Aimed at objectively know current status and impacts of Bt cotton application by small farmer households in Hebei province and provide a scientific basis for research department, production department and government, this paper synthetically analyzed current status and impacts of Bt cotton application by small farmer households in Hebei province based on a two years' survey involving cotton-farming householders from ten villages in Hengshui, Xingtai, Cangzhou, and Handan districts. The survey reveals that: Because in poor production condition region, pest stress is not serious, agricultural production condition is poor, especially households cannot irrigate, risks faced by households in agricultural are high, so now some households adopt non-Bt cotton. In adopting both Bt cotton and non-Bt cotton region, land size, age and education of household head and labor number do not affect adoption of Bt cotton. Social relation network, availability of Bt cottonseed and other inputs and our country promotional policies about Bt cotton promote widely adoption and diffusion of Bt cotton. Now, householders are lack comprehensive and correct knowledge about Bt cotton, householders save cottonseeds prevalently, households show a great confidence in chemical control, Some households are lacking command in controlling pests and diseases, householders have not measures to prevent cotton bollworm from developing resistance to Bt toxin, which will promote cotton bollworm develop resistance to Bt cotton, and influence Bt cotton's sustainablity. In the years of 2002 and 2003, yields and profits were increased with the application of Bt cotton varieties, but the increasements are not only because of this, these are also affected by other factors such as seed quality , cultivation and inputs .The Pesticide costs of non-Bt cotton are 6.5 times that of Bt cotton in 2002 and 3.2 times Bt cotton that of non-Bt cotton in 2003. In the 2 years, obvious change of the pesticide costs is relative to the sample village change, householder's cultivation practice and Bt cotton varities that householders adopt. In the years of 2002 and 2003, the pesticide costs of non-Bt cotton all are low, and are 15.0 yuan.hm-2 and 27.4 yuan.hm-2 respectively in 2002 and 2003. This is mainly related to the pests and diseases stresses of the sample villages that adopt non-Bt cotton are not serious, and is also related to the cultivation practice and attention of the householders. Yields and profits of American Bt cotton are higher than that of domestic Bt cotton. This is mainly because of the plenty of the domestic Bt cotton varieties and the qualities of the seeds. Yields with F1 seeds of Bt cotton varieties were higher than those with F2 and F3 seeds, while there was a variance in the differences of profits between using various filial generations of seeds between the two years. (Résumé d'auteur)

Cotton seedling dampinf-off and Verticillium wilt caused by Pythium sp. and Rhizoctonia solani and Verticillium dahliae, are the most important diseases of cotton in Iran. This experiment was conducted in Golestan (1998-1999) and Mazandaran (1999) Provinces to investigate the possibility of controlling these diseases by Ttichodermin B. The results of experiments revealed that as far as germinated and dead seedlings are concerned, there was not significant differences among the treated i.e. seeds treated with carbendazim- tiram at 5000 ppm, seeds treated with tricodermin at 10000 ppm, seed and soil treated with tricodermin at 10000 ppm but control check treatment differ significantly with other treatments with 85% germinated and 15% decayed seed and dead seedlings. The experiments was conducted in a randomized complete blocks design with 6 treatments in Golestan and 10 treatments in Mazandaran Provinces each with 4 replications . The resulted obtained in Golestan province showed that there was a significant differences among treatments in germinated and dead seedlings and mean of plant height, but tricodermin had no effect on weight of cotton bolls and verticillium wilt disease index. The results obtained in Mazandaran province showed that there was a significant differences in seedling mortality, lint height mean and verticillium wilt disease index among different treatments at 1% level and cotton boll weight at 5% level, but there was no differences in root lengtht.

