Thesis (Ph. D.)--University of Wisconsin--Madison, 1975. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Call number: LD2668 .T4 1948 V35 / Master of Science

The yield of short-season hybrids is lower than long-season hybrids, mainly as a result of the low final leaf area developed by the short-season plants. This is due to the smaller plant stature and smaller leaf number and size of short-season adapted hybrids. In addition, in short-season areas the thermal-time available may be insufficient to mature grain of current maize hybrids. Maize hybrids which accumulate leaf area quickly, mature earlier, yield well and tolerate higher population densities better than the currently available hybrids would be more suitable for production in short-season areas. The "Leafy reduced-stature" maize hybrids, which have only recently been developed, have traits which address these criteria. There has been no previous effort to evaluate the effects of more than two plant population densities or the effects of planting patterns on the yield, yield components and vegetative growth of these hybrids. in 1995, field experiments were conducted at two sites near Montreal to compare the response of leafy reduced-stature (LRS), non-leafy normal stature (NLNS), and non-leafy reduced-stature (NLRS) maize hybrids to plant population densities and planting patterns. LRS maize hybrids showed the most rapid growth of the first ear, and the highest yield per single plant and per hectare at high plant population densities in paired rows. LRS hybrids also had longer grain filling periods, lower grain moisture contents and higher harvest indices than conventional (NLNS) hybrids. Rapid growth of the first ear and a higher harvest index are indications that LRS hybrids should be more tolerant of higher population densities than currently available hybrids. Therefore, LRS hybrids show promise for production in short-season areas at high plant population densities where maize cultivation is not currently economical due to shortness of the growing-season.

Typescript. / Thesis (Ph. D.)--University of Hawaii at Manoa, 1990. / Includes bibliographical references (leaves 338-348) / Microfiche. / xx, 348 leaves, bound ill. (some col.) 29 cm

Thesis (Ph. D.)--University of Missouri-Columbia, 1999. / Typescript. Vita. Includes bibliographical references (leaves 93-96). Also available on the Internet.

Thesis (Ph. D.)--University of Missouri-Columbia, 1999. / Typescript. Vita. Includes bibliographical references (leaves 93-96). Also available on the Internet.

No description available.

Orientador: Antonio Carlos Busoli / Coorientador: Marcos Doniseti Michelotto / Banca: Júlio César Guerreiro / Banca: Arlindo Leal Boiça Júnior / Resumo: Com a adoção de sistemas de semeadura direta de milho logo após a colheita da soja, alguns percevejos como Dichelops melacanthus tem aumentado sua importância na fase inicial de desenvolvimento das plantas de milho no Sudeste e Oeste do Brasil, este trabalho teve como principal objetivo observar a infestação e respectivos danos em híbridos de milho convencionais e transgênicos, submetidos ao tratamento químico de sementes e pulverização de inseticida no colo das plantas. Os híbridos convencionais utilizados nos experimento foram: 30F35, 9110, AG8088, DKB390, 2B710, 2B688 e IMPACTO; e seus respectivos híbridos transgênicos foram: 30F35 H (Herculex), 9110 Y (Yeldgard), AG8088 YG (Yieldgard), DKB390 VTpro, 2B710 HX (Herculex), 2B688 H (Herculex) e IMPACTO TL (Total Libert). Os inseticidas utilizados foram: Cruiser® 350 FS (thiametoxam) e Cropstar® (imidacloprid) ambos via tratamento de sementes, e o inseticida Connect® (imidacloprid + beta-ciflutrina) aplicado no colo das plântulas. Os parâmetros avaliados foram porcentagem de plantas atacadas, atribuiu-se notas através de escala de notas visuais de sintomas ou injúrias, e durante o desenvolvimento das plantas, aferiu-se a altura das plantas. No momento da colheita foram avaliados os parâmetros de produtividade das plantas: número de fileiras de grãos/espiga, peso (g) de espiga com e sem palha, e peso (g) de grãos corrigidos a 13% de umidade. Os resultados demonstram que, o tratamento de sementes com inseticidas sistêmicos foi o melhor controle e o que mais reduziu a porcentagem de plantas atacadas no campo, tanto em infestação artificial quanto em infestação natural de D. melacanthus. Os híbridos transgênicos apresentaram menor porcentagem de plantas atacadas, menores notas de sintomas de injúrias ou danos,...(Resumo completo, clicar acesso eletrônico abaixo) / Abstract: With the adoption of no-tillage systems for maize after soybean harvest, some bugs, such as Dichelops melacanthus have increased in importance at the early development of maize plants in the Southeast and West areas of Brazil. This study aimed to observe the infestation and damage on conventional and transgenic maize hybrids submitted to chemical treatment of seeds, as well as chemical control by spraying insecticides to the base of the plants. It was used the following conventional hybrids: 30F35, 9110, AG8088, DKB390, 2B710, 2B688 and IMPACT, whereas their transgenic analogs were: 30F35 H (Herculex), 9110 Y (Yeldgard), AG8088 YG (YieldGard), DKB390 VTpro, 2B710 HX (Herculex), 2B688 H (Herculex) and IMPACT TL (Total Libert). The insecticides used were: FS 350 Cruiser® (thiamethoxam) and Cropstar® (imidacloprid), both of them were used for seed treatment, whereas it was used Connect® (imidacloprid + beta-cyfluthrin) to spray the seedlings. The parameters evaluated were the percentage of attacked plants by grading them based on visual scale of symptoms or injuries, and it was also measured the height of the plants during plant development. At harvest it was evaluated the following yield parameters: number of kernel rows/ear, weight (g) of ears with and without straw, and weight (g) of grain corrected to 13% moisture. It was shown that seed treatment with systemic insecticides was the best control tactic and the most effective way to decrease the percentage of attacked plants in the field, under both artificial and natural infestation of D. melacanthus. For the transgenic hybrids, it was shown a lower percentage of attacked plants, the lowest grades...(Complete abstract click electronic access below) / Mestre

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