scholarly journals 452 Evaluation of Midrib Nitrate-N Tests for Desert Lettuce

HortScience ◽  
1999 ◽  
Vol 34 (3) ◽  
pp. 522D-522
Author(s):  
Charles A. Sanchez ◽  
M. Peralta
Keyword(s):  
Field Experiments ◽  
Growth And Yield ◽  
Management Tool ◽  
Yield Potential ◽  
Tissue Samples ◽  
Nitrate N ◽  
Incorrect Diagnosis ◽  
Actual Response ◽  
N Management ◽  
Sap Test

Criteria for managing fertilizer nitrogen (N) applications for lettuce (Lactuca sativa L.) based on midrib nitrate-N analysis were developed 25 years ago. However, this test had not been recently evaluated for the newer cultivars of lettuce currently grown or the higher yield potential now obtained. More recently, quick sap nitrate-N tests have been correlated to the traditional dry midrib test and preliminary criteria for making diagnosis based on these sap tests have been proposed. Field experiments were conducted at 20 locations across the low desert region of the southwestern United States from 1996-1999 to evaluate the traditional dry midrib and sap nitrate-N tests. Tissue samples were collected before each sidedress N application and diagnostic accuracy was evaluated by determining lettuce growth and yield on both N-treated and untreated plots and comparing predicted to actual response. Overall, the variability associated with the quick sap test seemed to limit its application as a predictive N management tool in the low desert. Although less variable than the quick sap test, the high frequency with which the dry midrib test resulted in incorrect diagnosis suggests that either this test needs revision or that it is an unreliable N management tool.

scholarly journals Weed control under integrated nutrient management systems in faba bean (Vicia faba) production in Egypt

2008 ◽  
Vol 26 (3) ◽  
pp. 585-594 ◽  
Author(s):  
I.M. El-Metwally ◽  
M.T. Abdelhamid
Keyword(s):  
Weed Control ◽  
Faba Bean ◽  
Field Experiments ◽  
Nutrient Management ◽  
Weight Ratio ◽  
Nutrient Release ◽  
Growth And Yield ◽  
Yield Potential ◽  
Mineral Fertilizers ◽  
Net Assimilation

Two field experiments were conducted in two successive seasons, 2005/2006 and 2006/2007, to determine whether management can improve faba bean competitiveness with weeds, thus helping to achieve its yield potential. The experiment included five treatments, composed of organic and mineral fertilizers, alone and mixed at different rates, along with a control and six weed control treatments, including oxadiargyl, prometryn, hand hoeing treatments alone or mixed with the herbicides, and a nonweeded treatment (control).The herbicide treatments were not superior to the two hand-hoeing treatments. Using compost favored growth and yield of faba bean more than of weeds. Adding fertilizer also improved most yield parameters. Application of compost alone or combined with 50 or 100% of the recommended NPK rate improved faba bean growth in terms of net assimilation rate, specific leaf area, and leaf weight ratio as components of relative growth rate. This improvement in growth resulted in increase of seed yield, yield components and protein of faba bean. Faba bean yield performance improved under interactive fertilizer effects and weed control treatments as growth improved, as a result of nutrient release from fertilizers and weed control.

scholarly journals Developing Active Canopy Sensor-Based Precision Nitrogen Management Strategies for Maize in Northeast China

2019 ◽  
Vol 11 (3) ◽  
pp. 706 ◽  
Author(s):  
Xinbing Wang ◽  
Yuxin Miao ◽  
Rui Dong ◽  
Zhichao Chen ◽  
Yanjie Guan ◽  
...  
Keyword(s):  
Optimization Algorithm ◽  
Northeast China ◽  
Vegetation Index ◽  
Normalized Difference Vegetation Index ◽  
Field Experiments ◽  
Management Strategies ◽  
N Fertilizer ◽  
Yield Potential ◽  
Maize Production ◽  
N Management

