Zinc encapsulated chitosan nanoparticle to promote maize crop yield

2019 ◽  
Vol 127 ◽  
pp. 126-135 ◽  
Author(s):  
Ram Chandra Choudhary ◽  
R.V. Kumaraswamy ◽  
Sarita Kumari ◽  
S.S. Sharma ◽  
Ajay Pal ◽  
...  
2019 ◽  
Vol 18 (1) ◽  
pp. 123-132
Author(s):  
CRIZ RENÊ ZANOVELLO ◽  
FABIANO PACENTCHUK ◽  
JAQUELINE HUZAR-NOVAKOWISKI ◽  
GUILHERME ZAMBONIN ◽  
ANTHONY HASEGAWA SANDINI ◽  
...  

RESUMO – O milho é uma planta monoica, e a geração de novos híbridos exige a remoção do pendão das plantas.Sabe-se que a remoção do pendão possui efeito negativo na produtividade da cultura. Contudo, a aplicação de Ncomplementar, via foliar, poderia minimizar essas perdas. Assim, o objetivo deste estudo foi avaliar como o Ncomplementar afeta a produtividade e os componentes de rendimento da cultura do milho submetida ao despendoamento.O estudo foi conduzido em delineamento de blocos casualizados em esquema fatorial 2 x 3 x 5, sendo duas safras(2014/15 e 2015/16), três momentos de despendoamento (sem despondoamento, arranquio de 2-3 folhas e arranquiode 4-5 folhas antes do pendoamento) e cinco doses de N complementar (0, 5, 10, 15, 20 L ha-1) aplicadas no estádio depré-pendoamento (VT). Não foi verificada interação N complementar X despendoamento para nenhuma das variáveisestudadas. A menor produtividade foi verificada no despendoamento de 4-5 folhas. A aplicação de N complementaraumentou a produtividade da cultura do milho, e a aplicação de 11,5 L ha-1 incrementou a produtividade em 448 kgha-1. O despendoamento diminuiu a produtividade da cultura do milho, quanto mais precoce o despendoamento, maisnegativo é o efeito na produtividade.Palavras-chave: Melhoramento genético, N complementar, pendoamento, produção de sementes, Zea mays.FOLIAR APPLICATION OF COMPLEMENTARY NITROGEN,IN MAIZE SUBJECTED TO DETASSELINGABSTRACT – Maize is a monoic plant and the generation of new hybrids requires the removal of the tassel from theplants, which has a negative effect on crop yield. However, the use of complementary leaf nitrogen (N) fertilization,could minimize the yield losses. Therefore, the objective of this study was to evaluate the effect os the application ofcomplementary N affects on yield of the maize crop subjected to detasseling. The study was carried out in a randomizedcomplete block design, with a 2 x 3 x 5 factorial scheme and four replications. Two growing seasons (2014/15 and2015/16), three detasseling moments (without detasseling, detasseling of 2-3 leaves, and detasseling of 4-5 leaves)and five doses of complementary N (0, 5, 10, 15, 20 L ha-1) applied at the VT stage. There was no interaction betweencomplementary N and detasseling for any of the variables studied. The lowest yield was verified with the detasselingof 4-5 leaves. The application of complementary N showed a positive effect on maize yield, and the application of 11.5L ha-1 of complementary N provided yield increase of 448 kg ha-1. The detasseling technique had negative effects onmaize crop yield, the earlier is the detasseling, the more negative is the effect on yield.Keywords: Genetic improvement, Seed production, tasseling, Zea mays.


2016 ◽  
Vol 2 (1) ◽  
pp. 13-19 ◽  
Author(s):  
Saraswati Neupane ◽  
Ghanashyam Bhandari ◽  
Sheela Devi Sharma ◽  
Surendra Yadav ◽  
Subash Subedi

