Experimental control of the beet leafhopper on sugar beets grown for seed

1960 ◽  
Vol 11 (1) ◽  
pp. 12-14
Author(s):  
Howard E. Dorst
Plant Disease ◽  
1999 ◽  
Vol 83 (4) ◽  
pp. 351-355 ◽  
Author(s):  
Heping Wang ◽  
P. de A. Gurusinghe ◽  
Bryce W. Falk

Greenhouse and field studies were conducted to assess the effects of systemic insecticides and plant age on beet curly top virus (BCTV) transmission to sugar beet, tomato, pepper, melon, and cowpea. Sugar beets were the most susceptible to BCTV infection. For all BCTV-susceptible plants tested, younger plants showed greater susceptibility to infection than did older plants, even when inoculations were delayed by only 1 week. Systemic insecticides applied to test plants resulted in increased beet leafhopper (Circulifer tenellus) mortality and decreased the percent BCTV transmission. Soil treatment with imidacloprid (250 g a.i./ha) gave significantly better reductions in BCTV transmission than did dimethoate foliar sprays (280 g a.i./ha). These data suggest that the use of specific systemic insecticides only when crop plants are most susceptible to BCTV infection could be an effective alternative component of the curly top disease control program.


1960 ◽  
Vol 11 (1) ◽  
pp. 15-24 ◽  
Author(s):  
Orin A. Hills ◽  
A.C. Valcarce ◽  
H.K. Jewell ◽  
D.C. Courdriet

2014 ◽  
Vol 2 ◽  
pp. 174-177
Author(s):  
Aline de Paula ◽  
Marcelo A. Savi ◽  
Vahid Vaziri ◽  
Marian Wiercigroch ◽  
Ekaterina Pavlovskaia

1972 ◽  
Vol 68 (2_Supplb) ◽  
pp. S9-S25 ◽  
Author(s):  
John Urquhart ◽  
Nancy Keller

ABSTRACT Two techniques for organ perfusion with blood are described which provide a basis for exploring metabolic or endocrine dynamics. The technique of in situ perfusion with autogenous arterial blood is suitable for glands or small organs which receive a small fraction of the animal's cardiac output; thus, test stimulatory or inhibitory substances can be added to the perfusing blood and undergo sufficient dilution in systemic blood after passage through the perfused organ so that recirculation does not compromise experimental control over test substance concentration in the perfusate. Experimental studies with the in situ perfused adrenal are described. The second technique, termed the pilot organ method, is suitable for organs which receive a large fraction of the cardiac output, such as the liver. Vascular connections are made between the circulation of an intact, anaesthetized large (> 30 kg) dog and the liver of a small (< 3 kg) dog. The small dog's liver (pilot liver) is excised and floated in a bath of canine ascites, and its venous effluent is continuously returned to the large dog. Test substances are infused into either the hepatic artery or portal vein of the pilot liver, but the small size of the pilot liver and its blood flow in relation to the large dog minimize recirculation effects. A number of functional parameters of the pilot liver are described.


2018 ◽  
Vol 1 (94) ◽  
pp. 21-26
Author(s):  
M. L. Tyrus

Soil tillage and fertilization level are important in the system of agro-technical measures that increase soil fertility and sugar beets productivity. Today the cultivation of this crop requires a great deal of expense, therefore, there is a need for a wider study of the use of cheap soil cultivation, soil protection, energy-saving soil tillage technologies and appropriate ferti-lization levels. Under western Forest-Steppe of Ukraine conditions, investigations were conducted on dark grey podzolic light loamy soils where the influence of tillage models and fertilization levels on the formation of sugar beets root crops was studied. Shallow no-plow tillage of the soil on 14-16 cm is expedient to use as a main tillage under sugar beets. Under favorable weather and climatic conditions, it can provide yielding capacity at the level of deep fall plowing. The use of shallow no-plow tillage helped to increase the yielding capacity of sugar beet roots relative to plowing by 28-30 cm for 1.3 t / ha and the biological sugar output – for 0.2 t / ha. Then the sugar content was by 0.1% higher in the application of deep fall plowing on 28-30 cm. The optimization of the system of sugar beets fertilization allows ensuring the growth of the yielding capacity of root crops. It is established that the application of fertilizer norm N300P225K350 provides the yielding capacity at the level of 90 t / ha. The sugar content of root crops at the given fertilizer rate was the lowest in the experiment - 16.5 – 16.6%. Thanks to the high yielding capacity of root crops in terms of N300P225K350, the sugar harvesting was the highest and depending on the method of basic soil tillage was 14.95 – 14.79 t / ha. That is in 3.2 times more as to the control, in 1.3 times more than the norm of N180P135K210 and in 1.1 more than the fertilization level N240P180K280.


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