Orientador: Enes Furlani Junior / Banca: Luiz Henrique Carvalho / Banca: Edivaldo Cia / Banca: Marco Eustáquio de Sá / Banca: Fernando Tadeu de Carvalho / Resumo: A cotonicultura apresenta destaque no cenário mundial, pois emprega tecnologia avançada representada por maquinários modernos e técnicos com grande experiência de campo, elevados investimentos e pela diversidade de utilização da pluma. O objetivo deste trabalho foi avaliar o algodoeiro cv. FMT 701 em função de sistemas de aplicação de subdoses de glifosato e regulador de crescimento. O delineamento experimental foi o de blocos ao acaso em esquema fatorial 6x2 com 4 repetições, perfazendo um total de 48 parcelas, compostas por: a- número de aplicações da subdose do glifosato (20 g e.a. (equivalente ácido) ha -1 ): (zero, uma, duas, três, quatro e cinco), aplicadas via foliar respectivamente aos 40; 40 e 50; 40, 50 e 60; 40, 50, 60 e 70 e 40, 50, 60, 70 e 80 dias após emergência (d.a.e.) das plantas; e b- manejo do regulador de crescimento em aplicação foliar (50 g i.a. (ingrediente ativo - cloreto de mepiquat) ha -1 ) sendo por aplicações de forma parcelada (3 dias após a aplicação da subdose do glifosato) ou de forma única aos 70 d.a.e. (nas parcelas que não receberam a subdose); e sem aplicação. A cultivar de algodão FMT 701 submetida a duas aplicações da subdose do glifosato apresenta maior crescimento em altura e de concentração de Mg foliar além de maior número de capulhos por planta e produtividade de algodão em caroço quando associado ao cloreto de mepiquat. A utilização do regulador de crescimento proporciona aumento do diâmetro do caule, concentração de N e Mg foliar e índice SPAD de clorofila, e diminui o comprimento de ramos reprodutivos. Cinco aplicações da subdose de glifosato associadas à utilização do cloreto de mepiquat proporcionam redução de altura de plantas, produtividade e índice de micronaire no algodoeiro / Abstract: The cotton crop has featured on the world stage because employs advanced technology, represented by modern machinery and technicians with great field experience, high investments and the diversity of the plume use. The objective of this study was to evaluate the cotton cv. FMT 701 in function of application systems of glyphosate low dose and growth regulator. The experimental design was a randomized block in 6x2 factorial with four replications, totaling 48 plots with: a- number of glyphosate low dose applications (20 g a.e. (acid equivalent) ha -1 ): (zero, one, two, three, four and five), foliar applied respectively to 40; 40 and 50; 40, 50 and 60; 40, 50, 60, 70 and 40, 50, 60, 70 and 80 days after emergence of plants (d.a.e.); and b- managing of the growth regulator for foliar application (50 g a.i. (active ingredient - mepiquat chloride) ha -1 ) being split application form (3 days after application of glyphosate low dose) or only way at 70 d.a.e. (in plots that didn't receive a low dose); and without application. The cotton cultivar FMT 701 submitted to two applications glyphosate low dose has increased the height and leaf Mg concentration and greater number of bolls per plant and cotton seed yield when combined with mepiquat chloride. The use of the growth regulator provides increased stem diameter, leaf Mg and N concentration and SPAD chlorophyll content, and decreases the length of reproductive branches. Five applications of glyphosate low dose associated with the use of mepiquat chloride provide height plant reduction, yield and micronaire index in the cotton crop / Doutor

No description available.