Dr Mackson Banda, Deputy Director of Agricultural Research in Malawi on how farmers and policies are working to stop cotton pests spreading in the country. | Preventing pest plaguesCue: Insect pests are one of the greatest dangers to a cotton crop. Preventing the spread and build up of pests is therefore one of the most important aspects of cotton production, both for the individual farmer, and for cotton producing countries as a whole. Farmers have a key role to play in fighting pests at the end of the season, after the cotton crop has been harvested. This is the time when cotton plants should be uprooted and burnt. Governments may also guard against cotton pests, for example through laws which prevent the importing of unchecked cotton seed. To find out more about the battle against cotton pests, Excello Zidana spoke to Dr Mackson Banda, Deputy Director of Agricultural Research in Malawi. He began by asking Dr Banda whether the chemical pesticides commonly used on cotton plants are safe for the environment.IN:?These chemicals are safe?OUT:? in the interest of the whole nation.?DUR?N5?12?BACK ANNOUNCEMENT: Dr Mackson Banda on some of the mechanisms being used in Malawi to control both cotton pests, and pesticide use.TranscriptBandaThese chemicals are safe to the environment if they are used judiciously. By judiciously I mean they should only be used when there is need to do so. But if you just use them indiscriminately you will pollute the environment. You will kill a lot of insects or even animals in the environment because these are poisonous. We must accept it, it is a fact.ZidanaNow others talk of cultural practices trying to eradicate or eliminate or reduce pests and diseases in the cotton fields. Do you agree with that statement?BandaYes I do agree.ZidanaWhat are some of these cultural practices?BandaSome of the cultural practices: first and foremost is crop hygiene. Where you have grown cotton this year you must make sure that all the crop residues are uprooted, burnt. Because if you don?t do that some of these pests over-winter through this crop debris. So crop hygiene is one of the very important things. Plus early cultivation of the land, because some pests live in the ground, in the soil. They will form a cocoon and survive. But when you dig the soil you expose those which have been buried in the ground to the sunshine and then you disturb their life cycle. So this is very important in cotton production.ZidanaExtension workers advise farmers to uproot the cotton stalks soon after harvesting. How good is that practice? BandaThis is very good because if you have travelled to all cotton growing areas, if you leave cotton plants in the field you find these even late pests like cotton stainers flying all over the place. Now if you cut all these or you uproot all the cotton plants, you burn them, you reduce the breeding ground for these particular things. And then as you start the new season, you start with a fresh season, and a fresh crop, so that if there are any pests coming they should be coming within that season but not coming from one season to another. That would develop a bomb for the cotton crop.ZidanaNow there are some diseases and even pests that spread from region to region, country to country. Are there special rules to maybe check the spread of diseases of cotton?BandaYes we have a Cotton Act in the country which prohibits imports of unauthorised cotton varieties into the country. This is done first in the interest of protecting the crop from pests from other countries, even diseases being imported through seeds. So the government here has this Act which is in force so that we don?t just receive seed from elsewhere without proper verification of the phyto-sanitary, and sanitary measures that were taken in the place of production. So the law is there, it protects the farmer, it protects the economy, it protects the cotton industry so that it continues to flourish.ZidanaHow do you look at the use of chemicals as opposed to the cultural practices in cotton production?BandaWell at the moment we can say is, we don?t have a single method of controlling pests in cotton. What we are advocating at the moment is Integrated Pest Management. By Integrated Pest Management we mean use of cultural practices, use of improved varieties, use of chemicals where necessary, plus also crop hygiene, uprooting of stalks. Combining these is what we call Integrated Pest Management, so that no single method is the superior in pest management. We have to combine these methods in an integrated manner. Then it will be friendly to the environment. But if we just advocate chemical use, we will pollute the environment.ZidanaNow lastly how do you work with the companies producing and selling chemicals in the country?BandaThere is a law, there is the Cotton Act which is a binding thing. And we work in close liaison with all stakeholders in the cotton industry. This includes chemical manufacturers or sellers, ginners, cotton ginners, those who do bailing of cotton, those who do exporting of cotton, whoever is working on cotton we work with them. But the rule of thumb is that, if let?s say a chemical company wants to introduce a pesticide in the country, they have to come to the Ministry of Agriculture and apply and we have a committee which is called Agricultural Technology Clearing Committee which looks at the pesticides. So our scientists have to analyse that particular pesticide, evaluate it in the field, generate information under our local conditions and then be satisfied that it can work under our local conditions. Then we release it, officially release it, ask them to sell it in Malawi. We don?t just allow any importation of any junk to be sold on our soils because we are cautious, we need to protect the farmer.ZidanaI have also heard about the Pesticide Control Board. How serious is this Board?BandaThe Pesticide Control Board is very serious because if there is a banned pesticide they will take an action to say this must not be used on the soils of Malawi. This protects the environment, it protects us as human beings, it protects the natural fauna, the natural environment is protected. So people must realise that this Board is working in the interest of the whole nation. End of track.

