors affecting soybean (Glycine max (L.) Merr.) yield. The individual and synergistic effects of PD, SR, RM, and RS on seed yield and agronomic characteristics in North Dakota were herein investigated. Early and late PD, early and late RM cultivars, two SR (408,000 and 457,000 seed ha−1), and two RS (30.5 and 61 cm) were evaluated in four total environments in 2019 and 2020. Maximizing green canopy cover prior to the beginning of flowering improved seed yield. Individual factors of early PD and narrow RS resulted in yield increase of 311 and 266 kg ha−1, respectively. The combined factors of early PD, late RM, high SR, and narrow RS improved yield by 26% and provided a $350 ha−1 partial profit over conventional practices. Canopy cover and yield had relatively weak relationships with r2 of 0.36, 0.23, 0.14, and 0.21 at the two trifoliolate, four trifoliolate, beginning of flowering, and beginning of pod formation soybean growth stages, respectively. Producers in the most northern soybean region of the USA should combine early planting, optimum RM cultivars, 457,000 seed ha−1 SR, and 31 cm RS to improve yield and profit compared to current management practices.


Plant Disease ◽  
2005 ◽  
Vol 89 (7) ◽  
pp. 726-733 ◽  
Author(s):  
O. Carisse ◽  
H. A. McCartney ◽  
J. A. Gagnon ◽  
L. Brodeur

Botrytis leaf blight, caused by Botrytis squamosa, is a common and frequently damaging disease of onion crops, but the severity of epidemics varies widely from year to year. The disease is initiated and spread by airborne conidia. The relationship between airborne conidium concentration (ACC) and lesion development was studied in the field. A linear relationship was found between ACC and number of lesions per leaf: ACC values of 10 to 15 and 25 to 35 conidia m-3 were associated with 1 and 2.5 lesions per leaf, respectively. In 2000 and 2001, at three sites, four different criteria were used to start a fungicide spray program and their effect on epidemic development was compared with that of a grower's conventional schedule. The criteria were: at the fourth-true-leaf growth stage; according to an inoculum production index; when the ACC reached 10 to 15 conidia m-3; and when the ACC reached 25 to 35 conidia m-3. A nonsprayed control plot was included in the trial. Fungicide programs started when the ACC reached 10 to 15 conidia m-3 were as effective as the conventional program, but used fewer sprays. A fungicide spray program based on measurements of ACC and disease severity was evaluated in 2002 and 2003 in five and three commercial onion fields, respectively. At each site, half of the field was sprayed according to the grower's schedule and, in the other half, fungicide sprays were initiated when a threshold of 10 to 15 conidia m-3 or five lesions on the lower leaf (whichever came first) was reached. Overall, the number of fungicide applications was reduced by 75 and 56% in 2002 and 2003, respectively, without causing significant yield reduction. In both years, the reduction in number of fungicide applications was due mainly to the delay in initiation of the fungicide program.


2015 ◽  
Vol 52 (3) ◽  
pp. 359-370
Author(s):  
ADRIAN KOLLER ◽  
GUILHERME TORRES ◽  
MICHAEL BUSER ◽  
RANDY TAYLOR ◽  
BILL RAUN ◽  
...  

SUMMARYHand-planted plots of across-row-oriented corn seeds (Zeamays L.) produce highly structured leaf canopies and have shown significant yield advantage over randomly planted plots in prior studies. For further investigation of the phenomenon by simulation, the objective of this study was to develop a probabilistic model for the correlation between seed orientation and initial plant orientation. In greenhouse trials, the azimuthal orientation of kernels of four different hybrids was recorded at planting. At collar setting of the seed leaf, the orientation of the seed leaf was determined and the angular data subjected to the analytical methods of circular statistics. The results indicate that the correlation between seed azimuth and seed leaf azimuth can be described by a von Mises distribution. The probabilistic seed to seed leaf azimuth model described herein may be implemented in simulation models to investigate the effect of canopy architecture, canopy closure and light interception efficiency of corn under conditions of seed oriented planting.


