RESPONSE OF COTTON PLANT TO SEED COATING WITH GAUCHO OR CRUISER AND THE EFFICIENCY OF THESE TREATMENTS ON SUCKING PESTS POPULATION

Two field experiments were carried out at El-Gemmeiza Agricultural Research Station , El- Gharbia Governorate, Egypt, during 2010 and 2011 seasons to evaluate the efficiency of two systematic insecticides i.e Gaucho and Cruiser as seed coating before sowing at two rates against pests which attack cotton during seedling period ( from emergence until 60 days old ) as compared  with untreated seed treatment (control), in addition to some physiological aspects (growth attributes, earliness, seed cotton yield, components and fiber quality) of the  Egyptian cotton
( Gossypium barbadense, L.), Giza 86 cultivar.
The obtained results could be summarized as follow:
1-Applying systematic pesticides ie. Gaucho and Cruiser as seed coating significantly increased leaf chlorophyll a, b and total chlorophyll contents, leaf area / plant, total
    dry weight / plant at 60 and 75 days old in both seasons and  plant height at harvest
    and number of fruiting  branches / plant in one season only compared with the
    control (untreated seeds with Gaucho or Cruiser ).
2-Also, the two systematic pesticides significantly increased number of open bolls / plant, seed index, earliness % and seed cotton yield/ fed. in both seasons and boll
    weight in one season only as compared with the untreated control .
3-The tested treatments gave insignificant effect on micronaire reading and Pressley
    index in both seasons.
4-With regard to the effect of the rate used from the two systematic pesticides, the high rate of Gaucho or Cruiser increased the studied characters as compared to the low rate with one exception in the second season , where the low rate of Gaucho      increased seed cotton yield / fed, as compared to the high rate of Gaucho.
5-In generally, Gaucho treatments i.e. 5 gm or 7 gm / kg seed gave the highest values     of the studied characters as compared to the Cruiser treatments i.e 1 gm or 2 gm /kg seed.
6-The insecticidal activity of two neonicotinoides were studied as seed treatment  at   
    two rates against sucking pests Thrips tabaci (Lind.) and Aphis gosspii (Glover).Data indicated that the descending order of protective efficiency according to mean number of % reduction or the peak of activity of this insect were as follows: Gaucho with two rates , high rate of Cruiser and then the low rate of Cruiser. Therefore choosing will be according to economical consideration. i.e. availability of product  and unit price. On the other hand , the physiological and botanical aspects      differentiated between the rate of use of these products as follows , Gaucho 5g/kg      seeds had positive effect and Cruiser with 2g/ kg  seeds was better in this respect.
           According to this study, the economical consideration , insecticidal efficiency and  physiological and botanical aspects must be as three parameters in choosing the       recommended  insecticides .