Sweet Sorghum Planting Effects on Stalk Yield and Sugar Quality in Semi-Arid Tropical Environment

Sweet sorghum [Sorghum bicolor (L.) Moench] has potential as a bioenergy crop for producing food, fiber, and fermentable sugar. Unlike dryland grain sorghum, little information is available on the influence of staggered planting and genotypes, especially in semiarid tropical environments. The objectives of the present study were (i) to quantify the effects of planting time and genotype on stalk and biomass yields, juice sugar quality, and (ii) to identify the most productive genotypes and planting windows for sustainable feedstock supply. Four commercial sweet sorghum genotypes (SSV84, SSV74, CSV19SS, and CSH22SS) were planted on five planting dates (1 June, 16 June, 1 July, 16 July, and 1 August) during the rainy (June–October) season of 2008 and 2009 in Hyderabad (17°27´ N, 78°28´ E), India. Planting in early and mid-June produced significantly (P ≤ 0.05) higher fresh stalk yield and grain yield than later planting dates. Commercial hybrid CSH22SS produced significantly more stalk, grain, sugar, and ethanol yield over genotypes SSV84 or SSV74. Based on the stalk yield, juice sugar quality, sugar, and ethanol yields, the optimum planting dates for sweet sorghum in semiarid tropical climate is early June to early July. Planting sweet sorghum during this time allows more feedstock to be harvested and hence extends the period for sugar mill operation by about 1 mo, that is, from the first to the last week of October

Aprenda a plantar o sorgo sacarino.

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Selection of sorghum hybrids grown under aluminum saturation

The purpose of this study was to evaluate 165 hybrids derived from lines previously selected for aluminum (Al) tolerance. Nine check cultivars were used, eight commercial hybrids and one experimental hybrid. Hybrids were evaluated at three levels of Al saturation (0, 20 and 40% on average). The differences between the environments were significant. Environment with 0% Al saturation yielded 29.5% more than that with 40% Al saturation, showing the importance of genotype selection for acid soils. The best check cultivar was the hybrid DKB550. The hybrids AG1020 and AG1040 also performed well, where the latter was more tolerant but the former more responsive to environment improvement. The hybrid BRS304 was susceptible to high levels of Al saturation. The three commercial BRS hybrids (BRS310, BRS330 and BRS332) performed better than BRS304 at high Al saturation. The hybrid BRS330 was the best BRS hybrid to grow on a field with high Al saturation. The hybrid DKB559 performed well at high Al saturation but did not respond to environment improvement. The hybrids 727029, 727039, 729041, 729095, 729109, AG1040, and DKB550 were tolerant to higher levels of Al saturation and responsive to environment improvement, and showed good stability and adaptability at both low and high Al saturation.201

Padrões de deficiência hídrica para a cultura de milho (safra normal e safrinha) no estado de Goiás e suas conseqüencias para o melhoramento genético Water stress pattern for corn (first and second crop) in the Goiás State and their consequences for the breeding program

Deficiência hídrica é considerada a maior restrição na produção e estabilidade da produtividade de culturas em muitas regiões do mundo. No Estado de Goiás, região na qual predomina a produção em sequeiro, para a cultura do milho (Zea mays L.) implantada na safra normal e na safrinha, é comum sofrer períodos de estresse por deficiência hídrica intermitente ou terminal, que reduzem o rendimento de grãos. No processo de desenvolvimento de novos híbridos e variedades cultivadas, genótipos são selecionados em função de sua adaptabilidade em um determinado ambiente alvo. Assim, programas de melhoramento vegetal, com o objetivo de desenvolver híbridos e variedades cultivadas mais adaptados a um determinado ambiente, requerem informações sob a probabilidade de ocorrência dos diferentes tipos de deficiência hídrica, como também, suas características, intensidade e tempo, em função da fase fenológica da cultura. Um modelo de simulação de culturas foi utilizado para determinar os padrões de deficiência hídrica no estado de Goiás, considerando 12 locais e 6 diferentes datas de semeadura para a cultura do milho semeada na safra normal e na safrinha. Para a cultura do milho semeado na safra normal, a perda na produtividade decorrente do estresse por deficiência hídrica foi menor que 50%, sendo que os tipos de deficiência hídrica que provocam um maior impacto na produtividade iniciam-se no começo do período reprodutivo. Para o milho semeado na safrinha, a perda na produtividade é superior a 50%, sendo mais comum o estresse terminal, que tem sua maior intensidade no enchimento de grãos.<br>Water stress is a major constraint to crop production and yield stability in many regions of the world. The cultivation of corn (Zea mays L.) in the Brazilian State of Goiás, is frequent affected by periods of water stress resulting in yield reduction. During the process of developing new hybrids and cultivated varieties, new genotypes are selected based on their adaptability for a certain environment. In this context, plant breeding programs demand for information regarding as a function of the crop phenological phases. A crop simulation model was used to determine patterns of water stress for 12 locations of the State of Goiás and 6 different sowing for both, first and second corn harvest periods. For the first harvest period, yield loss due to water stress was lower than 50%, with higher effects on yield in the beginning of the reproductive period. For corn as a second crop, yield loss is higher than 50% with frequent occurrence of terminal stress, which presented higher intensity during the stage of grain filling