ที่มา:วิทยาสารเกษตรศาสตร์ สาขา วิทยาศาสตร์

หัวเรื่อง:ไม่มีชื่อไทย (ชื่ออังกฤษ : The Relationship between Environmental Factors during the Rainy Season and Un-opened Floret Yellowing in Dendrobium Sonia ‘Ear-Sakul’)

ผู้เขียน:Vimolchat SARNTINORANONT, ดร.สุรวิช วรรณไกรโรจน์, รองศาสตราจารย์

สื่อสิ่งพิมพ์:pdf

Abstract

The pre-harvest yellowing in the un-opened florets of Dendrobium Sonia ‘Ear-Sakul’ grown under 50% shade in a saran-house was studied. In the rainy season, the most sensitive period for yellowing in un-opened florets was found to be the ready-to-bloom stage. The highest percentage of inflorescence with un-opened floret yellowing was obtained from those with no open florets. The percentage of inflorescence with yellowed un-opened florets could be predicted (R2= 0.613) using an environmental model consisting of: 1) cumulative hours of daytime with 0 ?mol m-2s-1 light intensity; 2) average rainfall during 1000-1400 hours; 3) cumulative hours of daytime with the temperature less than 25?C; and 4) cumulative hours when the relative humidity (RH) was in the range 75-90% in the period 3 d before un-opened floret yellowing. The developmental stage of inflorescence did not affect un-opened floret yellowing. The simulated stress environment of the rainy season had no effect on the sucrose, glucose and fructose contents in the first- and second-largest un-opened florets, nor on the calcium and boron contents in the inflorescence and leaves. Under the simulated stress environment of the rainy season in a growth chamber, spraying 1% sucrose solution might be useful to reduce yellowing in un-opened florets.

Article Info

Agriculture and Natural Resources -- formerly Kasetsart Journal (Natural Science), Volume 044, Issue 6, Nov 10 - Dec 10, Page 1016 - 1025 |  PDF |  Page

ที่มา:วิทยาสารเกษตรศาสตร์ สาขา วิทยาศาสตร์

หัวเรื่อง:ผลของอุณภูมิและความชื้อสัมพันธ์ที่มีต่ออัตราการเหลืองของข้าวเปลือกชื้น

ผู้เขียน:Nirachara Srisubati, Somchart Soponronnarit, Tipaporn Yoovidhya

สื่อสิ่งพิมพ์:pdf

Abstract

The effects of temperature and relative humidity in storage chambers on yellowing rate of paddy were investigated and then an empirical equation for predicting the yellowing rate was developed. Paddy was conditioned using saturated salt solutions at relative humidities from 80 to 95 % and temperatures 35, 45, 55, 60, and 65?C. The yellowing rate was found to follow the zero order kinetics. The yellowing constant values (k) increased exponentially with temperature while increased linearly with water activity. The magnitude of activation energy varied from 130-145 kJ/mol. A predictive equation for determining yellowing rate was ln k = ? - ?aw - ?/T + (?aw)/T where aw is water activity (valid from 0.80 to 0.95), T is absolute temperature (valid from 308 to 338 K) and ?, ?, ? and ? are constants. The results of variance analysis showed that temperature, water activity and their interaction significantly influenced the yellowing rate of paddy.

Article Info

Agriculture and Natural Resources -- formerly Kasetsart Journal (Natural Science), Volume 032, Issue 3, Jul 98 - Sep 98, Page 309 - 318 |  PDF |  Page