Made available in DSpace on 2014-06-11T19:22:16Z (GMT). No. of bitstreams: 0 Previous issue date: 2004-01-29Bitstream added on 2014-06-13T18:48:48Z : No. of bitstreams: 1 souza_fs_me_botfca.pdf: 722599 bytes, checksum: bddbe2539a4c9c196d08d8670e432f38 (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / O presente trabalho teve por objetivo avaliar o comportamento de plantas de algodão submetidas à aplicação de doses de cloreto de mepiquat e precipitações pluviais ocorrendo em diferentes momentos após a aplicação do produto. Procurou-se ainda desenvolver um método simples de estimativa da dose do produto a ser aplicada. Os tratamentos foram constituídos de três doses do regulador a base de cloreto de mepiquat (PIX®): 7,5, 15,0 e 22,5 g ha-1 e seis intervalos de tempo para aplicação de chuva simulada de 20 mm de intensidade: 0, 1, 3, 6, 12 e 24 horas, mais um tratamento sem a aplicação de chuva. Foram utilizados vasos de 12 litros de capacidade e seis sementes pré-germinadas com posterior desbaste para duas plantas por vaso. O delineamento experimental utilizado foi o inteiramente casualizado com quatro repetições. Os parâmetros avaliados foram: altura de plantas, número de ramos reprodutivos, massa de matéria seca, retenção de estruturas reprodutivas (coleta de estruturas reprodutivas e estruturas perdidas) e área foliar. Os resultados mostraram que o efeito do regulador foi prejudicado pela ocorrência de chuva nos momentos mais próximos a sua pulverização. As maiores doses mostraram ter efeito mais significativo nos parâmetros de crescimento avaliados, mostrando que chuvas ocorridas em momentos mais próximos após a pulverização causam maior comprometimento da ação do regulador nas plantas de algodão. É possível calcular a dose de regulador a ser aplicada conhecendo-se a altura atual das plantas. / The research had the objective to evaluate the behavior of cotton plants submitted to the application of doses of Mepiquat Chloride and precipitations happening in different times after the application of the product. A tentative for developing a simple method for estimating the dose of the product that would be applied was tried. The treatments were constituted of three doses of the growth regulator, mepiquat chloride (PIX®): 7,5, 15,0 and 22,5 g ha-1 and six time intervals for the application of simulated rain of 20mm of intensity: 0, 1, 3, 6, 12 and 24 hours, and one treatment without rain. Plots of 12 liters of capacity and six pre-germinated seeds were used with subsequent rough-hewing for two plants per plot. The experimental design used was the completely randomized with four replications. The parameters analyzed were: height of plants, number of reproductive branches, weight of dry matter, collecting of reproductive structures and lost structures, and leaf area. The results showed that the effect of the growth regulator was harmed by the rain occurrence in the closest moments of the application of the growth regulator. It was possible to calculate the regulator dose to be applied knowing the actual height of the plants.

Orientador: Ciro Antonio Rosolem / Banca: João Domingos Rodrigues / Banca: Ederaldo José Chiavegato / Resumo: O presente trabalho teve por objetivo avaliar o comportamento de plantas de algodão submetidas à aplicação de doses de cloreto de mepiquat e precipitações pluviais ocorrendo em diferentes momentos após a aplicação do produto. Procurou-se ainda desenvolver um método simples de estimativa da dose do produto a ser aplicada. Os tratamentos foram constituídos de três doses do regulador a base de cloreto de mepiquat (PIX®): 7,5, 15,0 e 22,5 g ha-1 e seis intervalos de tempo para aplicação de chuva simulada de 20 mm de intensidade: 0, 1, 3, 6, 12 e 24 horas, mais um tratamento sem a aplicação de chuva. Foram utilizados vasos de 12 litros de capacidade e seis sementes pré-germinadas com posterior desbaste para duas plantas por vaso. O delineamento experimental utilizado foi o inteiramente casualizado com quatro repetições. Os parâmetros avaliados foram: altura de plantas, número de ramos reprodutivos, massa de matéria seca, retenção de estruturas reprodutivas (coleta de estruturas reprodutivas e estruturas perdidas) e área foliar. Os resultados mostraram que o efeito do regulador foi prejudicado pela ocorrência de chuva nos momentos mais próximos a sua pulverização. As maiores doses mostraram ter efeito mais significativo nos parâmetros de crescimento avaliados, mostrando que chuvas ocorridas em momentos mais próximos após a pulverização causam maior comprometimento da ação do regulador nas plantas de algodão. É possível calcular a dose de regulador a ser aplicada conhecendo-se a altura atual das plantas. / Abstract: The research had the objective to evaluate the behavior of cotton plants submitted to the application of doses of Mepiquat Chloride and precipitations happening in different times after the application of the product. A tentative for developing a simple method for estimating the dose of the product that would be applied was tried. The treatments were constituted of three doses of the growth regulator, mepiquat chloride (PIX®): 7,5, 15,0 and 22,5 g ha-1 and six time intervals for the application of simulated rain of 20mm of intensity: 0, 1, 3, 6, 12 and 24 hours, and one treatment without rain. Plots of 12 liters of capacity and six pre-germinated seeds were used with subsequent rough-hewing for two plants per plot. The experimental design used was the completely randomized with four replications. The parameters analyzed were: height of plants, number of reproductive branches, weight of dry matter, collecting of reproductive structures and lost structures, and leaf area. The results showed that the effect of the growth regulator was harmed by the rain occurrence in the closest moments of the application of the growth regulator. It was possible to calculate the regulator dose to be applied knowing the actual height of the plants. / Mestre