Agrikultura ◽  
2016 ◽  
Vol 27 (1) ◽  
Author(s):  
Nono Carsono ◽  
Gigih Ibnu Prayoga ◽  
Neni Rostini ◽  
Danar Dono

ABSTRACTMolecular Marker-based Selection on F2 Progeny for Development of Promising Rice Lines Resistant to Brown PlanthopperBrown planthopper (BPH) is the major insect pest of rice and accounts for significant yield loss. This experiment was aimed to develop BC1F1 and F3 brown planthopper resistant rice lines. Selection on the basis of SSR markers can be done by using two polymorphic SSR markers, i.e., RM586 dan RM8213, which screened from eight SSR markers for BPH resistant. Sixty-three F2 genotypes from IP-1 (derived from IR-64 x PTB-33) population and twenty F2 genotypes from PP-11 (derived from Pandan Wangi x PTB-33) population were selected and will be used for further research by selfed and backcrossed to recipient parents. Chi-squares test for segregation of DNA bands in F2 generation showed that RM8213 fitted with 1:2:1 Mendelian ratio for controlling photosynthetic rates and trichomes length in IP-1 population. This information could be used in programs to develop a durable brown planthopper resistant rice cultivar.Keywords: BPH, F2 population, Moleculer marker, SSRABSTRAKWereng coklat merupakan salah satu hama utama pada tanaman padi yang mampu menurunkan produksi padi secara nyata. Penelitian ini bertujuan untuk memperoleh galur-galur padi F2 yang memiliki marka-marka yang berasosisasi dengan ketahanannya terhadap wereng coklat. Seleksi pada galur padi F2 hasil persilangan telah dilakukan melalui teknik marka molekuler Simple Sequence Repeat (SSR) menggunakan dua marka SSR yang menunjukkan polimorphisme yaitu RM586 dan RM8213 dari delapan marka yang diskrining. Sebanyak 63 genotip dari populasi IP-1 (hasil persilangan IR-64 x PTB-33) dan 20 genotip dari populasi PP-11 (hasil persilangan Pandan Wangi x PTB-33) untuk disilangkan sendiri maupun disilang balik dengan tetua recipient. Selain itu, hasil analisis Chi-Kuadrat untuk segregasi pita DNA menunjukkan bahwa primer RM8213 memiliki rasio 1:2:1 (dominasi tidak sempurna) dalam mengontrol karakter laju fotosintesis dan panjang trikoma terhadap wereng coklat pada populasi IP-1. Informasi yang diperoleh dari penelitian ini nantinya dapat digunakan untuk program perakitan kultivar padi tahan wereng coklat yang durable.Kata Kunci: Marka molekuler, Populasi F2, SSR, Wereng coklat


2016 ◽  
Vol 12 (4) ◽  
Author(s):  
Sebastião Ferreira de Lima ◽  
Rita de Cássia Félix Alvarez ◽  
Lucymara Merquides Contardi

Weed Science ◽  
1987 ◽  
Vol 35 (1) ◽  
pp. 63-67 ◽  
Author(s):  
David C. Bridges ◽  
James M. Chandler

Research was conducted from 1982 through 1984 on a Shipps clay soil (Udic chromustert) in east-central Texas to determine the density-dependent effects and critical periods of johnsongrass [Sorghum halepense(L.) Pers. # SORHA] competition with cotton (Gossypium hirsutumL.). Two experiments were conducted each year, one to assess cotton yield response to increasing johnsongrass density and the second to establish the johnsongrass-free requirement of cotton and the johnsongrass competition period. A critical minimum density of 2 plants/9.8 m of row was observed. Full-season johnsongrass competition densities exceeding 2 plants/9.8 m of row resulted in seed cotton yield reductions each year. Yield decline was most rapid as density increased from 2 to 8 plants/9.8 m of row. Yield loss averaged 1, 4, 14, 40, 65, and 70% for johnsongrass densities of 1, 2, 4, 8, 16, and 32 plants/9.8 m of row, respectively. Percent yield loss was proportional to yield potential at johnsongrass densities of 4 and 8 plants/9.8 m of row. Three to four weeks of rhizome johnsongrass competition or 6 weeks of seedling johnsongrass competition resulted in significant yield reductions. Maintaining cotton johnsongrass free for 4 weeks did not prevent significant yield reductions.


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