Abstract
Full plant growth and development require, among others, air temperatures and water availability at levels appropriate to each crop. The effect of temperature on plant development can be represented by the thermal sum, which requires the lower basal temperature for each plant species. However, plant responses may be different when associated with different soil water contents. This work determined the lower and upper basal temperature of Jatropha curcas L. and verified the relationship between thermal sum and crop development under different water regimes, in the climatic conditions of Goiânia, GO, Brazil. We evaluated twenty-four plants cultivated at the planting density of 2,222.2 plants ha-1. Of these, twelve plants were irrigated from October 2010 to October 2012, whereas the other twelve remained unirrigated. Basal temperatures were estimated by four different methods described in the literature, in two phases of observation, maturity and total cycle. From the results, regression analysis was performed. The lower basal temperature was 4.9 and 7.2 °C, and upper basal temperature was 38.8 and 36.8 °C, respectively, for the maturity and total cycle stages. The accumulated thermal sum for the complete plant development of jatropha was 10,314.55 DD (±1574.73) for the non-irrigated treatment, and 9,260.67 DD (±735.06) for the irrigated treatment. The results of plant development showed good coefficient of determination in relation to the accumulated thermal sum.
Highlights
Jatropha curcas L. is a perennial monoic species belonging to the family Euphorbiaceae, which includes species of castor bean (Ricinus sp.), manioc (Manhiot sp.) and rubber tree (Hevea spp.)
Small differences were detected in the Tb values estimated by the four methods tested, SDDD, SDday, CVDD and CVday (Figure 1). This can be explained by the low variability and high stability of the maximum and minimum temperature data during the studied period, presenting a mean thermal amplitude of 13.85 °C (±4.4 °C)
Agroclimatic zoning for jatropha shows that average temperatures below 15 °C correspond to climatic risk, rendering the crop unsuitable for cultivation (Pena et al, 2016; Yamada and Sentelhas 2014)
Summary
Jatropha curcas L. is a perennial monoic species belonging to the family Euphorbiaceae, which includes species of castor bean (Ricinus sp.), manioc (Manhiot sp.) and rubber tree (Hevea spp.). Its main characteristic is to supply raw material for Biodiesel generation. It is considered a rustic, sunlight-demanding crop with high resistance to drought. Pena, Evangelista, Casaroli, and Alves Júnior (2016) determined the temperature range suitable for the development of jatropha: between 15 and 28 °C. The authors observed that there are no regions unfit for crop development in the state of Goiás. The water demand of jatropha, for its full development, is 1,200 mm annual water. Jatropha tolerates rainfall between 360 and 2,400 mm. As not to affect production, ideal cultivation would be in regions where the deficit does not exceed 720 mm (Yamada & Sentelhas, 2014)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