Cotton is a high-value commercial crop in Australia. Although cotton is largely self-pollinating, previous researchers have reported that honeybees, Apis mellifera, can assist in cross-pollination and contribute to improved yield. Until recently, use of bees in cotton had, however, been greatly limited by excessive use of pesticides to control arthropod pests. With the widespread use of transgenic (Bt) cotton varieties and the associated reduction in pesticide use, I decided to investigate the role and importance of honeybees in Bt cotton, under Australian conditions. I conducted two major field trials at Narrabri, in the centre of one of Australia’s major cotton-growing areas, in the 2005-6 and 2006-7 seasons. In the first trial, I particularly assessed methods of manipulating honeybee colonies by feeding pollen supplements of pollen/soybean patties, and by restricting pollen influx by the fitting of 30% efficient pollen traps. I aimed to test whether either of these strategies increased honeybee flight activity and, thus, increased foraging on cotton flowers. My results showed that although supplementary feeding increased bee flight activity and brood production, it did not increase pollen collection on cotton. Pollen traps initially reduced flight activity. They also reduced the amount of pollen stored in colonies, slowed down brood rearing activity, and honey production. However, they did not contribute to increased pollen collection in cotton. In the second trial, I spent more time investigating honeybee behaviour in cotton as well as assessing the effect of providing flowering cotton plants with access to honeybees for different time periods (e.g. 25 d, 15 d, 0 d). In this year, I used double the hive stocking rate of (16 colonies / ha) than in the previous year, because in 2005-6 I observed few bees in cotton flowers. I also conducted a preliminary investigation to assess whether there was any gene flow over a 16 m distance from Bt cotton to conventional cotton, in the presence of a relatively high honeybee population. Both of my field experiments showed that honeybees significantly increased cotton yield via increased boll set, mean weight of bolls, number of seeds / boll, and weight of lint / boll. It was obvious that cotton flowers, and particularly cotton pollen, were not attractive to honeybees, and this was also reflected in the low proportion (5.3% w/w) of pollen from cotton collected in the pollen traps. However, flower visitation rate was generally above the 0.5% level regarded as optimal for cross-pollination in cotton, and this was reflected in increased yield parameters. I recorded a gene flow of 1.7 % from Bollgard®II cotton to conventional cotton, over a distance of 16 m. This is much higher than had previously been reported for Australia, and may have been a result of high honeybee numbers in the vicinity, associated with my managed hives. In an attempt to attract more honeybees to cotton flowers, I conducted an investigation where I applied synthetic Queen Mandibular Pheromone (QMP) (Fruit Boost®) at two rates, 50 QEQ and 500 QEQ / ha, and for two applications, 2 d apart. Neither rate of QMP increased the level of bee visitation to flowers, either on the day of application or the subsequent day. There was also no increase in boll set or yield in plants treated with QMP. My observations of honeybee behaviour in cotton brought some interesting findings. First, honeybees totally ignored extra floral nectaries. Second, most flower-visiting honeybees collected nectar, but the overwhelming majority of them (84%) collected floral nectar from outside flowers: this meant these bees did not contribute to pollination. Those nectar gatherers which entered flowers did contribute to pollination. However, they were observed to exhibit rejection of cotton pollen by scraping pollen grains from their body and discarding them, prior to returning to their hives. Pollen gatherers collected only small, loose pellets from cotton. SEM studies showed that cotton pollen grains were the largest of all pollen commonly collected by bees in my investigations, and that they also had large spines. It is likely that these characteristics make cotton pollen unattractive to honeybees. Another possible reason for the unattractiveness of cotton flowers was the presence of pollen beetles, Carpophilus aterrimus, in them. I conducted a series of studies to determine the role of pollen beetles in pollination of cotton. I found that they did not contribute to pollination at low levels; at high populations they damaged flowers (with ≥ 10 beetles / flower, no flowers set bolls); and that honeybees, when given the choice, avoid flowers with pollen beetles. Because the insecticide fipronil was commonly used in Australian cotton at flowering time, and because I had some experience of its toxic effects against honeybees in my field investigations, I conducted a series of laboratory and potted plant bioassays, using young worker bees. The studies confirmed its highly toxic nature. I recorded an acute dermal LD50 of 1.9 ng / bee, and an acute oral LC50 of 0.62 ppm. Fipronil’s residual toxicity also remained high for an extended period in both laboratory and potted plant trials. For example, when applied to cotton leaves in weather-exposed potted cotton plants, it took 25 d and 20 d for full and half recommended rates of fipronil, respectively, to become non- toxic to honeybees. I had previously investigated whether a shorter period of exposure of cotton plants to honeybees would contribute adequately to increased yield, and concluded that a 10 d window within a 25 d flowering period would contribute 55% of the increase in total weight of bolls contributable to honeybee pollination, but only 36% of the increase in weight of lint. Given the highly residual activity of fipronil I recorded, the only opportunity for an insecticide-free period during flowering would be at its commencement. I concluded that, while there is evidence that honeybees can contribute to increased cotton yield in Bt cotton in Australia, this is unlikely with the continued use of fipronil at flowering. / Doctor of Philosophy (PhD)