Cresotic acid (3-hydroxy-4-methylbenzoic acid) was proved to be active in controlling wilt diseases of melon and cotton plants grown in the green- house. Soil drench with 200-1000 ppm cresotic acid induced 62-77 %, 69-79 % and 50-60 % protection against Fusarium oxysporum f.sp melonis (FOM) in melon, Fusarium oxysporum f.sp vasinfectum (FOV) and Verticillium dahliae in cotton, respectively. Since no inhibitory effect of cresotic acid on mycelial growth of these three fungal pathogens was observed in vitro, it is suggested that control of these wilt diseases with cresotic acid resulted from induced resistance. Cresotic acid induced resistance in melon plants not only against race 0, race 1, race 2 and race 1,2, but also against a mixture of these four races of FOM, suggesting a non-race-specific resistance. Level of induced resistance by cresotic acid against FOM depended on inoculum pressure applied to melon plants. At 25 day after inoculation with FOM, percentage protection induced by cresotic acid under low inoculum pressure retained a level of 51 %, while under high inoculum pressure percentage protection decreased to only 10 %. High concentrations of cresotic acid significantly reduced plant growth. Reduction in fresh weight of melon (36-51%) and cotton (42-71%) was obtained with 500-1000 ppm cresotic acid, while only less than 8 reduction occurred with 100-200 ppm.

This study was conducted to evaluate the side effects of fungicides Carboxin-thiram, Carbendazim,Triadimenol (baytan) and insecticides Thiodicarb larvin)and Imidachlopride (Gaucho) used in seed treatments for controling of early season pests or diseases in cotton crop , on seedling growth and damping –off fungi invitro and field experiments . Experiments were done by blotter method and Agar-pesticide plate method . Results showed that, all treatments of fungicide-larvin decreased seed germination and increased seed rot or anomally in cotton seedlings . Larvin not only decreased length of seedlings but also increased stem diameter and adventitues roots . In addition, insecticides have antifungal effects on test fungi Fusarium and Rhizoctonia in vitro. Therefore ,it is cocluded that use of Gaucho in seed treatments with a fungicide has low deleterious effect on seed germination,seedling growth and field establishments.

The fruit and seeds of Butea monosperma (Lam) Kuntze (Fabaceae) are useful in piles, anthelmintic, eye diseases, and inflammation in the Indian system of medicine. Hence, we have evaluated the anti-inflammatory activity of the fixed oil, mixed fatty acids, and unsaponifiable matter of B. monosperma against carrageenan-induced paw oedema and cotton pellet-induced granuloma in rats. The fixed oil, mixed fatty acids, and unsaponifiable matter of the oil exhibited significant anti-inflammatory activity on the experimental animal models.

Ageratum conyzoides (ageratum) is a common and widespread weed species that may act as a reservoir host for geminivirus diseases. Ageratum plants growing in Singapore and exhibiting yellow vein disease are infected with a complex mixture of viral, subviral and recombinant DNA components. This whitefly-transmitted disease is caused by the monopartite begomovirus ageratum yellow vein virus (AYVV) in association with a recently discovered satellite component referred to as DNA β. Diseased plants also contain a subviral component, referred to as DNA 1, that has probably become associated with the begomovirus and adapted to whitefly transmission during mixed infection with an aphid-transmitted nanovirus. Unlike DNA β, the nanovirus-like component is not essential for the disease. Recombination between the viral and subviral DNAs occurs frequently and may play an important evolutionary role by generating component diversity. The identification of a similar complex associated with cotton leaf curl disease (CLCuD), a serious constraint to cotton growing in Pakistan, and the isolation of DNA β homologues from diverse plant species growing in widespread geographical locations suggests that such disease complexes are common and may have a significant impact on agriculture in the eastern hemisphere.