scholarly journals Interaction between nitrogen, soil water condition and herbicides in Urochloa plantaginea control in irrigated rice crop

Author(s):  
Leandro L. Spatt ◽  
Sidinei J. Lopes ◽  
Sylvio H. B. Dornelles ◽  
Luciane A. Tabaldi ◽  
Vinicius S. Trivisiol ◽  
...  

ABSTRACT The present study sought to verify the existence of interactions between the soil water conditions, nitrogen and herbicides commonly used to control alexandergrass in irrigated rice crop. The experimental design was completely randomized, arranged in a 2 x 3 x 4 factorial scheme, corresponding to two soil water conditions (5 cm water depth and 100% soil water holding capacity [WHC]), three nitrogen doses (0, 80 and 160 kg of N ha-1) and four doses of herbicides (0, 0.5, 1 and 2 times the registration dose). The herbicides evaluated were cyhalofop-butyl, imazapyr + imazapic and imazethapyr. The treatments were repeated four times. Phytotoxicity and dry mass were evaluated 28 days after application. For cyhalofop-butyl and imazapyr + imazapic, the phytotoxicity at 100% WHC and 5 cm water depth conditions was higher in treatments with nitrogen fertilization. However, for imazethapyr under the 100% WHC condition of soil increased phytotoxicity in the absence of nitrogen fertilization. For the flooded condition, from the dose of 35 g of a.i. ha-1, the result in the control for the herbicide imazethapyr was optimized under the conditions of fertilization with 80 and 160 kg of N ha-1. Cyhalofop-butyl and imazapyr + imazapic undergo synergistic interaction with nitrogen fertilization and water status in the control efficiency, yet with imazethapyr, the synergistic interaction only occurs under 100% of soil WHC.

2013 ◽  
Vol 373 (1-2) ◽  
pp. 77-87 ◽  
Author(s):  
J. M. Torres-Ruiz ◽  
A. Diaz-Espejo ◽  
A. Morales-Sillero ◽  
M. J. Martín-Palomo ◽  
S. Mayr ◽  
...  

1968 ◽  
Vol 48 (2) ◽  
pp. 129-137 ◽  
Author(s):  
A. R. Maurer ◽  
H. F. Fletcher ◽  
D. P. Ormrod

Pea plants growing in "weighing lysimeters" were subjected to five soil-water regimes to determine their response to varying conditions of soil water imposed at different stages of development. Plants subjected to a minimal water stress developed luxuriantly and continued to grow up to the harvest period. Pea yield and plant height were not reduced, but fresh weight and dry matter were less if irrigation was applied when soil water fell to 60% rather than 88% of that available. A severe water stress after blossom reduced pea yield, irrespective of soil-water conditions prior to blossom. Plants which had been given ample soil water before blossom wilted visibly when a severe stress was imposed in the post-blossom period, yet wilting did not occur in plants subjected to severe water stress both before and after blossom. Severe water stress prior to blossom did not cause a decrease in pea yield if ample soil moisture was made available after blossom.


Author(s):  
Марек Дохойда ◽  
Йоанна Вітковска-Добрев

У роботі представлений перелік проблем, що супроводжують будівельні об'єкти великої площі, в тому числі й підземні гаражі. Здійснено технічний аналіз окремих проблем, що виникають в таких будівлях під час їх експлуатації. Проектування, а пізніше і будівництво підземних гаражів найчастіше, пов'язане з вирішеням складних інженерних питань. Згідно з ними до найпоширеніших конструкційних недоліків у підземних гаражах віднесні: тріщини нижньої плити, порушення поверхових перекриттів, невластиве кручення бетону, відсутність дилатації або також помилково прийняті ґрунтово-водні умови.The paper concerns complex engineering challenges associated with multi-storey underground car parks. An analysis of selected issues in underground garages during the exploitation was performed. The design and implementation of structures of which function are underground garages is most often associated with serious engineering challenges. For structural reasons frequently occurring faults in garages may include fracture of the bottom slab and intermediate floors resulting from improper design of reinforcement, concrete shrinkage, lack of expansion joints or incorrectly adopted soil-water conditions.


2020 ◽  
Vol 248 ◽  
pp. 107718 ◽  
Author(s):  
Li Zhang ◽  
Minfei Yan ◽  
Hongbing Li ◽  
Yuanyuan Ren ◽  
Kadambot HM Siddique ◽  
...  

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