Precision nitrogen (N) management (PNM) strategies are urgently needed for the sustainability of rain-fed maize (Zea mays L.) production in Northeast China. The objective of this study was to develop an active canopy sensor (ACS)-based PNM strategy for rain-fed maize through improving in-season prediction of yield potential (YP0), response index to side-dress N based on harvested yield (RIHarvest), and side-dress N agronomic efficiency (AENS). Field experiments involving six N rate treatments and three planting densities were conducted in three growing seasons (2015–2017) in two different soil types. A hand-held GreenSeeker sensor was used at V8-9 growth stage to collect normalized difference vegetation index (NDVI) and ratio vegetation index (RVI). The results indicated that NDVI or RVI combined with relative plant height (NDVI*RH or RVI*RH) were more strongly related to YP0 (R2 = 0.44–0.78) than only using NDVI or RVI (R2 = 0.26–0.68). The improved N fertilizer optimization algorithm (INFOA) using in-season predicted AENS optimized N rates better than the N fertilizer optimization algorithm (NFOA) using average constant AENS. The INFOA-based PNM strategies could increase marginal returns by 212 $ ha−1 and 70 $ ha−1, reduce N surplus by 65% and 62%, and improve N use efficiency (NUE) by 4%–40% and 11%–65% compared with farmer’s typical N management in the black and aeolian sandy soils, respectively. It is concluded that the ACS-based PNM strategies have the potential to significantly improve profitability and sustainability of maize production in Northeast China. More studies are needed to further improve N management strategies using more advanced sensing technologies and incorporating weather and soil information.

scholarly journals Growth and Yield of Vegetable Soybean (Edamame) in Mississippi

2007 ◽  
Vol 17 (1) ◽  
pp. 26-31 ◽  
Author(s):  
Lingxiao Zhang ◽  
S Kyei-Boahen
Keyword(s):  
Field Experiments ◽  
Mississippi Delta ◽  
Cropping System ◽  
Growth And Yield ◽  
Yield Potential ◽  
Vegetable Soybean ◽  
State Budget ◽  
Net Returns ◽  
Bean Yield ◽  
The U.S

Soybean (Glycine max) grown as a vegetable is gaining in popularity in the U.S. and demand is expected to increase over the long term. However, information on production in the U.S. is limited because most of the product is imported. Field experiments were conducted at Stoneville, Miss., in 2004 and 2005 to evaluate the production and yield potential and to estimate the net returns for sustainable production in the Mississippi Delta. In 2004, four vegetable soybean varieties were evaluated and 23 varieties were evaluated in 2005. The varieties varied from maturity group III to VII. The late-maturing varieties were generally taller, had more nodes/plant, pods/plant, and fresh green pod yield at R6 stage (full seed) than the early-maturing varieties. Fresh green bean yield ranged from 1438 to 19,119 lb/acre in 2004. The mean bean yield for the 18 Apr. 2005 planting was 26,538 lb/acre compared with a mean of 18,131 lb/acre for the 10 May 2005 planting. Interaction occurred between planting date and variety as well as soil type and variety for all the variables evaluated. ‘Envy’ produced the lowest yield, whereas ‘Garden Soy 01’, ‘Garden Soy 21’, ‘Midori Giant’, ‘Mojo Green’, and ‘Moon Cake’ produced the highest fresh bean yield. The estimated net returns, using the Mississippi State Budget Generator as a guide, indicated more than twice the returns from growing the regular commodity soybean. The data suggest that vegetable soybean can fit well into the existing cropping system and could be a viable alternative crop for growers in the Mississippi Delta who want to capitalize on a niche market.

scholarly journals Hop (Humulus lupulus L.) phenology, growth, and yield under subtropical climatic conditions: Effects of cultivars and crop management

2021 ◽  
pp. 764-772
Author(s):  
Aleyda Acosta- Rangel ◽  
Jack Rechcigl ◽  
Simon Bollin ◽  
Zhanao Deng ◽  
Shinsuke Agehara
Keyword(s):  
Field Experiments ◽  
Crop Management ◽  
Climatic Conditions ◽  
Humulus Lupulus ◽  
Growth And Yield ◽  
Yield Potential ◽  
Reproductive Phenology ◽  
Lateral Shoot ◽  
Humulus Lupulus L ◽  
Shoot Number

