Effect of growing environment and climate change on physiyology of tomato ( Lycopersicon esculentum Mill. )

Abstract

The present world production of tomato stands at 100 million tons fresh fruits produced on 3.7 million hectares. Even though productivity levels of tomato have increased, it will not be sufficient enough to the increasing population. Global climate change is any significant long term change in expected patterns of weather over a region which may be naturally induced or anthropogenic. The effect of climate change on crop and terrestrial food production are evident in several regions of the world. Negative impacts of climate trends have been more common than positive ones. Objectives of the study were to study the effect of different growing environment and climate change on the physiological traits of tomato development of crop weather relationships for the selected rice varieties and assessment of possible change in yield due to climate change. The studies were conducted during December 2014- March 15at the Central Nursery, Vellanikkara in the bacterial wilt resistant variety Anagha by providing three different growing environments namely polyhouse, rainshelter and open field conditions with four dates of transplanting. The results showed that the dates of transplanting and growing environment had a significant effect on the physiology of tomato. The crop transplanted inside the polyhouse took the longest duration. Maximum leaf area index (3.8) was observed in in the crop transplanted in open field, polyhouse and rain shelter on different dates on different dates (1 December 2014 and 20 January 2015 respectively). The highest values of leaf relative water content was observed in the first week following transplanting and the lowest values appeared prior to the last harvest regardless of the dates of transplanting and growing environment. The lycopene content was consistently highest in the crops inside the Polyhouse. The highest value for the same was 1.52 mg gm-1 was recorded in crops inside the polyhouse transplanted on 10 January 2015.The fruit ascorbic acid content (2.06 mg gm-1) was highest in the crop inside rain shelter transplanted on 10 December 2014. The highest mean length of style was documented in the flowers of the crop transplanted inside rain shelter (8.08 mm) on 1 December 2014 whereas, the highest mean stamen length was recorded in the flowers of the crop transplanted inside polyhouse (8.28 mm) on 1 December 135 2014). The difference in the length of the style and stamen and its relative position significantly affected the total yield obtained. A difference of more than -0.05 mm considerably reduced the yield. The highest yield (111.5 tons ha-1) was recorded inside the polyhouse in the crops transplanted on 1 December 2014. The net photosynthesis rate was highest in the rain shelter crops regardless of the dates of transplanting. The highest values recorded was 19.7 in the rain shelter and poly house for the crops transplanted on 10 and 20 January 2015. The temperature prevalent was the most crucial factor determining the rate of photosynthesis followed by Carbon dioxide. Under the projected climate change scenarios i.e. RCP 2.6, 4.5, 6.5 and 8.0, the ascorbic acid content increased in the fruit owing to higher temperature and lower soil moisture availability. The lycopene content remained unaffected as the UV radiation concentration is will be changing negligibly for the region where the study is conducted. The duration of the crop will be reduced drastically from 2030 to 2080 under all the scenarios. The results also showed that the effect of minimum temperature would drastically reduce the yield. The increasing atmospheric CO2 concentration is likely to have some positive effect on yield, but the effect is not significant compared to the negative impact of rise in temperature.