The stem borer (Chilo partellus Swinhoe) is one of the most destructive pests of maize crop. Research experimentations were carried out on maize to control stem borer using conventional pesticides under field condition during summer season of two consecutive years from 2015 to 2016 at Rampur, Chitwan. All used pesticides had significant effect (P≤0.05) on percent damage and crop yield over control. In 2015, the lower percent damage (5.3%) with higher crop yield (4.52 t ha-1) and lowest insect score (1.00) was observed in plot sprayed with spinosad 45% EC at 0.5 ml L-1 of water followed by plot treated with chloropyriphos 50% EC+cypermethrin 5% EC @1.5ml L-1 of water with percent damage of 6.60%, crop yield (4.23 t ha-1) and insect score of 1.60. Almost similar trend of insect incidence along with damage percentage and yield data were observed in 2016. The higher percent damage control (79.06%) was observed at the plot sprayed after spinosad 45% EC at 0.5 ml L-1 of water with higher crop yield (4.58 t ha-1) and lowest insect score (1.00) followed by the plot treated with imidacloprid 17.8% @ 0.5 ml L-1 of water with percent damage control of 73.10 %, crop yield (3.38 t/ha) and insect sore 1.50. The highest percent damage (20.63%) was observed in the control plot with lower yield (0.95 t ha-1) and highest insect score (6.00). Over the years, spinosad 45% EC at 0.5 ml L-1 of water was effective bio-pesticide to control maize stem borer damage and also increase the yield.


Atmosphere ◽  
2020 ◽  
Vol 11 (8) ◽  
pp. 843
Author(s):  
Qaisar Saddique ◽  
Muhammad Imran Khan ◽  
Muhammad Habib ur Rahman ◽  
Xu Jiatun ◽  
Muhammad Waseem ◽  
...  

The ongoing global warming and changing patterns of precipitation have significant implications for crop yields. Process-based models are the most commonly used method to assess the impacts of projected climate changes on crop yields. In this study, the crop-environment resource synthesis (CERES)-Maize 4.6.7 model was used to project the maize crop yield in the Shaanxi Province of China over future periods. In this context, the downscaled ensemble projections of 17 general circulation models (GCMs) under four representative concentration pathways (RCP 2.6, RCP 4.5, RCP 6.0, and RCP 8.5) were used as input for the calibrated CERES-Maize model. Results showed a negative correlation between temperature and maize yield in the study area. It is expected that each 1.0 °C rise in seasonal temperature will cause up to a 9% decrease in the yield. However, the influence of CO2 fertilization showed a positive response, as witnessed by the increase in the crop yield. With CO2 fertilization, the average increase in the maize crop yield compared to without CO2 fertilization per three decades was 10.5%, 11.6%, TA7.8%, and 6.5% under the RCP2.6, RCP4.5, RCP6.0, and RCP8.5 scenarios, respectively. An elevated CO2 concentration showed a pronounced positive impact on the rain-fed maize yield compared to the irrigated maize yield. The average water use efficiency (WUE) was better at elevated CO2 concentrations and improved by 7–21% relative to the without CO2 fertilization of the WUE. Therefore, future climate changes with elevated CO2 are expected to be favorable for maize yields in the Shaanxi Province of China, and farmers can expect further benefits in the future from growing maize.


2020 ◽  
Author(s):  
Tzu-Shun Lin ◽  
Yang Song ◽  
Atul K. Jain ◽  
Peter Lawrence ◽  
Haroon S. Kheshgi

Abstract. The land process model, ISAM, is extended to accurately simulate contemporary soybean and maize crop yields, and estimate changes in yield over the period 1901–2100 driven by past and future changes in environmental factors – atmospheric CO2 level ([CO2]) and climate (temperature and precipitation) – and management factors – nitrogen fertilizer and deposition, irrigation, and crop harvest areas. Over the 20th century, each of these factors contributes to the increase in global crop yield with increasing nitrogen fertilizer application the strongest of these drivers for maize and increasing [CO2] the strongest for soybean. Over the 21st century, two future scenarios – RCP4.5-SSP2 and RCP8.5-SSP5 – of the environmental and management factors are modeled to estimate their influence on future crop yield. For both crops under both scenarios, changing climate drives yield lower, while rising [CO2] drives yield higher. For soybean, the negative climate effect is more than offset by the other drivers – particularly the increase in [CO2] – leading to an increase in global soybean yield by the 2090s. For maize, combined negative climate and harvest area effects are offset in RCP4.5-SSP2, which has continued growth in nitrogen fertilizer application, leaving global yield roughly unchanged. However, in RCP8.5-SSP5 maize yield declines since this scenario has greater warming of climate and weaker nitrogen fertilizer application than RCP4.5-SSP2. The model also projects differences between geographical regions; notably, higher temperatures in tropical regions limit photosynthesis rates and reduce light interception by accelerating phenological development in both crops, particularly for RCP8.5-SSP5 and for soybean.


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