บทคัดย่องานวิจัย

หมวดหมู่ : ฐานข้อมูลงานวิจัย

The effects of preharvest plant growth regulator treatments and temperature on tomato fruit ripening; tomato fruit growth curves and ripening phenology

Mughrabi, Mustafa Abdel-Latif.

Thesis of Ph.D., Utah State University, 1983, 111 pages

1983

บทคัดย่อ

THE EFFECTS OF PREHARVEST PLANT GROWTH REGULATOR TREATMENTS AND TEMPERATURE ON TOMATO FRUIT RIPENING; TOMATO FRUIT GROWTH CURVES AND RIPENING PHENOLOGY.

Preharvest plant sprays of gibberellic acid significantly delayed chlorophyll degradation and lycopene and carotene synthesis in harvested tomato fruits.  The respiratory climateric was delayed for three days at 21(DEGREES)C and ethylene evolution was reduced significantly.  Results show a definite potential for such sprays in increasing the storage and shelf life of tomato fruits.

 Sprays of 1000 and 2500 parts per million gibberellic acid significantly delayed chlorophyll a and a + b in harvested fruit.  The same concentrations of gibberellin significantly reduced lycopene and beta-carotene synthesis of the harvested fruit.

 Benzyl adenine at 600 ppm showed significant effects on retention of chlorophyll a and a + b in postharvest tomato fruit.  Lycopene production was reduced by 800 and 1000 parts per million of benzyl adenine, and beta-carotene synthesis was significantly reduced by 600 and 800 parts per million.

 Combinations of gibberellic acid and benzyl adenine showed similar effects to benzyl adenine but to a lesser extent.  Gibberellic acid was most effective.

 Preharvest treatments of tomato plants with gibberellic acid at concentrations of 1000 and 2500 parts per million delayed the climacteric peak for 3 days at 21(DEGREES)C compared to untreated control plants.  The respiration of tomato fruits was less responsive to benzyl adenine application than to gibberellic acid.  The combination of gibberellic acid and benzyl adenine caused the tomato fruits to respire at a higher rate initially and through the seventh day and advanced the climacteric peak one day.  Ethylene evolution was delayed by gibberellic acid at concentrations of 1000 and 2500 parts per million.  Benzyl adenine effects on ethylene evolution appeared at an earlier stage of the ripening period.  The combination significantly increased ethylene evolution.

 Temperatures of 30 and 35(DEGREES)C prevented lycopene and beta-carotene syntheses of Moscow and Burpee Big Early Hybrid tomato fruits but a temperature of 25(DEGREES)C promoted them.  The growth curves for Moscow, DX52-12, Burpee Big Early Hybrid, Early Girl and Royal Chico tomato fruits were established with sigmoidal shapes.  Ripening degree hours of the detached Moscow and Burpee Big Early Hybrid tomatoes were estimated using a asymmetric curvilinear model.