Cotton has been grown in central Asia for over 2,000 years, and is a major crop in Turkmenistan, where medium staple G. hirsutum is the dominant species, cultivated on 80%of the cotton growing area. Many of the cultivars used in Turkmenistan until the time of independence from Russia were from Uzbekistan. Since independence, the original suite of long staple G. barbadense and medium staple Uzbek cultivars has been considerably changed in Turkmenistan by selection for early maturity and productivity. Cotton yields in Turkmenistan have been declining since independence and were below 2t/ha in 2001 when the TACIS ‘Support to the Cotton Sector Project’ commenced, of which research reported in this thesis was a part. The main factors determining seed cotton yields in this country are quantity of irrigation water applied, nitrogen fertilization, deep ploughing, and plant population. Of these four important factors, plant density is the only one that individual farmers can control, as the others are either state controlled or require equipment held collectively. The aim of the research described in this thesis was to improve cotton production in Turkmenistan through optimising plant population. The use of optimum plant populations in the cotton fields of Turkmenistan has a substantial potential for economic benefit to the farmers of that country. Changing plant populations would require none of the structural changes involved in changing the other important yield factors. Quantity of irrigation water applied is controlled by the state; nitrogen fertilizer is a state controlled input in Turkmenistan and deep ploughing depends on equipment communally held and sometimes unavailable. / Doctor of Philosophy (PhD) (Agriculture)

No description available.

No description available.

No description available.

No description available.