Commercial hop (Humulus lupulus L.) production occurs predominantly in temperate climates. The objectives of this study were to characterize the phenology of hops under subtropical climatic conditions and to determine the growth and yield potential. Two field experiments were conducted in Florida, southeastern United States. Rhizomes were planted in April. Data were collected during the establishment year. In the first experiment, we evaluated 7 American, 5 European, and 1 Japanese cultivars in a randomized complete block design. Bine height, main bine number, lateral shoot number, and dry cone yield (10% moisture) were recorded. Yield varied considerably, ranging from 0 to 197 kg ha–1. The top three yielding cultivars were ‘Cascade’, ‘CTZ’, and ‘Nugget’, all of which were American cultivars. Yield had positive correlations with main bine number and lateral shoot number, but it had no significant correlation with bine height. In the second experiment, we determined the duration of each phenological stage in ‘Cascade’. Reproductive phenology was characterized by premature and nonsynchronous flowering. Prolonged flowering resulted in multiple harvests over 61 days, starting in mid-June. We also evaluated crop management treatments, which consisted of three levels of hill spacing (76, 91, and 107 cm) and two nitrogen (N) rates (109 and 130 kg ha–1) in a factorial combination. Treatments were arranged in a split-plot design with hill spacing as the main-plot factor. Yield on a per-area basis increased with reducing hill spacing and increasing N rate by 41% and 38%, respectively. Our results demonstrate unique reproductive phenology of hops under subtropical climatic conditions, which prevents once-overharvest but enables the off-season supply of fresh hops over an extended period. This study provides a benchmark to develop production strategies for hops suitable to subtropical climates.

scholarly journals Performance of Pre Released Rice (Oryza sativa L.) Genotypes under Different Sowing Windows in Rabi Season

2020 ◽  
pp. 43-51
Author(s):  
D. Anil ◽  
Sreedhar Siddi
Keyword(s):  
Grain Yield ◽  
Field Experiments ◽  
Agricultural Research ◽  
Oryza Sativa L ◽  
Rice Crop ◽  
Growth And Yield ◽  
Yield Potential ◽  
Research Station ◽  
Net Returns ◽  
Sowing Dates

The aim of this study was to investigate the effect of different sowing dates on growth and yield potential of pre released rice genotypes under irrigated conditions of Northern Telangana zone. The field experiments were carried out during two consecutive rabi seasons of 2018-19 and 2019-20, on clay soils of agricultural research station, Kunaram, Telangana state, India. The experiment was laid out in strip plot design with three replications. The treatments comprised of three sowing dates i.e. 20th November, 5th December and 20th December in horizontal factor and four genotypes i.e. KNM 733, RNR 15048, KNM 1638 and KNM 118 in vertical factor. Pooled data analysis results revealed that the different sowing dates and genotypes significant effect on all the studied growth and yield characters. The rice crop sown on 20th December recorded significantly  higher grain yield ( 8138 kg ha-1) and Among the genotypes, the short slender, short duration genotype KNM 733 recorded the recorded the maximum grain yield ( 8024 kg ha-1), which was on par with the other genotypes. The treatment combinations data results concluded that the, among the genotypes the genotype KNM 118 was recorded highest grain yield (8438 kg ha-1) when sowing was taken up on 20th December and followed by  the genotype KNM 733 with sown on 20th  November. In respect of economics of treatment combinations, the highest net returns (Rs.91,165 ha-1) and B:C (2.47)  ratio were obtained when rice crop was sown during 20th December with the  genotype KNM 118 and followed by sown on 20th November with the  genotype KNM 733.

Agronomic studies on the productivity of kenaf (Hibiscus cannabinus L. cv. Guatemala 4) under rainfed and irrigated conditions in the Northern Territory

1990 ◽  
Vol 30 (3) ◽  
pp. 395 ◽  
Author(s):  
RC Muchow ◽  
JD Sturtz ◽  
MF Spillman ◽  
GE Routley ◽  
S Kaplan ◽  
...  
Keyword(s):  
Field Experiments ◽  
Plant Density ◽  
Northern Territory ◽  
Growth And Yield ◽  
Stem Length ◽  
Yield Potential ◽  
Yield Response ◽  
Rainfall Season ◽  
Wide Range ◽  
Average Rainfall

Field experiments were conducted at Berrimah, Douglas Daly and Katherine in the Northern Territory (NT) during the 1987-88 and 1988-89 wet seasons to obtain yield data for kenaf (Hibiscus cannabinzis L. cv. Guatemala 4) grown under rainfed and irrigated conditions. Under rainfed conditions, maximum stem yield was obtained from sowings early in the wet season. Yield decreased with delay in sowing until the late-December-January period. The maximum rainfed stem yield at Katherine in an above-average rainfall season was 18 400 kg/ha. The maximum yield in a below average rainfall season was 11 700 kg/ha at Katherine, 9200 kg/ha at Douglas Daly and 9400 kg/ha at Berrimah. The applicability to the NT of growth and yield relationships established for irrigated kenaf in the Ord Irrigation Area (OIA) was assessed. The yield potential under irrigated conditions in the NT (21 600 kg/ha at 131 days after sowing) was higher than that reported elsewhere in Australia for the same growth period, but similar to that reported elsewhere for longer growth duration (180-300 days). In the NT, in contrast to the OIA, stem yield showed little or no response to N fertilisation. Stem yield was not related to N uptake, and at high levels of N application, there was marked N accumulation in the stem. Kenaf was able to accumulate up to 110 kg N/ha from the soil reserve where no N was applied. The yield response to plant density varied with the yield level and was similar to that in the OIA. Bark and core yield could be estimated directly from biomass, and indirectly from stem length and plant density, over a wide range of yield levels and cultural conditions. It was concluded that data relating to yield potential and response to N fertilisation cannot be transferred directly from the OIA to the NT.

Effects of Planting Pattern and Cultivar on Weed and Crop Growth in Aerobic Rice System

2011 ◽  
Vol 25 (4) ◽  
pp. 521-525 ◽  
Author(s):  
Gulshan Mahajan ◽  
Bhagirath S. Chauhan
Keyword(s):  
Weed Management ◽  
Dry Matter ◽  
Field Experiments ◽  
Crop Growth ◽  
Growth And Yield ◽  
Yield Potential ◽  
Aerobic Rice ◽  
Rice Cultivars ◽  
Weed Species ◽  
Planting Pattern

Weeds are a major biotic constraint to aerobic rice production in Asia. Research is needed on the effects of cultural practices on weed management in aerobic rice, including techniques such as planting pattern and competitive cultivars. Field experiments were conducted in Punjab, India, in the wet seasons of 2008 and 2009 to study the growth of weeds and two rice cultivars [PR 115 and Punjab (P.) Mehak 1] in relation to planting pattern (uniform rows [23-cm row spacing] and paired rows [15-, 30-, and 15-cm row spacings]) under aerobic conditions. Junglerice and rice flatsedge were the dominant weed species during the early stages of the crop, while Chinese sprangletop and large crabgrass were the predominant species during flowering stage of the crop. Weed dry matter was not affected by planting pattern of P. Mehak 1; however, for PR 115, weed dry matter was greater in rice grown in uniform rows (244 g m−2) than in paired rows (183 g m−2). Planting patterns did not affect weed-free crop growth and yield, but weeds tended to be more abundant in the uniform planting system, particularly under cultivar PR 115. Consequently, this cultivar grew and yielded better under the paired rows when weeds were present. The cultivar PR 115 had greater yield potential than P. Mehak 1, but growth and productivity of P. Mehak 1 were unaffected by the planting patterns, suggesting better competitive ability against weeds than PR 115. The results imply that yield of some aerobic rice cultivars may be improved by exploring competitiveness of rice cultivars through paired row planting patterns. There is a need to study plasticity changes for cultivars which respond with more competiveness in paired rows. The identified traits could be useful as selection criteria for screening weed-competitive cultivars in paired row pattern.

The limiting effect of plant size at inflorescence initiation on subsequent growth and yield of oilseed rape (Brassica napus)

1975 ◽  
Vol 84 (3) ◽  
pp. 487-502 ◽  
Author(s):  
N. J. Mendham ◽  
R. K. Scott
Keyword(s):  
Oilseed Rape ◽  
Field Experiments ◽  
Critical Size ◽  
Plant Size ◽  
Growth And Yield ◽  
Yield Potential ◽  
Breeding Programmes ◽  
Cold Requirement ◽  
Low Erucic Acid ◽  
Better Than

SUMMARYA substantial loss in yield usually occurs when oilseed rape is sown later than mid-September. Field experiments in 1972–3 tested whether this is because all plants, irrespective of size, initiate inflorescences during the winter, thus restricting the eventual size of the leaf canopy and the yield potential of late-sown plants, which are still very small when the change to the reproductive phase occurs.Sowing a standard winter variety, Victor, from mid-August to mid-October resulted in initiation occurring from late October to February. When sown after mid-September yields were proportional to plant size at initiation. The winter was mild, and in colder conditions earlier sowing may be required to enable plants to reach a critical size before initiation takes place. When sown in August plants were very large but yield was not improved. A study of the development of the pod canopy showed that the extra yield potential was not realized because heavy losses of pods and seeds occurred, particularly in the more shaded positions.When a range of winter varieties, chosen to contrast the timing of phasic development, was sown on two dates yield was proportional to the interval between sowing and initiation, particularly when late sown, presumably because late initiators were able to lay the foundation of a more substantial root and shoot system. This has implications for plant breeding programmes because the low erucic acid varieties currently being grown initiate inflorescences early. When spring types were sown in mid-October they formed floral initials very early, and gave particularly small and weak plants, with a low yield. Winter types sown in March did initiate flowers and produce large plants, but yields were no better than spring types as flowering and ripening were irregular and late, the cold requirement for initiation being only marginally fulfilled.

Development of an algorithm for optimizing nitrogen fertilization in wheat using GreenSeeker proximal optical sensor

2020 ◽  
Vol 56 (5) ◽  
pp. 688-698
Author(s):  
Ali M. Ali
Keyword(s):  
Vegetation Index ◽  
Field Experiments ◽  
N Uptake ◽  
Yield Potential ◽  
N Recovery ◽  
Spatial And Temporal Variability ◽  
Fertilizer N ◽  
Total N ◽  
General Recommendation ◽  
N Management

AbstractProximal plant sensing with active canopy sensors offers a leap in the non-destructive assessment of crop agronomic information. For managing fertilizer nitrogen (N), sensor readings must be translated using functional models or algorithms to fertilizer amounts. Six field experiments were conducted in three wheat seasons in the West Nile Delta in Egypt to develop and validate an algorithm based on GreenSeeker canopy reflectance sensor for field-specific fertilizer N management in wheat, which takes into account both spatial and temporal variability of N during the crop growth season. The proposed algorithm is based on the prediction of total N uptake and response index of N uptake determined from normalized difference vegetation index measured by the sensor from plots differing in yield potential as established by applying a range of fertilizer N levels in the four experiments conducted in the first two wheat seasons. The treatments in the two experiments conducted in the third wheat season were designed to define appropriate fertilizer N management prior to applying a sensor-based dose at Feekes 6 stage (jointing stage). The application of 40 and 60 kg N ha−1 at 10 and 30 days after sowing of wheat and a sensor-guided dose of N estimated by using the algorithm developed in this study resulted in yields similar to those obtained by following the general recommendation, but with an average of 66 kg N ha−1 less fertilizer N. These results were also reflected in a substantial increase in N recovery (21.9%) and agronomic (7.7 kg grain kg−1 N) efficiencies compared with the general recommendation, thereby proving the usefulness of the sensor-based algorithm in optimizing fertilizer N management in wheat.

Development and use of a barley crop simulation model to evaluate production management strategies in north-eastern Australia

1996 ◽  
Vol 47 (7) ◽  
pp. 997 ◽  
Author(s):  
PJ Goyne ◽  
H Meinke ◽  
SP Milroy ◽  
GL Hammer ◽  
JM Hare
Keyword(s):  
Simulation Model ◽  
Production Management ◽  
Field Experiments ◽  
Management Strategies ◽  
Crop Growth ◽  
Growth And Yield ◽  
Yield Potential ◽  
Weather Data ◽  
Eastern Australia ◽  
North Eastern

A study was undertaken to identify improved management strategies for barley (Hordeum vulgare L.), particularly in relation to time of planting, location, and frost risk in the variable climate of north-eastern Australia. To achieve this objective, a crop growth simulation model (QBAR) was constructed to integrate the understanding, gained from field experiments, of the dynamics of crop growth as influenced by soil moisture and environmental variables. QBAR simulates the growth and yield potential of barley grown under optimal nutrient supply, in the absence of pests, diseases, and weeds. Genotypic variables have been determined for 4 cultivars commonly grown in the northern cereal production areas. Simulations were conducted using long-term weather data to generate the probabilistic yield outcome of cv. Grimmet for a range of times of planting at 10 locations in the north-eastern Australian grain belt. The study indicated that the common planting times used by growers could be too late under certain circumstances to gain full yield potential. Further applications of QBAR to generating information suitable for crop management decision support packages and crop yield forecasting are discussed.

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